Background: Maternal residency in Central Appalachia counties with coal production has been previously associated with increased rates of low birth weight (LBW). To refine the relationship between surface mining and birth outcomes, this study employs finer spatiotemporal estimates of exposure. Methods: We developed characterizations of annual surface mining boundaries in Central Appalachia between 1986 and 2015 using Landsat data. Maternal address on birth records was geocoded and assigned amount of surface mining within a 5 km radius of residence (street-level). Births were also assigned the amount of surface mining within residential ZIP code tabulation area (ZCTA). Associations between exposure to active mining during gestation year and birth weight, LBW, preterm birth (PTB), and term low birth weight (tLBW) were determined, adjusting for outcome rates before active mining and available covariates. Results: The percent of land actively mined within a 5 km buffer of residence (or ZCTA) was negatively associated with birth weight (5 km: β = –14.07 g; 95% confidence interval [CI] = –19.35, –8.79, P = 1.79 × 10–7; ZCTA: β = –9.93 g; 95% CI = –12.54, –7.33, P = 7.94 × 10–14). We also found positive associations between PTB and active mining within 5 km (odds ratio [OR] = 1.06; 95% CI = 1.03, 1.09, P = 1.43 × 10–4) and within ZCTA (OR = 1.04; 95% CI = 1.03, 1.06, P = 9.21 × 10–8). Positive relationships were also found between amount of active mining within 5 km or ZIP code of residence and LBW and tLBW outcomes. Conclusions: Maternal residency near active surface mining during gestation may increase risk of PTB and LBW.

A considerable body of research exists outlining ecological impacts of surface coal mining, but less work has explicitly focused on human health, and few studies have examined potential links between health and surface coal mining at fine spatial scales. In particular, relationships between individual birth outcomes and exposure to air contaminants from coal mining activities has received little attention. Central Appalachia (portions of Virginia, West Virginia, Kentucky, and Tennessee, USA), our study area, has a history of resource extraction, and epidemiologic research notes that the region experiences a greater level of adverse health outcomes compared to the rest of the country that are not fully explained by socioeconomic and behavioral factors. The purpose of this study is to examine associations between surface mining and birth outcomes at four spatial scales: individual, Census tract, county, and across county‐sized grid cells. Notably, this study is among the first to examine these associations at the individual scale, providing a more direct measure of exposure and outcome. Airsheds were constructed for surface mines using an atmospheric trajectory model. We then implemented linear (birthweight) and logistic (preterm birth [PTB]) regression models to examine associations between airsheds and birth outcomes, which were geocoded to home address for individual analyses and then aggregated for areal unit analyses, while controlling for a number of demographic variables. This study found that surface mining airsheds are significantly associated with PTB and decreased birthweight at all four spatial scales, suggesting that surface coal mining activities impact birth outcomes via airborne contaminants.

R21ES028396). Data use agreements with state health agencies prohibit authors from sharing birth record data used in the analysis. Satellite-derived datasets are publicly available, or available on request. Code required to replicate results are available upon request.

Background Previous work has determined an association between proximity to active surface mining in coal producing counties within Central Appalachia and an increased risk of preterm birth (PTB) and low birthweight (LBW); however, the relative importance of specific exposure pathways explaining this association remains poorly understood. Multiple potential exposure pathways to surface mining activities exist during gestation, including inhalation of particulate matter (airshed exposure), or via exposure to impacted surface waters (watershed exposure). Here, we perform a mediation analysis to explore these pathways and the odds of adverse birth outcomes. Methods We obtained birth records acquired through health departments in WV, KY, VA and TN between 1990 and 2015. Surface mine extents for each year were identified through remotely sensed Landsat imagery. Corresponding airsheds were estimated using the HYSPLIT4 atmospheric trajectory model, while watersheds were assigned using United States Geological Survey’s Watershed Boundary Dataset boundaries. We performed logistic regression to determine associations between exposure and the odds of preterm birth, low birthweight, and term low birthweight, and iteratively included within our models: a) the percent of active surface mining landcover within a 5 km buffer of maternal residence; b) the cumulative potential exposure to air pollutants via the airshed experienced at the maternal residence, and; c) the percent of land experiencing surface mining within the watershed of residency. Results Our baseline models found that active surface mining was associated with an increased odds of PTB (1.09, 1.05 – 1.13) and LBW (1.06, 1.02 – 1.11), while controlling for significant predictors. When mediators were added to the base model, the association between active mining and birth outcomes was reduced (PTB: 1.04, 0.99 – 1.09; LBW 1.04, 0.99 – 1.10), while the odds of PTB and LBW increased with airshed exposure (PTB: 1.14, 1.11 – 1.18; LBW: 1.06, 1.03 – 1.10). Conclusions Results were consistent with a hypothesis of mediation via airshed, but suggested mediation via watershed was less likely. These results suggest that air pollution resulting from surface mining activities may be the primary exposure pathway explaining the association between maternal residence proximity to active surface mining and PTB and LBW.

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