Exposure to animal feeding operations including concentrated animal feeding operations (CAFOs) and environmental justice in Iowa, USA

Health consequences of intensive livestock industry and implications for environmental justice are of great concern in Iowa, USA, which has an extensive history of animal feeding operations (AFOs). We examined disparities in exposure to AFOs including concentrated AFOs (CAFOs) with several environmental justice metrics and considered exposure intensity based on animal units (AUs). Using data on permitted AFOs from the Iowa Department of Natural Resources, we evaluated environmental disparities by multiple environmental justice metrics (e.g. race/ethnicity, socio-economic status (SES), income inequality (Gini index), racial isolation, and educational isolation) using 2010 Census tract-level variables. We used an exposure metric incorporating the density and intensity as the sum of AUs within each Census tract. We investigated exposure disparities by comparing distributions of environmental justice metrics based on operation type (e.g. confinement, open feedlot, large CAFOs), animal type, and Census tract-level AFOs exposure intensity categories (i.e. from low exposure (quartile 1) to high exposure (quartile 4)). AFOs in Iowa were located in areas with lower percentages of racial/ethnic minority persons and high SES communities. For example, the percent of the population that is non-Hispanic Black was over 9 times higher in Census tracts without AFOs than tracts with AFOs (5.14% vs. 0.55%). However, when we considered AFO exposure intensity within the areas having AFO exposure, areas with higher AFO exposure had higher percentages of racial/ethnic minority persons (e.g. Hispanic) and low SES communities (e.g. higher educational isolation) compared to areas with lower AFO exposure. Findings by AFO type (e.g. large CAFO, medium CAFO) showed similar patterns of the distribution of environmental justice metrics as the findings for AFOs overall. We identified complex disparities with higher exposure to non-disadvantaged subpopulations when considering areas with versus without AFOs, but higher exposure to disadvantaged communities within areas with AFOs.