title: Identification of Effects of Regulatory Actions on Air Quality in Goods Movement Corridors in California.
abstract: Few studies have assessed the impact of regulatory actions on air quality improvement through a comprehensive monitoring effort. In this study, we designed saturation sampling of nitrogen oxides (NOX) for the counties of Los Angeles and Alameda (San Francisco Bay) before (2003-2007) and after (2008-2013) implementation of goods movement actions in California. We further separated the research regions into three location categories, including goods movement corridors (GMCs), nongoods movement corridors (NGMCs), and control areas (CTRLs). Linear mixed models were developed to identify whether reductions in NOX were greater in GMCs than in other areas, after controlling for potential confounding, including weather conditions (e.g., wind speed and temperature) and season of sampling. We also considered factors that might confound the relationship, including traffic and cargo volumes that may have changed due to economic downturn impacts. Compared to the pre-policy period, we found reductions of average pollutant concentrations for nitrogen dioxide (NO2) and NOX in GMCs of 6.4 and 21.7 ppb. The reductions were smaller in NGMCs (5.9 and 16.3 ppb, respectively) and in CTRLs (4.6 and 12.1 ppb, respectively). After controlling for potential confounding from weather conditions, season of sampling, and the economic downturn in 2008, the linear mixed models demonstrated that reductions in NO2 and NOX were significantly greater in GMCs compared to reductions observed in CTRLs; there were no statistically significant differences between NGMCs and CTRLs. These results indicate that policies regulating goods movement are achieving the desired outcome of improving air quality for the state, particularly in goods movement corridors where most disadvantaged communities live.
authors.affiliation: 50 University Hall, Environmental Health Sciences, School of Public Health, University of California-Berkeley , Berkeley, California 94720-7360, United States.
authors.forename: Jason G
authors.initials: JG
authors.lastname: Su
authors.affiliation: Center for Health Policy Research, University of California-Los Angeles , Los Angeles, California 90095-7143, United States.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Meng
authors.affiliation: Center for Health Policy Research, University of California-Los Angeles , Los Angeles, California 90095-7143, United States.
authors.forename: Melissa
authors.initials: M
authors.lastname: Pickett
authors.affiliation: Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington , Seattle, Washington 98195-7234, United States.
authors.forename: Edmund
authors.initials: E
authors.lastname: Seto
authors.affiliation: Fielding School of Public Health, University of California-Los Angeles , Los Angeles, California 90095-1772, United States.
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz
authors.affiliation: 50 University Hall, Environmental Health Sciences, School of Public Health, University of California-Berkeley , Berkeley, California 94720-7360, United States.|Fielding School of Public Health, University of California-Los Angeles , Los Angeles, California 90095-1772, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Jerrett
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D002140:California; D003132:Commerce / Q000331:legislation & jurisprudence*; D004784:Environmental Monitoring; D016014:Linear Models; D009585:Nitrogen Dioxide / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis; D052638:Particulate Matter; D014186:Transportation / Q000331:legislation & jurisprudence*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D009585:Nitrogen Dioxide