Benefits of ZEV adoption reduced in disadvantaged communities – US Study finds

New research in California has found that while the increasing adoption of zero emission vehicles is obviously beneficial to air quality, those benefits are not being shared equally. 

The team looked at ZEV adoption in California between 2015 and 2020, and projected it to 2035, when they expect all new passenger vehicles sold to be ZEVs.

They then applied an integrated traffic model together with a dispersion model to simulate air quality changes near roads in the Greater Los Angeles.

Per capita ZEV ownership in non-disadvantaged communities (non-DACs) as defined by the state of California was found to be 3.8 times of that in disadvantaged communities* (DACs).

Despite these ownership disparities however, the research found that because ZEVs travel across different communities, even those with low ZEV ownership levels receive air quality benefits from ZEV trips.

In terms of the amount of NOx and PM2.5 taken out of the air, disadvantaged communities were found to receive more air quality benefits than non-DACs in 2020, and even more by 2035.

The researchers explain: ‘Unlike previous research that focused on regional air quality benefits from ZEVs using a top-down approach—based on vehicle registration locations—our study employs a bottom-up methodology centered on ZEV trip routes. Consequently, we discovered that near-roadway air quality benefits can be distributed irrespective of DAC designation.’

However, while disadvantaged communities experience greater reductions in pollutant concentration in terms of µg/m³ or ppb, their relative reductions – when considering the higher starting point – are much smaller compared to those of non-DACs. In fact they receive 40% and 31% fewer relative air quality benefits for NOx and PM2.5, respectively.

As the proportion of ZEVs on the road increases, this disparity narrows to the point where, in the 2035 scenario, DACs only receive 21% and 15% fewer relative air quality benefits for NOx and PM2.5, respectively. At this point however, to further reduce disparities, the researchers believe focus must switch to medium and heavy-duty trucks which are more prevalent in the disadvantaged communities, emphasizing the need for targeted ZEV policies that address persistent pollution burdens among DAC and racial and ethnic minority residents.

* Disadvantaged communities are defined using a tool developed by the California Environmental Protection Agency to identify communities disproportionately affected by pollution while considering health, socioeconomic, and population characteristic data.