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Netto BB, da Silva EP, de Aguiar da Costa M, de Rezende VL, Bolan SJ, Ceretta LB, Aschner M, Dominguini D, Gonçalves CL. Critical period of exposure to mercury and the diagnostic of autism spectrum disorder: A systematic review. J Neurochem 2024; 168:2092-2104. [PMID: 38344837 DOI: 10.1111/jnc.16076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 10/04/2024]
Abstract
Autism spectrum disorder (ASD) is characterized by repetitive behaviors and deficits in social interaction. Its etiology is not completely clear, but both genetic and environmental factors contribute to and influence its development and course. The increased number of autism cases in recent years has been strongly associated with increased exposure to heavy metals. Mercury (Hg) has gained prominence in the scientific literature as a result of its presence as an urban pollutant and well-described neurotoxicity. This review assessed the relationship between Hg exposure in the pre- and post-natal period and ASD. The systematic review identified observational clinical studies and pre-clinical trials in journals indexed in the PubMed, Embase, ProQuest, and LILACS databases. The aim of this study was to investigate the association between exposure to Hg and ASD and to define the critical period of exposure. A total of 57 articles were selected for this review, with 35 articles (61.40%) identifying a positive association between ASD and Hg, while 22 articles (38.60%) did not find the same outcome. The biological samples most used to analyze Hg body burdens were hair (36.84%) and blood (36.84%). Most case-control studies found an increase in Hg levels in individuals with ASD who were exposed to a polluted environment in the post-natal period. Taken together, the studies suggest that these patients have a deficient detoxification system, and this could worsen the symptoms of the disorder. However, new studies addressing the influence of Hg on the post-natal nervous system and its relationship with ASD should be carried out.
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Affiliation(s)
- Bruna Bittencourt Netto
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
- Medical School, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | | | - Maiara de Aguiar da Costa
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Victória Linden de Rezende
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Sofia Januário Bolan
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | | | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Diogo Dominguini
- Program in Collective Health, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, Houston, Texas, USA
| | - Cinara Ludvig Gonçalves
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
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Ramazani Z, Nakhaee S, Sharafi K, Rezaei Z, Mansouri B. Autism spectrum disorder: Cadmium and mercury concentrations in different biological samples, a systematic literature review and meta-analysis of human studies. Heliyon 2024; 10:e27789. [PMID: 38496888 PMCID: PMC10944282 DOI: 10.1016/j.heliyon.2024.e27789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 03/19/2024] Open
Abstract
The present study was conducted to investigate the differences in cadmium (Cd) and mercury (Hg) concentrations between children with autism spectrum disorder (ASD) and controls. In this systematic review and meta-analysis study, three thousand one hundred forty-five studies were collected from scientific databases including Web of Science, Scopus, PubMed, and Google Scholar from January 2000 to October 2022 and were investigated for eligibility. As a result, 37 studies published in the period from 2003 to 2022 met our inclusion criteria and were considered in the meta-analysis. The heterogeneity assumption was evaluated using the Chi-squared-based Q-test and I-squared (I2) statistics. The pooled estimates were shown in the forest plots with Hedges' g (95% confidence interval) values. The random effects model demonstrated that there is no significant difference in the blood (Hedges' g: 0.14, 95% CI: 0.45, 0.72, p > 0.05), hair (Hedges' g: 0.12, 95% CI: 0.26, 0.50, p > 0.05), and urinary (Hedges' g: 0.05, 95% CI: 0.86, 0.76, p > 0.05) Cd levels of the case group versus control subjects. Moreover, the pooled findings of studies showed no significant difference in the blood (Hedges' g: 1.69, 95% CI: 0.09, 3.48, p > 0.05), hair (Hedges' g: 3.42, 95% CI: 1.96, 8.80, p > 0.05), and urinary (Hedges' g: 0.49, 95% CI: 1.29 - 0.30, p > 0.05) Hg concentrations. The results demonstrated no significant differences in Hg and Cd concentrations in different biological samples of children with ASD compared to control subjects.
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Affiliation(s)
- Zana Ramazani
- Substance Abuse Prevention Research Center, Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Samaneh Nakhaee
- Medical Toxicology and Drug Abuse Research Center (MTDRC), Birjand University of Medical Sciences, Birjand, Iran
| | - Kiomars Sharafi
- Research Center for Environmental Determinants of Health (RCEDH), Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Zaynab Rezaei
- Substance Abuse Prevention Research Center, Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Borhan Mansouri
- Substance Abuse Prevention Research Center, Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Stojsavljević A, Lakićević N, Pavlović S. Mercury and Autism Spectrum Disorder: Exploring the Link through Comprehensive Review and Meta-Analysis. Biomedicines 2023; 11:3344. [PMID: 38137565 PMCID: PMC10741416 DOI: 10.3390/biomedicines11123344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/02/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Mercury (Hg) is a non-essential trace metal with unique neurochemical properties and harmful effects on the central nervous system. In this study, we present a comprehensive review and meta-analysis of peer-reviewed research encompassing five crucial clinical matrices: hair, whole blood, plasma, red blood cells (RBCs), and urine. We assess the disparities in Hg levels between gender- and age-matched neurotypical children (controls) and children diagnosed with autism spectrum disorder (ASD) (cases). After applying rigorous selection criteria, we incorporated a total of 60 case-control studies into our meta-analysis. These studies comprised 25 investigations of Hg levels in hair (controls/cases: 1134/1361), 15 in whole blood (controls/cases: 1019/1345), 6 in plasma (controls/cases: 224/263), 5 in RBCs (controls/cases: 215/293), and 9 in urine (controls/cases: 399/623). This meta-analysis did not include the data of ASD children who received chelation therapy. Our meta-analysis revealed no statistically significant differences in Hg levels in hair and urine between ASD cases and controls. In whole blood, plasma, and RBCs, Hg levels were significantly higher in ASD cases compared to their neurotypical counterparts. This indicates that ASD children could exhibit reduced detoxification capacity for Hg and impaired mechanisms for Hg excretion from their bodies. This underscores the detrimental role of Hg in ASD and underscores the critical importance of monitoring Hg levels in ASD children, particularly in early childhood. These findings emphasize the pressing need for global initiatives aimed at minimizing Hg exposure, thus highlighting the critical intersection of human-environment interaction and neurodevelopment health.
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Affiliation(s)
- Aleksandar Stojsavljević
- Innovative Centre, Faculty of Chemistry, University of Belgrade, Studentski Trg 12–16, 11000 Belgrade, Serbia
| | - Novak Lakićević
- Clinical Centre of Montenegro, Clinic for Neurosurgery, Ljubljanska bb, 81000 Podgorica, Montenegro;
| | - Slađan Pavlović
- Institute for Biological Research “Siniša Stanković”—National Institute of the Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia;
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Ding M, Shi S, Qie S, Li J, Xi X. Association between heavy metals exposure (cadmium, lead, arsenic, mercury) and child autistic disorder: a systematic review and meta-analysis. Front Pediatr 2023; 11:1169733. [PMID: 37469682 PMCID: PMC10353844 DOI: 10.3389/fped.2023.1169733] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/23/2023] [Indexed: 07/21/2023] Open
Abstract
Background Studies have found that toxic heavy metals exposure could induce the generation of reactive oxygen species (ROS), and is of epigenetic effect, which might be associated with the occurrence of Autistic Disorder (ASD). This systematic review and meta-analysis aims to elucidate the association between exposure to 4 heavy metals, cadmium (Cd), lead (Pb), arsenic(As), and mercury (Hg), and the occurrence of ASD in children. Methods We searched PubMed, Web of Science, Embase, and Cochrane Library, from their inception to October 2022, for epidemiological investigations that explore the association between exposure to Cd, Pb, As, or Hg and the occurrence of child ASD. Results A total of 53 studies were included, involving 5,054 individuals aged less than 18 (2,533 ASD patients and 2,521 healthy controls). Compared with the healthy controls, in hair and blood tests, concentrations of the 4 heavy metals were significantly higher in the ASD group than in the healthy control group, and the differences in Pb, arsenic and Hg were statistically significant (P < 0.05). In the urine test, concentrations of arsenic and Hg were significantly higher in the ASD group than in the healthy control group (P < 0.05), while the results of Cd and Pb were opposite to those of arsenic and Hg (P > 0.05). Subgroup analysis for geographic regions showed that ASD patients in Asia and Europe had higher concentrations of the 4 heavy metals, compared with the healthy controls, in which the differences in Pb, arsenic, and Hg were statistically significant (P < 0.05), while in North America, the healthy controls had higher Cd, arsenic, and Hg concentrations (P > 0.05). Conclusion Compared with the healthy control group, the ASD group had higher concentrations of Cd, Pb, arsenic, and Hg. These 4 heavy metals play different roles in the occurrence and progression of ASD. Moreover, there is significant heterogeneity among the included studies due to controversies about the study results among different countries and regions and different sources of detection materials. The results of this study firmly support the policies to limit heavy metals exposure, especially among pregnant women and young children, so as to help reduce the incidence of ASD.
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Affiliation(s)
- Mengmeng Ding
- Correspondence: Mengmeng Ding Shanshan Shi Shuyan Qie
| | - Shanshan Shi
- Correspondence: Mengmeng Ding Shanshan Shi Shuyan Qie
| | - Shuyan Qie
- Correspondence: Mengmeng Ding Shanshan Shi Shuyan Qie
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Shiani A, Sharafi K, Omer AK, Kiani A, Karamimatin B, Massahi T, Ebrahimzadeh G. A systematic literature review on the association between exposures to toxic elements and an autism spectrum disorder. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159246. [PMID: 36220469 DOI: 10.1016/j.scitotenv.2022.159246] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/30/2022] [Accepted: 10/01/2022] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIM Autism spectrum disorder (ASD) is a neurodevelopmental illness characterized by difficulties in social communication and repetitive behaviors. There have been many previous studies of toxic metals in ASD. Therefore, the priority of this study is to review the relationships between exposure to toxic metals and ASD. MATERIALS & METHODS This study was based on a comprehensive search of international databases, such as Web of Science, Science Direct, Scopus, PubMed, and Google Scholar, for all works related to the subject under discussion from 1982 to 2022. We further summarize published data linked to this topic and discuss with clarifying evidence that agrees and conflicts with the association between exposure to toxic metals, including mercury (Hg), lead (Pb), cadmium (Cd), arsenic (As), and aluminum (Al) and ASD. RESULTS 40 out of 63 papers met the requirements for meta-analysis. Blood Pb levels (standardized mean difference (SMD) = 0.81; 95 % confidence interval (CI): 0.36-1.25), blood Hg (SMD = 0.90; CI: 0.30-1.49), hair Pb (SMD = 1.47; CI: 0.03-2.92), urine As (SMD = 0.65; CI: 0.22-1.09), and urine Al levels (SMD = 0.85; CI: 0.40-1.29) in autistic individuals were significantly higher than those of healthy control (HC). Whereas, blood As levels (SMD = 1.33; CI: -1.32-3.97), hair As (SMD = 0.55; CI: -0.14-1.24), hair Cd (SMD = 0.60; CI: -0.31-1.51), hair Hg (SMD = 0.41; CI: -0.30-1.12), hair Al (SMD = 0.87; CI: -0.02-1.77), urine Pb (SMD = -0.68; CI: -2.55-1.20), urine Cd (SMD = -0.26; CI: -0.94-0.41), and urine Hg levels (SMD = 0.47; CI: -0.09-1.04) in autistic individuals were significantly lower than those of HC. CONCLUSION Toxic metal content significantly differed between individuals with ASD and HC in the current meta-analysis. The results assist in clarifying the significance of toxic metals as environmental factors in the development of ASD.
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Affiliation(s)
- Amir Shiani
- Department of Speech Therapy, School of Rehabilitation Sciences, Kermanshah University of Medical Sciences, Kermanshah, Iran; Clinical Research Development Center, Taleghani and Imam Ali Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Kiomars Sharafi
- Research Center for Environmental Determinants of Health (RCEDH), Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran; Department of Environmental Health Engineering, School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Abdullah Khalid Omer
- Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran; Razga Company, Kurdistan Region, Iraq.
| | - Amir Kiani
- Regenerative Medicine Research Center (RMRC), Kermanshah University of Medical Sciences, Kermanshah, Iran; Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Behzad Karamimatin
- Research Center for Environmental Determinants of Health (RCEDH), Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Tooraj Massahi
- Students Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Gholamreza Ebrahimzadeh
- Department of Environmental Health Engineering, School of Public Health, Zabol University of Medical Sciences, Zabol, Iran
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Goldman GS. Examples of Outcome Reporting Bias in Vaccine Studies: Illustrating How Perpetuating Medical Consensus Can Impede Progress in Public Health. Cureus 2022; 14:e29399. [PMID: 36304385 PMCID: PMC9585808 DOI: 10.7759/cureus.29399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction: Outcome reporting bias in vaccine studies is a widespread problem among all researchers who have a tendency to report selective results and conclusions that support their beliefs and values or those of sponsoring agencies. Especially during the COVID-19 pandemic, this bias surfaced through the unprecedented proliferation of conflicting vaccine studies. Many researchers strongly recommend and report on the safety and effectiveness of the COVID-19 vaccine. Those researchers who embrace the COVID-19 vaccine and vaccines, in general, are often dismissive of other researchers who present views that differ from medical orthodoxy and oppose medical consensus. Methods: The aim of this analysis is to critically evaluate seven vaccine studies using qualitative and/or quantitative approaches to identify outcome reporting bias and assess its potential impact on the stated conclusions that align with medical consensus. Four studies claim to have found no association between autism and (a) blood levels of mercury, (b) measles, mumps, and rubella (MMR) vaccine, and (c) thimerosal-containing vaccines. Three other studies claim no association exists between infant mortality rate and the number of vaccine doses, universal varicella vaccination and herpes zoster, and pandemic influenza vaccines and fetal losses. Results: The presence of outcome reporting bias and independent reanalysis demonstrated an impact on both the direction and magnitude of the observed effect - raising questions concerning the robustness of the original study design and conclusions and challenging the current medical consensus. Medical consensus has exonerated vaccines as having any causal relationship to autism spectrum disorders (ASDs), yet no other reasonable cause has been proposed. Medical consensus attributes significant ASD increases to better case ascertainment and broadened clinical diagnosis. According to 2018 data, an estimated 1 in 44 eight-year-olds has been identified with ASD. From 1990 to 2019, there have been an estimated two million new cases of ASD in the US, with lifetime social costs exceeding $7 trillion (in 2019 dollars). Can perpetuating medical consensus impede the advancement of public health? Or has it already done so? Conclusions: Conflicts of interest (e.g., financial) that abound between health regulatory agencies and the pharmaceutical industry impact what is ultimately reckoned as medical consensus. Outcome reporting bias that is inherent to all researchers to some degree, obscures medical and scientific truth. Advancement of public health requires that researchers have integrity and an openness and willingness to collaborate to resolve contradictory findings. In fact, it is usually through meticulous, rigorous, scientific investigation of contradictory findings that medical science has advanced and contributed to improvements in public health - since medical consensus and orthodoxy can be incorrect.
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Baj J, Flieger W, Flieger M, Forma A, Sitarz E, Skórzyńska-Dziduszko K, Grochowski C, Maciejewski R, Karakuła-Juchnowicz H. Autism spectrum disorder: Trace elements imbalances and the pathogenesis and severity of autistic symptoms. Neurosci Biobehav Rev 2021; 129:117-132. [PMID: 34339708 DOI: 10.1016/j.neubiorev.2021.07.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 02/08/2023]
Abstract
The identification of biomarkers as diagnostic tools and predictors of response to treatment of neurological developmental disorders (NDD) such as schizophrenia (SZ), attention deficit hyperactivity disorder (ADHD), or autism spectrum disorder (ASD), still remains an important challenge for clinical medicine. Metallomic profiles of ASD patients cover, besides essential elements such as cobalt, chromium, copper, iron, manganese, molybdenum, zinc, selenium, also toxic metals burden of: aluminum, arsenic, mercury, lead, beryllium, nickel, cadmium. Performed studies indicate that children with ASD present a reduced ability of eliminating toxic metals, which leads to these metals' accumulation and aggravation of autistic symptoms. Extensive metallomic studies allow a better understanding of the importance of trace elements as environmental factors in the pathogenesis of ASD. Even though a mineral imbalance is a fact in ASD, we are still expecting relevant tests and the elaboration of reference levels of trace elements as potential biomarkers useful in diagnosis, prevention, and treatment of ASD.
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Affiliation(s)
- Jacek Baj
- Department of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland.
| | - Wojciech Flieger
- Faculty of Medicine, Medical University of Lublin, Aleje Racławickie 1, 20-059, Lublin, Poland
| | - Michał Flieger
- Faculty of Medicine, Medical University of Lublin, Aleje Racławickie 1, 20-059, Lublin, Poland
| | - Alicja Forma
- Chair and Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego Street 8b, 20-090, Lublin, Poland
| | - Elżbieta Sitarz
- Chair and 1st Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland
| | - Katarzyna Skórzyńska-Dziduszko
- Chair and Department of Human Physiology, Medical University of Lublin, Radziwillowska Street 11, Lublin, 20-080, Poland
| | - Cezary Grochowski
- Laboratory of Virtual Man, Chair of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland
| | - Ryszard Maciejewski
- Department of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland
| | - Hanna Karakuła-Juchnowicz
- Chair and 1st Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland; Department of Clinical Neuropsychiatry, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland
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Associations of Metabolic Genes ( GSTT1, GSTP1, GSTM1) and Blood Mercury Concentrations Differ in Jamaican Children with and without Autism Spectrum Disorder. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041377. [PMID: 33546147 PMCID: PMC7913200 DOI: 10.3390/ijerph18041377] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 12/12/2022]
Abstract
We investigated interactive roles of three metabolic glutathione S-transferase (GST) genes (GSTP1, GSTT1, and GSTM1) and autism spectrum disorder (ASD) status in relation to blood Hg concentrations (BHC) of Jamaican children. We used data from 266 children (2-8 years) with ASD and their 1:1 age- and sex-matched typically developing (TD) controls. After adjusting General Linear Models for child’s age, socioeconomic status, consumption of leafy vegetables, fried plantain, canned fish, and the interaction between GSTP1 and GSTT1, we found significant interactions between GSTP1 and ASD status in relation to BHC either in a co-dominant or dominant genetic model for GSTP1(P < 0.001, P = 0.007, respectively). In the co-dominant model for the Ile105Val GSTP1 polymorphism, geometric mean (GM) BHC in ASD cases with genotype Ile/Ile were significantly higher than in cases with the Ile/Val genotype (0.73 vs. 0.48 µg/L, P = 0.01). In contrast, in TD controls with the Ile/Val genotype GM BHC were significantly higher than in those with the Ile/Ile genotype (0.72 vs. 0.49 µg/L, P = 0.03) or the Val/Val genotype (0.72 vs. 0.51 µg/L, P = 0.04). Although our findings are consistent with the role of GSTP1 in detoxification of Hg, replication in other populations is warranted.
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Sulaiman R, Wang M, Ren X. Exposure to Aluminum, Cadmium, and Mercury and Autism Spectrum Disorder in Children: A Systematic Review and Meta-Analysis. Chem Res Toxicol 2020; 33:2699-2718. [DOI: 10.1021/acs.chemrestox.0c00167] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Rosalind Sulaiman
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, The State University of New York, Buffalo, New York 14214, United States
| | - Meng Wang
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, The State University of New York, Buffalo, New York 14214, United States
- Research and Education in Energy, Environment and Water Institute, University at Buffalo, Buffalo, New York 14260, United States
| | - Xuefeng Ren
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, The State University of New York, Buffalo, New York 14214, United States
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, The State University of New York, Buffalo, New York 14214, United States
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Ali W, Junaid M, Aslam MW, Ali K, Rasool A, Zhang H. A Review on the Status of Mercury Pollution in Pakistan: Sources and Impacts. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 76:519-527. [PMID: 30915486 DOI: 10.1007/s00244-019-00613-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/27/2019] [Indexed: 05/24/2023]
Abstract
Mercury (Hg) contamination in environmental matrices and associated human exposure has been recognized as a critical long-lasting issue worldwide. However, studies are still elusive that summarized the overall status of Hg pollution and its impacts on public health in Pakistan. Hence, this review encompasses the environmental prevalence, potential sources, and human exposure tendencies to Hg contamination in Pakistan. Reviewed literature revealed jolting levels of Hg in various environmental samples, such as dust, soil, water, and air collected from the residential and industrial areas. Inhalation of Hg via dust particle was identified as the primary pathway for human exposure, while atmospheric deposition and gold mining are identified as the two primary sources of Hg contamination in the environment. Considering human exposure, the highest bioaccumulation of Hg was ranged from 5885 to 8698 µg/kg in hair samples collected from the residents of the Kashmir Valley, Pakistan. However, in the lower Himalayan regions, including Islamabad and Swabi, the concentration of Hg in hair samples was reported at 1085 µg/kg, slightly beyond WHO devised reference dose (RfD) of Hg (1000 µg/kg). This review revealed the worst scenario of Hg contamination in human biomatrices and environmental compartments in Pakistan, which needed immediate rehabilitation measures.
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Affiliation(s)
- Waqar Ali
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Muhammad Junaid
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Muhammad Wajahat Aslam
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kamran Ali
- Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Science and Technology (NUST) Islamabad, Islamabad, Pakistan
| | - Atta Rasool
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hua Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
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Bjørklund G, Skalny AV, Rahman MM, Dadar M, Yassa HA, Aaseth J, Chirumbolo S, Skalnaya MG, Tinkov AA. Toxic metal(loid)-based pollutants and their possible role in autism spectrum disorder. ENVIRONMENTAL RESEARCH 2018; 166:234-250. [PMID: 29902778 DOI: 10.1016/j.envres.2018.05.020] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/18/2018] [Accepted: 05/18/2018] [Indexed: 06/08/2023]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social interaction, verbal and non-verbal communication, and stereotypic behaviors. Many studies support a significant relationship between many different environmental factors in ASD etiology. These factors include increased daily exposure to various toxic metal-based environmental pollutants, which represent a cause for concern in public health. This article reviews the most relevant toxic metals, commonly found, environmental pollutants, i.e., lead (Pb), mercury (Hg), aluminum (Al), and the metalloid arsenic (As). Additionally, it discusses how pollutants can be a possible pathogenetic cause of ASD through various mechanisms including neuroinflammation in different regions of the brain, fundamentally occurring through elevation of the proinflammatory profile of cytokines and aberrant expression of nuclear factor kappa B (NF-κB). Due to the worldwide increase in toxic environmental pollution, studies on the role of pollutants in neurodevelopmental disorders, including direct effects on the developing brain and the subjects' genetic susceptibility and polymorphism, are of utmost importance to achieve the best therapeutic approach and preventive strategies.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway.
| | - Anatoly V Skalny
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia; Yaroslavl State University, Yaroslavl, Russia; All-Russian Research Institute of Medicinal and Aromatic Plants, Moscow, Russia
| | - Md Mostafizur Rahman
- Department of Environmental Sciences, Jahangirnagar University, Dhaka, Bangladesh; Graduate School of Environmental Science, Hokkaido University, Japan
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Heba A Yassa
- Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Jan Aaseth
- Faculty of Health and Social Sciences, Inland Norway University of Applied Sciences, Elverum, Norway; Department of Research, Innlandet Hospital Trust, Brumunddal, Norway
| | - Salvatore Chirumbolo
- Department of Neurological and Movement Sciences, University of Verona, Verona, Italy
| | | | - Alexey A Tinkov
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia; Yaroslavl State University, Yaroslavl, Russia
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12
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Wu J, Liu DJ, Shou XJ, Zhang JS, Meng FC, Liu YQ, Han SP, Zhang R, Jia JZ, Wang JY, Han JS. Chinese children with autism: A multiple chemical elements profile in erythrocytes. Autism Res 2018; 11:834-845. [DOI: 10.1002/aur.1949] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/31/2018] [Accepted: 02/19/2018] [Indexed: 01/20/2023]
Affiliation(s)
- Jing Wu
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
| | - Duo-Jian Liu
- School of Public Health, Peking University; Beijing PR China
| | - Xiao-Jing Shou
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
| | - Ji-Shui Zhang
- Department of Neurology; Beijing Children's Hospital Affiliated Capital Medical University; Beijing PR China
| | - Fan-Chao Meng
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
| | - Ya-Qiong Liu
- School of Public Health, Peking University; Beijing PR China
| | - Song-Ping Han
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
| | - Rong Zhang
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
| | - Jin-Zhu Jia
- School of Public Health, Peking University; Beijing PR China
- Center of Statistical Science, Peking University; Beijing PR China
| | - Jing-Yu Wang
- School of Public Health, Peking University; Beijing PR China
| | - Ji-Sheng Han
- Neuroscience Research Institute, Peking University; Beijing PR China
- Key Laboratory for Neuroscience, Ministry of Education of China; Peking University; Beijing PR China
- Key Laboratory for Neuroscience, National Committee of Health and Family Planning of China; Peking University; Beijing PR China
- Department of Neurobiology, School of Basic Medical Sciences; Peking University; Beijing PR China
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13
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Li H, Li H, Li Y, Liu Y, Zhao Z. Blood Mercury, Arsenic, Cadmium, and Lead in Children with Autism Spectrum Disorder. Biol Trace Elem Res 2018; 181:31-37. [PMID: 28480499 DOI: 10.1007/s12011-017-1002-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 03/17/2017] [Indexed: 12/15/2022]
Abstract
Environmental factors have been implicated in the etiology of autism spectrum disorder (ASD); however, the role of heavy metals has not been fully defined. This study investigated whether blood levels of mercury, arsenic, cadmium, and lead of children with ASD significantly differ from those of age- and sex-matched controls. One hundred eighty unrelated children with ASD and 184 healthy controls were recruited. Data showed that the children with ASD had significantly (p < 0.001) higher levels of mercury and arsenic and a lower level of cadmium. The levels of lead did not differ significantly between the groups. The results of this study are consistent with numerous previous studies, supporting an important role for heavy metal exposure, particularly mercury, in the etiology of ASD. It is desirable to continue future research into the relationship between ASD and heavy metal exposure.
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Affiliation(s)
- Huamei Li
- Children's Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Hui Li
- Laboratory of Neuroinflammation, StVincent's Centre for Applied Medical Research and University of New South Wales, Sydney, NSW, Australia
| | - Yun Li
- Children's Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Yujie Liu
- Children's Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Zhengyan Zhao
- Children's Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
- Department of Pediatric Health Care, Children's Hospital of Zhejiang University School of Medicine, 57 Zhuganxiang Road, Hangzhou, People's Republic of China, 310003.
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Skalny AV, Simashkova NV, Skalnaya MG, Klyushnik TP, Chernova LN, Tinkov AA. Mercury and autism spectrum disorders. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 118:75-79. [DOI: 10.17116/jnevro20181185275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Kern JK, Geier DA, Deth RC, Sykes LK, Hooker BS, Love JM, Bjørklund G, Chaigneau CG, Haley BE, Geier MR. RETRACTED ARTICLE: Systematic Assessment of Research on Autism Spectrum Disorder and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research. SCIENCE AND ENGINEERING ETHICS 2017; 23:1689-1690. [PMID: 26507205 PMCID: PMC5705728 DOI: 10.1007/s11948-015-9713-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
| | | | | | | | | | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway
| | | | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
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16
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Kern JK, Geier DA, Deth RC, Sykes LK, Hooker BS, Love JM, Bjørklund G, Chaigneau CG, Haley BE, Geier MR. Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research. SCIENCE AND ENGINEERING ETHICS 2017; 23:1691-1718. [PMID: 29119411 PMCID: PMC5705731 DOI: 10.1007/s11948-017-9983-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Historically, entities with a vested interest in a product that critics have suggested is harmful have consistently used research to back their claims that the product is safe. Prominent examples are: tobacco, lead, bisphenol A, and atrazine. Research literature indicates that about 80-90% of studies with industry affiliation found no harm from the product, while only about 10-20% of studies without industry affiliation found no harm. In parallel to other historical debates, recent studies examining a possible relationship between mercury (Hg) exposure and autism spectrum disorder (ASD) show a similar dichotomy. Studies sponsored and supported by industry or entities with an apparent conflict of interest have most often shown no evidence of harm or no "consistent" evidence of harm, while studies without such affiliations report positive evidence of a Hg/autism association. The potentially causal relationship between Hg exposure and ASD differs from other toxic products since there is a broad coalition of entities for whom a conflict of interest arises. These include influential governmental public health entities, the pharmaceutical industry, and even the coal burning industry. This review includes a systematic literature search of original studies on the potential relationship between Hg and ASD from 1999 to August 2015, finding that of the studies with public health and/or industry affiliation, 86% reported no relationship between Hg and ASD. However, among studies without public health and/or industry affiliation, only 21% find no relationship between Hg and ASD. The discrepancy in these results suggests a bias indicative of a conflict of interest.
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Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
| | | | | | | | | | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway
| | | | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
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17
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Jafari T, Rostampour N, Fallah AA, Hesami A. The association between mercury levels and autism spectrum disorders: A systematic review and meta-analysis. J Trace Elem Med Biol 2017; 44:289-297. [PMID: 28965590 DOI: 10.1016/j.jtemb.2017.09.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS The relationship between mercury and autism spectrum disorders (ASD) has always been a topic of controversy among researchers. This study aimed to assess the relationship between ASD and mercury levels in hair, urine, blood, red blood cells (RBC), and brain through a meta-analysis. METHODS A systematic search was performed in several databases including PubMed, ISI Web of Science, Cochrane register of controlled trials, Google Scholar, Scopus, and MagIran until June 2017. Case-control studies evaluating concentration of total mercury in different tissues of ASD patients and comparing them to the healthy subjects (control group) were identified. Necessary data were extracted and random effects model was used to calculate overall effect and its 95% corresponding confidence interval (CI) from the effect sizes. RESULTS A total of 44 studies were identified that met the necessary criteria for meta-analysis. The mercury level in whole blood (Hedges=0.43, 95% CI: 0.12, 0.74, P=0.007), RBC (Hedges=1.61, 95% CI: 0.83, 2.38, P<0.001), and brain (0.61ng/g, 95% CI, 0.02, 1.19, P=0.043) was significantly higher in ASD patients than healthy subjects, whereas mercury level in hair (-0.14mg/g, 95% CI: -0.28, -0.01, P=0.039) was significantly lower in ASD patients than healthy subjects. The mercury level in urine was not significantly different between ASD patients and healthy subjects (0.51mg/g creatinine, 95% CI: -0.14, 1.16, P=0.121). CONCLUSIONS Results of the current meta-analysis revealed that mercury is an important causal factor in the etiology of ASD. It seems that the detoxification and excretory mechanisms are impaired in ASD patients which lead to accumulation of mercury in the body. Future additional studies on mercury levels in different tissues of ASD patients should be undertaken.
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Affiliation(s)
- Tina Jafari
- Clinical Biochemistry Research Center, Shahrekord University of Medical Sciences, Sharhekord, Iran; Department of Biochemistry and Nutrition, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran.
| | - Noushin Rostampour
- Department of Pediatrics, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Aziz A Fallah
- Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord 34141, Iran
| | - Afshin Hesami
- Clinical Biochemistry Research Center, Shahrekord University of Medical Sciences, Sharhekord, Iran
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18
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Saghazadeh A, Rezaei N. Systematic review and meta-analysis links autism and toxic metals and highlights the impact of country development status: Higher blood and erythrocyte levels for mercury and lead, and higher hair antimony, cadmium, lead, and mercury. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:340-368. [PMID: 28716727 DOI: 10.1016/j.pnpbp.2017.07.011] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that affects cognitive and higher cognitive functions. Increasing prevalence of ASD and high rates of related comorbidities has caused serious health loss and placed an onerous burden on the supporting families, caregivers, and health care services. Heavy metals are among environmental factors that may contribute to ASD. However, due to inconsistencies across studies, it is still hard to explain the association between ASD and toxic metals. Therefore the objective of this study was to investigate the difference in heavy metal measures between patients with ASD and control subjects. METHODS We included observational studies that measured levels of toxic metals (antimony, arsenic, cadmium, lead, manganese, mercury, nickel, silver, and thallium) in different specimens (whole blood, plasma, serum, red cells, hair and urine) for patients with ASD and for controls. The main electronic medical database (PubMed and Scopus) were searched from inception through October 2016. RESULTS 52 studies were eligible to be included in the present systematic review, of which 48 studies were included in the meta-analyses. The hair concentrations of antimony (standardized mean difference (SMD)=0.24; 95% confidence interval (CI): 0.03 to 0.45) and lead (SMD=0.60; 95% confidence interval (CI): 0.17 to 1.03) in ASD patients were significantly higher than those of control subjects. ASD patients had higher erythrocyte levels of lead (SMD=1.55, CI: 0.2 to 2.89) and mercury (SMD=1.56, CI: 0.42 to 2.70). There were significantly higher blood lead levels in ASD patients (SMD=0.43, CI: 0.02 to 0.85). Sensitivity analyses showed that ASD patients in developed but not in developing countries have lower hair concentrations of cadmium (SMD=-0.29, CI: -0.46 to -0.12). Also, such analyses indicated that ASD patients in developing but not in developed lands have higher hair concentrations of lead (SMD=1.58, CI: 0.80 to 2.36) and mercury (SMD=0.77, CI: 0.31 to 1.23). These findings were confirmed by meta-regression analyses indicating that development status of countries significantly influences the overall effect size of mean difference for hair arsenic, cadmium, lead, and mercury between patients with ASD and controls. CONCLUSION The findings help highlighting the role of toxic metals as environmental factors in the etiology of ASD, especially in developing lands. While there are environmental factors other than toxic metals that greatly contribute to the etiology of ASD in developed lands. It would be, thus, expected that classification of ASD includes etiological entities of ASD on the basis of implication of industrial pollutants (developed vs. developing ASD).
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Affiliation(s)
- Amene Saghazadeh
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; MetaCognition Interest Group (MCIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Nima Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Systematic Review and Meta-analysis Expert Group (SRMEG), Universal Scientific Education and Research Network (USERN), Boston, MA, USA.
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19
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El-Ansary A, Bjørklund G, Tinkov AA, Skalny AV, Al Dera H. Relationship between selenium, lead, and mercury in red blood cells of Saudi autistic children. Metab Brain Dis 2017; 32:1073-1080. [PMID: 28326463 DOI: 10.1007/s11011-017-9996-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/15/2017] [Indexed: 12/22/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that can cause significant social, communication and behavioral challenges. Environmental contribution to ASD is due in large part to the sensitivity of the developing brain to external exposures such as lead (Pb), and mercury (Hg) as toxic heavy metals or due to a poor detoxification ability as the phenotype of this disorder. Selenium (Se) as an antioxidant element that counteracts the neurotoxicity of Hg, and Pb, presumably through the formation of nontoxic complexes. In the present study, Pb, Hg, and Se were measured in red blood cells (RBCs) of 35 children with ASD and 30 age- and gender-matched healthy control children using atomic absorption spectrometry. Receiver Operating Characteristics (ROC) analysis of the obtained data was performed to measure the predictive value of their absolute and relative concentrations. The obtained data demonstrates a significant elevation of Hg and Pb together with a significant decrease in the Se levels in RBCs of patients with ASD when compared to the healthy controls. The ratios of Se to both Pb and Hg were remarkably altered, being indicative of heavy metal neurotoxicity in patients with ASD. In conclusion, the present study indicates the importance of Se for prevention and/or therapy of heavy metal neurotoxicity.
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Affiliation(s)
- Afaf El-Ansary
- Central Laboratory, Center for Female Scientific and Medical Colleges, King Saud University, Riyadh, Saudi Arabia
- Autism Research and Treatment Center, Riyadh, Saudi Arabia
- Medicinal Chemistry Department, National Research Centre, Dokki, Cairo, Egypt
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610, Mo i Rana, Norway.
| | - Alexey A Tinkov
- Orenburg State University, Orenburg, Russia
- Orenburg State Medical University, Orenburg, Russia
- Yaroslavl State University, Yaroslavl, Russia
| | - Anatoly V Skalny
- Orenburg State Medical University, Orenburg, Russia
- Yaroslavl State University, Yaroslavl, Russia
- RUDN University, Moscow, Russia
- All-Russian Research Institute of Medicinal and Aromatic Plants, Moscow, Russia
| | - Hussain Al Dera
- Basic Medical Science Department, College of Medicine, King Saud bin Abdul Aziz University for Health Sciences, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
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20
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Antunes Dos Santos A, Appel Hort M, Culbreth M, López-Granero C, Farina M, Rocha JBT, Aschner M. Methylmercury and brain development: A review of recent literature. J Trace Elem Med Biol 2016; 38:99-107. [PMID: 26987277 PMCID: PMC5011031 DOI: 10.1016/j.jtemb.2016.03.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 03/02/2016] [Indexed: 02/02/2023]
Abstract
Methylmercury (MeHg) is a potent environmental pollutant, which elicits significant toxicity in humans. The central nervous system (CNS) is the primary target of toxicity, and is particularly vulnerable during development. Maternal exposure to MeHg via consumption of fish and seafood can have irreversible effects on the neurobehavioral development of children, even in the absence of symptoms in the mother. It is well documented that developmental MeHg exposure may lead to neurological alterations, including cognitive and motor dysfunction. The neurotoxic effects of MeHg on the developing brain have been extensively studied. The mechanism of toxicity, however, is not fully understood. No single process can explain the multitude of effects observed in MeHg-induced neurotoxicity. This review summarizes the most current knowledge on the effects of MeHg during nervous system development considering both, in vitro and in vivo experimental models. Considerable attention was directed towards the role of glutamate and calcium dyshomeostasis, mitochondrial dysfunction, as well as the effects of MeHg on cytoskeletal components/regulators.
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Affiliation(s)
| | - Mariana Appel Hort
- Institute of Biological Sciences, Federal University of Rio Grande, Campus Carreiros, Rio Grande do Sul, Brazil
| | - Megan Culbreth
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Caridad López-Granero
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Marcelo Farina
- Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Joao B T Rocha
- Department of Biochemistry, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.
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21
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Zhou X, Chen Z, Cui Y. Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2016; 38:1067-1082. [PMID: 26486131 DOI: 10.1007/s10653-015-9773-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 10/14/2015] [Indexed: 06/05/2023]
Abstract
The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should incorporate soil gas and/or gas flux measurements in the environmental assessment of areas of possible risk. A survey of all houses along seismic ruptures is advised as structural measures to prevent the ingress of soil gases, including CO2 and Rn, were needed in some houses.
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Affiliation(s)
- Xiaocheng Zhou
- CEA Key Laboratory of Earthquake Prediction (Institute of Earthquake Science), China Earthquake Administration, Beijing, 100036, China.
| | - Zhi Chen
- CEA Key Laboratory of Earthquake Prediction (Institute of Earthquake Science), China Earthquake Administration, Beijing, 100036, China
| | - Yueju Cui
- CEA Key Laboratory of Earthquake Prediction (Institute of Earthquake Science), China Earthquake Administration, Beijing, 100036, China
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22
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Kern JK, Geier DA, Sykes LK, Haley BE, Geier MR. The relationship between mercury and autism: A comprehensive review and discussion. J Trace Elem Med Biol 2016; 37:8-24. [PMID: 27473827 DOI: 10.1016/j.jtemb.2016.06.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/17/2016] [Accepted: 06/01/2016] [Indexed: 12/28/2022]
Abstract
The brain pathology in autism spectrum disorders (ASD) indicates marked and ongoing inflammatory reactivity with concomitant neuronal damage. These findings are suggestive of neuronal insult as a result of external factors, rather than some type of developmental mishap. Various xenobiotics have been suggested as possible causes of this pathology. In a recent review, the top ten environmental compounds suspected of causing autism and learning disabilities were listed and they included: lead, methyl-mercury, polychorinated biphenyls, organophosphate pesticides, organochlorine pesticides, endocrine disruptors, automotive exhaust, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and perfluorinated compounds. This current review, however, will focus specifically on mercury exposure and ASD by conducting a comprehensive literature search of original studies in humans that examine the potential relationship between mercury and ASD, categorizing, summarizing, and discussing the published research that addresses this topic. This review found 91 studies that examine the potential relationship between mercury and ASD from 1999 to February 2016. Of these studies, the vast majority (74%) suggest that mercury is a risk factor for ASD, revealing both direct and indirect effects. The preponderance of the evidence indicates that mercury exposure is causal and/or contributory in ASD.
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Affiliation(s)
- Janet K Kern
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; Council for Nutritional and Environmental Medicine, Mo i Rana, Norway; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA.
| | - David A Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Lisa K Sykes
- CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Boyd E Haley
- University of Kentucky, 410 Administration Drive, Lexington, KY, 40506 USA
| | - Mark R Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
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23
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Hubbs-Tait L, Nation JR, Krebs NF, Bellinger DC. Neurotoxicants, Micronutrients, and Social Environments. Psychol Sci Public Interest 2016; 6:57-121. [DOI: 10.1111/j.1529-1006.2005.00024.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
SUMMARY—Systematic research evaluating the separate and interacting impacts of neurotoxicants, micronutrients, and social environments on children's cognition and behavior has only recently been initiated. Years of extensive human epidemiologic and animal experimental research document the deleterious impact of lead and other metals on the nervous system. However, discrepancies among human studies and between animal and human studies underscore the importance of variations in child nutrition as well as social and behavioral aspects of children's environments that mitigate or exacerbate the effects of neurotoxicants. In this monograph, we review existing research on the impact of neurotoxic metals, nutrients, and social environments and interactions across the three domains. We examine the literature on lead, mercury, manganese, and cadmium in terms of dispersal, epidemiology, experimental animal studies, effects of social environments, and effects of nutrition. Research documenting the negative impact of lead on cognition and behavior influenced reductions by the Center for Disease Control in child lead-screening guidelines from 30 micrograms per deciliter (μg/dL) in 1975 to 25 μg/dL in 1985 and to 10 μg/dL in 1991. A further reduction is currently being considered. Experimental animal research documents lead's alteration of glutamate-neurotransmitter (particularly N-methyl-D-aspartate) activity vital to learning and memory. In addition, lead induces changes in cholinergic and dopaminergic activity. Elevated lead concentrations in the blood are more common among children living in poverty and there is some evidence that socioeconomic status influences associations between lead and child outcomes. Micronutrients that influence the effects of lead include iron and zinc. Research documenting the negative impact of mercury on children (as well as adults) has resulted in a reference dose (RfD) of 0.1 microgram per kilogram of body weight per day (μg/kg/day). In animal studies, mercury interferes with glutamatergic, cholinergic, and dopaminergic activity. Although evidence for interactions of mercury with children's social contexts is minimal, researchers are examining interactions of mercury with several nutrients. Research on the effects of cadmium and manganese on child cognition and behavior is just beginning. Experimental animal research links cadmium to learning deficits, manganese to behaviors characteristic of Parkinson's disease, and both to altered dopaminergic functioning. We close our review with a discussion of policy implications, and we recommend interdisciplinary research that will enable us to bridge gaps within and across domains.
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Affiliation(s)
- Laura Hubbs-Tait
- Department of Human Development and Family Science, Oklahoma State University
| | | | - Nancy F. Krebs
- Department of Pediatrics, University of Colorado School of Medicine
| | - David C. Bellinger
- Department of Neurology, Harvard Medical School; Department of Environmental Health, Harvard School of Public Health; and Children's Hospital Boston
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Fujiwara T, Morisaki N, Honda Y, Sampei M, Tani Y. Chemicals, Nutrition, and Autism Spectrum Disorder: A Mini-Review. Front Neurosci 2016; 10:174. [PMID: 27147957 PMCID: PMC4837386 DOI: 10.3389/fnins.2016.00174] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/04/2016] [Indexed: 12/22/2022] Open
Abstract
The rapid increase of the prevalence of autism spectrum disorder (ASD) suggests that exposure to chemicals may impact the development of ASD. Therefore, we reviewed literature on the following chemicals, nutrient to investigate their association with ASD: (1) smoke/tobacco, (2) alcohol, (3) air pollution, (4) pesticides, (5) endocrine-disrupting chemicals, (6) heavy metals, (7) micronutrients, (8) fatty acid, and (9) parental obesity as a proxy of accumulation of specific chemicals or nutritional status. Several chemical exposures such as air pollution (e.g., particular matter 2.5), pesticides, bisphenol A, phthalates, mercury, and nutrition deficiency such as folic acid, vitamin D, or fatty acid may possibly be associated with an increased risk of ASD, whereas other traditional risk factors such as smoking/tobacco, alcohol, or polychlorinated biphenyls are less likely to be associated with ASD. Further research is needed to accumulate evidence on the association between chemical exposure and nutrient deficiencies and ASD in various doses and populations.
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Affiliation(s)
- Takeo Fujiwara
- Department of Social Medicine, National Research Institute for Child Health and Development, Okura, Setagaya-ku, Tokyo, Japan; Department of Global Health Promotion, Tokyo Medical and Dental UniversityTokyo, Japan
| | - Naho Morisaki
- Department of Social Medicine, National Research Institute for Child Health and Development , Okura, Setagaya-ku, Tokyo, Japan
| | - Yukiko Honda
- Department of Social Medicine, National Research Institute for Child Health and Development, Okura, Setagaya-ku, Tokyo, Japan; Global Cooperation Institute for Sustainable Cities, Yokohama City UniversityYokohama, Japan
| | - Makiko Sampei
- Department of Social Medicine, National Research Institute for Child Health and Development , Okura, Setagaya-ku, Tokyo, Japan
| | - Yukako Tani
- Department of Social Medicine, National Research Institute for Child Health and Development, Okura, Setagaya-ku, Tokyo, Japan; Department of Global Health Promotion, Tokyo Medical and Dental UniversityTokyo, Japan; Department of Health Education and Health Sociology, School of Public Health, The University of TokyoTokyo, Japan
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Wong VCN, Fung CW, Lee SL, Wong PTY. Review of evolution of clinical, training and educational services and research program for autism spectrum disorders in Hong Kong. SCIENCE CHINA-LIFE SCIENCES 2015; 58:991-1009. [PMID: 26335731 DOI: 10.1007/s11427-012-4294-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The evolution of a local fragmented model of services for children with autism in Hong Kong emerged gradually over the past three decades with lack of government funding or support. This had been due to increasing number of children with autism being detected and referred for earlier assessment. With increasing pressure from parents due to long waiting time for assessment and training services and the increasing polarization by mass media there had been a gradual increasing public awareness over the past five years. Though still highly fragmented in the availability of services, there is a growing "business model" available in the community due to increasing need and lack of public funding for support. There is a lack of strategic planning for medical diagnostic and management issues in Hong Kong. Our University of Hong Kong based Autism Research Program was pioneered in 1985 based on the increasing load of autism cases referred for assessment for other developmental problems and diagnosed as Autism in the Duchess of Kent Children's Hospital. As the first author has been the staff of the University of Hong Kong, this program flourished as a research based program. The benefits of early identification and intervention of autism spectrum disorder (ASD) had been increasingly recognized, and with the increased public awareness and increasing trend of earlier diagnosis, there has been a continuously high demand from parents for earlier assessment and training for children suspected to have ASD. This model had not received extra funding for this integrated program for research, teaching and training in autism. We had to apply for various donations and grants to support the development of this pioneer program. The research output and organization of forums for public education and awareness are reviewed. The latter part of the paper reports the summary of clinical profile of autism cases (N=1441) assessed from 1985 to 2010 June under the University of Hong Kong. As the waiting time for initial developmental assessment for any children in Hong Kong is 12-24 months, we also report our preliminary experience with a newly launched triaging service provision for children suspected to be ASD since 2009, including multi-disciplinary assessment and parallel interim training in our university affiliated child assessment centre in Hong (N=89).
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Affiliation(s)
- Virginia Chun-Nei Wong
- Department of Paediatrics and Adolescent Medicine, the University of Hong Kong, Queen Mary Hospital, Hong Kong, China.
| | - Cheuk-Wing Fung
- Department of Paediatrics and Adolescent Medicine, the University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - So-Lun Lee
- Department of Paediatrics and Adolescent Medicine, the University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Polly Tsz Yan Wong
- Department of Paediatrics and Adolescent Medicine, the University of Hong Kong, Queen Mary Hospital, Hong Kong, China
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McKean SJ, Bartell SM, Hansen RL, Barfod GH, Green PG, Hertz-Picciotto I. Prenatal mercury exposure, autism, and developmental delay, using pharmacokinetic combination of newborn blood concentrations and questionnaire data: a case control study. Environ Health 2015; 14:62. [PMID: 26198445 PMCID: PMC4508765 DOI: 10.1186/s12940-015-0045-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/08/2015] [Indexed: 05/28/2023]
Abstract
BACKGROUND Methylmercury (MeHg), known for well over a century as a neurotoxin in adults, has more recently been studied for potential detrimental effects during early brain development. While several studies have estimated mercury exposure, they usually rely on either a single biomarker or questionnaire data, each of which has limitations. The goal of this paper was to develop a toxicokinetic model that incorporates both biomarker and questionnaire data to estimate the cumulative exposure to MeHg through seafood consumption using data collected from the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. METHODS We utilized a previously described discrete-time model that estimates blood MeHg concentration given a piecewise-constant ingestion rate and single-compartment pharmacokinetics. We measured newborn bloodspot Hg concentrations and obtained information pertaining to maternal fish consumption using a questionnaire. Using MeHg concentration estimates from the toxicokinetic model, cumulative MeHg exposure was estimated in children with autism, children with developmental delay, and typically developing children. Median estimated cumulative MeHg was compared among diagnostic groups using the Kruskal-Wallis Test. Multinomial logistic regression models were constructed to assess the association between cumulative MeHg concentration and the risk of autism and developmental delay (vs. typical development). RESULTS The estimated average MeHg concentration of for all fish species consumed by mothers was 42 ppb. Median cumulative MeHg over gestation was similar across diagnostic groups (p-values raged from 0.91 to 0.98). After adjusting for potential confounding, we found no association between cumulative MeHg exposure and the risk of autism (OR = 0.95, 95% CI: 0.95, 1.12) or developmental delay (OR = 1.00, 95% CI: 0.89, 1.13). CONCLUSIONS The toxicokinetic model described in this paper yielded fish MeHg concentration estimates that are consistent with fish species containing lower levels of MeHg. Overall, cumulative MeHg exposure does not appear to detectably elevate the risk of autism or developmental delay. Based on the regression standard error for the association between ASD and TD, we would have reported statistical significance for an adjusted odds ratio of 1.09 or larger. This method can easily be extended to other epidemiologic studies in which there is a biomarker measurement and questionnaire data regarding exposure.
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Affiliation(s)
| | - Scott M Bartell
- Program in Public Health and Department of Statistics, University of California, Irvine, Irvine, CA, USA.
| | - Robin L Hansen
- Department of Pediatrics, University of California, Davis, Sacramento, CA, USA.
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA.
| | - Gry H Barfod
- Interdisciplinary Center for Plasma Mass Spectrometry, University of California, Davis, Davis, CA, 95616, USA.
| | - Peter G Green
- Department of Civil and Environmental Engineering, University of California, Davis, Davis, CA, USA.
| | - Irva Hertz-Picciotto
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA.
- Department of Public Health Sciences, University of California, Davis, Davis, CA, USA.
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Weisleder P. The Ethics Writings of Roger A. Brumback, MD. J Child Neurol 2015; 30:1096-8. [PMID: 24810089 DOI: 10.1177/0883073814533421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 04/05/2014] [Indexed: 11/17/2022]
Abstract
Roger A. Brumback, MD (1953-2013), a renaissance man, shared with the world his knowledge and opinions on many subjects. Thus, it should come as no surprise that ethics did not escape Dr Brumback's consideration. Reading Dr Brumback's vitae, I came across several publications that afford insights into topics that tugged at his moral fabric. Dr Brumback was a steadfast defender of the scientific method. Reading his commentaries, one gets the sense that Dr Brumback felt personally attacked when quackery challenged science. In addition, and as long-time Editor-in-Chief of the Journal of Child Neurology, Dr Brumback considered it a personal affront every time a paper he published, or for that matter published by any scientific journal, had to be retracted or corrected. In the following paragraphs, I review a selection of Dr Brumback's ethics writings.
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Affiliation(s)
- Pedro Weisleder
- Division of Child Neurology, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
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Sivaratnam CS, Newman LK, Tonge BJ, Rinehart NJ. Attachment and Emotion Processing in Children with Autism Spectrum Disorders: Neurobiological, Neuroendocrine, and Neurocognitive Considerations. REVIEW JOURNAL OF AUTISM AND DEVELOPMENTAL DISORDERS 2015. [DOI: 10.1007/s40489-015-0048-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
ABSTRACT:Because of a temporal correlation between the first notable signs and symptoms of autism and the routine childhood vaccination schedule, many parents have become increasingly concerned regarding the possible etiologic role vaccines may play in the development of autism. In particular, some have suggested an association between the Measles-Mumps-Rubella vaccine and autism. Our literature review found very few studies supporting this theory, with the overwhelming majority showing no causal association between the Measles-Mumps-Rubella vaccine and autism. The vaccine preservative thimerosal has alternatively been hypothesized to have a possible causal role in autism. Again, no convincing evidence was found to support this claim, nor for the use of chelation therapy in autism. With decreasing uptake of immunizations in children and the inevitable occurrence of measles outbreaks, it is important that clinicians be aware of the literature concerning vaccinations and autism so that they may have informed discussions with parents and caregivers.
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Affiliation(s)
- Asif Doja
- Division of Neurology, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
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Shevell M, Fombonne E. Autism and MMR Vaccination or Thimerosal Exposure: An Urban Legend? Can J Neurol Sci 2014; 33:339-40. [PMID: 17168157 DOI: 10.1017/s0317167100005278] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
The present study examined genetic and shared environment contributions to quantitatively-measured autism symptoms and categorically-defined autism spectrum disorders (ASD). Participants included 568 twins from the Interactive Autism Network. Autism symptoms were obtained using the Social Communication Questionnaire and Social Responsiveness Scale. Categorically-defined ASD was based on clinical diagnoses. DeFries-Fulker and liability threshold models examined etiologic influences. Very high heritability was observed for extreme autism symptom levels ([Formula: see text]). Extreme levels of social and repetitive behavior symptoms were strongly influenced by common genetic factors. Heritability of categorically-defined ASD diagnosis was comparatively low (.21, 95 % CI 0.15-0.28). High heritability of extreme autism symptom levels confirms previous observations of strong genetic influences on autism. Future studies will require large, carefully ascertained family pedigrees and quantitative symptom measurements.
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Biamonte F, Latini L, Giorgi FS, Zingariello M, Marino R, De Luca R, D'Ilio S, Majorani C, Petrucci F, Violante N, Senofonte O, Molinari M, Keller F. Associations among exposure to methylmercury, reduced Reelin expression, and gender in the cerebellum of developing mice. Neurotoxicology 2014; 45:67-80. [PMID: 25305366 DOI: 10.1016/j.neuro.2014.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 09/24/2014] [Accepted: 09/28/2014] [Indexed: 12/30/2022]
Abstract
Genetic risk factors acting during pregnancy or early after birth have been proposed to account for the exponential increase of autism diagnoses in the past 20 years. In particular, a potential link with exposure to environmental mercury has been suggested. Male sex constitutes a second risk factor for autism. A third potential genetic risk factor is decreased Reelin expression. Male heterozygous reeler (rl(+/-)) mice show an autism-like phenotype, including Purkinje cells (PCs) loss and behavioral rigidity. We evaluated the complex interactions between 3 risk factors, i.e. genetic status, sex, and exposure to methylmercury (MeHg), in rl(+/-) mice. Mice were exposed to MeHg during the prenatal and early postnatal period, either at a subtoxic dose (2 ppm in Dams' drinking water), or at a toxic dose (6 ppm Dams' drinking water), based on observations in other rodent species and mice strains. We show that: (a) 2 ppm MeHg does not cause PCs loss in the different animal groups, and does not enhance PCs loss in rl(+/-) males; consistent with a lack of overt neurotoxicity, 2 ppm MeHg per se does not cause behavioral alterations (separation-induced ultrasonic calls in newborns, or sociability and social preference in adults); (b) in stark contrast, 6 ppm MeHg causes a dramatic reduction of PCs number in all groups, irrespective of genotype and sex. Cytochrome C release from mitochondria of PCs is enhanced in 6 ppm MeHg-exposed groups, with a concomitant increase of μ-calpain active subunit. At the behavioral level, 6 ppm MeHg exposure strongly increases ultrasonic vocalizations in all animal groups. Notably, 6 ppm MeHg significantly decreases sociability in rl(+/-) male mice, while the 2 ppm group does not show such as decrease. At a subtoxic dose, MeHg does not enhance the autism-like phenotype of male rl(+/-) mice. At the higher MeHg dose, the scenario is more complex, with some "autism-like" features (loss of sociability, preference for sameness) being evidently affected only in rl(+/-) males, while other neuropathological and behavioral parameters being altered in all groups, independently from genotype and sex. Mitochondrial abnormalities appear to play a crucial role in the observed effects.
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Affiliation(s)
- Filippo Biamonte
- Laboratory of Developmental Neuroscience and Neural Plasticity, University Campus Biomedico, Via A. del Portillo 21, 00198 Rome, Italy
| | - Laura Latini
- Santa Lucia Foundation, I.R.C.C.S., Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Filippo Sean Giorgi
- Section of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy
| | | | - Ramona Marino
- Laboratory of Developmental Neuroscience and Neural Plasticity, University Campus Biomedico, Via A. del Portillo 21, 00198 Rome, Italy
| | - Roberto De Luca
- Laboratory of Developmental Neuroscience and Neural Plasticity, University Campus Biomedico, Via A. del Portillo 21, 00198 Rome, Italy
| | - Sonia D'Ilio
- Istituto Superiore di Sanità, Centro Nazionale Sostanze Chimiche, Viale Regina Elena 299, Rome, Italy
| | - Costanza Majorani
- Istituto Superiore di Sanità, Dipartimento di Ambiente e Prevenzione Primaria, Viale Regina Elena 299, Rome, Italy
| | - Francesco Petrucci
- Istituto Superiore di Sanità, Dipartimento di Ambiente e Prevenzione Primaria, Viale Regina Elena 299, Rome, Italy
| | - Nicola Violante
- Istituto Superiore di Sanità, Dipartimento di Ambiente e Prevenzione Primaria, Viale Regina Elena 299, Rome, Italy
| | - Oreste Senofonte
- Istituto Superiore di Sanità, Dipartimento di Ambiente e Prevenzione Primaria, Viale Regina Elena 299, Rome, Italy
| | - Marco Molinari
- Santa Lucia Foundation, I.R.C.C.S., Via del Fosso di Fiorano 64, 00143 Rome, Italy.
| | - Flavio Keller
- Laboratory of Developmental Neuroscience and Neural Plasticity, University Campus Biomedico, Via A. del Portillo 21, 00198 Rome, Italy.
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Yau VM, Green PG, Alaimo CP, Yoshida CK, Lutsky M, Windham GC, Delorenze G, Kharrazi M, Grether JK, Croen LA. Prenatal and neonatal peripheral blood mercury levels and autism spectrum disorders. ENVIRONMENTAL RESEARCH 2014; 133:294-303. [PMID: 24981828 DOI: 10.1016/j.envres.2014.04.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND Prenatal and early-life exposures to mercury have been hypothesized to be associated with increased risk of autism spectrum disorders (ASDs). OBJECTIVES This study investigated the association between ASDs and levels of total mercury measured in maternal serum from mid-pregnancy and infant blood shortly after birth. METHODS The study sample was drawn from the Early Markers for Autism (EMA) Study. Three groups of children who were born in Orange County, CA in 2000-2001 were identified: children with ASD (n=84), children with intellectual disability or developmental delay (DD) (n=49), and general population controls (GP) (n=159). Maternal serum specimens and newborn bloodspots were retrieved from the California Department of Public Health prenatal and newborn screening specimen archives. Blood mercury levels were measured in maternal serum samples using mass spectrometer and in infant bloodspots with a 213 nm laser. RESULTS Maternal serum and infant blood mercury levels were significantly correlated among all study groups (all correlations >0.38, p<0.01). Adjusted logistic regression models showed no significant associations between ASD and log transformed mercury levels in maternal serum samples (ASD vs. GP: OR [95% CI]=0.96 [0.49-1.90]; ASD vs. DD: OR [95% CI]=2.56 [0.89-7.39]). Results for mercury levels in newborn blood samples were similar (ASD vs. GP: OR [95% CI]=1.18 [0.71-1.95]; ASD vs. DD: OR [95% CI]=1.96 [0.75-5.14]). CONCLUSIONS Results indicate that levels of total mercury in serum collected from mothers during mid-pregnancy and from newborn bloodspots were not significantly associated with risk of ASD, though additional studies with greater sample size and covariate measurement are needed.
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Affiliation(s)
- Vincent M Yau
- Division of Research, Kaiser Permanente, Oakland, CA, USA
| | - Peter G Green
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA, USA
| | - Christopher P Alaimo
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA, USA
| | | | - Marta Lutsky
- Division of Research, Kaiser Permanente, Oakland, CA, USA
| | - Gayle C Windham
- Division of Environmental and Occupational Disease Control, California Department of Public Health, Richmond, CA, USA
| | | | - Martin Kharrazi
- Genetic Disease Screening Program, California Department of Public Health, Richmond, CA, USA
| | - Judith K Grether
- Division of Environmental and Occupational Disease Control, California Department of Public Health, Richmond, CA, USA
| | - Lisa A Croen
- Division of Research, Kaiser Permanente, Oakland, CA, USA.
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Rossignol DA, Genuis SJ, Frye RE. Environmental toxicants and autism spectrum disorders: a systematic review. Transl Psychiatry 2014; 4:e360. [PMID: 24518398 PMCID: PMC3944636 DOI: 10.1038/tp.2014.4] [Citation(s) in RCA: 302] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/15/2013] [Accepted: 01/06/2014] [Indexed: 11/21/2022] Open
Abstract
Although the involvement of genetic abnormalities in autism spectrum disorders (ASD) is well-accepted, recent studies point to an equal contribution by environmental factors, particularly environmental toxicants. However, these toxicant-related studies in ASD have not been systematically reviewed to date. Therefore, we compiled publications investigating potential associations between environmental toxicants and ASD and arranged these publications into the following three categories: (a) studies examining estimated toxicant exposures in the environment during the preconceptional, gestational and early childhood periods; (b) studies investigating biomarkers of toxicants; and (c) studies examining potential genetic susceptibilities to toxicants. A literature search of nine electronic scientific databases through November 2013 was performed. In the first category examining ASD risk and estimated toxicant exposures in the environment, the majority of studies (34/37; 92%) reported an association. Most of these studies were retrospective case-control, ecological or prospective cohort studies, although a few had weaker study designs (for example, case reports or series). Toxicants implicated in ASD included pesticides, phthalates, polychlorinated biphenyls (PCBs), solvents, toxic waste sites, air pollutants and heavy metals, with the strongest evidence found for air pollutants and pesticides. Gestational exposure to methylmercury (through fish exposure, one study) and childhood exposure to pollutants in water supplies (two studies) were not found to be associated with ASD risk. In the second category of studies investigating biomarkers of toxicants and ASD, a large number was dedicated to examining heavy metals. Such studies demonstrated mixed findings, with only 19 of 40 (47%) case-control studies reporting higher concentrations of heavy metals in blood, urine, hair, brain or teeth of children with ASD compared with controls. Other biomarker studies reported that solvent, phthalate and pesticide levels were associated with ASD, whereas PCB studies were mixed. Seven studies reported a relationship between autism severity and heavy metal biomarkers, suggesting evidence of a dose-effect relationship. Overall, the evidence linking biomarkers of toxicants with ASD (the second category) was weaker compared with the evidence associating estimated exposures to toxicants in the environment and ASD risk (the first category) because many of the biomarker studies contained small sample sizes and the relationships between biomarkers and ASD were inconsistent across studies. Regarding the third category of studies investigating potential genetic susceptibilities to toxicants, 10 unique studies examined polymorphisms in genes associated with increased susceptibilities to toxicants, with 8 studies reporting that such polymorphisms were more common in ASD individuals (or their mothers, 1 study) compared with controls (one study examined multiple polymorphisms). Genes implicated in these studies included paraoxonase (PON1, three of five studies), glutathione S-transferase (GSTM1 and GSTP1, three of four studies), δ-aminolevulinic acid dehydratase (one study), SLC11A3 (one study) and the metal regulatory transcription factor 1 (one of two studies). Notably, many of the reviewed studies had significant limitations, including lack of replication, limited sample sizes, retrospective design, recall and publication biases, inadequate matching of cases and controls, and the use of nonstandard tools to diagnose ASD. The findings of this review suggest that the etiology of ASD may involve, at least in a subset of children, complex interactions between genetic factors and certain environmental toxicants that may act synergistically or in parallel during critical periods of neurodevelopment, in a manner that increases the likelihood of developing ASD. Because of the limitations of many of the reviewed studies, additional high-quality epidemiological studies concerning environmental toxicants and ASD are warranted to confirm and clarify many of these findings.
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Affiliation(s)
- D A Rossignol
- Family Medicine, Rossignol Medical Center, Irvine, CA, USA
| | - S J Genuis
- Faculty of Medicine, University of Alberta, Edmonton, AB, Canada
| | - R E Frye
- Arkansas Children's Hospital Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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A human pluripotent carcinoma stem cell-based model for in vitro developmental neurotoxicity testing: effects of methylmercury, lead and aluminum evaluated by gene expression studies. Int J Dev Neurosci 2013; 31:679-91. [PMID: 23501475 DOI: 10.1016/j.ijdevneu.2013.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 01/24/2013] [Accepted: 03/03/2013] [Indexed: 12/23/2022] Open
Abstract
The major advantage of the neuronal cell culture models derived from human stem cells is their ability to replicate the crucial stages of neurodevelopment such as the commitment of human stem cells to the neuronal lineage and their subsequent stages of differentiation into neuronal and glial-like cell. In these studies we used mixed neuronal/glial culture derived from the NTERA-2 (NT-2) cell line, which has been established from human pluripotent testicular embryonal carcinoma cells. After characterization of the different stages of cell differentiation into neuronal- and glial-like phenotype toxicity studies were performed to evaluate whether this model would be suitable for developmental neurotoxicity studies. The cells were exposed during the differentiation process to non-cytotoxic concentrations of methylmercury chloride, lead chloride and aluminum nitrate for two weeks. The toxicity was then evaluated by measuring the mRNA levels of cell specific markers (neuronal and glial). The results obtained suggest that lead chloride and aluminum nitrate at low concentrations were toxic primarily to astrocytes and at the higher concentrations it also induced neurotoxicity. In contrast, MetHgCl was toxic for both cell types, neuronal and glial, as mRNA specific for astrocytes and neuronal markers were affected. The results obtained suggest that a neuronal mixed culture derived from human NT2 precursor cells is a suitable model for developmental neurotoxicity studies and gene expression could be used as a sensitive endpoint for initial screening of potential neurotoxic compounds.
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Goines PE, Ashwood P. Cytokine dysregulation in autism spectrum disorders (ASD): possible role of the environment. Neurotoxicol Teratol 2013; 36:67-81. [PMID: 22918031 PMCID: PMC3554862 DOI: 10.1016/j.ntt.2012.07.006] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/03/2012] [Accepted: 07/31/2012] [Indexed: 02/07/2023]
Abstract
Autism spectrum disorders (ASD) are neurodevelopmental diseases that affect an alarming number of individuals. The etiological basis of ASD is unclear, and evidence suggests it involves both genetic and environmental factors. There are many reports of cytokine imbalances in ASD. These imbalances could have a pathogenic role, or they may be markers of underlying genetic and environmental influences. Cytokines act primarily as mediators of immunological activity but they also have significant interactions with the nervous system. They participate in normal neural development and function, and inappropriate activity can have a variety of neurological implications. It is therefore possible that cytokine dysregulation contributes directly to neural dysfunction in ASD. Further, cytokine profiles change dramatically in the face of infection, disease, and toxic exposures. Imbalances in cytokines may represent an immune response to environmental contributors to ASD. The following review is presented in two main parts. First, we discuss select cytokines implicated in ASD, including IL-1Β, IL-6, IL-4, IFN-γ, and TGF-Β, and focus on their role in the nervous system. Second, we explore several neurotoxic environmental factors that may be involved in the disorders, and focus on their immunological impacts. This review represents an emerging model that recognizes the importance of both genetic and environmental factors in ASD etiology. We propose that the immune system provides critical clues regarding the nature of the gene by environment interactions that underlie ASD pathophysiology.
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Affiliation(s)
- Paula E. Goines
- University of California, Davis, School of Veterinary Medicine, Department of Molecular Biosciences
| | - Paul Ashwood
- University of California, Davis, School of Medicine, Department of Medical Microbiology and Immunology
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Li HB, Yu S, Li GL, Deng H, Xu B, Ding J, Gao JB, Hong YW, Wong MH. Spatial distribution and historical records of mercury sedimentation in urban lakes under urbanization impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 445-446:117-125. [PMID: 23327992 DOI: 10.1016/j.scitotenv.2012.12.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 12/07/2012] [Accepted: 12/15/2012] [Indexed: 06/01/2023]
Abstract
China is assumed one of the largest contributors to the world's total mercury (Hg) emissions, with a rapid increase in anthropogenic Hg emissions. However, little is known about Hg fate and transport in urban areas of China. In this study, total Hg contents in surface (0-5 cm) sediments from lakes in 14 parks (3 in the central urban core (CUC) area, 5 in the developed urban (DDU) area, 2 in the developing urban (DIU) area, and 4 in the suburban (SU) area) and (210)Pb-dated sediment cores from lakes in 5 parks (3 in the CUC and 2 in the DDU) in Shanghai were assessed to compare current patterns (urbanization effect) with the historical records of Hg emissions over the past century. Total Hg content in surface sediments showed a clear urbanization pattern. Dated sediment cores revealed a 2-3 fold increase in total Hg content, while Hg fluxes exponentially increased from ~1900 to present and accelerated since 1990 when China's economy and urbanization booms started. Anthropogenic Hg fluxes in post-2000 ranged from 253 to 1452 μg m(-2) yr(-1), 2-7 times greater than preindustrial (pre-1900) Hg fluxes. Total Hg and Pb contents in both surface sediments and sediment cores were highly correlated and Hg flux in sediment cores also significantly correlated with annual coal consumption in the period 1949-2008. The significant correlations suggest that coal combustion is a major source of Hg emission in Shanghai.
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Affiliation(s)
- Hong-Bo Li
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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Wołowiec P, Michalak I, Chojnacka K, Mikulewicz M. Hair analysis in health assessment. Clin Chim Acta 2013; 419:139-71. [PMID: 23415695 DOI: 10.1016/j.cca.2013.02.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 01/30/2013] [Accepted: 02/03/2013] [Indexed: 01/30/2023]
Abstract
BACKGROUND Hair analysis is used for estimation of the nutritional status of individuals. In the present work, a systematic review on the relation between the mineral composition of hair and the physical or mental disorders is discussed. Detailed information of examined populations, methods of sample preparations and analytical techniques are presented. METHODS A systematic literature search in four electronic databases Scopus, PubMed, Web of Science and Medline (from 1997 to 2012/01/31) for English language articles was performed. In addition, a reference list and manual search was undertaken. RESULTS The following number of studies was included: 66. Most of the authors reported that there exists a correlation between deficiency or excess of some elements in hair and occurrence of some diseases, such as: autism, cancer, hypertension, myocardial infarction, kidney disease and diabetes mellitus. However, not all results were consistent. CONCLUSIONS Most of the authors concluded that the profile of hair mineral imbalance might be useful as a diagnostic tool for the early diagnosis of many diseases. However, it seems that there is a need to standardize sample preparation procedures, in particular washing and mineralization methods.
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Affiliation(s)
- Paulina Wołowiec
- Institute of Inorganic Technology and Mineral Fertilizers, Wrocław University of Technology, Wrocław, Poland.
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Adams JB, Audhya T, McDonough-Means S, Rubin RA, Quig D, Geis E, Gehn E, Loresto M, Mitchell J, Atwood S, Barnhouse S, Lee W. Toxicological status of children with autism vs. neurotypical children and the association with autism severity. Biol Trace Elem Res 2013. [PMID: 23192845 DOI: 10.1007/s12011-012-9551-1] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This study investigates both the level of toxic metals in children with autism and the possible association of those toxic metals with autism severity. This study involved 55 children with autism ages 5-16 years compared to 44 controls with similar age and gender. The study included measurements of toxic metals in whole blood, red blood cells (RBC), and urine. The autism group had higher levels of lead in RBC (+41 %, p = 0.002) and higher urinary levels of lead (+74 %, p = 0.02), thallium (+77 %, p = 0.0001), tin (+115 %, p = 0.01), and tungsten (+44 %, p = 0.00005). However, the autism group had slightly lower levels of cadmium in whole blood (-19 %, p = 0.003). A stepwise, multiple linear regression analysis found a strong association of levels of toxic metals with variation in the degree of severity of autism for all the severity scales (adjusted R(2) of 0.38-0.47, p < 0.0003). Cadmium (whole blood) and mercury (whole blood and RBC) were the most consistently significant variables. Overall, children with autism have higher average levels of several toxic metals, and levels of several toxic metals are strongly associated with variations in the severity of autism for all three of the autism severity scales investigated.
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Affiliation(s)
- James B Adams
- Arizona State University, Tempe, AZ 85287-6006, USA.
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Rahbar MH, Samms-Vaughan M, Loveland KA, Ardjomand-Hessabi M, Chen Z, Bressler J, Shakespeare-Pellington S, Grove ML, Bloom K, Pearson DA, Lalor GC, Boerwinkle E. Seafood consumption and blood mercury concentrations in Jamaican children with and without autism spectrum disorders. Neurotox Res 2013; 23:22-38. [PMID: 22488160 PMCID: PMC3969434 DOI: 10.1007/s12640-012-9321-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 03/22/2012] [Accepted: 03/23/2012] [Indexed: 01/22/2023]
Abstract
Mercury is a toxic metal shown to have harmful effects on human health. Several studies have reported high blood mercury concentrations as a risk factor for autism spectrum disorders (ASDs), while other studies have reported no such association. The goal of this study was to investigate the association between blood mercury concentrations in children and ASDs. Moreover, we investigated the role of seafood consumption in relation to blood mercury concentrations in Jamaican children. Based on data for 65 sex- and age-matched pairs (2-8 years), we used a General Linear Model to test whether there is an association between blood mercury concentrations and ASDs. After controlling for the child's frequency of seafood consumption, maternal age, and parental education, we did not find a significant difference (P = 0.61) between blood mercury concentrations and ASDs. However, in both cases and control groups, children who ate certain types of seafood (i.e., salt water fish, sardine, or mackerel fish) had significantly higher (all P < 0.05) geometric means blood mercury concentration which were about 3.5 times that of children living in the US or Canada. Our findings also indicate that Jamaican children with parents who both had education up to high school are at a higher risk of exposure to mercury compared to children with at least one parent who had education beyond high school. Based on our findings, we recommend additional education to Jamaican parents regarding potential hazards of elevated blood mercury concentrations, and its association with seafood consumption and type of seafood.
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Affiliation(s)
- Mohammad H. Rahbar
- Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), The University of Texas School of Public Health at Houston, Houston, TX 77030, USA. Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston (UTHealth), 6410 Fannin Street, UT Professional Building Suite 1100.05, Houston, TX 77030, USA
| | - Maureen Samms-Vaughan
- Department of Child Health, The University of the West Indies (UWI), Mona Campus, Kingston, Jamaica
| | - Katherine A. Loveland
- Department of Psychiatry and Behavioral Sciences/Center of Excellence on Development and Psychopathology, and Changing Lives Through Autism Spectrum Services (C.L.A.S.S.) Clinic, UTHealth Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
| | - Manouchehr Ardjomand-Hessabi
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston (UTHealth), 6410 Fannin Street, UT Professional Building Suite 1100.48, Houston, TX 77030, USA
| | - Zhongxue Chen
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston (UTHealth), 6410 Fannin Street, UT Professional Building Suite 1100.30, Houston, TX 77030, USA
| | - Jan Bressler
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
| | | | - Megan L. Grove
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
| | - Kari Bloom
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), The University of Texas Health Science Center at Houston (UTHealth), 6410 Fannin Street, UT Professional Building Suite 1100.08, Houston, TX 77030, USA
| | - Deborah A. Pearson
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Behavioral Sciences, UTHealth Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
| | - Gerald C. Lalor
- International Centre for Environmental Nuclear Science, The University of the West Indies, Mona Campus, Kingston, Jamaica
| | - Eric Boerwinkle
- Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), The University of Texas School of Public Health at Houston, Houston, TX 77030, USA. Human Genetics Center, School of Public Health, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
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Hassauer M, Kaiser E, Schneider K, Schuhmacher‐Wolz U. Collate the literature on toxicity data on mercury in experimental animals and humans (Part I – Data on organic mercury). ACTA ACUST UNITED AC 2012. [DOI: 10.2903/sp.efsa.2012.en-297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Hassauer
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Eva Kaiser
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
| | - Klaus Schneider
- Forschungs‐ und Beratungsinstitut Gefahrstoffe GmbH (FoBiG) Freiburg Germany
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Scientific Opinion on the risk for public health related to the presence of mercury and methylmercury in food. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2985] [Citation(s) in RCA: 276] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Wright B, Pearce H, Allgar V, Miles J, Whitton C, Leon I, Jardine J, McCaffrey N, Smith R, Holbrook I, Lewis J, Goodall D, Alderson-Day B. A comparison of urinary mercury between children with autism spectrum disorders and control children. PLoS One 2012; 7:e29547. [PMID: 22355303 PMCID: PMC3280241 DOI: 10.1371/journal.pone.0029547] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/30/2011] [Indexed: 11/22/2022] Open
Abstract
Background Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings. Methods Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD) compared to their siblings (n = 42) and a control sample of children without ASD in mainstream (n = 121) and special schools (n = 34). Results There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings. Conclusions This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors.
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Affiliation(s)
- Barry Wright
- North Yorkshire and York Primary Care Trust, York, United Kingdom.
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Newmark SC. Autism Spectrum Disorder. Integr Med (Encinitas) 2012. [DOI: 10.1016/b978-1-4377-1793-8.00007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Lack of Correlation Between Metallic Elements Analyzed in Hair by ICP-MS and Autism. J Autism Dev Disord 2011; 42:342-53. [DOI: 10.1007/s10803-011-1245-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kern JK, Geier DA, Adams JB, Mehta JA, Grannemann BD, Geier MR. Toxicity biomarkers in autism spectrum disorder: a blinded study of urinary porphyrins. Pediatr Int 2011; 53:147-53. [PMID: 20626635 DOI: 10.1111/j.1442-200x.2010.03196.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Recent studies suggest that children diagnosed with an autism spectrum disorder (ASD) have significantly increased levels of urinary porphyrins associated with mercury (Hg) toxicity, including pentacarboxyporphyrin (5cxP), precoproporphyrin (prcP), and coproporphyrin (cP), compared to typically developing controls. However, these initial studies were criticized because the controls were not age- and gender-matched to the children diagnosed with an ASD. METHODS Urinary porphyrin biomarkers in a group of children (2-13 years of age) diagnosed with an ASD (n= 20) were compared to matched (age, gender, race, location, and year tested) group of typically developing controls (n= 20). RESULTS Participants diagnosed with an ASD had significantly increased levels of 5cxP, prcP, and cP in comparison to controls. No significant differences were found in non-Hg associated urinary porphyrins (uroporphyrins, hexacarboxyporphyrin, and heptacarboxyporphyrin). There was a significantly increased odds ratio for an ASD diagnosis relative to controls among study participants with precoproporphyrin (odds ratio = 15.5, P < 0.01) and coproporphyrin (odds ratio = 15.5, P < 0.01) levels in the second through fourth quartiles in comparison to the first quartile. CONCLUSION These results suggest that the levels of Hg-toxicity-associated porphyrins are higher in children with an ASD diagnosis than controls. Although the pattern seen (increased 5cxP, prcP, and cP) is characteristic of Hg toxicity, the influence of other factors, such as genetics and other metals cannot be completely ruled out.
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Affiliation(s)
- Janet K Kern
- Research Department, Genetics Consultants of Dallas/ASD Centers, LLC., 408 N. Allen Dr, Allen, TX 75013, USA.
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Lim MH, Kwon HJ. Environmental Factors in Autism and Autistic Spectrum Disorder. Soa Chongsonyon Chongsin Uihak 2011. [DOI: 10.5765/jkacap.2011.22.1.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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El-baz F, Elhossiny RM, Elsayed AB, Gaber GM. Hair mercury measurement in Egyptian autistic children. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2010. [DOI: 10.1016/j.ejmhg.2010.10.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Adams JB, Baral M, Geis E, Mitchell J, Ingram J, Hensley A, Zappia I, Newmark S, Gehn E, Rubin RA, Mitchell K, Bradstreet J, El-Dahr J. Safety and efficacy of oral DMSA therapy for children with autism spectrum disorders: Part A--medical results. BMC CLINICAL PHARMACOLOGY 2009; 9:16. [PMID: 19852789 PMCID: PMC2774660 DOI: 10.1186/1472-6904-9-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Accepted: 10/23/2009] [Indexed: 01/26/2023]
Abstract
Background This study investigated the effect of oral dimercapto succinic acid (DMSA) therapy for children with autism spectrum disorders ages 3-8 years. Methods Phase 1 involved 65 children who received one round of DMSA (3 days). Participants who had high urinary excretion of toxic metals were selected to continue on to phase 2. In phase 2, 49 participants were randomly assigned in a double-blind design to receive an additional 6 rounds of either DMSA or placebo. Results DMSA greatly increased the excretion of lead, substantially increased excretion of tin and bismuth, and somewhat increased the excretion of thallium, mercury, antimony, and tungsten. There was some increase in urinary excretion of essential minerals, especially potassium and chromium. The Phase 1 single round of DMSA led to a dramatic normalization of RBC glutathione in almost all cases, and greatly improved abnormal platelet counts, suggesting a significant decrease in inflammation. Conclusion Overall, DMSA therapy seems to be reasonably safe, effective in removing several toxic metals (especially lead), dramatically effective in normalizing RBC glutathione, and effective in normalizing platelet counts. Only 1 round (3 days) was sufficient to improve glutathione and platelets. Additional rounds increased excretion of toxic metals.
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Affiliation(s)
- James B Adams
- Division of Basic Medical Sciences, Southwest College of Naturopathic Medicine, Tempe, AZ, USA.
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