1
|
Schildroth S, Valeri L, Kordas K, Shi B, Friedman A, Smith D, Placidi D, Wright RO, Lucchini RG, White RF, Horton M, Claus Henn B. Assessing the mediating role of iron status on associations between an industry-relevant metal mixture and verbal learning and memory in Italian adolescents. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167435. [PMID: 37774885 PMCID: PMC10918745 DOI: 10.1016/j.scitotenv.2023.167435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
BACKGROUND Metals, including lead (Pb), manganese (Mn), chromium (Cr) and copper (Cu), have been associated with neurodevelopment; iron (Fe) plays a role in the metabolism and neurotoxicity of metals, suggesting Fe may mediate metal-neurodevelopment associations. However, no study to date has examined Fe as a mediator of the association between metal mixtures and neurodevelopment. OBJECTIVE We assessed Fe status as a mediator of a mixture of Pb, Mn, Cr and Cu in relation to verbal learning and memory in a cohort of Italian adolescents. METHODS We used cross-sectional data from 383 adolescents (10-14 years) in the Public Health Impact of Metals Exposure Study. Metals were quantified in blood (Pb) or hair (Mn, Cr, Cu) using ICP-MS, and three markers of Fe status (blood hemoglobin, serum ferritin and transferrin) were quantified using luminescence assays or immunoassays. Verbal learning and memory were assessed using the California Verbal Learning Test for Children (CVLT-C). We used Bayesian Kernel Machine Regression Causal Mediation Analysis to estimate four mediation effects: the natural direct effect (NDE), natural indirect effect (NIE), controlled direct effect (CDE) and total effect (TE). Beta (β) coefficients and 95 % credible intervals (CIs) were estimated for all effects. RESULTS The metal mixture was jointly associated with a greater number of words recalled on the CVLT-C, but these associations were not mediated by Fe status. For example, when ferritin was considered as the mediator, the NIE for long delay free recall was null (β = 0.00; 95 % CI = -0.22, 0.23). Conversely, the NDE (β = 0.23; 95 % CI = 0.01, 0.44) indicated a beneficial association of the mixture with recall that operated independently of Fe status. CONCLUSION An industry-relevant metal mixture was associated with learning and memory, but there was no evidence of mediation by Fe status. Further studies in populations with Fe deficiency and greater variation in metal exposure are warranted.
Collapse
Affiliation(s)
- Samantha Schildroth
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
| | - Linda Valeri
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Katarzyna Kordas
- Department of Epidemiology and Environmental Health, University at Buffalo, Buffalo, NY, USA
| | - Baoyi Shi
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Alexa Friedman
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| | - Donald Smith
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Donatella Placidi
- Department of Occupational Health, University of Brescia, Brescia, Italy
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Roberto G Lucchini
- Department of Occupational Health, University of Brescia, Brescia, Italy; Department of Environmental Health Sciences, Florida International University, Miami, FL, USA
| | - Roberta F White
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Department of Neurology, Boston University, Boston, MA, USA
| | - Megan Horton
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Birgit Claus Henn
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| |
Collapse
|
2
|
Basu N, Bastiansz A, Dórea JG, Fujimura M, Horvat M, Shroff E, Weihe P, Zastenskaya I. Our evolved understanding of the human health risks of mercury. AMBIO 2023; 52:877-896. [PMID: 36790578 PMCID: PMC10073381 DOI: 10.1007/s13280-023-01831-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 05/25/2023]
Abstract
Mercury (Hg) is a chemical of health concern worldwide that is now being acted upon through the Minamata Convention. Operationalizing the Convention and tracking its effectiveness requires empathy of the diversity and variation of mercury exposure and risk in populations worldwide. As part of the health plenary for the 15th International Conference on Mercury as a Global Pollutant (ICMGP), this review paper details how scientific understandings have evolved over time, from tragic poisoning events in the mid-twentieth century to important epidemiological studies in the late-twentieth century in the Seychelles and Faroe Islands, the Arctic and Amazon. Entering the twenty-first century, studies on diverse source-exposure scenarios (e.g., ASGM, amalgams, contaminated sites, cosmetics, electronic waste) from across global regions have expanded understandings and exemplified the need to consider socio-environmental variables and local contexts when conducting health studies. We conclude with perspectives on next steps for mercury health research in the post-Minamata Convention era.
Collapse
Affiliation(s)
- Niladri Basu
- McGill University, 204 CINE Building, Ste. Anne de Bellevue, Montreal, QC H9X 3V9 Canada
| | - Ashley Bastiansz
- McGill University, 204 CINE Building, Ste. Anne de Bellevue, Montreal, QC H9X 3V9 Canada
| | - José G. Dórea
- Faculdade de Ciencias da Saude, Universidade de Brasília, Brasília, 70919-970 Brazil
| | - Masatake Fujimura
- National Institute for Minamata Disease, Minamata, Kumamoto 867-0008 Japan
| | - Milena Horvat
- Department of Environmental Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Emelyn Shroff
- Public Health Authority of Seychelles, Mont Fleuri, Mahe, Seychelles
| | - Pál Weihe
- Department of Occupational Medicine and Public Health, Sigmundargøta 5, 100 Tórshavn, Faroe Islands
| | - Irina Zastenskaya
- WHO European Centre for Environment and Health, Platz Der Vereinten Nationen 1, 53113 Bonn, Germany
| |
Collapse
|
3
|
Schildroth S, Friedman A, White RF, Kordas K, Placidi D, Bauer JA, Webster TF, Coull BA, Cagna G, Wright RO, Smith D, Lucchini RG, Horton M, Claus Henn B. Associations of an industry-relevant metal mixture with verbal learning and memory in Italian adolescents: The modifying role of iron status. ENVIRONMENTAL RESEARCH 2023; 224:115457. [PMID: 36773645 PMCID: PMC10117691 DOI: 10.1016/j.envres.2023.115457] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/30/2023] [Accepted: 02/08/2023] [Indexed: 05/18/2023]
Abstract
BACKGROUND Biomarker concentrations of metals are associated with neurodevelopment, and these associations may be modified by nutritional status (e.g., iron deficiency). No prior study on associations of metal mixtures with neurodevelopment has assessed effect modification by iron status. OBJECTIVES We aimed to quantify associations of an industry-relevant metal mixture with verbal learning and memory among adolescents, and to investigate the modifying role of iron status on those associations. METHODS We used cross-sectional data from 383 Italian adolescents (10-14 years) living in proximity to ferroalloy industry. Verbal learning and memory was assessed using the California Verbal Learning Test for Children (CVLT-C), and metals were quantified in hair (manganese, copper, chromium) or blood (lead) using inductively coupled plasma mass spectrometry. Serum ferritin, a proxy for iron status, was measured using immunoassays. Covariate-adjusted associations of the metal mixture with CVLT subtests were estimated using Bayesian Kernel Machine Regression, and modification of the mixture associations by ferritin was examined. RESULTS Compared to the 50th percentile of the metal mixture, the 90th percentile was associated with a 0.12 standard deviation [SD] (95% CI = -0.27, 0.50), 0.16 SD (95% CI = -0.11, 0.44), and 0.11 SD (95% CI = -0.20, 0.43) increase in the number of words recalled for trial 5, long delay free, and long delay cued recall, respectively. For an increase from its 25th to 75th percentiles, copper was beneficially associated the recall trials when other metals were fixed at their 50th percentiles (for example, trial 5 recall: β = 0.31, 95% CI = 0.14, 0.48). The association between copper and trial 5 recall was stronger at the 75th percentile of ferritin, compared to the 25th or 50th percentiles. CONCLUSIONS In this metal mixture, copper was beneficially associated with neurodevelopment, which was more apparent at higher ferritin concentrations. These findings suggest that metal associations with neurodevelopment may depend on iron status, which has important public health implications.
Collapse
Affiliation(s)
- Samantha Schildroth
- Department of Environmental Health, Boston University School of Public Health, Boston MA, USA.
| | - Alexa Friedman
- Department of Environmental Health, Boston University School of Public Health, Boston MA, USA
| | - Roberta F White
- Department of Environmental Health, Boston University School of Public Health, Boston MA, USA; Department of Neurology, Boston University, Boston MA, USA
| | - Katarzyna Kordas
- Department of Epidemiology and Environmental Health, University at Buffalo, Buffalo, NY, USA
| | - Donatella Placidi
- Department of Occupational Health, University of Brescia, Brescia, Italy
| | - Julia A Bauer
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Lebanon, NH, USA
| | - Thomas F Webster
- Department of Environmental Health, Boston University School of Public Health, Boston MA, USA
| | - Brent A Coull
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston MA, USA
| | - Giuseppa Cagna
- Department of Occupational Health, University of Brescia, Brescia, Italy
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York NY, USA
| | - Donald Smith
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz CA, USA
| | - Roberto G Lucchini
- Department of Occupational Health, University of Brescia, Brescia, Italy; Department of Environmental Health Sciences, Florida International University, Miami FL, USA
| | - Megan Horton
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York NY, USA
| | - Birgit Claus Henn
- Department of Environmental Health, Boston University School of Public Health, Boston MA, USA
| |
Collapse
|
4
|
Guidi C, Martínez-López E, Oliver JA, Sánchez-Vázquez FJ, Vera LM. Behavioural response to toxic elements, detoxification and organ accumulation are time-of-day-dependent in zebrafish. CHEMOSPHERE 2023; 316:137862. [PMID: 36642134 DOI: 10.1016/j.chemosphere.2023.137862] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
Toxic elements, such as mercury (Hg) and arsenic (As), are major pollutants in aquatic environments, posing ecological threats to living organisms due to their toxicity and bioaccumulation. This paper investigated whether zebrafish response to Hg and As displayed day/night differences. Fish were exposed to either 35 μg/L of mercury chloride for 6 h or 65 mg/L of sodium arsenate for 4 h, at two different times of the day: mid-light (day; ML) and mid-darkness (night; MD). Fish were video-recorded to investigate their behavioural response and at the end of each trial, gills and liver samples were collected for gene expression measurement. Gills, liver and brain samples were also obtained to determine Hg and As concentration. A control group (non-exposed) was video-recorded and sampled too. The effect of Hg and As on zebrafish swimming activity and the expression of antioxidant and metallothionein genes was time-of-day-dependent, with a stronger response being observed during the day than at night. However, the neurobehavioural effect of Hg was more affected by the time of exposure than the effect of As. In addition, Hg concentration in the gills was significantly higher in zebrafish exposed at ML than at MD. Altogether, these findings suggest that zebrafish response to Hg and As is time-of-day-dependent and remark the importance of considering toxicity rhythms when using this fish species as a model in toxicological research.
Collapse
Affiliation(s)
- Costanza Guidi
- Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, 30100, Spain
| | - Emma Martínez-López
- Area of Toxicology, Department of Health Sciences, Faculty of Veterinary Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, 30100, Spain; Toxicology and Risk Assessment Group, Biomedical Research Institute of Murcia (IMIB-Arrixaca), University of Murcia, Murcia, 30100, Spain
| | - José A Oliver
- Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, 30100, Spain
| | - Francisco J Sánchez-Vázquez
- Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, 30100, Spain
| | - Luisa M Vera
- Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, 30100, Spain.
| |
Collapse
|
5
|
Islam F, Shohag S, Akhter S, Islam MR, Sultana S, Mitra S, Chandran D, Khandaker MU, Ashraf GM, Idris AM, Emran TB, Cavalu S. Exposure of metal toxicity in Alzheimer’s disease: An extensive review. Front Pharmacol 2022; 13:903099. [PMID: 36105221 PMCID: PMC9465172 DOI: 10.3389/fphar.2022.903099] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Metals serve important roles in the human body, including the maintenance of cell structure and the regulation of gene expression, the antioxidant response, and neurotransmission. High metal uptake in the nervous system is harmful because it can cause oxidative stress, disrupt mitochondrial function, and impair the activity of various enzymes. Metal accumulation can cause lifelong deterioration, including severe neurological problems. There is a strong association between accidental metal exposure and various neurodegenerative disorders, including Alzheimer’s disease (AD), the most common form of dementia that causes degeneration in the aged. Chronic exposure to various metals is a well-known environmental risk factor that has become more widespread due to the rapid pace at which human activities are releasing large amounts of metals into the environment. Consequently, humans are exposed to both biometals and heavy metals, affecting metal homeostasis at molecular and biological levels. This review highlights how these metals affect brain physiology and immunity and their roles in creating harmful proteins such as β-amyloid and tau in AD. In addition, we address findings that confirm the disruption of immune-related pathways as a significant toxicity mechanism through which metals may contribute to AD.
Collapse
Affiliation(s)
- Fahadul Islam
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, Bangladesh
| | - Sheikh Shohag
- Department of Genetic Engineering and Biotechnology, Faculty of Earth and Ocean Science, Bangabandhu Sheikh Mujibur Rahman Maritime University, Dhaka, Bangladesh
| | - Shomaya Akhter
- Department of Genetic Engineering and Biotechnology, Faculty of Earth and Ocean Science, Bangabandhu Sheikh Mujibur Rahman Maritime University, Dhaka, Bangladesh
| | - Md. Rezaul Islam
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, Bangladesh
| | - Sharifa Sultana
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, Bangladesh
| | - Saikat Mitra
- Department of Pharmacy, Faculty of Pharmacy, University of Dhaka, Dhaka, Bangladesh
| | - Deepak Chandran
- Department of Veterinary Sciences and Animal Husbandry, Amrita School of Agricultural Sciences, Amrita Vishwa Vidyapeetham University, Coimbatore, India
| | - Mayeen Uddin Khandaker
- Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University, Subang Jaya, Malaysia
| | - Ghulam Md Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- *Correspondence: Ghulam Md Ashraf, ; Abubakr M. Idris, ; Talha Bin Emran, ; Simona Cavalu,
| | - Abubakr M. Idris
- Department of Chemistry, College of Science, King Khalid University, Abha, Saudi Arabia
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Saudi Arabia
- *Correspondence: Ghulam Md Ashraf, ; Abubakr M. Idris, ; Talha Bin Emran, ; Simona Cavalu,
| | - Talha Bin Emran
- Department of Pharmacy, BGC Trust University Bangladesh, Chittagong, Bangladesh
- *Correspondence: Ghulam Md Ashraf, ; Abubakr M. Idris, ; Talha Bin Emran, ; Simona Cavalu,
| | - Simona Cavalu
- Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
- *Correspondence: Ghulam Md Ashraf, ; Abubakr M. Idris, ; Talha Bin Emran, ; Simona Cavalu,
| |
Collapse
|
6
|
Wei L, Huang H, Chen X, Wang X, Zhang R, Su L, Duan W, Rahman M, Golam Mostofa M, Qamruzzaman Q, Shen H, Hu Z, Wei Y, Christiani DC, Chen F. Umbilical cord serum elementomics of 52 trace elements and early childhood neurodevelopment: Evidence from a prospective birth cohort in rural Bangladesh. ENVIRONMENT INTERNATIONAL 2022; 166:107370. [PMID: 35772314 PMCID: PMC9926395 DOI: 10.1016/j.envint.2022.107370] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Prenatal exposures to neurotoxic metals and trace elements are associated with early childhood neurodevelopmental outcomes. However, consequences of simultaneous exposure to mixtures of elements remain unclear. OBJECTIVE To examine individual and joint effects of prenatal trace element exposure on early childhood neurodevelopment. METHODS Using a well-established Bangladesh prospective birth cohort (2008-2011), we measured concentrations of 52 trace elements in umbilical cord serum of 569 mother-infant pairs using inductively coupled plasma mass spectrometry. Neurodevelopment was evaluated at 20-40 months of age using Bayley Scales of Infant and Toddler Development, Third Edition. Stability elastic net (ENET) was used to screen elements individually associated with the outcome; candidate exposures were combined by weighted linear combination to form a risk score representing their mixture effect on early childhood neurodevelopment. RESULTS Stability ENET identified 15 trace elements associated with cognitive composite score and 14 associated with motor composite score, which were linearly combined to form the element risk score (ERS). Children with higher ERScognitive had lower probability of cognitive developmental delay (ORhighest vs lowest: 0.21; 95 %CI: 0.10, 0.40; P < 0.001; Ptrend < 0.001). Children with ERSmotor in the top quintile had a significantly lower risk of motor developmental delay (OR: 0.16; 95 %CI: 0.09, 0.31; P < 0.001; Ptrend < 0.001) versus the lowest quintile. In Bayesian kernel machine regression analyses, lithium [conditional posterior inclusion probability (cPIP) = 0.68], aluminum (cPIP = 0.83) and iron (cPIP = 1.00) contributed most to the lower cognitive composite score; zinc (cPIP = 1.00), silver (cPIP = 0.81), and antimony (cPIP = 0.65) mainly contributed to the change of motor composite score. CONCLUSION Co-exposure to lithium/aluminum/iron or zinc/silver/antimony appears to impact children's neurodevelopment. ERS score reflecting maternal exposure could indicate children's risk of neurodevelopmental delay, warranting further studies to explore the underlying mechanism.
Collapse
Affiliation(s)
- Liangmin Wei
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Hui Huang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Xin Chen
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Xiang Wang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Ruyang Zhang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Li Su
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Weiwei Duan
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | | | | | | | - Hongbing Shen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing 211166, China; China International Cooperation Center for Environment and Human Health, Center of Global Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhibin Hu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing 211166, China; China International Cooperation Center for Environment and Human Health, Center of Global Health, Nanjing Medical University, Nanjing 211166, China
| | - Yongyue Wei
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China; China International Cooperation Center for Environment and Human Health, Center of Global Health, Nanjing Medical University, Nanjing 211166, China.
| | - David C Christiani
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; China International Cooperation Center for Environment and Human Health, Center of Global Health, Nanjing Medical University, Nanjing 211166, China.
| | - Feng Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China; China International Cooperation Center for Environment and Human Health, Center of Global Health, Nanjing Medical University, Nanjing 211166, China.
| |
Collapse
|
7
|
Oppenheimer AV, Bellinger DC, Coull BA, Weisskopf MG, Korrick SA. Prenatal exposure to chemical mixtures and working memory among adolescents. ENVIRONMENTAL RESEARCH 2022; 205:112436. [PMID: 34843721 PMCID: PMC8760169 DOI: 10.1016/j.envres.2021.112436] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/15/2021] [Accepted: 11/23/2021] [Indexed: 05/06/2023]
Abstract
Working memory is the ability to keep information in one's mind and mentally manipulate it. Decrements in working memory play a key role in many behavioral and psychiatric disorders, therefore identifying modifiable environmental risk factors for such decrements is important for mitigating these disorders. There is some evidence that prenatal exposure to individual chemicals may adversely impact working memory among children, but few studies have explored the association of co-exposure to multiple chemicals with this outcome in adolescence, a time when working memory skills undergo substantial development. We investigated the association of organochlorines (DDE, HCB, PCBs) and metals (lead, manganese) measured in cord serum and cord blood, respectively, with working memory measured with the Wide Range Assessment of Memory and Learning, 2nd Edition among 373 adolescents living near a Superfund site in New Bedford, Massachusetts. We used Bayesian Kernel Machine Regression (BKMR) and linear regression analyses and assessed effect modification by sex and prenatal social disadvantage. In BKMR models, we observed an adverse joint association of the chemical mixture with Verbal, but not Symbolic, Working Memory. In co-exposure and covariate-adjusted linear regression models, a twofold increase in cord blood manganese was associated with lower working memory scaled scores, with a stronger association with Verbal Working Memory (difference = -0.75; 95% CI: -1.29, -0.20 points) compared to Symbolic Working Memory (difference = -0.44; 95% CI: -1.00, 0.12 points). There was little evidence of effect modification by sex and some evidence associating organochlorine pesticides with poorer working memory scores among those with greater prenatal social disadvantage. This study provided evidence of an adverse joint association of a chemical mixture with a verbal working memory task among adolescents, as well as an adverse association of prenatal manganese exposure with working memory.
Collapse
Affiliation(s)
- Anna V Oppenheimer
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - David C Bellinger
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Psychiatry, Boston Children's Hospital, Boston, MA, USA
| | - Brent A Coull
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Marc G Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Susan A Korrick
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
8
|
Saxena R, Gamble M, Wasserman GA, Liu X, Parvez F, Navas-Acien A, Islam T, Factor-Litvak P, Uddin MN, Kioumourtzoglou MA, Gibson EA, Shahriar H, Slavkovich V, Ilievski V, LoIacono N, Balac O, Graziano JH. Mixed metals exposure and cognitive function in Bangladeshi adolescents. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 232:113229. [PMID: 35131582 PMCID: PMC10045507 DOI: 10.1016/j.ecoenv.2022.113229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 11/30/2021] [Accepted: 01/20/2022] [Indexed: 05/09/2023]
Abstract
BACKGROUND Over 57 million people in Bangladesh have been chronically exposed to arsenic-contaminated drinking water. They also face environmental exposure to elevated levels of cadmium (Cd), manganese (Mn), and lead (Pb), all of which have been previously observed in environmental and biological samples for this population. These metals have been linked to adverse neurocognitive outcomes in adults and children, though their effects on adolescents are not yet fully characterized. Additionally, previous studies have linked selenium (Se) to protective effects against the toxicity of these other metals. OBJECTIVES To examine the associations between mixed metals exposure and cognitive function in Bangladeshi adolescents. METHODS The Metals, Arsenic, & Nutrition in Adolescents study (MANAs) is a cross-sectional study of 572 Bangladeshi adolescents aged 14-16 years, whose parents were enrolled in the Health Effects of Arsenic Longitudinal Study (HEALS). Biosamples were collected from these adolescents for measurement of whole blood metalloid/metal levels of As, Cd, Mn, Pb, and Se. Participants also completed an abbreviated version of The Cambridge Neuropsychological Test Automated Battery (CANTAB), a cognitive function test designed to measure performance across several aspects of executive function. Linear regression was used to examine associations for each metal while controlling for the other metals. Bayesian Kernel Machine Regression (BKMR) assessed the overall mixture effect in addition to confirming the effects of individual metal components observed via linear regression. RESULTS Linear regression revealed negative associations for Spatial Working Memory and both As and Mn (As B=-2.40, Mn B=-5.31, p < 0.05). We also observed negative associations between Cd and Spatial Recognition Memory (B=-2.77, p < 0.05), and Pb and Delayed Match to Sample, a measure of visual recognition and memory (B=-3.67, p < 0.05). Finally, we saw a positive association for Se and Spatial Span Length (B=0.92, p < 0.05). BKMR results were largely consistent with the regression analysis, showing meaningful associations for individual metals and CANTAB subtests, but no overall mixture effect. Via BKMR, we observed negative associations between Pb and Delayed Match to Sample, and Cd and Spatial Recognition Memory; this analysis also showed positive associations for Se and the Planning, Reaction Time, and Spatial Span subtests. BKMR posterior inclusion probability consistently reported that Se, the only component of the mixture to show a positive association with cognition, was the most important member of the mixture. CONCLUSIONS Overall, we found Se to be positively associated with cognition, while Mn and As were linked to poorer working memory, and Cd and Pb were associated with poorer visual recognition and memory. Our observations are consistent with previous reports on the effects of these metal exposures in adults and children. Our findings also suggest agreement between linear regression and BKMR methods for analyzing metal mixture exposures. Additional studies are needed to evaluate the impact of mixed metals exposure on adverse health and poorer cognition later in life for those exposed during adolescence. Findings also suggest that metal exposure mitigation efforts aimed at adolescents might influence lifelong cognitive outcomes in regions where environmental exposure to metals is endemic.
Collapse
Affiliation(s)
| | - Mary Gamble
- Mailman School of Public Health, New York, NY, USA.
| | | | - Xinhua Liu
- Mailman School of Public Health, New York, NY, USA
| | | | | | | | | | | | | | | | | | | | | | | | - Olgica Balac
- Mailman School of Public Health, New York, NY, USA
| | | |
Collapse
|
9
|
Oppenheimer AV, Bellinger DC, Coull BA, Weisskopf MG, Korrick SA. Prenatal Exposure to Chemical Mixtures and Cognitive Flexibility among Adolescents. TOXICS 2021; 9:toxics9120329. [PMID: 34941764 PMCID: PMC8708222 DOI: 10.3390/toxics9120329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/16/2022]
Abstract
Cognitive flexibility, the ability to smoothly adapt to changing circumstances, is a skill that is vital to higher-level executive functions such as problem-solving, planning, and reasoning. As it undergoes substantial development during adolescence, decrements in cognitive flexibility may not become apparent until this time. There is evidence that prenatal exposure to individual chemicals may adversely impact executive functions in children, but few studies have explored the association of co-exposure to multiple chemicals with cognitive flexibility specifically among adolescents. We investigated this association among a diverse group of adolescents living near a Superfund site in New Bedford, Massachusetts. Specifically, using Bayesian kernel machine regression (BKMR) and multivariable regression analyses, we investigated the association of biomarkers of prenatal exposure to organochlorines (DDE, HCB, PCBs) and metals (lead, manganese) with cognitive flexibility, measured with four subtests of the Delis-Kaplan Executive Function System. In BKMR models, we observed adverse joint associations of the chemical mixture with two of the four cognitive flexibility subtests. In covariate-adjusted linear regression models, a two-fold increase in cord blood Mn was associated with poorer performance on two of the subtests: Trail-Making (scaled score difference = −0.60; 95% CI: −1.16, −0.05 points) and Color-Word Interference (scaled score difference = −0.53; 95% CI: −1.08, 0.01 points). These adverse Mn-cognitive flexibility associations were supported by the results of the BKMR. There was little evidence of effect modification by sex and some evidence of effect modification by a measure of social disadvantage, particularly for the associations between HCB and cognitive flexibility. This study is among the first to provide evidence of an adverse association of prenatal exposure to a chemical mixture with cognitive flexibility in adolescence.
Collapse
Affiliation(s)
- Anna V. Oppenheimer
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Correspondence: ; Tel.: +1-781-264-0697
| | - David C. Bellinger
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Psychiatry, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Brent A. Coull
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Susan A. Korrick
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
10
|
Oppenheimer AV, Bellinger DC, Coull BA, Weisskopf MG, Zemplenyi M, Korrick SA. Prenatal Exposure to Chemical Mixtures and Inhibition among Adolescents. TOXICS 2021; 9:311. [PMID: 34822702 PMCID: PMC8619850 DOI: 10.3390/toxics9110311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/05/2021] [Accepted: 11/10/2021] [Indexed: 02/06/2023]
Abstract
Inhibition, one of the building blocks of executive function, is the ability to focus one's attention despite interference from external stimuli. It undergoes substantial development during adolescence and may be susceptible to adverse impacts of prenatal exposure to chemical mixtures, yet few studies have explored this association. The New Bedford Cohort (NBC) is a birth cohort of residents living near the New Bedford Harbor Superfund site in Massachusetts. Among adolescents from the NBC, we investigated the association of biomarkers of prenatal exposure to organochlorines (DDE, HCB, PCBs) and metals (Pb, Mn) with inhibition, assessed with the Delis-Kaplan Executive Function System Design Fluency (non-verbal task) and Color-Word Interference (verbal task) subtests. An exploratory mixtures analysis using Bayesian kernel machine regression (BKMR) informed a traditional multivariable regression approach. NBC adolescents are diverse with 29% non-white and 31% in a low-income household at birth. Cord serum organochlorine concentrations and cord blood metals concentrations were generally similar to other birth cohorts. In BKMR models, we observed a suggestive adverse association of the chemical mixture with Color-Word Interference but not Design Fluency. In covariate-adjusted linear regression models including all five chemical exposure measures, a doubling of cord blood Mn was associated with poorer Color-Word Interference completion time scaled scores (difference = -0.74; 95% CI: -1.34, -0.14). This study provided evidence of an adverse joint association between prenatal exposure to a five-chemical mixture and verbal inhibition in adolescence with exposure to Mn potentially driving this overall association.
Collapse
Affiliation(s)
- Anna V. Oppenheimer
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
| | - David C. Bellinger
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Psychiatry, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Brent A. Coull
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA;
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Michele Zemplenyi
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA;
| | - Susan A. Korrick
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; (D.C.B.); (B.A.C.); (M.G.W.); (S.A.K.)
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
11
|
Fruh V, Rifas-Shiman SL, Coull BA, Devick KL, Amarasiriwardena C, Cardenas A, Bellinger DC, Wise LA, White RF, Wright RO, Oken E, Claus Henn B. Prenatal exposure to a mixture of elements and neurobehavioral outcomes in mid-childhood: Results from Project Viva. ENVIRONMENTAL RESEARCH 2021; 201:111540. [PMID: 34166661 PMCID: PMC8502495 DOI: 10.1016/j.envres.2021.111540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/26/2021] [Accepted: 06/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Lead (Pb), manganese (Mn), selenium (Se) and methylmercury (MeHg) can be neurotoxic individually, despite Mn and Se also being essential elements. Little is known about the joint effects of essential and non-essential elements on neurobehavior, particularly for prenatal exposures. OBJECTIVES To evaluate associations of prenatal exposure to multiple elements with executive function and neurobehavior in children. METHODS Participants included 1009 mother-child pairs from the Project Viva pre-birth cohort. We estimated maternal erythrocyte Pb, Mn, Se, and Hg concentrations prenatally. In 6-11-year old children (median 7.6 years), parents and teachers rated children's executive function-related behaviors using the Behavior Rating Inventory of Executive Function (BRIEF) Global Executive Composite score and behavioral difficulties using the Strengths and Difficulties Questionnaire (SDQ) total difficulties score. We evaluated associations of element mixtures with neurobehavior using Bayesian kernel machine regression (BKMR), multivariable linear regression, and quantile g-computation. RESULTS Median erythrocyte Pb, Mn, Se, and Hg concentrations were 1.1 μg/dL, 33.1 μg/L, 204.5 ng/mL, and 3.1 ng/g, respectively. Findings from BKMR and quantile g-computation models both showed worse (higher) parent-rated BRIEF and SDQ z-scores with higher concentrations of the mixture, although estimates were imprecise. When remaining elements were set at their median within BKMR models, increases in Pb and Se from the 25th to 75th percentile of exposure distributions were associated with 0.08 (95% CI: 0.02, 0.19) and 0.07 (95% CI: 0.03, 0.16) standard deviation increases in parent-rated BRIEF scores, and 0.08 (95% CI: 0.02, 0.17) and 0.05 (95% CI: 0.03, 0.13) standard deviation increases in SDQ scores, respectively. There was no evidence of element interactions. DISCUSSION Although associations were small in magnitude, we found a trend of worsening neurobehavioral ratings with increasing prenatal exposure to an element mixture. However, we may be observing a limited range of dose-dependent impacts given the levels of exposure within our population.
Collapse
Affiliation(s)
- Victoria Fruh
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
| | - Sheryl L Rifas-Shiman
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
| | - Brent A Coull
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Katrina L Devick
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Scottsdale, AZ, USA
| | - Chitra Amarasiriwardena
- Department of Environmental Medicine and Public Health, Icahn School of Medicine, Mount Sinai, New York, NY, USA
| | - Andres Cardenas
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - David C Bellinger
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Lauren A Wise
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Roberta F White
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine, Mount Sinai, New York, NY, USA
| | - Emily Oken
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
| | - Birgit Claus Henn
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| |
Collapse
|
12
|
Carrasco P, Estarlich M, Iñiguez C, Ferrero A, Murcia M, Esplugues A, Vioque J, Marina LS, Zabaleta C, Iriarte G, Fernández-Somoano A, Tardon A, Vrijheid M, Sunyer J, Ballester F, Llop S. Pre and postnatal exposure to mercury and respiratory health in preschool children from the Spanish INMA Birth Cohort Study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 782:146654. [PMID: 33838378 DOI: 10.1016/j.scitotenv.2021.146654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Effects of mercury on maturing immune system have been reported, however the association with respiratory and allergy problems during infancy remains unclear. The aim of this study is to evaluate the association between pre and postnatal mercury exposure and respiratory and allergy problems among preschool children and to examine the role of potential modifying factors. Study subjects were children participant in Spanish Childhood and Environment Project (INMA, 2003-2008). We measured total mercury levels in cord blood (n = 1868) and hair at 4 years of age (n = 1347). Respiratory outcomes (wheezing, severe wheezing, chestiness, persistent cough, eczema and otitis) were obtained by questionnaires administered to parents. Associations were investigated by logistic regression adjusted for socio-demographic and lifestyle-related variables in each cohort and subsequent meta-analysis. We tested effect modification by factors related to individual susceptibility, diet and co-exposure with other pollutants. The geometric mean of cord blood and hair total mercury was 8.20 μg/L and 0.97 μg/g, respectively. No statistically significant association between pre or postnatal mercury exposure and respiratory and allergy outcomes was found. Notwithstanding, lower maternal intake of fruits and vegetables increased the risk of some respiratory outcomes due to the prenatal exposure to mercury (pint < 0.05). Moreover, an inverse association between prenatal mercury exposure and some respiratory outcomes was observed among children with higher maternal exposure to organocholorine compounds or smoking (pint < 0.05). Also, sex and postnatal smoking exposure modulated mercury postnatal effects on persistent cough (pint < 0.05). In conclusion, no association between pre and postnatal mercury exposure and respiratory and allergy problems among the whole population at study was found. However, diet and other toxicants could modulate this relation, especially during prenatal period. More research on this topic is warranted due to the limited evidence.
Collapse
Affiliation(s)
- Paula Carrasco
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Department of Medicine, Universitat Jaume I, Avenida de Vicent Sos Baynat s/n, 12071 Castellón de la Plana, Spain
| | - Marisa Estarlich
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Nursing School, Universitat de València, C/Jaume Roig s/n, 46010, Valencia, Spain.
| | - Carmen Iñiguez
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Department of Statistics and Computational Research. Universitat de València, València, Dr. Moliner, 50 46100, Spain
| | - Amparo Ferrero
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain
| | - Mario Murcia
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Servicio de Análisis de Sistemas de Información Sanitaria, Conselleria de Sanitat, Generalitat Valenciana. C/Micer Mascó, 31-33, 46010, Valencia, Spain
| | - Ana Esplugues
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Nursing School, Universitat de València, C/Jaume Roig s/n, 46010, Valencia, Spain
| | - Jesús Vioque
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Institute for Health and Biomedical Research (ISABIAL), Avda Pinto Baeza, 12, 03010 AlicanteAlicante, Spain
| | - Loreto Santa Marina
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Health Department of Basque Government, Sub-directorate of Public Health of Gipuzkoa, Avenida de Navarra 4, 20013 San Sebastián, Spain; Biodonostia Health Research Institute, Group of Environmental Epidemiology and Child Development, Public Health Division of Gipuzkoa, Doctor Begiristain, s/n, 20014 San Sebastián, Spain
| | - Carlos Zabaleta
- Biodonostia Health Research Institute, Group of Environmental Epidemiology and Child Development, Public Health Division of Gipuzkoa, Doctor Begiristain, s/n, 20014 San Sebastián, Spain; Nuestra señora de la Antigua Hospital, OSI Goierri-Alto Urola, OSAKIDETZA-Basque Health Service, Barrio Argixao, s/n, 20700 Zumarraga, Spain
| | - Gorka Iriarte
- Laboratorio de Salud Pública de Alava, Santiago 11, 01002 Vitoria Gasteiz, Spain
| | - Ana Fernández-Somoano
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; IUOPA-Departamento de Medicina, University of Oviedo, Av. Julián Clavería, 6, 33006 Oviedo, Spain; Institute of Health Research of the Principality of Asturias - Foundation for Biosanitary Research of Asturias (ISPA-FINBA), Avenida Hospital Universitario s/n, 33011, Oviedo, Spain
| | - Adonina Tardon
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; IUOPA-Departamento de Medicina, University of Oviedo, Av. Julián Clavería, 6, 33006 Oviedo, Spain; Institute of Health Research of the Principality of Asturias - Foundation for Biosanitary Research of Asturias (ISPA-FINBA), Avenida Hospital Universitario s/n, 33011, Oviedo, Spain
| | - Martine Vrijheid
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Barcelona Institute for Global Health (ISGlobal), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Plaça de la Mercè 10-12, 08002 Barcelona, Spain
| | - Jordi Sunyer
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Barcelona Institute for Global Health (ISGlobal), Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Plaça de la Mercè 10-12, 08002 Barcelona, Spain; Municipal Institute of Medical Research, IMIM-Hospital del Mar, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Ferran Ballester
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain; Nursing School, Universitat de València, C/Jaume Roig s/n, 46010, Valencia, Spain
| | - Sabrina Llop
- Epidemiology and Environmental Health Joint Research Unit, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, FISABIO-Universitat Jaume I-Universitat de València, Av. Catalunya 21, 46020 Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5. Pabellón 11, 28029 Madrid, Spain
| |
Collapse
|
13
|
Nyanza EC, Bernier FP, Martin JW, Manyama M, Hatfield J, Dewey D. Effects of prenatal exposure and co-exposure to metallic or metalloid elements on early infant neurodevelopmental outcomes in areas with small-scale gold mining activities in Northern Tanzania. ENVIRONMENT INTERNATIONAL 2021; 149:106104. [PMID: 32948351 DOI: 10.1016/j.envint.2020.106104] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/07/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Artisanal and small-scale gold mining (ASGM) is associated with release of neurotoxic metallic or metalloid chemical elements including lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As). OBJECTIVE To examine associations between prenatal exposure and co-exposure to total lead (T-Pb), total mercury (T-Hg), total cadmium (T-Cd) and total arsenic (T-As) and infant neurodevelopment at 6 to 12 months of age in areas with ASGM activities in Tanzania. METHODS Women in their second trimester of pregnancy who resided in ASGM areas were enrolled from 2015 to 2017 (n = 883). At 6 to 12 months of age, children were assessed with the Malawi Developmental Assessment Tool (MDAT) (n = 439). We measured T-Pb, T-Hg, and T-Cd in maternal dried blood spots and T-As in maternal urines. Poisson regression was used to examine associations between prenatal concentrations of these elements and neurodevelopmental outcomes. RESULTS Prenatal T-Hg concentration was associated with global neurodevelopment status (aPR 1.03, CI:1.01-1.04; p < 0.001) and language impairment (aPR 1.05, CI:1.03-1.07; p < 0.001) on the MDAT. When prenatal T-Hg and T-As values were at or above the human biomonitoring reference values (≥95%) of the German Environmental Survey for Human Biomonitoring, that is 0.80 µg/L and 15 µg/L, respectively, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0-4.3; p = 0.034). There was a 40% increase in the prevalence ratio of global neurodevelopmental impairment (aPR 1.4, CI:0.90-2.10, p = 0.027), when prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-Pb was at or above the reference value of 35 µg/L. When prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-As was at or above the reference value of 15 µg/L, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0-4.3; p < 0.034). DISCUSSION Infants born to women in areas with ASGM activities are at significant risk for neurodevelopmental impairment and this is associated with exposure to higher concentrations of Hg prenatally. Co-exposure to high concentrations of Hg and Pb, or Hg and As appeared to have negative potentiated effects on infants' neurodevelopment.
Collapse
Affiliation(s)
- Elias C Nyanza
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada; Department of Environmental, Occupational Health and GIS, School of Public Health, Catholic University of Health and Allied Sciences, P.O. Box 1464, Bugando, Mwanza, Tanzania
| | - Francois P Bernier
- Department of Paediatrics, University of Calgary, Alberta Children's Hospital, 28 Oki Drive NW, Calgary, AB T3B 6A8, Canada; Department of Medical Genetics, Cumming School of Medicine, 3330 Hospital Drive NW University of Calgary, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Room 294, Heritage Medical Research Building, 3330 Hospital Drive, NW Calgary, AB T2N 4N1, Canada
| | - Jonathan W Martin
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden; Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Mange Manyama
- Division of Medical Education, Weill-Cornell Medicine-Qatar, Doha, Qatar
| | - Jennifer Hatfield
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada
| | - Deborah Dewey
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada; Department of Paediatrics, University of Calgary, Alberta Children's Hospital, 28 Oki Drive NW, Calgary, AB T3B 6A8, Canada; Department of Medical Genetics, Cumming School of Medicine, 3330 Hospital Drive NW University of Calgary, Canada; Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Room 294, Heritage Medical Research Building, 3330 Hospital Drive, NW Calgary, AB T2N 4N1, Canada; Owerko Centre, #397 Child Development Centre, University of Calgary, 2500 University Dr. NW Calgary, AB T2N 1N4, Canada.
| |
Collapse
|
14
|
Fletcher S, Miranda A, Paiva J, Benoliel MJ, Almeida CMM. Optimization and in-house validation of the TDA-AAS method for mercury control in water and wastewater treatment plant sludges. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:5503-5513. [PMID: 33155578 DOI: 10.1039/d0ay01839b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The thermal decomposition, amalgamation, and atomic absorption spectrometry (TDA-AAS) method was validated for mercury (Hg) determination in sludge samples. A linear range was obtained from 30 to 200 ng. The TDA-AAS method provides a limit of quantification (LOQ) well below the legal maximum admitted concentration of Hg in sludge samples, which makes it suitable to measure its concentrations at the imposed legal limits, and for monitoring studies of Hg trace levels in sludge samples. Repeatability and within-laboratory reproducibility of the method were good with relative standard deviations lower than 6%. Expanded uncertainty, estimated using a top-down approach with the data obtained from accuracy and precision studies, was 18% for a coverage factor k = 2. Mercury concentration in sludge samples from water treatment plants was below the LOQ (0.33 mg Hg per kg dw) and in wastewater treatment plants was well below the legal limit for their reuse in agriculture (16 mg Hg per kg dw).
Collapse
Affiliation(s)
- Salomé Fletcher
- iMed.UL, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | | | | | | | | |
Collapse
|
15
|
Tatsuta N, Nakai K, Kasanuma Y, Iwai-Shimada M, Sakamoto M, Murata K, Satoh H. Prenatal and postnatal lead exposures and intellectual development among 12-year-old Japanese children. ENVIRONMENTAL RESEARCH 2020; 189:109844. [PMID: 32678746 DOI: 10.1016/j.envres.2020.109844] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Low-level lead exposure during childhood is associated with deficit in child IQ. However, the association between prenatal lead exposure and child IQ remains inconsistent. The objective of our study was to examine the association between prenatal/postnatal lead exposure and child IQ at the age of 12. METHODS We obtained data pertaining to cord-blood and child-blood lead levels and IQ for 286 children from a prospective birth cohort study (Tohoku Study of Child Development). IQ was assessed using the Wechsler Intelligence Scale for Children-Fourth Edition. Simultaneously, the Boston Naming Test (BNT) was used to assess the children's language ability. RESULTS The median lead level in the cord blood was 0.8 μg/dL (5th-95th percentiles, 0.4-1.4 μg/dL), and that in the blood of 12-year-old children was 0.7 μg/dL (0.4-1.1 μg/dL). IQ and BNT scores were significantly lower in boys than in girls; therefore, multiple regression analysis was conducted separately for boys and girls. Among boys, IQ was associated with child-blood lead (B = -16.362, p = 0.033) but not cord-blood lead (B = -6.844, p = 0.309). When boys were divided into four groups according to the child-blood lead levels, there was a significant decreasing trend for IQ. The score with cues of the BNT was associated with both cord-blood (B = -5.893, p = 0.025) and child-blood (B = -7.108, p = 0.022) lead concentrations in boys. Among girls, there was no significant association of the outcomes with cord-blood or child-blood lead level. CONCLUSIONS These findings suggest that postnatal lead exposure adversely affects the intellectual ability in boys. Furthermore, the language ability is sensitive to prenatal/postnatal lead exposure in boys.
Collapse
Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
| | - Yuichi Kasanuma
- Kesen-numa City Hospital, Kesen-numa 988-0181, Japan; Minami-Kesennuma Medical Clinic 988-0025, Japan
| | - Miyuki Iwai-Shimada
- Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
| | - Mineshi Sakamoto
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Katsuyuki Murata
- Akita University Graduate School of Medicine, Akita 010-8543, Japan
| | - Hiroshi Satoh
- Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| |
Collapse
|
16
|
Shah-Kulkarni S, Lee S, Jeong KS, Hong YC, Park H, Ha M, Kim Y, Ha EH. Prenatal exposure to mixtures of heavy metals and neurodevelopment in infants at 6 months. ENVIRONMENTAL RESEARCH 2020; 182:109122. [PMID: 32069757 DOI: 10.1016/j.envres.2020.109122] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 01/06/2020] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Exposure to mixture of neurotoxic metals such as lead, mercury and cadmium occurs at a specific point of time. When exposed to metal mixtures, one metal may act as an agonist or antagonist to another metal. Thus, it is important to study the effects of exposure to a combination of metals on children's development using advance statistical methods. OBJECTIVES In this study, we explored the effects of prenatal metal exposure including lead, mercury and cadmium in early pregnancy (12-20 weeks), late pregnancy (>28 weeks), and at birth on neurodevelopment of infants at 6 months of age. METHODS We included 523 eligible mother-child pairs from the mothers and children environmental health (MOCEH) study, a prospective birth cohort study in Korea. We used linear regression, Bayesian kernel machine regression (BKMR) and generalized additive models (GAM), to evaluate the effects of exposure to metal mixtures on neurodevelopment of infants aged 6 months. The Korean version of Bayley scale of infant and toddler development-II was used to measure the child's neurodevelopment. RESULTS Linear regression models showed a significant negative effect of lead exposure during late pregnancy on the mental development index (MDI) [β = -2.51 (-4.92, -0.10)] scores of infants aged 6 months following co-exposure to mercury. Further, linear regression analysis showed a significant interaction between late pregnancy lead and mercury concentrations. BKMR analysis showed similar results as those obtained in linear regression models. These results were also replicated in the GAM. Stratification analysis showed that greater than 50 percentile concentration of mercury in late pregnancy potentiated the adverse effects of lead in late pregnancy on MDI [β = -4.33 (-7.66, -1.00)] and psychomotor development index (PDI) [β = -5.30 (-9.13, -1.46)] at 6 months of age. Prenatal cadmium exposure did not show a significant association with MDI and PDI at 6 months in the linear regression or BKMR analysis. CONCLUSION Based on all the statistical methods used, we demonstrated the effect of combined exposure to metals on the neurodevelopment of infants aged 6 months, with significant interaction between lead and mercury.
Collapse
Affiliation(s)
- Surabhi Shah-Kulkarni
- Department of Occupational and Environmental Medicine, Ewha Womans University College of Medicine, Seoul, Republic of Korea
| | - Seulbi Lee
- Department of Occupational and Environmental Medicine, Ewha Womans University College of Medicine, Seoul, Republic of Korea
| | - Kyoung Sook Jeong
- Department of Occupational and Environmental Medicine, Hallym University Sacred Heart Hospital, Gyeonggido, Republic of Korea
| | - Yun-Chul Hong
- Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Hyesook Park
- Department of Preventive Medicine, Ewha Womans University College of Medicine, Seoul, Republic of Korea
| | - Mina Ha
- Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea
| | - Yangho Kim
- Department of Occupational and Environmental Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Republic of Korea
| | - Eun-Hee Ha
- Department of Occupational and Environmental Medicine, Ewha Womans University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
17
|
Gagnon-Chauvin A, Bastien K, Saint-Amour D. Environmental toxic agents: The impact of heavy metals and organochlorides on brain development. HANDBOOK OF CLINICAL NEUROLOGY 2020; 173:423-442. [PMID: 32958188 DOI: 10.1016/b978-0-444-64150-2.00030-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Exposure to environmental toxicants can have deleterious effects on the development of physical, cognitive, and mental health. Extensive laboratory and clinical studies have demonstrated how the developing brain is uniquely sensitive to toxic agents. This chapter focuses on the main neurologic impairments linked to prenatal and postnatal exposure to lead, methylmercury, and polychlorinated biphenyls, three legacy environmental contaminants whose neurotoxic effects have been extensively studied with respect to cognitive and behavioral development. The main cognitive, emotion regulation, sensory, and motor impairments in association with these contaminants are briefly reviewed, including the underlying neural mechanisms such as neuropathologic damages, brain neurotransmission, and endocrine system alterations. The use of neuroimaging as a novel tool to better understand how the brain is affected by exposure to environmental contaminants is also discussed.
Collapse
Affiliation(s)
- Avril Gagnon-Chauvin
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Kevin Bastien
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Dave Saint-Amour
- Department of Psychology, Université du Québec à Montréal, Montréal, QC, Canada; Research Centre, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada.
| |
Collapse
|
18
|
Dórea JG. Environmental exposure to low-level lead (Pb) co-occurring with other neurotoxicants in early life and neurodevelopment of children. ENVIRONMENTAL RESEARCH 2019; 177:108641. [PMID: 31421445 DOI: 10.1016/j.envres.2019.108641] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
Lead (Pb) is a worldwide environmental contaminant that even at low levels influences brain development and affects neurobehavior later in life; nevertheless it is only a small fraction of the neurotoxicant (NT) exposome. Exposure to environmental Pb concurrent with other NT substances is often the norm, but their joint effects are challenging to study during early life. The aim of this review is to integrate studies of Pb-containing NT mixtures during the early life and neurodevelopment outcomes of children. The Pb-containing NT mixtures that have been most studied involve other metals (Mn, Al, Hg, Cd), metalloids (As), halogen (F), and organo-halogen pollutants. Co-occurring Pb-associated exposures during pregnancy and lactation depend on the environmental sources and the metabolism and half-life of the specific NT contaminant; but offspring neurobehavioral outcomes are also influenced by social stressors. Nevertheless, Pb-associated effects from prenatal exposure portend a continued burden on measurable neurodevelopment; they thus favor increased neurological health issues, decrements in neurobehavioral tests and reductions in the quality of life. Neurobehavioral test outcomes measured in the first 1000 days showed Pb-associated negative outcomes were frequently noticed in infants (<6 months). In older (preschool and school) children studies showed more variations in NT mixtures, children's age, and sensitivity and/or specificity of neurobehavioral tests; these variations and choice of statistical model (individual NT stressor or collective effect of mixture) may explain inconsistencies. Multiple exposures to NT mixtures in children diagnosed with 'autism spectrum disorders' (ASD) and 'attention deficit and hyperactivity disorders' (ADHD), strongly suggest a Pb-associated effect. Mixture potency (number or associated NT components and respective concentrations) and time (duration and developmental stage) of exposure often showed a measurable impact on neurodevelopment; however, net effects, reversibility and/or predictability of delays are insufficiently studied and need urgent attention. Nevertheless, neurodevelopment delays can be prevented and/or attenuated if public health policies are implemented to protect the unborn and the young child.
Collapse
Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília, 70919-970, DF, Brazil.
| |
Collapse
|
19
|
Lazarevic N, Barnett AG, Sly PD, Knibbs LD. Statistical Methodology in Studies of Prenatal Exposure to Mixtures of Endocrine-Disrupting Chemicals: A Review of Existing Approaches and New Alternatives. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:26001. [PMID: 30720337 PMCID: PMC6752940 DOI: 10.1289/ehp2207] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Prenatal exposures to endocrine-disrupting chemicals (EDCs) during critical developmental windows have been implicated in the etiologies of a wide array of adverse perinatal and pediatric outcomes. Epidemiological studies have concentrated on the health effects of individual chemicals, despite the understanding that EDCs act together via common mechanisms, that pregnant women are exposed to multiple EDCs simultaneously, and that substantial toxicological evidence of adverse developmental effects has been documented. There is a move toward multipollutant models in environmental epidemiology; however, there is no current consensus on appropriate statistical methods. OBJECTIVES We aimed to review the statistical methods used in these studies, to identify additional applicable methods, and to determine the strengths and weaknesses of each method for addressing the salient statistical and epidemiological challenges. METHODS We searched Embase, MEDLINE, and Web of Science for epidemiological studies of endocrine-sensitive outcomes in the children of mothers exposed to EDC mixtures during pregnancy and identified alternative statistical methods from the wider literature. DISCUSSION We identified 74 studies and analyzed the methods used to estimate mixture health effects, identify important mixture components, account for nonmonotonicity in exposure–response relationships, assess interactions, and identify windows of exposure susceptibility. We identified both frequentist and Bayesian methods that are robust to multicollinearity, performing shrinkage, variable selection, dimension reduction, statistical learning, or smoothing, including methods that were not used by the studies included in our review. CONCLUSIONS Compelling motivation exists for analyzing EDCs as mixtures, yet many studies make simplifying assumptions about EDC additivity, relative potency, and linearity, or overlook the potential for bias due to asymmetries in chemical persistence. We discuss the potential impacts of these choices and suggest alternative methods to improve analyses of prenatal exposure to EDC mixtures. https://doi.org/10.1289/EHP2207.
Collapse
Affiliation(s)
- Nina Lazarevic
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Adrian G Barnett
- School of Public Health and Social Work, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Peter D Sly
- Child Health Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Luke D Knibbs
- School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Air Quality & Health Research and Evaluation, Glebe, New South Wales, Australia
| |
Collapse
|
20
|
Dórea JG. Multiple low-level exposures: Hg interactions with co-occurring neurotoxic substances in early life. Biochim Biophys Acta Gen Subj 2018; 1863:129243. [PMID: 30385391 DOI: 10.1016/j.bbagen.2018.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/01/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
All chemical forms of Hg can affect neurodevelopment; however, low levels of organic Hg (methylmercury-MeHg and ethylmercury-EtHg in Thimerosal-containing vaccines, hereafter 'TCV') exposures during early life (pregnancy and lactation) co-occur with other environmental neurotoxic substances. These neurotoxicants may act in parallel, synergistically, or antagonistically to Hg. Nevertheless, the risks of neurotoxicity associated with multiple neuro-toxicants depend on type, time, combinations of exposure, and environmental and/or genetic-associated factors. Neurological developmental disorders, delays in cognition and behavioral outcomes associated with multiple exposures (which include Hg) may show transient or lasting outcomes depending on constitutional and/or environmental factors that can interact to neutralize, aggravate or attenuate these effects; often these studies are challenging to interpret. During pregnancy and lactation, fish-MeHg exposure is frequently confounded with the opposing effects of neuroactive nutrients (in fish) that lead to positive, negative, or no effects on neurobehavioral tests. In infancy, exposures to acute binary mixtures (TCV- EtHg and Al-adjuvants in infant immunizations) are associated with increased risks of tics and other developmental disorders. Despite the certitude that promulgates single environmental neurotoxicants, empirical comparisons of combined exposures indicate that Hg-related outcome is uneven. Hg in combination with other neurotoxic mixtures may elevate risks of neurotoxicity, but these risks arise in circumstances that are not yet predictable. Therefore, to achieve the goals of the Minamata treaty and to safeguard the health of children, low levels of mercury exposure (in any chemical form) needs to be further reduced whether the source is environmental (air- and food-borne) or iatrogenic (pediatric TCVs).
Collapse
Affiliation(s)
- José G Dórea
- Universidade de Brasília, Brasília 70919-970, DF, Brazil..
| |
Collapse
|
21
|
Tatsuta N, Nakai K, Sakamoto M, Murata K, Satoh H. Methylmercury Exposure and Developmental Outcomes in Tohoku Study of Child Development at 18 Months of Age. TOXICS 2018; 6:toxics6030049. [PMID: 30134554 PMCID: PMC6161177 DOI: 10.3390/toxics6030049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 08/14/2018] [Accepted: 08/18/2018] [Indexed: 11/21/2022]
Abstract
Seafood is an important component in a healthy diet and may contain methylmercury or other contaminants. It is important to recognize the risks and benefits of consuming seafood. A longitudinal prospective birth cohort study has been conducted to clarify the effects of neurotoxicants on child development—the Tohoku Study of Child Development (TSCD) in Japan. TSCD comprises two cohorts; a polychlorinated biphenyls (PCB) cohort (urban area) and a methylmercury cohort (coastal area). Our previous results from the coastal area showed prenatal methylmercury exposure affected psychomotor development in 18-month-olds, and boys appear to be more vulnerable to the exposure than girls. In this report, we have added the urban area cohort and we reanalyzed the impact of prenatal exposure to methylmercury, which gave the same results as before. These findings suggest prenatal exposure to low levels methylmercury may have adverse effects on child development, especially in boys.
Collapse
Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
| | - Mineshi Sakamoto
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
- Environmental Health Section, Department of Environmental Science and Epidemiology, National Institute for Minamata Disease, Kumamoto 867-0008, Japan.
| | - Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine, Akita 010-8502, Japan.
| | - Hiroshi Satoh
- Environmental Health Science, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
| |
Collapse
|
22
|
Unsal V. Natural Phytotherapeutic Antioxidants in the Treatment of Mercury Intoxication-A Review. Adv Pharm Bull 2018; 8:365-376. [PMID: 30276132 PMCID: PMC6156483 DOI: 10.15171/apb.2018.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 07/23/2018] [Accepted: 08/09/2018] [Indexed: 12/11/2022] Open
Abstract
Heavy metals taken into the organism can make the toxic effects on the metabolism in various ways. For example, they may interact with proteins to alter and inhibit their enzymatic and structural functions. Mercury is one of the toxic elements that are widely distributed in nature. Mercury toxicity poses a serious threat to human health. It is an element that causes oxidative stress to increase in individuals, leading to tissue damage. Oxidative stress is the result of the imbalance between the production of oxidative species and cellular antioxidant defense. Phytotherapy continues to play an important role in health care. Natural phytotherapeutic antioxidants, exhibit a broad sequence of biological impacts, including anti-oxidative stress, anti-aging, anti-toxicicity and anticancer. Many studies have also shown that the phytotherapeutic agents play an important role in the removal of mercury from the tissue and in reducing oxidative stress. Our goal in this review was to investigate alternative ways of extracting the mercury in the tissue.
Collapse
Affiliation(s)
- Velid Unsal
- Corresponding author: Velid Unsal, Tel: 0482 2121395,
| |
Collapse
|
23
|
Assessment of Cardiac Autonomic Function in Relation to Methylmercury Neurotoxicity. TOXICS 2018; 6:toxics6030038. [PMID: 30036985 PMCID: PMC6161203 DOI: 10.3390/toxics6030038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 07/12/2018] [Accepted: 07/18/2018] [Indexed: 11/17/2022]
Abstract
After the European Food Safety Authority reviewed reports of methylmercury and heart rate variability (HRV) in 2012, the panel concluded that, although some studies of cardiac autonomy suggested an autonomic effect of methylmercury, the results were inconsistent among studies and the implications for health were unclear. In this study, we reconsider this association by adding a perspective on the physiological context. Cardiovascular rhythmicity is usually studied within different frequency domains of HRV. Three spectral components are usually detected; in humans these are centered at <0.04 Hz, 0.15 Hz (LF), and 0.3 Hz (HF). LF and HF (sympathetic and parasympathetic activities, respectively) are evaluated in terms of frequency and power. By searching PubMed, we identified 13 studies examining the effect of methylmercury exposure on HRV in human populations in the Faroe Islands, the Seychelles and other countries. Considering both reduced HRV and sympathodominant state (i.e., lower HF, higher LF, or higher LF/HF ratio) as autonomic abnormality, eight of them showed the significant association with methylmercury exposure. Five studies failed to demonstrate any significant association. In conclusion, these data suggest that increased methylmercury exposure was consistently associated with autonomic abnormality, though the influence of methylmercury on HRV (e.g., LF) might differ for prenatal and postnatal exposures. The results with HRV should be included in the risk characterization of methylmercury. The HRV parameters calculated by frequency domain analysis appear to be more sensitive to methylmercury exposure than those by time domain analysis.
Collapse
|
24
|
Murata K, Iwata T, Maeda E, Karita K. [Dilemma of Environmental Health Research]. Nihon Eiseigaku Zasshi 2018; 73:148-155. [PMID: 29848867 DOI: 10.1265/jjh.73.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This article presents not only a brief overview of birth cohort studies focusing on environmental health in which the associations between health and environment were examined, but also a tentative plan to apply epidemiological data to benchmark dose calculation. According to the preceding studies, the checkpoints to be scrutinized when a result is not consistent with those of other researchers are as follows: (1) whether the study included all crucial confounders, (2) whether it included any exposure marker or confounder with a U-shaped dose-response curve, (3) whether the outcome measure was conducted by two or more examiners that might lead to measurement bias, (4) whether such examiners picked up information about exposure levels of the subjects before measuring the endpoints, and (5) whether subjects with different genetic factors were included in the analysis. In addition, (6) researchers conducting a children's study on developmental effects due to toxic substances must keep in mind that the impact of prenatal methylmercury exposure, independent of postnatal exposure, may continue for at least seven years. (7) When an environmental health research emphasizes to be population-based study, the levels of exposure to environmental chemical substances in developed countries with strict environmental regulations may be too low to examine a dose-response relationship for critical dose estimation. Such risk assessment should be carried out among the subjects with a wide range of exposure levels.
Collapse
Affiliation(s)
- Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine
| | - Toyoto Iwata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine
| | - Eri Maeda
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine
| | - Kanae Karita
- Department of Hygiene and Public Health, Kyorin University School of Medicine
| |
Collapse
|
25
|
Oliveira CS, Nogara PA, Ardisson-Araújo DMP, Aschner M, Rocha JBT, Dórea JG. Neurodevelopmental Effects of Mercury. ADVANCES IN NEUROTOXICOLOGY 2018; 2:27-86. [PMID: 32346667 PMCID: PMC7188190 DOI: 10.1016/bs.ant.2018.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The toxicology of mercury (Hg) is of concern since this metal is ubiquitously distributed in the environment, and living organisms are routinely exposed to Hg at low to high levels. The toxic effects of Hg are well studied and it is known that they may differ depending on the Hg chemical species. In this chapter, we emphasize the neurotoxic effects of Hg during brain development. The immature brain is more susceptible to Hg exposure, since all the Hg chemical forms, not only the organic ones, can harm it. The possible consequences of Hg exposure during the early stages of development, the additive effects with other co-occurring neurotoxicants, and the known mechanisms of action and targets will be addressed in this chapter.
Collapse
Affiliation(s)
- Cláudia S Oliveira
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Pablo A Nogara
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Daniel M P Ardisson-Araújo
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
- Laboratório de Virologia de Insetos, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, NY, USA
| | - João B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - José G Dórea
- Professor Emeritus, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, DF, Brazil
| |
Collapse
|
26
|
Tatsuta N, Nakai K, Iwai-Shimada M, Mizutani F, Murata K, Chisaki Y, Satoh H. A methodological consideration for blood lead concentrations obtained from the earlobe in Japanese adults occupationally unexposed to lead. Environ Health Prev Med 2017; 22:78. [PMID: 29228902 PMCID: PMC5725893 DOI: 10.1186/s12199-017-0685-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 11/23/2017] [Indexed: 11/16/2022] Open
Abstract
Background Neuropsychological effects of considerably low levels of lead exposure are observed in children, and a reliable and possibly painless technique that can detect such levels is required for the assessment of such exposure. We examined whether the blood lead (BPb) concentrations obtained from the earlobe were as valid and useful as those from the median cubital vein. Methods Paired blood samples were collected from the earlobe and cubital vein of 112 Japanese participants occupationally unexposed to lead, and the BPb levels were determined using ICP-MS. Results The limit of detection of BPb for the ICP-MS method was 0.015 μg/dL, and there was no participant with a BPb level below this limit. The median values of BPb concentrations were 0.91 (range, 0.41–2.48) μg/dL for earlobe blood using a 175-μL capillary tube and 0.85 (0.35–2.39) μg/dL for venous blood using a 5-mL vacuum tube. There was a significant correlation between the earlobe BPb levels and cubital vein BPb levels (Spearman rank correlation rS = 0.941), though the earlobe BPb levels were significantly higher than the cubital vein BPb levels. Most of the participants regarded earlobe puncture as a painless method. Conclusions These data suggest that earlobe BPb levels can be used to assess lead exposure in children. Blood collection using a capillary tube should be done carefully and promptly because slow withdrawal may lead to measurement bias.
Collapse
Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.,, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Miyuki Iwai-Shimada
- Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan
| | - Futoshi Mizutani
- Institute of Environmental Ecology, IDEA Consultants, Inc., Yaizu, Japan
| | - Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine, Akita, Japan
| | - Yoichi Chisaki
- Institute of Environmental Ecology, IDEA Consultants, Inc., Yaizu, Japan
| | - Hiroshi Satoh
- Environmental Health Science, Tohoku University Graduate School of Medicine, Sendai, Japan
| |
Collapse
|
27
|
Alvarez-Ortega N, Caballero-Gallardo K, Olivero-Verbel J. Low blood lead levels impair intellectual and hematological function in children from Cartagena, Caribbean coast of Colombia. J Trace Elem Med Biol 2017; 44:233-240. [PMID: 28965581 DOI: 10.1016/j.jtemb.2017.08.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/25/2017] [Accepted: 08/07/2017] [Indexed: 02/08/2023]
Abstract
Lead produces numerous biochemical and physiological changes in humans, including hematological disorders, toxic effects on the central nervous system and in the function of several organs. The aim of this study was to determine blood lead levels (BLL) in children from Cartagena, Colombia, associating those with hematological and liver damage markers, the intelligence quotient (IQ), as well as with gene expression of the aminolevulinate dehydratase (ALAD), superoxide dismutase 1 (SOD1), gamma interferon (INF-γ), tumor necrosis factor (TNF) and tumor protein (p53). To achieve this purpose, 118 blood samples were collected from children 5-16 years old, with their respective informed consent from their parents. BLL was measured by atomic absorption; hematological parameters were obtained with automated systems; plasma was utilized to analyze hepatic toxicity markers, alanine aminotransferase (ALT), gamma-glutamyltransferase (γ-GT) and alkaline phosphatase (ALP); the Kaufman Brief Intelligence Test (K-BIT) was administered to measure the IQ; and gene expression was quantified from blood RNA. The mean BLL was 1.7±0.3μg/dL. A low proportion of the children (3.4%) had BLL above the CDC recommended limit (5μg/dL). BLL were correlated weakly, but negatively with child age, weight, height, body mass index, platelets wide distribution, mean platelet volume, γ-GT and IQ. There were not significant changes in the expression of evaluated genes. These results support the hypothesis that BLL below 5μg/dL may still be a detrimental factor on children's cognitive abilities, development and hematology, in line with recent concerns that there is no safe level of pediatric lead exposure.
Collapse
Affiliation(s)
- Neda Alvarez-Ortega
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia
| | - Karina Caballero-Gallardo
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia
| | - Jesus Olivero-Verbel
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia.
| |
Collapse
|
28
|
Weihe P, Debes F, Halling J, Petersen MS, Muckle G, Odland JØ, Dudarev A, Ayotte P, Dewailly É, Grandjean P, Bonefeld-Jørgensen E. Health effects associated with measured levels of contaminants in the Arctic. Int J Circumpolar Health 2016; 75:33805. [PMID: 27974137 PMCID: PMC5156856 DOI: 10.3402/ijch.v75.33805] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The Human Health Assessment Group has over the past decade recommended that effect studies be conducted in the circumpolar area. Such studies examine the association between contaminant exposure in the Arctic populations and health effects. Because foetuses and young children are the most vulnerable, effect studies are often prospective child cohort studies. The emphasis in this article is on a description of the effects associated with contaminant exposure in the Arctic. The main topics addressed are neurobehavioural, immunological, reproductive, cardiovascular, endocrine and carcinogenic effect. For each topic, the association between exposure and effects is described, and some results are reported for similar studies outside the Arctic.
Collapse
Affiliation(s)
- Pál Weihe
- Department of Occupational Medicine and Public Health, The Faroese Hospital System, Torshavn, Faroe Islands;
| | - Fróði Debes
- Department of Occupational Medicine and Public Health, The Faroese Hospital System, Torshavn, Faroe Islands
| | - Jónrit Halling
- Department of Occupational Medicine and Public Health, The Faroese Hospital System, Torshavn, Faroe Islands
| | - Maria Skaalum Petersen
- Department of Occupational Medicine and Public Health, The Faroese Hospital System, Torshavn, Faroe Islands
| | - Gina Muckle
- École de psychologie, Université Laval and Centre de recherche du CHU de Québec, Québec, City, QC, Canada
| | - Jon Øyvind Odland
- Department of Community Medicine, UiT The Arctic University of Norway, Tromso, Norway
| | - Alexey Dudarev
- Northwest Public Health Research Center, St. Petersburg, Russia
| | | | | | - Philippe Grandjean
- Department of Environmental Medicine, Univerisity of Southern Denmark, Odense, Denmark
| | - Eva Bonefeld-Jørgensen
- Centre for Arctic Health, Department of Public Health, Aarhus University, Aarhus, Denmark
| |
Collapse
|
29
|
Dey S, Choudhury MD, Das S. Sublethal effects of pulp and paper mill effluent on two commonly cultured carps: a SEM- and EDS-based hematological biomarker analysis. FISH PHYSIOLOGY AND BIOCHEMISTRY 2016; 42:1791-1805. [PMID: 27378480 DOI: 10.1007/s10695-016-0258-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/24/2016] [Indexed: 06/06/2023]
Abstract
Blood being a vehicle for the transport of industrial pollutants in living system, fish hematology is considered as potent biomarker. In the present study, we investigated respective sublethal effects of pulp and paper mill effluents on hematology of two commonly cultured carps, Cyprinus carpio and Ctenopharyngodon idella, using optical, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Irrespective of species, results showed significant decrease in erythrocyte, hematocrit and hemoglobin contents while an increase in white blood cell counts (P < 0.05). We observed an increasing trend of MCV (170.0 ± 3.07 to 193.16 ± 2.5) and MCH (34.31 ± 1.89 to 38.71 ± 3.61) up to 28th day in C. carpio (P < 0.05), while, in C. idella, the highest percent increase in MCV (180.8 ± 2.19) and MCH (32.9 ± 0.62) was observed on seventh exposure day, which subsequently declined, respectively, to 173.1 ± 17.1 and 27.9 ± 2.45 on 28th day. Unlike C. carpio, significant and progressive MCHC declining trend (18.23 ± 0.28 to 16.13 ± 0.31) was observed in C. idella. The most commonly observed abnormalities under SEM include echinocytes, cytoplasmic blebbing, cytoplasmic ring, spherocytes, lobopodial projections and acanthocytes in red blood cells of exposed fishes. EDS further revealed the presence of aluminum, antimony, arsenic, cadmium, mercury, tungsten, zinc and titanium; some of these metals were not even detected in the effluent samples, suggesting the probable metal bio-concentration in fish tissue, and subsequent jeopardization is a major concern particularly in the industrial area. Our study further suggested the use of sensitive and specific techniques like SEM and EDS in fish hematological biomarker analysis along with the conventional approach.
Collapse
Affiliation(s)
- Sangeeta Dey
- Aquatic Toxicology and Remediation Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India
| | - Manabendra Dutta Choudhury
- Ethnobotany and Medicinal Plants Research Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India
| | - Suchismita Das
- Aquatic Toxicology and Remediation Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India.
| |
Collapse
|
30
|
Boucher O, Muckle G, Ayotte P, Dewailly E, Jacobson SW, Jacobson JL. Altered fine motor function at school age in Inuit children exposed to PCBs, methylmercury, and lead. ENVIRONMENT INTERNATIONAL 2016; 95:144-51. [PMID: 27575364 PMCID: PMC5035542 DOI: 10.1016/j.envint.2016.08.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 05/11/2023]
Abstract
BACKGROUND Motor deficits have frequently been reported in methylmercury (MeHg) poisoning in adults. However, whether exposure to neurotoxic contaminants from environmental sources early in life is associated with neuromotor impairments has received relatively little attention. This study examines the relation of developmental exposure to MeHg, polychlorinated biphenyls (PCBs), and lead to motor function in school-age Inuit children exposed through their traditional diet. METHODS In a prospective study in Nunavik, children (mean age=11.3years) were assessed on a battery of fine motor tasks, namely the Stanford-Binet Copying subtest (N=262), the Santa Ana Form Board, and the Finger Tapping Test (N=215). The relation of mercury (Hg; as an index of MeHg exposure), PCB congener 153 (PCB153), and lead concentrations in cord and current blood samples to task performance was examined using linear regression analyses. RESULTS After adjustment for potential confounders and control for the other contaminants, higher current PCB concentrations were associated with poorer Santa Ana Form Board and Finger Tapping performance. Results were virtually identical when PCB153 was replaced by other PCB congeners. Higher current Hg levels were independently associated with poorer Finger Tapping performance. CONCLUSIONS This is the first prospective longitudinal study in children to provide evidence of neuromotor impairments associated with postnatal exposure to seafood contaminants from environmental sources. Fine motor speed appears particularly sensitive to the effects of postnatal PCB exposure, which is unusually high in this population. Results with postnatal MeHg are concordant with previous cross-sectional studies with children and adults.
Collapse
Affiliation(s)
- Olivier Boucher
- Département de psychologie, Université de Montréal, Montréal, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada
| | - Gina Muckle
- Centre de recherche du CHU de Québec, Québec, Québec, Canada; Université Laval, Québec, Québec, Canada
| | - Pierre Ayotte
- Centre de recherche du CHU de Québec, Québec, Québec, Canada; Université Laval, Québec, Québec, Canada
| | - Eric Dewailly
- Centre de recherche du CHU de Québec, Québec, Québec, Canada; Université Laval, Québec, Québec, Canada
| | - Sandra W Jacobson
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Joseph L Jacobson
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA.
| |
Collapse
|
31
|
Abstract
Metals play important roles in the human body, maintaining cell structure and regulating gene expression, neurotransmission, and antioxidant response, to name a few. However, excessive metal accumulation in the nervous system may be toxic, inducing oxidative stress, disrupting mitochondrial function, and impairing the activity of numerous enzymes. Damage caused by metal accumulation may result in permanent injuries, including severe neurological disorders. Epidemiological and clinical studies have shown a strong correlation between aberrant metal exposure and a number of neurological diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, autism spectrum disorders, Guillain–Barré disease, Gulf War syndrome, Huntington’s disease, multiple sclerosis, Parkinson’s disease, and Wilson’s disease. Here, we briefly survey the literature relating to the role of metals in neurodegeneration.
Collapse
Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, New York, USA
| | - Mahfuzur Rahman Miah
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, New York, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, New York, USA
| |
Collapse
|
32
|
Perinatal and Childhood Exposure to Cadmium, Manganese, and Metal Mixtures and Effects on Cognition and Behavior: A Review of Recent Literature. Curr Environ Health Rep 2016; 2:284-94. [PMID: 26231505 DOI: 10.1007/s40572-015-0058-8] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Lead (Pb) and mercury (Hg) neurotoxicity is well established. In recent years, a growing body of evidence suggests that environmental exposure to other metals including arsenic (As), cadmium (Cd), and manganese (Mn) and their mixtures also poses public health threats. In this paper, we summarize the recent literature examining the relationship of prenatal and childhood environmental metal exposures with cognitive and behavioral outcomes in children. We conducted a literature search to identify epidemiologic studies that examined the relationship of Cd, Mn, and metal mixtures with children's neurodevelopmental/cognitive and behavioral outcomes. We restricted the search to peer-reviewed studies published in English between January 2009 and March 2015. We identified a total of 31 articles of which 16, 17, and 16 studies examined the effects of Cd, Mn, or metal mixtures, respectively. Based on our review, there is suggestive evidence that prenatal/childhood Cd exposure may be associated with poorer cognition, but additional research is clearly needed. We found little evidence of behavioral effects of early life Cd exposure, and no studies found a significant relationship with attention deficit hyperactivity disorder. Studies of early life Mn exposure consistently reported negative impacts on both cognition and behavior. There is also growing evidence that co-exposure to multiple metals can result in increased neurotoxicity compared to single-metal exposure, in particular during early life. Few studies have evaluated behavioral effects related to metal co-exposure.
Collapse
|
33
|
Karita K, Sakamoto M, Yoshida M, Tatsuta N, Nakai K, Iwai-Shimada M, Iwata T, Maeda E, Yaginuma-Sakurai K, Satoh H, Murata K. [Recent Epidemiological Studies on Methylmercury, Mercury and Selenium]. Nihon Eiseigaku Zasshi 2016; 71:236-251. [PMID: 27725427 DOI: 10.1265/jjh.71.236] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
More than sixty years has passed since the outbreak of Minamata disease, and high-level methylmercury contaminations now seem nonexistent in Japan. However, mercury has been continuously discharged from natural sources and industrial activities, and the health effects on children susceptible to methylmercury exposure at low levels, in addition to mercury contamination from mercury or gold mining areas in developing countries, become a worldwide concern. In this article, we provide a recent overview of epidemiological studies regarding methylmercury and mercury. The following findings were obtained. (1) Many papers on exposure assessment of methylmercury/mercury have been published since the Minamata Convention on Mercury was adopted in 2013. (2) The most crucial problem is child developmental neurotoxicity resulting from prenatal exposure to methylmercury, but its precise assessment seems to be difficult because most of such effects are neither severe nor specific. (3) Several problems raised in birth cohort studies (e.g., whether IQ deficits due to prenatal methylmercury exposure remain when the children become adults, or whether the postnatal exposure at low levels also causes such adverse effects in children) remain unsolved. (4) Concurrent exposure models of methylmercury, lead, polychlorinated biphenyls, aresenic, and organochlorine pesticides, as well as possible antagonists such as polyunsaturated fatty acids and selenium, should be considered in the study design because the exposure levels of methylmercury are extremely low in developed countries. (5) Further animal experiments and molecular biological studies, in addition to human studies, are required to clarify the mechanism of methylmercury toxicity.
Collapse
Affiliation(s)
- Kanae Karita
- Department of Hygiene and Public Health, Kyorin University School of Medicine
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Barbieri FL, Gardon J, Ruiz-Castell M, Paco V. P, Muckelbauer R, Casiot C, Freydier R, Duprey JL, Chen CM, Müller-Nordhorn J, Keil T. Toxic trace elements in maternal and cord blood and social determinants in a Bolivian mining city. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2015; 26:158-74. [PMID: 26179629 PMCID: PMC4733940 DOI: 10.1080/09603123.2015.1061114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Accepted: 04/25/2015] [Indexed: 05/19/2023]
Abstract
This study assessed lead, arsenic, and antimony in maternal and cord blood, and associations between maternal concentrations and social determinants in the Bolivian mining city of Oruro using the baseline assessment of the ToxBol/Mine-Niño birth cohort. We recruited 467 pregnant women, collecting venous blood and sociodemographic information as well as placental cord blood at birth. Metallic/semimetallic trace elements were measured using inductively coupled plasma mass spectrometry. Lead medians in maternal and cord blood were significantly correlated (Spearman coefficient = 0.59; p < 0.001; 19.35 and 13.50 μg/L, respectively). Arsenic concentrations were above detection limit (3.30 μg/L) in 17.9% of maternal and 34.6% of cord blood samples. They were not associated (Fischer's p = 0.72). Antimony medians in maternal and cord blood were weakly correlated (Spearman coefficient = 0.15; p < 0.03; 9.00 and 8.62 μg/L, respectively). Higher concentrations of toxic elements in maternal blood were associated with maternal smoking, low educational level, and partner involved in mining.
Collapse
Affiliation(s)
- Flavia L. Barbieri
- Institut de Recherche pour le Développement (IRD), La Paz, Bolivia
- Servicios de Laboratorio de Investigación en Salud (SELADIS), Universidad Mayor de San Andrés, La Paz, Bolivia
- Berlin School of Public Health (BSPH), Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Jacques Gardon
- Institut de Recherche pour le Développement (IRD), La Paz, Bolivia
- Servicios de Laboratorio de Investigación en Salud (SELADIS), Universidad Mayor de San Andrés, La Paz, Bolivia
- Hydrosciences Montpellier (HSM), Maison des Sciences de l’eau, Montpellier, France
| | - María Ruiz-Castell
- Institut de Recherche pour le Développement (IRD), La Paz, Bolivia
- Servicios de Laboratorio de Investigación en Salud (SELADIS), Universidad Mayor de San Andrés, La Paz, Bolivia
- Centre de Recherche du Centre Hospitalier Universitaire de Québec (CHUQ), Université Laval, Québec, Canada
| | - Pamela Paco V.
- Institut de Recherche pour le Développement (IRD), La Paz, Bolivia
- Servicios de Laboratorio de Investigación en Salud (SELADIS), Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Rebecca Muckelbauer
- Berlin School of Public Health (BSPH), Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Corinne Casiot
- Hydrosciences Montpellier (HSM), Maison des Sciences de l’eau, Montpellier, France
- Centre National de la Recherche Scientifique (CNRS), Maison des Sciences de l’eau, Montpellier, France
| | - Rémi Freydier
- Hydrosciences Montpellier (HSM), Maison des Sciences de l’eau, Montpellier, France
- Centre National de la Recherche Scientifique (CNRS), Maison des Sciences de l’eau, Montpellier, France
| | - Jean-Louis Duprey
- Institut de Recherche pour le Développement (IRD), La Paz, Bolivia
- Laboratorio de Calidad Ambiental (LCA), Universidad Mayor de San Andrés, Instituto de Ecología, La Paz, Bolivia
| | - Chih-Mei Chen
- Berlin School of Public Health (BSPH), Charité – Universitätsmedizin Berlin, Berlin, Germany
- Institute of Social Medicine, Epidemiology and Health Economics, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | | | - Thomas Keil
- Institute of Social Medicine, Epidemiology and Health Economics, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Institute of Clinical Epidemiology and Biometry, University of Würzburg, Würzburg, Germany
| |
Collapse
|
35
|
Debes F, Weihe P, Grandjean P. Cognitive deficits at age 22 years associated with prenatal exposure to methylmercury. Cortex 2015; 74:358-69. [PMID: 26109549 DOI: 10.1016/j.cortex.2015.05.017] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 05/03/2015] [Accepted: 05/11/2015] [Indexed: 10/23/2022]
Abstract
Prenatal exposure to mercury has been associated with adverse effects on child neurodevelopment. The present study aims to determine the extent to which methylmercury-associated cognitive deficits persist into adult age. In a Faroese birth cohort originally formed in 1986-1987 (N = 1,022), prenatal methylmercury exposure was assessed in terms of the mercury concentration in cord blood and maternal hair. Clinical examinations of 847 cohort members at age 22 years were carried out in 2008-2009 using a panel of neuropsychological tests that reflected major functional domains. Subjects with neurological and psychiatric diagnoses were excluded from the data analysis, thus leaving 814 subjects. Multiple regression analysis included covariates previously identified for adjustment. Deficits in Boston Naming Test (BNT) and other tests of verbal performance were significantly associated with the cord-blood mercury concentration. Deficits were also present in all other tests applied, although most were not statistically significant. Structural equation models were developed to ascertain the possible differences in vulnerability of specific functional domains and the overall association with general intelligence. In models for individual domains, all of them showed negative associations, with crystallized intelligence being highly significant. A hierarchical model for general intelligence based on all domains again showed a highly significant negative association with the exposure, with an approximate deficit that corresponds to about 2.2 IQ points at a 10-fold increased prenatal methylmercury exposure. Thus, although the cognitive deficits observed were smaller than at examinations at younger ages, maternal diets with contaminated seafood were associated with adverse effects in this birth cohort at age 22 years. The deficits affected major domains of brain functions as well as general intelligence. Thus, prenatal exposure to this marine contaminant appears to cause permanent adverse effects on cognition.
Collapse
Affiliation(s)
- Frodi Debes
- Faroese Hospital System, Torshavn, Faroe Islands
| | - Pal Weihe
- Faroese Hospital System, Torshavn, Faroe Islands
| | - Philippe Grandjean
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA; Institute of Public Health, University of Southern Denmark, Odense, Denmark.
| |
Collapse
|
36
|
|
37
|
Spear M, Thomas R, Shrader-Frechette K. Commentary: flawed science delays smelter cleanup and worsens health. Account Res 2014; 22:41-60. [PMID: 25275623 DOI: 10.1080/08989621.2014.939746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
For 6,000 years, humans have known about smelter hazards. Yet these metals threats continue. Why? This commentary provides one preliminary answer. It (1) summarizes the history of smelter pollution and (2) suggests that at least 3 problems-especially flawed smelter-polluter science-allow continuing health threats. It (3) illustrates this flawed science by using one of the most dangerous of U.S. former smelters, in DePue, Illinois. There polluters are avoiding violating the law yet trying to minimize smelter-caused health threats, thus clean-up costs, by using two questionable scientific claims. The causality-denial claim denies that smelter metals cause neurodegenerative diseases. The biomagnification-denial claim denies that food-chain biomagnification of smelter metals can put citizens at risk. The commentary shows both claims err, and (4) suggests ways to address flawed smelter science and resulting health harms.
Collapse
Affiliation(s)
- Michael Spear
- a Department of Biological Sciences , University of Notre Dame , Notre Dame , Indiana , USA
| | | | | |
Collapse
|
38
|
Tatsuta N, Nakai K, Murata K, Suzuki K, Iwai-Shimada M, Kurokawa N, Hosokawa T, Satoh H. Impacts of prenatal exposures to polychlorinated biphenyls, methylmercury, and lead on intellectual ability of 42-month-old children in Japan. ENVIRONMENTAL RESEARCH 2014; 133:321-6. [PMID: 24998460 DOI: 10.1016/j.envres.2014.05.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 05/08/2014] [Accepted: 05/27/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND The age-specific impacts of perinatal exposures to polychlorinated biphenyls (PCB), methylmercury (MeHg), and lead on child neurodevelopment remain controversial. Since we have already reported the prenatal effects of these chemicals on neurodevelopment in 3-day-old and 30-month-old children of a birth cohort, the following effects were analyzed in the 42-month-old children in the same cohort. METHODS The Kaufman Assessment Battery for Children (K-ABC), comprised of four scales, was used to assess their intelligence and achievement. The relationships between the chemicals and K-ABC scores were analyzed using multivariate analyses. RESULTS The median values of chemicals in cord blood of 387 children were 46.5 (5th and 95th percentiles, 16.7-115.7)ng/g-lipid for total PCB, 10.1 (4.3-22.2)ng/g for total mercury (THg), and 1.0 (0.5-1.8) μg/dL for lead. Of the highly chlorinated PCB homologs, 9 CBs was negatively correlated with the sequential and mental processing score of the K-ABC (p<0.05). There were no significant correlations between any K-ABC score and either THg or lead. The negative effect of 9 CBs remained even after adjusting for THg, lead, and other confounders. The K-ABC scores were significantly lower in the boys than in the girls, and the standardized β of 9 CBs for the sequential and mental processing scores in multiple regression analysis was statistically significant in boys. CONCLUSIONS These findings suggest that intellectual ability in the developmental stage may be impaired by prenatal exposures to highly chlorinated PCB homologs, especially in Japanese boys.
Collapse
Affiliation(s)
- Nozomi Tatsuta
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Miyagi, Sendai 980-8575, Japan
| | - Kunihiko Nakai
- Development and Environmental Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Miyagi, Sendai 980-8575, Japan.
| | - Katsuyuki Murata
- Environmental Health Sciences, Akita University Graduate School of Medicine, Akita 010-8543, Japan
| | - Keita Suzuki
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Miyuki Iwai-Shimada
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Naoyuki Kurokawa
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Toru Hosokawa
- Human Development and Disabilities, Tohoku University Graduate School of Education, Sendai 980-8576, Japan
| | - Hiroshi Satoh
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| |
Collapse
|
39
|
The Role of Heavy Metal Pollution in Neurobehavioral Disorders: a Focus on Autism. REVIEW JOURNAL OF AUTISM AND DEVELOPMENTAL DISORDERS 2014. [DOI: 10.1007/s40489-014-0028-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
40
|
Evans AM, Rice GE, Teuschler LK, Wright JM. Joint exposure to chemical and nonchemical neurodevelopmental stressors in U.S. women of reproductive age in NHANES. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:4384-401. [PMID: 24758893 PMCID: PMC4024991 DOI: 10.3390/ijerph110404384] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/05/2014] [Accepted: 04/10/2014] [Indexed: 12/03/2022]
Abstract
Lead (Pb) and methyl mercury (MeHg) are well established neurodevelopmental toxicants (NDTs), but joint exposure to chemical and nonchemical (e.g., maternal stress) stressors has rarely been considered. We characterized exposure to Pb, MeHg and a measure of physiological dysregulation associated with chronic stress and examined race/ethnicity as a predictor of joint NDT exposure. Using data from the 2003-2004 NHANES, potential chronic stress exposure was estimated using allostatic load (AL), a quantitative measure of physiological dysregulation. A Hazard Index was calculated for joint exposure to Pb and MeHg (HI(NDT)). Logistic regression was used to assess the relationship between an indicator of elevated joint NDT exposures (HI(NDT) > 1) and race/ethnicity. The multivariate model was stratified by AL groups to examine effect measure modification. African American (adjusted odds ratio [OR] [95% confidence interval] = 2.2 [1.4, 3.3]) and Mexican American (1.4 [0.7, 2.6]) women were more likely to have an HI(NDT) > 1 compared to Caucasian women. Chronic stress was identified as an effect measure modifier with the largest ORs among women with high AL scores (African Americans = 4.3 [2.0, 9.5]; Mexican Americans = 4.2 [1.3, 14.1]). Chronic stress was found to modify the association between elevated joint NDT exposure and race/ethnicity, highlighting the importance of evaluating chemical and nonchemical stressor exposures leading to a common endpoint.
Collapse
Affiliation(s)
- Amanda M. Evans
- Oak Ridge Institute for Science and Education (ORISE), U.S. Environmental Protection Agency (EPA), Office of Research and Development, National Center for Environmental Assessment, Cincinnati, OH 45268, USA
| | - Glenn E. Rice
- U.S. EPA, Office of Research and Development, National Center for Environmental Assessment, Cincinnati, OH 45268, USA; E-Mails: (G.R.); (M.W.)
| | | | - J. Michael Wright
- U.S. EPA, Office of Research and Development, National Center for Environmental Assessment, Cincinnati, OH 45268, USA; E-Mails: (G.R.); (M.W.)
| |
Collapse
|
41
|
Abstract
PURPOSE OF REVIEW Humans are routinely exposed to multiple chemicals simultaneously or sequentially. There is evidence that the toxicity of individual chemicals may depend on the presence of other chemicals. Studies on chemical mixtures are limited, however, because of the lack of sufficient exposure data, limited statistical power, and difficulty in the interpretation of multidimensional interactions. This review summarizes the recent literature examining chemical mixtures and pediatric health outcomes, with an emphasis on metal mixtures. RECENT FINDINGS Several studies report significant interactions between metals in relation to pediatric health outcomes. Two prospective studies found interactive effects of early-life lead and manganese exposures on cognition. In two different cohorts, interactions between lead and cadmium exposures were reported on reproductive hormone levels and on neurodevelopment. Effects of lead exposure on impulsive behavior and cognition were modified by mercury exposure in studies from Canada and Denmark. However, there is little consistency related to exposure indicators and statistical approaches for evaluating interaction. SUMMARY Several studies suggest that metals interact to cause health effects that are different from exposure to each metal alone. Despite the nearly infinite number of possible chemical combinations, mixtures research represents real-life exposure scenarios and warrants more attention, particularly in the context of uniquely vulnerable children.
Collapse
|
42
|
Ferguson KT, Cassells RC, MacAllister JW, Evans GW. The physical environment and child development: an international review. INTERNATIONAL JOURNAL OF PSYCHOLOGY 2013; 48:437-68. [PMID: 23808797 PMCID: PMC4489931 DOI: 10.1080/00207594.2013.804190] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Accepted: 04/01/2013] [Indexed: 01/07/2023]
Abstract
A growing body of research in the United States and Western Europe documents significant effects of the physical environment (toxins, pollutants, noise, crowding, chaos, and housing, school and neighborhood quality) on children and adolescents' cognitive and socioemotional development. Much less is known about these relations in other contexts, particularly the global South. We thus briefly review the evidence for relations between child development and the physical environment in Western contexts, and discuss some of the known mechanisms behind these relations. We then provide a more extensive review of the research to date outside of Western contexts, with a specific emphasis on research in the global South. Where the research is limited, we highlight relevant data documenting the physical environment conditions experienced by children, and make recommendations for future work. In these recommendations, we highlight the limitations of employing research methodologies developed in Western contexts (Ferguson & Lee, 2013). Finally, we propose a holistic, multidisciplinary, and multilevel approach based on Bronfenbrenner's (1979) bioecological model to better understand and reduce the aversive effects of multiple environmental risk factors on the cognitive and socioemotional development of children across the globe.
Collapse
Affiliation(s)
- Kim T Ferguson
- Psychology Faculty Group, Sarah Lawrence College, Bronxville, NY, USA.
| | | | | | | |
Collapse
|
43
|
Farina M, Avila DS, da Rocha JBT, Aschner M. Metals, oxidative stress and neurodegeneration: a focus on iron, manganese and mercury. Neurochem Int 2012; 62:575-94. [PMID: 23266600 DOI: 10.1016/j.neuint.2012.12.006] [Citation(s) in RCA: 357] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 02/08/2023]
Abstract
Essential metals are crucial for the maintenance of cell homeostasis. Among the 23 elements that have known physiological functions in humans, 12 are metals, including iron (Fe) and manganese (Mn). Nevertheless, excessive exposure to these metals may lead to pathological conditions, including neurodegeneration. Similarly, exposure to metals that do not have known biological functions, such as mercury (Hg), also present great health concerns. This review focuses on the neurodegenerative mechanisms and effects of Fe, Mn and Hg. Oxidative stress (OS), particularly in mitochondria, is a common feature of Fe, Mn and Hg toxicity. However, the primary molecular targets triggering OS are distinct. Free cationic iron is a potent pro-oxidant and can initiate a set of reactions that form extremely reactive products, such as OH. Mn can oxidize dopamine (DA), generating reactive species and also affect mitochondrial function, leading to accumulation of metabolites and culminating with OS. Cationic Hg forms have strong affinity for nucleophiles, such as -SH and -SeH. Therefore, they target critical thiol- and selenol-molecules with antioxidant properties. Finally, we address the main sources of exposure to these metals, their transport mechanisms into the brain, and therapeutic modalities to mitigate their neurotoxic effects.
Collapse
Affiliation(s)
- Marcelo Farina
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC, Brazil
| | | | | | | |
Collapse
|
44
|
Monensin potentiates lead chelation efficacy of MiADMSA in rat brain post chronic lead exposure. Food Chem Toxicol 2012; 50:4449-60. [PMID: 22982480 DOI: 10.1016/j.fct.2012.08.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 08/29/2012] [Accepted: 08/30/2012] [Indexed: 01/04/2023]
Abstract
The present study evaluates combination therapy with a chelating agent, MiADMSA and a Na(+) ionophore, monensin against sub-chronic lead toxicity in rats. Animals were exposed to 0.1% lead in drinking water for 16 weeks and then treated with either MiADMSA at 50mg/kg body weight, or monensin at 10mg/kg, or both in combination for a period of 5 days was administered. Biomarkers indicative of oxidative stress like ROS, GSH, GSSG and TBARS demonstrated lead-induced toxic manifestations in blood, kidney and brain. Antioxidants like SOD, catalase and glutathione peroxidase along with specific lead biomarker, blood ALAD were also severely depleted in lead intoxicated animals. Serum parameters and histopathological findings supported the said results. MiADMSA treatment during both mono- and combination therapy with monensin, restored the antioxidant status and recovered biochemical and haematological variables due to lead. However, monensin alone was not found to be effective in the given scenario. Interestingly, combination therapy in its ability to revert lead-induced overall systemic toxicity was only found at par with the MiADMSA monotherapy except for its chelation potential. Monensin given in combination with MiADMSA potentiated its lead chelation ability especially from brain, along with maintaining the normal copper concentrations in the organ unlike MiADMSA monotherapy.
Collapse
|
45
|
Grandjean P, Weihe P, Nielsen F, Heinzow B, Debes F, Budtz-Jørgensen E. Neurobehavioral deficits at age 7 years associated with prenatal exposure to toxicants from maternal seafood diet. Neurotoxicol Teratol 2012; 34:466-72. [PMID: 22705177 PMCID: PMC3407364 DOI: 10.1016/j.ntt.2012.06.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 06/01/2012] [Accepted: 06/01/2012] [Indexed: 10/28/2022]
Abstract
To determine the possible neurotoxic impact of prenatal exposure to polychlorinated biphenyls (PCBs), we analyzed banked cord blood from a Faroese birth cohort for PCBs. The subjects were born in 1986-1987, and 917 cohort members had completed a series of neuropsychological tests at age 7 years. Major PCB congeners (118, 138, 153, and 180), the calculated total PCB concentration, and the PCB exposure estimated in a structural equation model showed weak associations with test deficits, with statistically significant negative associations only with the Boston Naming test. Likewise, neither hexachlorobenzene nor p,p'-dichlorodiphenyldichloroethylene showed clear links to neurobehavioral deficits. Thus, these associations were much weaker than those associated with the cord-blood mercury concentration, and adjustment for mercury substantially attenuated the regression coefficients for PCB exposure. When the outcomes were joined into motor and verbally mediated functions in a structural equation model, the PCB effects remained weak and virtually disappeared after adjustment for methylmercury exposure, while mercury remained statistically significant. Thus, in the presence of elevated methylmercury exposure, PCB neurotoxicity may be difficult to detect, and PCB exposure does not explain the methylmercury neurotoxicity previously reported in this cohort.
Collapse
Affiliation(s)
- Philippe Grandjean
- Institute of Public Health, University of Southern Denmark, Odense, Denmark.
| | | | | | | | | | | |
Collapse
|
46
|
Partition of metals in the maternal/fetal unit and lead-associated decreases of fetal iron and manganese: an observational biomonitoring approach. Arch Toxicol 2012; 86:1571-81. [DOI: 10.1007/s00204-012-0869-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 05/15/2012] [Indexed: 01/05/2023]
|
47
|
Tatsuta N, Nakai K, Murata K, Suzuki K, Iwai-Shimada M, Yaginuma-Sakurai K, Kurokawa N, Nakamura T, Hosokawa T, Satoh H. Prenatal exposures to environmental chemicals and birth order as risk factors for child behavior problems. ENVIRONMENTAL RESEARCH 2012; 114:47-52. [PMID: 22421256 DOI: 10.1016/j.envres.2012.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 01/13/2012] [Accepted: 02/06/2012] [Indexed: 05/23/2023]
Abstract
OBJECTIVES To assess whether polychlorinated biphenyls (PCBs), methylmercury, lead, or parental child-rearing attitudes was most crucial for maladaptive behavior problems, we examined Japanese 30-month-old children followed up from pregnancy. METHODS The Child Behavior Checklist (CBCL) was used to assess the behavior problems in 306 children. The associations of cord-blood total PCBs (ΣPCB), total mercury (THg), and lead with each CBCL subscale were examined by multivariate analyses. RESULTS The median values in cord blood of the 306 children were 48.3 (5 and 95 percentiles, 18.6-116.3) ng/g-lipid for ΣPCB, 10.2 (4.1-24.5)ng/g for THg, and 1.0 (0.5-1.7)μg/dl for lead. The internalizing score of the CBCL was significantly correlated with ΣPCB (r=0.113) in the children, though no significant correlation was seen between any CBCL score and either THg or lead. The significant correlation disappeared when conducting multiple regression analysis with possible confounders; at that time, the birth order, home environment, and maternal intelligence quotient were significantly related to the internalizing score. Three CBCL scores and ΣPCB levels were significantly higher in the first-born children than in the second-born or following children, and the partial correlation coefficient with the adjustment for all confounders except birth order was significant between the internalizing score and ΣPCB in the latter children (r=0.175). CONCLUSIONS Internalizing behavior appears to be affected by prenatal exposure to PCBs at low levels. Under lower-level exposures, however, behavior problems may be more strongly associated with parental child-rearing attitudes involved in birth order, than with such hazardous chemicals.
Collapse
Affiliation(s)
- Nozomi Tatsuta
- Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Murata K, Yoshida M, Sakamoto M, Iwai-Shimada M, Yaginuma-Sakurai K, Tatsuta N, Iwata T, Karita K, Nakai K. Recent evidence from epidemiological studies on methylmercury toxicity. Nihon Eiseigaku Zasshi 2011; 66:682-95. [PMID: 21996768 DOI: 10.1265/jjh.66.682] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
More than fifty years have passed since the outbreak of Minamata disease, and large-scale methylmercury poisoning due to industrial effluents or methylmercury-containing fungicide intoxication has scarcely happened in developed countries. On the other hand, widespread environmental mercury contamination has occurred in gold and mercury mining areas of developing countries. In this article, we provided an overview of recent studies addressing human health effects of methylmercury, which we searched using the PubMed of the US National Library of Medicine. The following suggestions were obtained for low-level methylmercury exposure: (1) In recent years, the proportion of human studies addressing methylmercury has tended to decrease. (2) Prenatal exposure to methylmercury through fish intake, even at low levels, adversely affects child development after adjusting for polychlorinated biphenyls and maternal fish intake during pregnancy, whereas maternal seafood intake has some benefits. (3) Long-term methylmercury exposure through consumption of fish such as bigeye tuna and swordfish may pose a potential risk of cardiac events involving sympathovagal imbalance. (4) In measuring methylmercury levels in preserved umbilical cord collected from inhabitants born in Minamata areas between 1945 and 1989, the elevated concentrations (≥1 mg/g) were observed mainly in inhabitants born between 1947 and 1968, and the peak coincided with the peak of acetaldehyde production in Minamata. (5) Since some developing countries appear to be in similar situations to Japan in the past, attention should be directed toward early recognition of a risky agent and precautions should be taken against it.
Collapse
Affiliation(s)
- Katsuyuki Murata
- Department of Environmental Health Sciences, Akita University Graduate School of Medicine, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|