Geography of animal feeding operations and their contribution to fine particulate matter pollution in vulnerable communities in the United States

Abstract Animal Feeding Operations or AFOs, such as beef feedlots, dairy farms, and hog farms, are associated with elevated levels of harmful fine particulate matter (e.g., PM 2.5 ). The geographic distribution of AFOs in the United States is not well-documented, hindering efforts to identify affected communities and assess health impacts from this pollution. This study introduces the most comprehensive spatial database of these operations available for the United States, composed of 8763 cattle operations and 6963 hog farms, and clarifies their influence on particulate matter concentrations. Results reveal a high geographic concentration, with just thirty counties containing roughly 25% of all identified feeding operations. PM 2.5 levels are significantly higher in census tracts with these operations than in those without: 28% higher in tracts with cattle operations and 11% higher in tracts with hog farms. Pollution burdens disproportionately affect socially vulnerable, minority populations with limited health insurance coverage, underscoring the need for targeted interventions.