Mitigating Impacts of Non-Exhaust Motor Vehicle Pollutant Emissions
Research Idea Scope
Objective: Develop methods to characterize and mitigate harmful effects of non-exhaust (tire wear, brake wear, re-entrained road dust) motor vehicle pollutant emissions to water quality, air pollution, and environmental and human health.
Background: As electric vehicles (EVs) expand in the US and worldwide fleet, decreasing fossil fuel combustion exhaust emissions, the impacts of non-exhaust pollutant (NEP) emissions will continue and could increase. Research indicates that the increased weight of EVs may alter brake wear emissions and increase emissions from tire wear. Heavier vehicles may also increase the amount of road surface materials that are re-entrained into the atmosphere. Studies have also shown that many components of tires, brakes, and re-entrained road dust are toxic to humans (e.g. heavy metals, PAHs). More recently, research has shown these emissions, notably from tire wear, can also impact aquatic life (e.g. 6PPD/6PPD-quinone, microplastics).
Recent research has shown the compound 6PPD used in tires as an anti-degradation chemical can be highly toxic to certain fish species including coho salmon when emitted and present in water as 6PPD-quinone. The impact of 6PPD tire wear emissions has been especially damaging to tribes in the US Northwest where coho salmon are a critical resource. In addition, research suggests that human exposures to 6PPD compounds can be high, especially for pregnant women, which has raised concerns about human health impacts. As a result, the states of Washington and California are enacting legislation to regulate 6PPD tire wear emissions.
Urgency and Payoff
To protect human and aquatic health, strategies will be needed to mitigate the adverse impacts of these NEP motor vehicle emissions. Designing effective mitigation best management practices (BMPs) requires techniques that address and control NEP in the air, on soil and impervious surfaces adjacent and away from the road, and in surface water runoff. This research will also need to evaluate emission rates of NEP emissions, the fate and transport of these emissions after release, and the integration and effectiveness of multi-media BMPs. Example BMPs to evaluate include implementation of green infrastructure for air and water mitigation, street and other impervious surface cleaning, and control of emissions from the vehicle directly through alternative materials or vehicle treatment devices.
Health Committee: Characterize adverse health impacts from exposures to NEP and design BMPs that promote healthy communities and environments. This research could also include improvements to health impact and cumulative impact assessments
Air Quality/GHG Committee: Characterize emission rates and air quality impacts as well as design effective BMPs for air quality. This research could include improvements to MOVES, AERMOD, and other air quality assessments
Land Use Committee: Development of BMPs that address multi-media impacts and create healthier communities
Roadside Maintenance Committee: Develop BMPs for NEP impacts that also adhere to and integrate maintenance BMPs
Stormwater Committee: Characterize emissions and fate/transport of NEP in stormwater runoff