Unveiling the Invisible Threat: Aerosols and Air Quality in the US
Air pollution is a silent killer, and understanding its sources is crucial for public health. The SARP West 2025 Aerosols Group, guided by esteemed faculty and graduate mentors, delves into the intricate world of aerosols and their impact on our atmosphere.
Comparing Agricultural Regions
Air quality has improved since the Clean Air Act, but pollution persists. Fertilizers and pesticides release pollutants, impacting nearby residents. By studying aerosols, we can trace agricultural sources. We compared California's Central Valley, with its diverse farms, to the Delmarva Peninsula's chicken hatcheries and vegetable farms. Using the Aerosol Mass Spectrometer (AMS), we analyzed ammonium, chloride, nitrates, organics, and sulfates. Our findings? These regions differ significantly in aerosol composition and concentration. Delmarva's pollution is regional, with higher but uniform levels. Central Valley's pollution is localized, with higher peaks near communities.
Urban Aerosol Sources
Aerosols affect urban air quality, too. In Los Angeles, various sources contribute to below-average air quality. We examined NASA's flight data from missed approaches, revealing local aerosol compositions. Using mass spectrometry, we measured organics, sulfates, nitrates, ammonium, and chlorides. At busy airports, nitrates dominate, while industrial areas like Long Beach have higher sulfates. Identifying these sources is key to targeted pollution mitigation.
Uncovering Hidden Emissions
And this is where it gets intriguing... In California's Imperial Valley, asthma rates are high, yet particulate matter readings are low. We suspect unmeasured emissions from cattle feedlots. The valley's CAFO and slaughterhouse produce methane, PM, nitrous oxide, and ammonia, forming complex aerosols with health impacts. We combined NASA, EPA, IPCC, and wastewater data to quantify emissions. Our analysis revealed significant correlations between emissions and health indicators. Large-scale cattle operations have measurable environmental impacts, even with federal air quality compliance.
Dust Storms and Drying Lakes
California's Owens Dry Lake is the largest dust source in the US, with toxic dust storms. The Salton Sea, also in California, is drying, mirroring Owens Lake's fate. Research by Edwards et al. (2024) predicted increased dust emissions. Our NASA flight data analysis over a decade supports this. We used spectrometers to measure aerosol size and quantity, finding a rise in dust particles over 500 nm. This poses health risks to nearby residents, and if the lake dries, massive toxic storms may form.
Atmospheric Layers and Wildfires
The planetary boundary layer (PBL) is the lower atmosphere, crucial for climate and air quality. This project explores seasonal PBL differences in Los Angeles. Aircraft measurements of trace gases and aerosols reveal deeper summer boundary layers due to solar intensity, while winter layers are shallower and more stable. Ozone and ammonium show vertical gradients, affecting layer dynamics. Ozone increases above PBL, and aerosol counts vary with altitude. These insights enhance air quality modeling and our understanding of local meteorology.
Smoke Plumes and Fire Signatures
California's wildfires demand attention. We studied the 2025 Juniper and Eaton fires. NASA's P-3B aircraft intercepted the Juniper Fire plume, allowing us to analyze biomass burning aerosols. By comparing aircraft and ground measurements, we determined that aerosols and trace gases can identify fire signatures. Absorption measurements revealed mixed black and brown carbon, typical of biomass burning. Elevated CO ratios confirmed inefficient fires. This multi-platform approach improves smoke composition characterization, benefiting atmospheric modeling and public health assessments.
But here's where it gets controversial: Are we doing enough to address these complex air quality issues? The research highlights the need for comprehensive strategies to tackle pollution from various sources. What are your thoughts on balancing agricultural productivity, industrial growth, and environmental health? Share your insights in the comments below!
