Ofodile Jennifer, Pfannerstill Eva Y, Arata Caleb, Pusede Sally E, Ivey Cesunica E, Goldstein Allen H
Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California 94720, United States.
Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22904, United States.
Environ Sci Technol. 2025 Apr 22;59(15):7588-7599. doi: 10.1021/acs.est.5c00808. Epub 2025 Apr 12.
In Los Angeles, air pollution disproportionately impacts communities of color and low-income residents. Routine city-wide measurements of hazardous air pollutants (HAPs), of concern for health and contributing to urban air pollution, are notably lacking. In this study, we use the highest spatially resolved (∼2 km) measurements of emissions and concentrations ever reported of HAPs while covering a whole megacity and combine observations with US Census information. We observe higher concentrations and emissions of 17 measured HAPs, such as benzene, naphthalene, and -chlorobenzotrifluoride (PCBTF), in California-designated Disadvantaged Communities (DACs) and census tracts with low-income Hispanics and Asians. These groups share an unequal burden from traffic-related emissions, with benzene, nitrogen oxides (NO), and carbon monoxide (CO) concentrations up to 60% higher. However, in DACs and census tracts with large Hispanic populations (>50%), we observe toluene-to-benzene emission ratios above 3, pointing to inequalities in other HAPs primarily caused by non-traffic emission sources such as industry and solvents. In these communities, regulatory inventories also significantly underestimate emissions. We find that efforts to address HAP inequalities and environmental justice concerns in Los Angeles will need to consider contributions from volatile chemical products, which represent a growing source of emissions driving inequalities in impacted communities.
在洛杉矶，空气污染对有色人种社区和低收入居民的影响尤为严重。目前明显缺乏针对危害空气污染物（HAPs）的全市常规测量数据，而这些污染物关乎健康且是城市空气污染的成因之一。在本研究中，我们使用了有史以来报道过的最高空间分辨率（约2公里）的HAPs排放和浓度测量数据，覆盖了整个特大城市，并将观测数据与美国人口普查信息相结合。我们发现，在加利福尼亚州指定的弱势社区（DACs）以及有低收入西班牙裔和亚裔居民的普查区，17种被测HAPs（如苯、萘和对氯三氟甲苯（PCBTF））的浓度和排放量更高。这些群体承受着与交通相关排放带来的不平等负担，苯、氮氧化物（NO）和一氧化碳（CO）的浓度高出多达60%。然而，在西班牙裔人口众多（>50%）的DACs和普查区，我们观察到甲苯与苯的排放比高于3，这表明其他HAPs存在不平等现象，主要是由工业和溶剂等非交通排放源造成的。在这些社区，监管清单也严重低估了排放量。我们发现，要解决洛杉矶HAPs不平等问题和环境正义问题，需要考虑挥发性化学产品的影响，这些产品是导致受影响社区不平等现象加剧的日益增长的排放源。
