A groundbreaking study led by researchers from the University of Virginia has used satellite measurements to show the long-term persistence of air pollution inequalities tied to industrialized swine facilities in Eastern North Carolina. Using satellite data spanning a 15-year period from 2008–2023, the study quantifies disparities in ammonia (NH₃) — an air pollutant emitted by swine operations — for Black, Hispanic and Indigenous communities. These inequalities, exacerbated by hot and calm weather conditions, extend for multiple kilometers beyond the immediate vicinity of the facilities, highlighting the widespread impact of this environmental issue.
The study , published in the American Chemical Society journal Environmental Science & Technology by Sally Pusede and her team in the Department of Environmental Sciences at UVA, uses data from the Infrared Atmospheric Sounding Interferometer (IASI) aboard multiple polar-orbiting satellites. By analyzing NH₃ levels in the atmosphere, UVA researchers were able to show that emissions from industrial swine operations result in systematic environmental inequalities.
Among the study's key findings were that air pollution inequalities can be measured from space. Satellite data analyzed by the research team revealed that NH₃ levels were significantly higher in areas with dense populations of Black, Hispanic and Indigenous residents. Compared to non-Hispanic white populations, NH₃ concentrations were on average 27% higher for Black communities, 35% higher for Hispanic communities and 49% higher for Indigenous communities during the years 2016–2021.
The study also finds that calm and hot weather conditions amplify these disparities, as low wind speeds reduce pollutant dispersion from swine facilities and because higher temperatures increase NH₃ emissions through the evaporation of NH3 at and even downwind of swine facilities. On calm days, NH₃ inequalities for Indigenous communities were more than twice as severe as on windy days, while hot days intensified NH3 exposures for Black and Hispanic populations.
Elevated NH₃ concentrations were also observed several kilometers downwind of swine feeding operations under calm and hot weather conditions, confirming that the environmental impacts of these operations reach far beyond their immediate surroundings. This challenges claims that only those living very near facilities experience adverse effects.
Analysis of NH₃ satellite data over a 15-year period, from 2008 to 2023, shows that disparities in NH3 concentrations have not lessened over time, underscoring the long-term nature of the issue.
The study highlights the role of industrial agriculture in perpetuating environmental racism, with communities of color bearing the brunt of air pollution linked to swine operations. These findings come amid ongoing debates about air quality regulations and the lack of federal standards for NH₃, which is not currently covered by the Environmental Protection Agency's National Ambient Air Quality Standards.
"The satellite ammonia measurements are independent, observational evidence of inequalities in the air pollution impacts of industrial swine operations across Eastern North Carolina," said Pusede. "The satellite measurements are consistent with residents' claims of unfair and unaddressed air quality issues and highlight the urgent need for regulatory action."
