A UVA study utilizes satellite data to reveal that air pollution from industrial pig farms in Eastern North Carolina has a disproportionate effect on marginalized communities.
A pioneering research project conducted by scientists from the University of Virginia has employed satellite observations to demonstrate the enduring air pollution disparities associated with industrial hog farming in Eastern North Carolina. The study, using satellite data collected over 15 years from 2008 to 2023, evaluates the disparities in ammonia (NH₃)—a pollutant released by pig farming—impacting Black, Hispanic, and Indigenous populations. The study highlights that these discrepancies, worsened by hot and calm weather, extend several kilometers beyond the immediate surroundings of the farms, emphasizing the broad reach of this environmental challenge.
The findings, published in the American Chemical Society journal Environmental Science & Technology by Sally Pusede and her team from UVA’s Department of Environmental Sciences, utilized data from the Infrared Atmospheric Sounding Interferometer (IASI) on various polar-orbiting satellites. By scrutinizing NH₃ levels in the atmosphere, UVA researchers were able to uncover significant environmental inequalities caused by emissions from industrial pig operations.
One notable conclusion from the study is that air pollution disparities can be detected from space. The satellite data indicated that NH₃ levels were considerably elevated in regions with large populations of Black, Hispanic, and Indigenous individuals. During the years 2016-2021, NH₃ concentrations were, on average, 27% higher in Black communities, 35% higher in Hispanic communities, and 49% higher in Indigenous communities compared to non-Hispanic white populations.
The research also found that calm and hot weather conditions exacerbate these inequalities. Low wind speeds hinder the dispersion of pollutants from pig farms, while elevated temperatures lead to increased NH₃ emissions due to evaporation both at and downwind of these facilities. On calm days, the NH₃ disparities for Indigenous communities were more than double those on windy days, with hot weather further heightening NH₃ exposures for Black and Hispanic populations.
Increased NH₃ levels were detected several kilometers downwind of pig feeding operations during calm and hot weather, confirming that the environmental effects of these operations extend well beyond their immediate vicinity. This contradicts the notion that only those living near the facilities are negatively impacted.
Analysis of NH₃ satellite data over 15 years, from 2008 to 2023, shows that these disparities have remained consistent over time, highlighting the persistent nature of the issue.
The study draws attention to how industrial agriculture contributes to environmental racism, with communities of color disproportionately affected by air pollution associated with pig farms. These findings emerge amidst ongoing discussions regarding air quality regulations and the absence of federal standards for NH₃, which is not currently included in the Environmental Protection Agency’s National Ambient Air Quality Standards.
“The satellite ammonia measurements provide independent, observational proof of the inequalities stemming from the air pollution impacts of industrial pig farming across Eastern North Carolina,” Pusede stated. “The satellite data aligns with residents’ reports of inadequate and unresolved air quality issues and underscores the pressing need for regulatory action.”
