Inequitable Exposure to Air Pollution from Vehicles in California (2019)

Published Jan 28, 2019


Latinos, African-Americans, Asian-Americans and low-income communities are exposed to substantially more air pollution from cars, trucks and buses than other demographic groups in California. For many years, this has been a known fact among affected communities, whom have experienced first hand the dangerous impacts of air pollution, like lung and heart ailments, asthma, and premature death.

We quantified the exposure of these groups to particulate matter (PM2.5)  from on-road sources and compared it to other demographic segments. Beyond the scope of this analysis, emissions from ports, agricultural practices, dust, and other sources are well known to contribute to poor air quality and negative health outcomes for affected areas. 

What is PM2.5 pollution?

Fine particles — less than one-tenth the diameter of a human hair — pose a serious threat to human health, as they can penetrate deep into the lungs. Some PM2.5 is formed during the burning of gasoline and diesel in an engine, while additional PM2.5 is created in the atmosphere from the reaction of exhaust gases and other air pollutants. Diesel exhaust is a major contributor to PM pollution. 

Key findings 

  • On average, African American Californians are exposed to PM2.5 pollution that is 43 percent higher than that for white Californians.
  • Latino Californians are exposed to PM2.5 pollution 39 percent higher, on average, than that for white Californians.
  • The lowest-income households in the state live where PM2.5 pollution is 10 percent higher than the state average.
  • The highest income households live where PM2.5 pollution is 13 percent below the state average.
  • Californians living in households without a personal vehicle are also exposed to much higher levels of vehicle pollution than other households because they tend to live in urban areas surrounded by vehicle traffic.

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