PM2.5 exposure disparities persist despite strict vehicle emissions controls in California

Abstract

As policymakers increasingly focus on environmental justice, a key question is whether emissions reductions aimed at addressing air quality or climate change can also ameliorate persistent air pollution exposure disparities. We examine evidence from California’s aggressive vehicle emissions control policy from 2000-2019. We find a 65% reduction in statewide average exposure to PM2.5 from on-road vehicles, yet for people of color and overburdened community residents, relative exposure disparities increased. Light-duty vehicle emissions are the main driver of the exposure and exposure disparity, although smaller contributions from heavy-duty vehicles especially impact some overburdened groups. Our findings suggest that a continued trend of emissions reductions will likely reduce concentrations but may not reduce relative disparities without greater attention to the systemic factors leading to this disparity.

Societal Co-benefits of Zero-Emission Vehicles in the Freight Industry

“…It is expected that EV penetration would be associated with changes in delivery, resulting in potentially higher mileage to accommodate charging. Besides, disparities in exposure cannot be completely resolved by relying only on electrification, ,, initiatives that reduce truck mileage in disadvantaged neighborhoods should be pursued. In this study, the assumptions for the non-exhaust emissions of electric trucks used in the CTM model are subject to substantial uncertainty due to the limited number of studies on the non-exhaust emissions of electric trucks resulting in generalizable emission factors.…”

“…Air pollution has been a driver of environmental justice studies for decades due to the inequitable distribution of air pollutants and consequent health impacts. − Recently, studies have stressed the importance of focusing on the emissions of heavy-duty diesel vehicles as the main contributors to disparities in traffic-related air pollution exposure in urban areas. − The spatial distribution of diesel truck emissions in metropolitan areas can have crucial environmental justice implications as disadvantaged populations often live close to major highways and arterial roads, where most truck movements occur. As one-third of Canadians reside within 250 m of major roads, residents or daily commuters along truck corridors are exposed to high levels of diesel exhaust that stresses the need to identify the disparities in exposure and identify mitigation actions that can reduce this inequality.…”

Distributional impacts of fleet-wide change in light duty transportation: mortality risks of PM2.5 emissions from electric vehicles and Tier 3 conventional vehicles

“…The key contribution of this work is to assess how less polluting conventional vehicles (Tier-3 ICVs) would fare when compared to electric vehicles in terms of air pollution and distributional equity across the nation. While past studies have detailed the increasing stringency of emissions over time [21,55] and their positive impact on air quality [56][57][58], our work incorporates Tier-3 vehicles and provides important regional conclusions.…”