Data Gap: Air Quality Networks Miss Air Pollution from Concentrated Animal Feeding Operations

• Published in: Environmental science & technology Vol. 57; no. 49; pp. 20718 - 20725
• Main Authors: Burns, Alyssa M., Chandler, Gabriel, Dunham, Kira J., Carlton, Annmarie G.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 12.12.2023
• Subjects: Agricultural industry; Agricultural runoff; Agricultural wastes; Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Air quality; Ammonia; Ammonia - analysis; Animal wastes; Animals; Atmospheric Infrared Sounder; Atmospheric sounding; Controllability; Density; Environmental impact; Environmental Monitoring - methods; Factory farming; Intensive farming; Livestock; Mixing ratio; Occurrence, Fate, and Transport of Contaminants in Indoor Air and Atmosphere; Outdoor air quality; Particulate matter; Particulate Matter - analysis; Pollutants; Pollution control; Quality control; Trends; Urban populations; United States > US; agriculture; ammonia; livestock waste; air quality
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.3c06947

In the U.S., the agricultural sector is the largest controllable source of several air pollutants, including ammonia (NH3), which is a key precursor to PM2.5 formation. Livestock waste is the dominant contributor to ammonia emissions. In contrast to most controllable air pollutants, satellite records show ammonia mixing ratios are rising. The number of confined animal feeding operations (CAFOs) that generate considerable livestock waste is also increasing. Spatial and temporal trends in USDA-reported animal numbers normalized by county area at medium and large CAFOs provide plausible explanations for patterns in satellite-derived NH3 over the contiguous U.S. (CONUS). The correlation between summertime ammonia derived from the European Space Agency’s (ESA) Infrared Atmospheric Sounding Interferometer (IASI) and CAFO animal unit density in 2017 is positive and significant (r = 0.642; p ≈ 0). The temporal changes from 2002 to 2017 in animal unit density and NH3 derived from NASA’s Atmospheric Infrared Sounder (AIRS) are spatially similar. Trends and ambient concentrations of PM2.5 mass in agricultural regions are difficult to assess relative to those of urban population centers given the sparseness of rural monitors in regulatory surface networks. Results suggest that in agricultural areas where ammonia concentrations and animal density are highest, air quality improvement lags behind the national average.