Monitoring hazardous air pollutants in a heavy industry fenceline community: coupled mobile-lab and fixed-site VOC and source-apportioned PM measurements during HAPMAP 2021

The Chester-Trainer-Marcus Hook industrial corridor southwest of Philadelphia, PA along the Delaware River has a high density of both industry facilities and residential populations. The area is home to oil refining and petrochemical processing, solid waste incineration, large-scale power generation, and a variety of other industrial operations, and has a legacy of air pollution problems, raising concerns from local residents and community organizations. The Hazardous Air Pollutant Monitoring and Assessment Project (HAP-MAP) was established to identify the presence of HAPs around these facilities and their associated risk in adjacent communities. We report volatile organic compound (VOC) and source-apportioned particulate matter (PM) concentrations from simultaneous mobile-lab and stationary site measurements over the span of three weeks in September 2021. The mobile lab performed on-road sampling, while the stationary site was situated in an adjacent community and served to monitor the urban background pollution levels. We combine these datasets to account for temporal variability and produce pollutant maps with fine spatial resolution, which show meaningful variability in pollutant concentrations. As examples, spatially-resolved benzene concentrations ranged from 0.16 - 2.99 ppb and formaldehyde ranged from 1.06 - 4.11 ppb. We also perform a programmatic analysis of mobile-lab VOC plume data to identify a variety of plume classes and typical VOC groupings, and map the location of those plume types. We found parts of our study domain to have higher HAPs concentrations than were measured at a nearby regulatory monitoring site. The concentrations we measured were also higher than spatially-resolved EPA AirTox concentration estimates for the area. This study highlights the value of spatio-temporal data to assess possible exposures for those living near industrial sites. The measurements presented here form the basis of a multi-pollutant cumulative risk assessment that is another part of HAP-MAP, which highlights how the fields of analytical atmospheric chemistry and public health can come together to advance the understanding of how pollution affects communities in high-impact areas.