Proximity to point sources of environmental mercury release as a predictor of autism prevalence

University of Texas Health Science Center, San Antonio Department of Family and Community Medicine, 7703 Floyd Curl Drive, San Antonio Texas, Mail Code 7794, TX 78229-3900, USA.
Health & Place (Impact Factor: 2.81). 02/2008; 15(1):18-24. DOI: 10.1016/j.healthplace.2008.02.001
Source: PubMed


The objective of this study was to determine if proximity to sources of mercury pollution in 1998 were related to autism prevalence in 2002. Autism count data from the Texas Educational Agency and environmental mercury release data from the Environmental Protection Agency were used. We found that for every 1000 pounds of industrial release, there was a corresponding 2.6% increase in autism rates (p<.05) and a 3.7% increase associated with power plant emissions(P<.05). Distances to these sources were independent predictors after adjustment for relevant covariates. For every 10 miles from industrial or power plant sources, there was an associated decreased autism Incident Risk of 2.0% and 1.4%, respectively (p<.05). While design limitations preclude interpretation of individual risk, further investigations of environmental risks to child development issues are warranted.

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Available from: Raymond F Palmer
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    • "In addition, environmental factors, including constituents of air pollution, have been found to be related to an increased risk of autism[6,7]. These include: PM 2.5 , ozone, NO 2 , pesticides, heavy metals, solvents, and diesel exhaust78910111213141516. Although there are differences in the time periods of the investigations, geographical regions under study and the exposure assessments, a growing number of studies suggest a potential role of ASD and air pollution. "
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    ABSTRACT: Background: Autism spectrum disorders (ASD) constitute a major public health problem affecting one in 68 children. There is little understanding of the causes of ASD despite its serious social impact. Air pollution contains many toxicants known to have adverse effects on the fetus. We conducted a population based case-control study in southwestern Pennsylvania to estimate the association between ASD and 2005 US EPA modeled NATA (National Air Toxics Assessment) levels for 30 neurotoxicants. Methods: A total of 217 ASD cases born between 2005 and 2009 were recruited from local ASD diagnostic and treatment centers. There were two different control groups: 1) interviewed controls (N = 224) frequency matched by child's year of birth, sex and race with complete residential histories from prior to pregnancy through the child's second birthday, and 2) 5,007 controls generated from a random sample of birth certificates (BC controls) using residence at birth. We used logistic regression analysis comparing higher to first quartile of exposure to estimate odds ratios (ORs) and 95 % confidence intervals (CI), adjusting for mother's age, education, race, smoking status, child's year of birth and sex. Results: Comparing fourth to first quartile exposures for all births, the adjusted OR for styrene was 2.04 (95 % CI = 1.17-3.58, p = 0.013) for the interviewed case-control analysis and 1.61 (95 % CI = 1.08-2.40, p = 0.018) for the BC analysis. In the BC comparison, chromium also exhibited an elevated OR of 1.60 (95 % CI = 1.08-2.38, p = 0.020), which was similarly elevated in the interviewed analysis (OR = 1.52, 95 % CI = 0.87-2.66). There were borderline significant ORs for the BC comparison for methylene chloride (OR = 1.41, 95 % CI = 0.96-2.07, p = 0.082) and PAHs (OR = 1.44, 95 % CI = 0.98-2.11, p = 0.064). Conclusions: Living in areas with higher levels of styrene and chromium during pregnancy was associated with increased risk of ASD, with borderline effects for PAHs and methylene chloride. These results are consistent with other studies. It is unclear, however, whether these chemicals are risk factors themselves or if they reflect the effect of a mixture of pollutants. Future work should include improved spatiotemporal estimates of exposure to air toxics, taking into account the dynamic movement of individuals during daily life.
    Full-text · Article · Oct 2015 · Environmental Health
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    • "The second factor that could be implicated in the case of clustering is an environmental mechanism that led to more cases in exposed areas. Importantly, there are no coal-fired power plants in Costa Rica, which are significant emitters of mercury and have been linked to spatial patterns of ASD diagnosis (Palmer et al., 2009). In terms of previously identified environmental factors, the most plausible mechanism for an environmental agent in Costa Rica is air pollution (e.g., Becerra et al., 2013), and because of the mountains that surround the densely populated Central Valley, the highest levels of air pollution are spatially concentrated near the HNN (Barrientos, 2010). "
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    ABSTRACT: In the U.S., children with autism spectrum disorder (ASD) have been found to live in spatial clusters. Studies have suggested that the clustering is caused by social or environmental factors, but determining the cause of the clustering is difficult in the U.S. setting because of unmeasured variation in healthcare access and diagnostic practices. The present study explores the diffusion of ASD in a small setting in which the diagnosis is not widely publicised and there is no variation in healthcare access or diagnostic practices. Costa Rica provides universal healthcare and only has one diagnosing clinic for young children, and the diagnosis is relatively new and little known among clinicians and parents. In addition, the potential for mercury exposure from the source that has been associated with ASD is absent, and areas with high levels of air pollution are spatially concentrated. Focusing on all young children who underwent an ASD assessment from 2010 to 2013, we identify spatial clusters that suggest a mechanism that does not depend on information about ASD, healthcare access, diagnostic practices, or environmental toxicants. These findings provide details of the "contextual drivers" of the increasing worldwide prevalence of ASD. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Aug 2015 · Health & Place
    • "Several of these studies have demonstrated associations between ASD and prenatal or perinatal air concentrations of various air pollutants, including particulate matter (Becerra et al., 2013; Kalkbrenner et al., 2010, 2014; Roberts et al., 2013; Talbott et al., 2015; Windham et al., 2006). Additionally, proximity to sources of airborne pollutants, including industrial facilities (Palmer et al., 2009), agricultural pesticides (Shelton et al., 2014), and high-traffic roadways (Volk et al., 2011), have been associated with ASD diagnosis and school-reported administrative prevalence , respectively. Based on results from these studies, observed relationships should be further investigated on a larger scale using highly reliable data. "
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    ABSTRACT: Prenatal and perinatal exposures to air pollutants have been shown to adversely affect birth outcomes in offspring and may contribute to prevalence of autism spectrum disorder (ASD). For this ecologic study, we evaluated the association between ASD prevalence, at the census tract level, and proximity of tract centroids to the closest industrial facilities releasing arsenic, lead or mercury during the 1990s. We used 2000 to 2008 surveillance data from five sites of the Autism and Developmental Disabilities Monitoring (ADDM) network and 2000 census data to estimate prevalence. Multi-level negative binomial regression models were used to test associations between ASD prevalence and proximity to industrial facilities in existence from 1991 to 1999 according to the US Environmental Protection Agency Toxics Release Inventory (USEPA-TRI). Data for 2489 census tracts showed that after adjustment for demographic and socio-economic area-based characteristics, ASD prevalence was higher in census tracts located in the closest 10th percentile compared of distance to those in the furthest 50th percentile (adjusted RR=1.27, 95% CI: (1.00, 1.61), P=0.049). The findings observed in this study are suggestive of the association between urban residential proximity to industrial facilities emitting air pollutants and higher ASD prevalence. Copyright © 2015 Elsevier B.V. All rights reserved.
    No preview · Article · Jul 2015 · Science of The Total Environment
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