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Payne-Sturges DC, Taiwo TK, Ellickson K, Mullen H, Tchangalova N, Anderko L, Chen A, Swanson M. Disparities in Toxic Chemical Exposures and Associated Neurodevelopmental Outcomes: A Scoping Review and Systematic Evidence Map of the Epidemiological Literature. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:96001. [PMID: 37754677 PMCID: PMC10525348 DOI: 10.1289/ehp11750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/29/2023] [Accepted: 08/10/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND Children are routinely exposed to chemicals known or suspected of harming brain development. Targeting Environmental Neuro-Development Risks (Project TENDR), an alliance of > 50 leading scientists, health professionals, and advocates, is working to protect children from these toxic chemicals and pollutants, especially the disproportionate exposures experienced by children from families with low incomes and families of color. OBJECTIVE This scoping review was initiated to map existing literature on disparities in neurodevelopmental outcomes for U.S. children from population groups who have been historically economically/socially marginalized and exposed to seven exemplar neurotoxicants: combustion-related air pollution (AP), lead (Pb), mercury (Hg), organophosphate pesticides (OPs), phthalates (Phth), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs). METHODS Systematic literature searches for the seven exemplar chemicals, informed by the Population, Exposure, Comparator, Outcome (PECO) framework, were conducted through 18 November 2022, using PubMed, CINAHL Plus (EBSCO), GreenFILE (EBSCO), and Web of Science sources. We examined these studies regarding authors' conceptualization and operationalization of race, ethnicity, and other indicators of sociodemographic and socioeconomic disadvantage; whether studies presented data on exposure and outcome disparities and the patterns of those disparities; and the evidence of effect modification by or interaction with race and ethnicity. RESULTS Two hundred twelve individual studies met the search criteria and were reviewed, resulting in 218 studies or investigations being included in this review. AP and Pb were the most commonly studied exposures. The most frequently identified neurodevelopmental outcomes were cognitive and behavioral/psychological. Approximately a third (74 studies) reported investigations of interactions or effect modification with 69% (51 of 74 studies) reporting the presence of interactions or effect modification. However, less than half of the studies presented data on disparities in the outcome or the exposure, and fewer conducted formal tests of heterogeneity. Ninety-two percent of the 165 articles that examined race and ethnicity did not provide an explanation of their constructs for these variables, creating an incomplete picture. DISCUSSION As a whole, the studies we reviewed indicated a complex story about how racial and ethnic minority and low-income children may be disproportionately harmed by exposures to neurotoxicants, and this has implications for targeting interventions, policy change, and other necessary investments to eliminate these health disparities. We provide recommendations on improving environmental epidemiological studies on environmental health disparities. To achieve environmental justice and health equity, we recommend concomitant strategies to eradicate both neurotoxic chemical exposures and systems that perpetuate social inequities. https://doi.org/10.1289/EHP11750.
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Affiliation(s)
| | | | - Kristie Ellickson
- Minnesota Pollution Control Agency, St. Paul, Minnesota, USA
- Union of Concerned Scientists, Cambridge, Massachusetts, USA
| | - Haley Mullen
- Department of Geographical Sciences, University of Maryland, College Park, Maryland, USA
| | | | - Laura Anderko
- M. Fitzpatrick College of Nursing, Villanova University, Villanova, Pennsylvania, USA
| | - Aimin Chen
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Evaluation of Individuals with Non-Syndromic Global Developmental Delay and Intellectual Disability. CHILDREN 2023; 10:children10030414. [PMID: 36979972 PMCID: PMC10047567 DOI: 10.3390/children10030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023]
Abstract
Global Developmental Delay (GDD) and Intellectual Disability (ID) are two of the most common presentations encountered by physicians taking care of children. GDD/ID is classified into non-syndromic GDD/ID, where GDD/ID is the sole evident clinical feature, or syndromic GDD/ID, where there are additional clinical features or co-morbidities present. Careful evaluation of children with GDD and ID, starting with detailed history followed by a thorough examination, remain the cornerstone for etiologic diagnosis. However, when initial history and examination fail to identify a probable underlying etiology, further genetic testing is warranted. In recent years, genetic testing has been shown to be the single most important diagnostic modality for clinicians evaluating children with non-syndromic GDD/ID. In this review, we discuss different genetic testing currently available, review common underlying copy-number variants and molecular pathways, explore the recent evidence and recommendations for genetic evaluation and discuss an approach to the diagnosis and management of children with non-syndromic GDD and ID.
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Grineski SE, Renteria R, Collins TW, Mangadu A, Alexander C, Bilder D, Bakian A. Associations between estimates of perinatal industrial pollution exposures and intellectual disability in Utah children. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 836:155630. [PMID: 35508240 PMCID: PMC10077518 DOI: 10.1016/j.scitotenv.2022.155630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
While heavy metals exposure is associated with intellectual disability (ID), little is known about associations between industrial pollution and ID. The objective of this analysis is to assess associations between estimated perinatal industrial pollution exposures from the US Environmental Protection Agency's Risk Screening Environmental Indicators Microdata and children's ID risk. We conducted a case-control study of children born in Utah from 2000 to 2008 (n = 1679). Cases were identified through the Center for Disease Control's Autism and Developmental Disabilities Monitoring Network's Utah site and matched with controls based on birth year, sex, and birth county. We used multivariable generalized estimating equations to examine associations between estimated perinatal industrial pollution exposures and ID risk. The fourth quartile of industrial pollution exposure was associated with increased odds of ID relative to the first (Odds Ratio [OR]: 1.73, 95% Confidence Interval [CI]: 1.23-2.44) and second (OR: 1.67, CI: 1.19-2.35) quartiles. Similarly, the third quartile was associated with increased odds of ID relative to the first (OR: 1.47, CI: 1.06-2.03) and second (OR: 1.41, CI: 1.02-1.96) quartiles. Findings were robust to varied model specifications. Maternal residential exposures to industrial pollution were associated with increased ID prevalence in Utah. Since environmental correlates of ID are understudied, additional research is needed.
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Affiliation(s)
- Sara E Grineski
- University of Utah, Department of Sociology, 380 S. 1530 E., Rm. 301, Salt Lake City, UT 84112, USA.
| | - Roger Renteria
- University of Utah, Department of Sociology, 380 S. 1530 E., Rm. 301, Salt Lake City, UT 84112, USA
| | - Timothy W Collins
- University of Utah, Department of Geography, 260 Central Campus Dr., Rm. 4728, Salt Lake City, UT 84112, USA
| | - Aparna Mangadu
- University of Texas at El Paso, BUILDing SCHOLARS Program, Chemistry & Computer Science Building, Room g0706, 500 W University, El Paso, TX 79968, USA
| | - Camden Alexander
- University of Utah, Department of Sociology, 380 S. 1530 E., Rm. 301, Salt Lake City, UT 84112, USA
| | - Deborah Bilder
- University of Utah School of Medicine, Department of Psychiatry, 30 N. 1900 E., Salt Lake City, UT 84132, USA
| | - Amanda Bakian
- University of Utah School of Medicine, Department of Psychiatry, 30 N. 1900 E., Salt Lake City, UT 84132, USA
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Leonard H, Montgomery A, Wolff B, Strumpher E, Masi A, Woolfenden S, Williams K, Eapen V, Finlay-Jones A, Whitehouse A, Symons M, Licari M, Varcin K, Alvares G, Evans K, Downs J, Glasson E. A systematic review of the biological, social, and environmental determinants of intellectual disability in children and adolescents. Front Psychiatry 2022; 13:926681. [PMID: 36090348 PMCID: PMC9453821 DOI: 10.3389/fpsyt.2022.926681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/27/2022] [Indexed: 11/24/2022] Open
Abstract
AIM This systematic review aimed to identify the most important social, environmental, biological, and/or genetic risk factors for intellectual disability (ID). METHODS Eligible were published prospective or retrospective comparative studies investigating risk factors for ID in children 4-18 years. Exclusions were single group studies with no comparator without ID and a sample size <100. Electronic databases (Medline, Cochrane Library, EMBASE, PsycInfo, Campbell Collaboration, and CINAHL) were searched for eligible publications from 1980 to 2020. Joanna Briggs Institute critical appraisal instruments, appropriate for study type, were used to assess study quality and risk of bias. Descriptive characteristics and individual study results were presented followed by the synthesis for individual risk factors, also assessed using GRADE. RESULTS Fifty-eight individual eligible studies were grouped into six exposure topics: sociodemographic; antenatal and perinatal; maternal physical health; maternal mental health; environmental; genetic or biological studies. There were few eligible genetic studies. For half the topics, the certainty of evidence (GRADE) was moderate or high. CONCLUSION Multiple studies have examined individual potential determinants of ID, but few have investigated holistically to identify those populations most at risk. Our review would indicate that there are vulnerable groups where risk factors we identified, such as low socioeconomic status, minority ethnicity, teenage motherhood, maternal mental illness, and alcohol abuse, may cluster, highlighting a target for preventive strategies. At-risk populations need to be identified and monitored so that interventions can be implemented when appropriate, at preconception, during pregnancy, or after birth. This could reduce the likelihood of ID and provide optimal opportunities for vulnerable infants. SYSTEMATIC REVIEW REGISTRATION [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=120032], identifier [CRD42019120032].
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Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Alicia Montgomery
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Brittany Wolff
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Elissa Strumpher
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Anne Masi
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Susan Woolfenden
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Katrina Williams
- Department of Paediatrics, Monash University, Clayton, VIC, Australia
| | - Valsamma Eapen
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Amy Finlay-Jones
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Andrew Whitehouse
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Martyn Symons
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Melissa Licari
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Kandice Varcin
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Gail Alvares
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Kiah Evans
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Jenny Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
| | - Emma Glasson
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia
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Liu X, Taylor MP, Aelion CM, Dong C. Novel Application of Machine Learning Algorithms and Model-Agnostic Methods to Identify Factors Influencing Childhood Blood Lead Levels. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:13387-13399. [PMID: 34546733 DOI: 10.1021/acs.est.1c01097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Blood lead (Pb) poisoning remains a global concern, particularly for children in their early developmental years. Broken Hill is Australia's oldest operating silver-zinc-lead mine. In this study, we utilized recent advances in machine learning to assess multiple algorithms and identify the most optimal model for predicting childhood blood Pb levels (BLL) using Broken Hill children's (<5 years of age) data (n = 23,749) from 1991 to 2015, combined with demographic, socio-economic, and environmental influencing factors. We applied model-agnostic methods to interpret the most optimal model, investigating different environmental and human factors influencing childhood BLL. Algorithm assessment showed that stacked ensemble, a method for automatically and optimally combining multiple prediction algorithms, enhanced predictive performance by 1.1% with respect to mean absolute error (p < 0.01) and 2.6% for root-mean-squared error (p < 0.01) compared to the best performing constituent algorithm (random forest). By interpreting the model, the following information was acquired: children had higher BLL if they resided within 1.0 km to the central mine area or 1.37 km to the railroad; year of testing had the greatest interactive strength with all other factors; BLL increased faster in Aboriginal than in non-Aboriginal children at 9-10 and 12-18 months of age. This "stacked ensemble + model-agnostic interpretation" framework achieved both prediction accuracy and model interpretability, identifying previously unconnected variables associated with elevated childhood BLL, offering a marked advantage over previous works. Thus, this approach has a clear value and potential for application to other environmental health issues.
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Affiliation(s)
- Xiaochi Liu
- School of Information Engineering, China University of Geosciences, Beijing 100083, China
- Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney 2109, New South Wales, Australia
| | - Mark P Taylor
- Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney 2109, New South Wales, Australia
| | - C Marjorie Aelion
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts, Amherst 01003, Massachusetts, United States
| | - Chenyin Dong
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
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McDermott S, Hailer MK, Lead JR. Meconium identifies high levels of metals in newborns from a mining community in the U.S. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:135528. [PMID: 31780146 DOI: 10.1016/j.scitotenv.2019.135528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND This pilot study was conducted to determine if we could identify intrauterine exposure to metals in meconium, as a measure of exposure for mother-child pairs living in proximity to a mining operation. OBJECTIVES We used meconium as a means to measure metal exposure in utero. We set out to quantify the exposure to selected metals that are currently being mined and also are found in the Superfund site in Butte, Montana, and to compare it to that of Columbia, South Carolina, US, where mining is not occurring. METHODS This cross-sectional study was conducted between May and November 2018. We received Institutional Review Board approval and we consented women following the birth of their newborns, and collected meconium within 24 h of birth, without any identifiers. Each laboratory used the same protocol for collection, transport, and storage; and the same laboratory protocol was used for the analysis of all samples. Samples were digested using standard acid/peroxide digestion methods and measured by inductively coupled plasma mass spectroscopy. RESULTS We collected meconium specimens from 17 infants in Columbia, South Carolina and 15 infants in Butte, Montana. The concentrations found in Columbia were in the low μg kg-1 range (or less) and were similar to the low levels that have been identified in other studies of meconium. The magnitude of the differences in concentrations found in Butte compared to Columbia was 1792 times higher for Cu, 1650 times higher for Mn, and 1883 times higher for Zn. CONCLUSION Using meconium to measure exposure of newborns has implications for risk assessment in a mining-exposed population. This approach was inexpensive and thorough. The magnitude of the differences in the metal levels identified from the two study sites suggests there is an urgent need for further research to learn if there are health consequences to these highly exposed infants.
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Affiliation(s)
- Suzanne McDermott
- Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, United States of America.
| | - M Katie Hailer
- Department of Chemistry, Montana Tech, Butte, United States of America
| | - Jamie R Lead
- Center for Environmental Nanoscience and Risk, Department of Environmental Health Science, University of South Carolina Columbia, United States of America
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雨洋 张, 宁睿 刘, 瀛 龙, Yuyang Z, Ningrui L, Ying L. [Research on Healthy Neighborhood Evaluation System Based on the Combined Perspectives of Urban Planning and Public Health]. FENG JING YUAN LIN = LANDSCAPE ARCHITECTURE 2020; 27:96-103. [PMID: 38420146 PMCID: PMC7615674 DOI: 10.14085/j.fjyl.2020.11.0096.08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Neighborhoods are places where people spend the most time in their lives. Neighborhoods have a decisive impact on the residents' health. With several important tasks, including the transformation of old neighborhoods, the maintenance of existing neighborhoods, and the construction of new neighborhoods in the future, a scientific and reasonable evaluation standard is urgently needed to guide the development of healthy neighborhoods. To build the evaluation system, this paper first clarifies the principles for selecting evaluation indicators, which include: 1) the indicators are selected from a humanistic perspective; 2) the pathways between neighborhoods environment and health outcomes are deeply considered; 3) the indicators are selected from multiple scales. Secondly, based on the combined perspectives of urban planning and public health, it identifies the indicators that affect the residents' health in neighborhoods and searches the literature through the quality assessment to provide evidence to support the accuracy and effectiveness of the indicators. Finally, it proposes prospect to the evaluation, including 1) it is urgent to improve and utilize the healthy neighborhoods based on the Chinese condition; 2) advanced technologies need to be widely applied in neighborhoods in the future; 3) the transitions in cities should be considered in the future development of neighborhoods. It hopes that relevant researchers and government leaders to realize the importance and urgency of healthy neighborhoods to build more healthy neighborhoods in China.
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Affiliation(s)
- 张 雨洋
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
| | - 刘 宁睿
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
| | - 龙 瀛
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
| | - Zhang Yuyang
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
| | - Liu Ningrui
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
| | - Long Ying
- / / /
- ZHANG Yuyang is a postdoctoral researcher in the School of Architecture, Tsinghua University. His research focuses on healthy city and healthy neighborhood
- / / / 、
- LIU Ningrui is a Ph.D. candidate in the Department of Building Science, School of Architecture, Tsinghua University. His research focuses on indoor air quality, healthy building and healthy city
- / / / / (Corresponding author Email):
- LONG Ying, Ph.D., is a research fellow in the School of Architecture, Tsinghua University. His research focuses on urban and rural planning technical science
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Aelion CM, Davis HT. Blood lead levels in children in urban and rural areas: Using multilevel modeling to investigate impacts of gender, race, poverty, and the environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 694:133783. [PMID: 31756823 DOI: 10.1016/j.scitotenv.2019.133783] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/02/2019] [Accepted: 08/04/2019] [Indexed: 05/27/2023]
Abstract
Many studies of children's exposure to lead (Pb) are carried out in urban and industrialized environments. This study analyzed blood lead level (BLL) data collected from 2011 to 2016 from approximately 140,000 children ages <1 to 6 years across South Carolina (SC), including urban and rural areas. Individual-level characteristics included children's age, and race/ethnicity. Block group variables examined included population by race and ethnicity, households below the poverty level, median year homes built, urban/rural classification, and percent road coverage. BLL were higher in urban compared to rural children but increased to a greater extent in rural children from age < 1 year to 2 years. Road coverage was strongly associated with higher BLL in urban areas, and with home age more weakly, but neither road coverage nor home age was associated with BLL in rural areas. Young urban children may receive greater exposure to Pb from house dust and outdoor legacy Pb contamination, and young rural children through diet and drinking water. Black children had higher BLL in urban areas than white children, and the converse was true in rural areas. Population data indicated that rural areas had more poverty than urban areas, but strong associations between increased children's BLL and either ethnicity or socio-economic status (SES) at the block group level was not observed, likely due to distinct characteristics of poverty and geographic distribution by ethnicity in urban as compared to rural areas of SC. Individual demographics and environmental characteristics may be more closely associated with BLL than geographically aggregated SES and race/ethnicity characteristics. Interventions to reduce children's exposure to Pb should occur at as early an age as possible, and differences between rural and urban areas should be considered as interventions are developed to reduce children's BLL.
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Affiliation(s)
- C M Aelion
- University of Massachusetts Amherst, School of Public Health and Health Sciences, Department of Environmental Health Sciences, Amherst, MA, USA
| | - H T Davis
- South Carolina Department of Health and Environmental Control, Bureau of Health Improvement and Equity, Columbia, SC, USA.
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Johnston JE, Franklin M, Roh H, Austin C, Arora M. Lead and Arsenic in Shed Deciduous Teeth of Children Living Near a Lead-Acid Battery Smelter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6000-6006. [PMID: 31056909 PMCID: PMC6996839 DOI: 10.1021/acs.est.9b00429] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Lead (Pb) is a potent neurotoxicant with no safe level of exposure. Elevated levels of Pb and arsenic (As) are found in the air and soil near facilities that recycle lead-acid batteries in the United States. In urban Los Angeles County, California, a facility processed ∼11 million batteries per year and operated for decades without proper environmental review. Measuring Pb and As in shed deciduous teeth is a promising technique to assess prenatal and early life exposure. In this pilot study coined the "Truth Fairy" Project, 50 shed deciduous teeth from 43 children living their entire lives within 2 miles of the smelter were analyzed to understand retrospective exposure to toxic metals using a community-driven research approach. Concentrations of Pb and As in teeth were assessed using laser-ablation-inductively coupled plasma-mass spectrometry. Soil Pb concentrations were determined using spatial kriging of surface soil measurements. The mean prenatal calcium normalized Pb levels in teeth samples (reported as a ratio 208Pb:43Ca) was 4.104 × 10-4 (SD 4.123 × 10-4), and the mean postnatal 208Pb:43Ca level was 4.109 × 10-4 (SD 3.369 × 10-4). Adjusted for maternal education and batch, we observe positive significant relationship between prenatal teeth Pb per 100 ppm increase in soil Pb (β = 3.48, 95% CI 1.11, 5.86). The Truth Fairy study suggests prenatal and early life exposure to toxic metals is associated with legacy soil contamination in an urban community near a smelter.
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Affiliation(s)
- Jill E Johnston
- Department of Preventive Medicine , University of Southern California , Los Angeles California 90032 , United States
| | - Meredith Franklin
- Department of Preventive Medicine , University of Southern California , Los Angeles California 90032 , United States
| | - Hannah Roh
- Department of Preventive Medicine , University of Southern California , Los Angeles California 90032 , United States
| | - Christine Austin
- Department of Environmental Medicine and Public Health , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Manish Arora
- Department of Environmental Medicine and Public Health , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
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Hiller E, Filová L, Jurkovič Ľ, Lachká L, Kulikova T, Šimurková M. Arsenic in Playground Soils from Kindergartens and Green Recreational Areas of Bratislava City (Slovakia): Occurrence and Gastric Bioaccessibility. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 75:402-414. [PMID: 29770841 DOI: 10.1007/s00244-018-0534-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 05/07/2018] [Indexed: 06/08/2023]
Abstract
In this study, playground soils of kindergartens and green recreational zones in Bratislava were investigated for the occurrence and gastric bioaccessibility of arsenic (As) in the < 150 μm soil size fraction. Eighty topsoil (0-10 cm) samples were collected from playgrounds in kindergartens and green recreational zones throughout the urban area. Bioaccessibility measurements of As were performed using the Simple Bioaccessibility Extraction Test that mimics the human gastric environment, and resulting extracts were analyzed by hydride generation-atomic absorption spectrometry to assess bioaccessible As concentrations in the collected playground soils. Single selective chemical extractions using hydroxylamine hydrochloride-hydrochloric acid and dithionite-citrate-bicarbonate solutions also were used to determine the amount of As associated with amorphous and amorphous/crystalline Fe oxy-hydroxides in soils, respectively. The results showed that the spatial distribution of total As concentrations was related to the historical development of the city, with higher soil concentrations of As found in the old city centre and related urban zones and the lower ones on the outskirts of Bratislava. There was a variation in the values of bioaccessible concentrations and fractions of As, with ranges from 0.40 to 5.60 mg/kg and 7.29 to 56.1%, respectively. Correlation and multivariable linear regression analyses revealed that bioaccessible concentrations of As were linearly related to its total concentrations in the soils, whereas dithionite-citrate-bicarbonate extractable Fe (FeDCB) was the main soil property, controlling the bioaccessibility of As. When the amount of FeDCB in the soils increased, As bioaccessibility decreased, confirming an importance of Fe bound to amorphous and crystalline iron oxy-hydroxides to the limitation of As bioaccessibility in urban playground soils of Bratislava. Additionally, single selective extractions showed that As concentrations extracted by hydroxylamine hydrochloride (AsHH) and dithionite-citrate-bicarbonate (AsDCB) were positively correlated with its bioaccessible concentrations (Spearman r = 0.75 and 0.62, respectively; p < 0.001).
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Affiliation(s)
- Edgar Hiller
- Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovak Republic.
| | - Lenka Filová
- Department of Applied Mathematics and Statistics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina, 842 48, Bratislava, Slovak Republic
| | - Ľubomír Jurkovič
- Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Lucia Lachká
- Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Tatsiana Kulikova
- Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
| | - Mária Šimurková
- Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15, Bratislava, Slovak Republic
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11
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The road less traveled: from genotype to phenotype in flies and humans. Mamm Genome 2017; 29:5-23. [DOI: 10.1007/s00335-017-9722-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/05/2017] [Indexed: 12/20/2022]
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12
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Zhou S, Luoma SE, St. Armour GE, Thakkar E, Mackay TFC, Anholt RRH. A Drosophila model for toxicogenomics: Genetic variation in susceptibility to heavy metal exposure. PLoS Genet 2017; 13:e1006907. [PMID: 28732062 PMCID: PMC5544243 DOI: 10.1371/journal.pgen.1006907] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 08/04/2017] [Accepted: 07/06/2017] [Indexed: 12/20/2022] Open
Abstract
The genetic factors that give rise to variation in susceptibility to environmental toxins remain largely unexplored. Studies on genetic variation in susceptibility to environmental toxins are challenging in human populations, due to the variety of clinical symptoms and difficulty in determining which symptoms causally result from toxic exposure; uncontrolled environments, often with exposure to multiple toxicants; and difficulty in relating phenotypic effect size to toxic dose, especially when symptoms become manifest with a substantial time lag. Drosophila melanogaster is a powerful model that enables genome-wide studies for the identification of allelic variants that contribute to variation in susceptibility to environmental toxins, since the genetic background, environmental rearing conditions and toxic exposure can be precisely controlled. Here, we used extreme QTL mapping in an outbred population derived from the D. melanogaster Genetic Reference Panel to identify alleles associated with resistance to lead and/or cadmium, two ubiquitous environmental toxins that present serious health risks. We identified single nucleotide polymorphisms (SNPs) associated with variation in resistance to both heavy metals as well as SNPs associated with resistance specific to each of them. The effects of these SNPs were largely sex-specific. We applied mutational and RNAi analyses to 33 candidate genes and functionally validated 28 of them. We constructed networks of candidate genes as blueprints for orthologous networks of human genes. The latter not only provided functional contexts for known human targets of heavy metal toxicity, but also implicated novel candidate susceptibility genes. These studies validate Drosophila as a translational toxicogenomics gene discovery system. Although physiological effects of environmental toxins are well documented, we know little about the genetic factors that determine individual variation in susceptibility to toxins. Such information is difficult to obtain in human populations due to heterogeneity in genetic background and environmental exposure, and the diversity of symptoms and time lag with which they appear after toxic exposure. Here, we show that the fruit fly, Drosophila, can serve as a powerful genetic model system to elucidate the genetic underpinnings that contribute to individual variation in resistance to toxicity, using lead and cadmium exposure as an experimental paradigm. We identified genes that harbor genetic variants that contribute to individual variation in resistance to heavy metal exposure. Furthermore, we constructed genetic networks on which we could superimpose human counterparts of Drosophila genes. We were able to place human genes previously implicated in heavy metal toxicity in biological context and identify novel targets for heavy metal toxicity. Thus, we demonstrate that based on evolutionary conservation of fundamental biological processes, we can use Drosophila as a powerful translational model for toxicogenomics studies.
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Affiliation(s)
- Shanshan Zhou
- Program in Genetics, W. M. Keck Center for Behavioral Biology, and Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Sarah E. Luoma
- Program in Genetics, W. M. Keck Center for Behavioral Biology, and Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Genevieve E. St. Armour
- Program in Genetics, W. M. Keck Center for Behavioral Biology, and Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Esha Thakkar
- Enloe Magnet High School, Raleigh, North Carolina, United States of America
| | - Trudy F. C. Mackay
- Program in Genetics, W. M. Keck Center for Behavioral Biology, and Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Robert R. H. Anholt
- Program in Genetics, W. M. Keck Center for Behavioral Biology, and Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
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13
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Li T, Zhang S, Tan Z, Dai Y. Trend of childhood blood lead levels in cities of China in recent 10 years. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:5824-5830. [PMID: 28054269 DOI: 10.1007/s11356-016-8335-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 12/25/2016] [Indexed: 06/06/2023]
Abstract
The adverse effects of lead on human especially childhood have been well established. Largely due to the phase out of lead in gasoline, blood lead levels (BLLs) had declined substantially all over the world including China. In 2004, 2007, 2010, and 2013, we conducted a continuous project including 47,346 children aged 0-6 years old from 11 cities all over China to show how the decline happened and to explore what to do next to improve the BLLs of children of China. Our data shown the BLLs of Chinese children decreased from 46.38, 43.58, 38.95 to 37.17 μg/L, but the decline was not enough. These decline was mainly because of the number decrease of children with high BLLs. Integrated strategy should be used to promote the BLLs of Chinese children, like striving to improve the environment, setting new cutoff for high BLLs, and establishing routine blood lead screening.
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Affiliation(s)
- Tao Li
- Capital Institute of Pediatrics, Beijing, 100020, China
| | | | - Zangwen Tan
- Capital Institute of Pediatrics, Beijing, 100020, China
| | - Yaohua Dai
- Capital Institute of Pediatrics, Beijing, 100020, China.
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14
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Beamer PI, Klimecki WT, Loh M, Van Horne YO, Sugeng AJ, Lothrop N, Billheimer D, Guerra S, Lantz RC, Canales RA, Martinez FD. Association of Children's Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:E521. [PMID: 27223295 PMCID: PMC4881146 DOI: 10.3390/ijerph13050521] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/06/2016] [Accepted: 05/16/2016] [Indexed: 02/08/2023]
Abstract
Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = -0.43, p = 0.001, R² = 0.08), water (b = -0.22, p = 0.07, R² = 0.03), house dust (b = -0.37, p = 0.07, R² = 0.04), and dust loading (b = -0.21, p = 0.04, R² = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = -0.42, p = 0.02, R² = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities.
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Affiliation(s)
- Paloma I Beamer
- Asthma and Airways Disease Research Center, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
- Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721, USA.
| | - Walter T Klimecki
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, P.O. Box 210207, Tucson, AZ 85724, USA.
| | - Miranda Loh
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
- Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK.
| | - Yoshira Ornelas Van Horne
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
| | - Anastasia J Sugeng
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
| | - Nathan Lothrop
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
| | - Dean Billheimer
- Asthma and Airways Disease Research Center, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
| | - Stefano Guerra
- Asthma and Airways Disease Research Center, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.
| | - Robert Clark Lantz
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
- Department of Cellular and Molecular Medicine, University of Arizona, P.O. Box 245044, Tucson, AZ 85724, USA.
| | - Robert A Canales
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85724, USA.
| | - Fernando D Martinez
- Asthma and Airways Disease Research Center, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA.
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15
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Davis HT, Aelion CM, Liu J, Burch JB, Cai B, Lawson AB, McDermott S. Potential sources and racial disparities in the residential distribution of soil arsenic and lead among pregnant women. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:622-30. [PMID: 26897405 PMCID: PMC4808624 DOI: 10.1016/j.scitotenv.2016.02.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 05/20/2023]
Abstract
Exposure to arsenic (As) or lead (Pb) has been associated with adverse health outcomes, and high-risk populations can be disproportionately exposed to these metals in soils. The objectives of this study were: to examine if predicted soil As and Pb concentrations at maternal residences of South Carolina (SC) low-income mothers differed based on maternal race (non-Hispanic black versus white), to examine whether differences in predicted residential soil As and Pb concentrations among black and white mothers differed by socioeconomic status (SES), and to examine whether such disparities persisted after controlling for anthropogenic sources of these metals, including direction from, and distance to industrial facilities. Kriged soil As and Pb concentrations were estimated at maternal residences in 11 locations in SC, and models with maternal race and individual and US Census block group level SES measures were examined. US Environmental Protection Agency Toxics Release Inventory (TRI) facility As and Pb releases categorized by distance and direction to block groups in which mothers resided were also identified, as were proxy measures for historic use of leaded gasoline (road density) and Pb-based paint (categories of median year home built by US Census block group). Consistent racial disparities were observed for predicted residential soil As and Pb concentrations, and the disparity was stronger for Pb than As (betas from adjusted models for black mothers were 0.12 and 2.2 for As and Pb, respectively, all p<0.006). Higher road density and older homes in block groups were more closely associated with higher predicted soil As and Pb concentrations than on-site releases of As and Pb categorized by facility location. These findings suggest that non-Hispanic black mothers in this study population had elevated residential As and Pb soil concentrations, after adjusting for SES, and that soil As and Pb concentrations were not associated with recent industrial releases.
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Affiliation(s)
- Harley T Davis
- Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Columbia, SC 29208, USA
| | - C Marjorie Aelion
- School of Public Health and Health Sciences, University of Massachusetts Amherst, 715 No. Pleasant Street, Amherst, MA 01003, USA.
| | - Jihong Liu
- Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Columbia, SC 29208, USA
| | - James B Burch
- Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Columbia, SC 29208, USA
| | - Bo Cai
- Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Columbia, SC 29208, USA
| | - Andrew B Lawson
- Department of Public Health Sciences, Medical University of South Carolina, 135 Cannon Street Suite 303, Charleston, SC 29401, USA
| | - Suzanne McDermott
- Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Columbia, SC 29208, USA
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16
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Hong J, Wang Y, McDermott S, Cai B, Aelion CM, Lead J. The use of a physiologically-based extraction test to assess relationships between bioaccessible metals in urban soil and neurodevelopmental conditions in children. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 212:9-17. [PMID: 26840511 DOI: 10.1016/j.envpol.2016.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/22/2015] [Accepted: 01/01/2016] [Indexed: 05/25/2023]
Abstract
Intellectual disability (ID) and cerebral palsy (CP) are serious neurodevelopment conditions and low birth weight (LBW) is correlated with both ID and CP. The actual causes and mechanisms for each of these child outcomes are not well understood. In this study, the relationship between bioaccessible metal concentrations in urban soil and these child conditions were investigated. A physiologically based extraction test (PBET) mimicking gastric and intestinal processes was applied to measure the bio-accessibility of four metals (cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb)) in urban soil, and a Bayesian Kriging method was used to estimate metal concentrations in geocoded maternal residential sites. The results showed that bioaccessible metal concentrations of Cd, Ni, and Pb in the intestinal phase were statistically significantly associated with the child outcomes. Lead and nickel were associated with ID, lead and cadmium was associated with LBW, and cadmium was associated with CP. The total concentrations and stomach concentrations were not correlated to significant effects in any of the analyses. For lead, an estimated threshold value was found that was statistically significant in predicting low birth weight. The change point test was statistically significant (p value = 0.045) at an intestine threshold level of 9.2 mg/kg (95% confidence interval 8.9-9.4, p value = 0.0016), which corresponds to 130.6 mg/kg of total Pb concentration in the soil. This is a narrow confidence interval for an important relationship.
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Affiliation(s)
- Jie Hong
- Center for Environmental NanoScience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA
| | - Yinding Wang
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA
| | - Suzanne McDermott
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
| | - Bo Cai
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA
| | - C Marjorie Aelion
- Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Jamie Lead
- Center for Environmental NanoScience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
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17
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Discontinuity in the genetic and environmental causes of the intellectual disability spectrum. Proc Natl Acad Sci U S A 2015; 113:1098-103. [PMID: 26711998 PMCID: PMC4743770 DOI: 10.1073/pnas.1508093112] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Intellectual disability (ID) is present in almost 3% of children and fundamentally characterized by IQ scores below 70. Genetic research has shown that it is among the most heritable traits, and it has been accepted that ID is the extreme low of the normal IQ distribution. However, we show that, while the genetic and environmental factors influencing mild ID (lowest 3% of IQ distribution) are similar to those influencing IQ in the normal range, factors influencing severe ID (lowest 0.5%) differ from those influencing mild ID or IQ scores in the normal range. Therefore, severe ID is a distinct disorder, qualitatively different from the majority of ID, which in turn represents the low extreme of the normal distribution of intelligence. Intellectual disability (ID) occurs in almost 3% of newborns. Despite substantial research, a fundamental question about its origin and links to intelligence (IQ) still remains. ID has been shown to be inherited and has been accepted as the extreme low of the normal IQ distribution. However, ID displays a complex pattern of inheritance. Previously, noninherited rare mutations were shown to contribute to severe ID risk in individual families, but in the majority of cases causes remain unknown. Common variants associated with ID risk in the population have not been systematically established. Here we evaluate the hypothesis, originally proposed almost 1 century ago, that most ID is caused by the same genetic and environmental influences responsible for the normal distribution of IQ, but that severe ID is not. We studied more than 1,000,000 sibling pairs and 9,000 twin pairs assessed for IQ and for the presence of ID. We evaluated whether genetic and environmental influences at the extremes of the distribution are different from those operating in the normal range. Here we show that factors influencing mild ID (lowest 3% of IQ distribution) were similar to those influencing IQ in the normal range. In contrast, the factors influencing severe ID (lowest 0.5% of IQ distribution) differ from those influencing mild ID or IQ scores in the normal range. Taken together, our results suggest that most severe ID is a distinct condition, qualitatively different from the preponderance of ID, which, in turn, represents the low extreme of the normal distribution of intelligence.
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18
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Laird BD, Weiseth B, Packull-McCormick SR, Peak D, Dodd M, Siciliano SD. Solid-liquid separation method governs the in vitro bioaccessibility of metals in contaminated soil-like test materials. CHEMOSPHERE 2015; 134:544-549. [PMID: 25600322 DOI: 10.1016/j.chemosphere.2014.12.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 11/25/2014] [Accepted: 12/04/2014] [Indexed: 06/04/2023]
Abstract
An in vitro gastrointestinal model was used to explore the role of solid-liquid separation method on the bioaccessibility of trace elements in a smelter-impacted soil (NIST-2711) from Helena, MT and a mine overburden from an open-pit gold and silver mine in Mount Nansen, YK (YK-OVB). Separation methods studied included centrifugation (5,000 g, 12,000 g), syringe microfiltration (0.45 μm), and ultrafiltration (1,000 kDa, 50 kDa, 30 kDa, 10 kDa, 3 kDa). Results indicated that the use of syringe microfiltration generally yields the same bioaccessibility as the use of centrifugation and that the speed of centrifugation does not typically affect metal bioaccessibility. However, ultrafiltration consistently yields a significantly lower bioaccessibility than the use of centrifugation and syringe microfiltration. There are rarely any differences between bioaccessibility estimates generated using a low-resistance (1,000 kDa) and a high-resistance (3 kDa) ultrafiltration membrane; therefore, under the in vitro gastrointestinal conditions modeled herein, negligible quantities of trace elements are complexed to small molecules between 3 and 1,000 kDa. The primary exceptions to these trends were observed for Pb in NIST-2711 (5,000 g>12,000 g>0.45 μm>ultrafiltration) and for Tl in NIST-2711 and YK-OVB (5000 g∼12,000 g>0.45 μm>ultrafiltration). These results provide valuable information to researchers attempting to expand the use of in vitro bioaccessibility beyond soil Pb and As.
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Affiliation(s)
- Brian D Laird
- School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada.
| | - Blake Weiseth
- Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | | | - Derek Peak
- Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Matt Dodd
- Royal Roads University, Victoria, British Columbia, Canada
| | - Steven D Siciliano
- Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Lewis J, Gonzales M, Burnette C, Benally M, Seanez P, Shuey C, Nez H, Nez C, Nez S. Environmental exposures to metals in Native communities and implications for child development: basis for the Navajo birth cohort study. ACTA ACUST UNITED AC 2015; 14:245-69. [PMID: 26151586 DOI: 10.1080/1536710x.2015.1068261] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Two disparate statistics often cited for the Western United States raise concern about risks for developmental disabilities in Native American children. First, 13 of the states with the highest percentage of Native American population are located in the Western United States (U.S. Census Bureau, 2012 ). Second, more than 161,000 abandoned hard-rock mines are located in 12 Western states (General Accounting Office, 2014 ). Moreover, numerous studies have linked low-level metals exposure with birth defects and developmental delays. Concern has emerged among tribal populations that metals exposure from abandoned mines might threaten development of future generations.
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Affiliation(s)
- Johnnye Lewis
- a University of New Mexico Health Sciences Center , Albuquerque , New Mexico , USA
| | - Melissa Gonzales
- a University of New Mexico Health Sciences Center , Albuquerque , New Mexico , USA
| | - Courtney Burnette
- a University of New Mexico Health Sciences Center , Albuquerque , New Mexico , USA
| | - Malcolm Benally
- a University of New Mexico Health Sciences Center , Albuquerque , New Mexico , USA
| | - Paula Seanez
- b Growing in Beauty, Window Rock Agency , Navajo Nation Office of Special Education and Rehabilitation Services , Window Rock , Arizona , USA
| | - Christopher Shuey
- c Uranium Impact Assessment Program , Southwest Research and Information Center , Albuquerque , New Mexico , USA
| | - Helen Nez
- d Tachee Uranium Concerns Committee , Blue Gap , Arizona , USA
| | - Christopher Nez
- d Tachee Uranium Concerns Committee , Blue Gap , Arizona , USA
| | - Seraphina Nez
- d Tachee Uranium Concerns Committee , Blue Gap , Arizona , USA
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