Development of over 30-years of high spatiotemporal resolution air pollution models and surfaces for California

• Published in: Environment international 2024-11, Vol.193, p.109100, Article 109100
• Main Authors: Su, Jason G., Shahriary, Eahsan, Sage, Emma, Jacobsen, John, Park, Katherine, Mohegh, Arash
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air pollution; Air Pollution - statistics & numerical data; California; Deletion/substitution/addition; Environmental Monitoring; Fine particulate matter; Land use regression; Models, Theoretical; Nitrogen dioxide; Nitrogen Dioxide - analysis; Ozone; Ozone - analysis; Particulate Matter - analysis; Remote sensing; Spatio-Temporal Analysis
• ISSN: 0160-4120; 1873-6750; 1873-6750
• DOI: 10.1016/j.envint.2024.109100

•Integrated traffic, land use, weather, vegetation, and satellite data for predictions.•High-resolution daily LUR models for NO2, PM2.5, and O3 in California (1989–2021).•Extended air pollution predictions back to 1989 for historical exposure insights.•Identification of pollution hotspots informs targeted regulatory actions.•Models support long-term public health protection and environmental justice. California’s diverse geography and meteorological conditions necessitate models capturing fine-grained patterns of air pollution distribution. This study presents the development of high-resolution (100 m) daily land use regression (LUR) models spanning 1989–2021 for nitrogen dioxide (NO2), fine particulate matter (PM2.5), and ozone (O3) across California. These machine learning LUR algorithms integrated comprehensive data sources, including traffic, land use, land cover, meteorological conditions, vegetation dynamics, and satellite data. The modeling process incorporated historical air quality observations utilizing continuous regulatory, fixed site saturation, and Google Streetcar mobile monitoring data. The model performance (adjusted R2) for NO2, PM2.5, and O3 was 84 %, 65 %, and 92 %, respectively. Over the years, NO2 concentrations showed a consistent decline, attributed to regulatory efforts and reduced human activities on weekends. Traffic density and weather conditions significantly influenced NO2 levels. PM2.5 concentrations also decreased over time, influenced by aerosol optical depth (AOD), traffic density, weather, and land use patterns, such as developed open spaces and vegetation. Industrial activities and residential areas contributed to higher PM2.5 concentrations. O3 concentrations exhibited no significant annual trend, with higher levels observed on weekends and lower levels associated with traffic density due to the scavenger effect. Weather conditions and land use, such as commercial areas and water bodies, influenced O3 concentrations. To extend the prediction of daily NO2, PM2.5, and O3 to 1989, models were developed for predictors such as daily road traffic, normalized difference vegetation index (NDVI), Ozone Monitoring Instrument (OMI)–NO2, monthly AOD, and OMI-O3. These models enabled effective estimation for any period with known daily weather conditions. Longitudinal analysis revealed a consistent NO2 decline, regulatory-driven PM2.5 decreases countered by wildfire impacts, and spatially variable O3 concentrations with no long-term