Air toxics and the risk of autism spectrum disorder: the results of a population based case-control study in southwestern Pennsylvania.

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.

Assessment and longitudinal analysis of health impacts and stressors perceived to result from unconventional shale gas development in the Marcellus Shale region.

INTRODUCTION: Concerns for health and social impacts have arisen as a result of Marcellus Shale unconventional natural gas development. Our goal was to document the self-reported health impacts and mental and physical health stressors perceived to result from Marcellus Shale development. METHODS: Two sets of interviews were conducted with a convenience sample of community members living proximal to Marcellus Shale development, session 1 March-September 2010 (n = 33) and session 2 January-April 2012 (n = 20). Symptoms of health impacts and sources of psychological stress were coded. Symptom and stressor counts were quantified for each interview. The counts for each participant were compared longitudinally. RESULTS: Participants attributed 59 unique health impacts and 13 stressors to Marcellus Shale development. Stress was the most frequently-reported symptom. Over time, perceived health impacts increased (P = 0·042), while stressors remained constant (P = 0·855). DISCUSSION: Exposure-based epidemiological studies are needed to address identified health impacts and those that may develop as unconventional natural gas extraction continues. Many of the stressors can be addressed immediately.

The association of respiratory hospitalization rates in WV counties, total, underground, and surface coal production and sociodemographic covariates.

BACKGROUND: Exposures associated with coal mining have long been linked to occupational disease. More recently, investigators have suggested that this industry may affect community health. METHODS: We explored associations between age-adjusted, county-level respiratory disease hospitalization rates (RHRs) in West Virginia and total, surface, and underground coal production, taking into account relevant sociodemographic and behavioral covariates. RHRs were calculated for 2005 to 2009, and analyses were performed to assess the effect of coal production after adjusting for sociodemographic factors. RESULTS: After controlling for percent below poverty, percent urban, and smoking, neither total nor underground tonnage was associated with RHR. Surface coal production, however, was significantly related with RHR (P < 0.05). CONCLUSIONS: Surface coal production makes a small but significant contribution to RHR in West Virginia after accounting for other important sociodemographic and behavioral determinants of health.