Abstract 14197: Industrial Developmental Toxicant Emissions and Congenital Heart Disease in Urban and Rural Alberta, Canada

Abstract

Background: We have previously demonstrated a downward temporal association between mixtures of organic solvents released into air from industrial sources and congenital heart disease (CHD) in Alberta. Hypothesis: In the current study we hypothesized that the downward temporal associations between developmental toxicants (DTs) and CHD would have a different industrial sector participation in the urban and rural areas of Alberta. Methods: We extracted yearly emissions of DTs (tonnes) from Canada’s National Pollutant Release Inventory as released to air between 2003-2010. We identified at the postal code level, all CHD cases born between 2004-2011 through our provincial-wide echocardiography database. We calculated yearly urban and rural CHD crude rates. Urban and rural were defined according to Forward Sortation Areas. Principal Component Analysis was undertaken to reduce the dimensionality of the number of DTs and the yearly solution was applied to rural and urban areas to test correlations with corresponding yearly CHD rates. Results: Three principal components (PCs) were identified: PC1 consisted of a mixture of organics and gases, PC2 consisted of a mixture of organics only and PC3 consisted of metals. There were strong positive correlations between CHD rates and urban PC1 emissions from mining and manufacturing, (r=0.76, p=0.03; 0.74, p=0.04); whereas in rural areas, PC1 emissions from mining and utilities and PC2 emissions from mining and manufacturing were associated with rates of CHD, (r=0.71, p=0.05; r=0.74, p=0.04 and r=0.86, p=0.01; r=0.74, p=0.04, respectively). PC3 showed no positive correlations (Table 1). Conclusions: CHD rates are consistently strongly correlated with mixtures of organic compounds and gases, with different patterns of chemicals and sectors involved in the urban and rural settings. This provides an opportunity to further investigate spatial correlations between DTs and CHD rates at a higher resolution scale.