Traffic pollutants are a group of air contaminants that are generated by cars and trucks. Traffic pollutants are harmful to human health. To learn more, scroll down or select from a topic below.
- What are traffic pollutants?
- What are the health effects of traffic pollutants?
- Who is at risk?
- Measures of traffic pollutants
Cars and trucks produce pollutants that can be harmful to your health. These include:
- Diesel Particulate Matter (PM)
- Nitrogen Oxides (NOx)
- Carbon Monoxide (CO)
- Volatile Organic Compounds (VOCs)
- Diesel particulate matter (PM)
- Diesel trucks generate particulate matter (PM10 and PM2.5), which can exacerbate asthma, cause heart disease, and lead to premature death
- Diesel PM can damage DNA and cause cancer
- To learn more, see the California Air Resources Board's factsheet: Health effects of diesel exhaust particulate matter (PDF)
- Nitrogen oxides
- Nitrogen oxides can cause increased sensitivity to allergens.
- When nitrogen oxides combine with VOCs in the presence of sunlight, they form ground-level ozone
- This ozone can cause difficulty breathing, exacerbate asthma, and cause lung inflammation
- Over time, untreated inflammation can result in permanent damage to the lungs
- Carbon Monoxide
- Carbon monoxide can cause chest pain in people with heart problems, headaches, nausea, decreased mental alertness, and death at very high levels
- Volatile organic compounds (VOCs)
- VOCs from vehicles include formaldehyde, acetaldehyde, acrolein, 1,3-butadiene, and benzene-- all of these chemicals can cause cancer
People who live close to busy roads may be at higher risk for exposure to traffic pollutants. People who spend a lot of time inside vehicles are also at risk.
There are many ways to measure traffic pollutant exposure.
- Some researchers measure distance to a major road
- Others examine the total length of road within a certain area
- Others measure one pollutant that may indicate exposure to all traffic pollutants
Below is the traffic pollutant measure currently available on our air quality data query:
- Percent of population living near busy roads (2004 traffic data and 2000 census data)
- This measure gives the percent of the population in each county living within 300 meters of a busy road
- A busy road is defined as having more than 10,000 vehicles drive on it each day
- Living near busy roads is associated with a variety of health outcomes, including heart disease, asthma, and reproductive outcomes
- Distance from busy roads has been found to be a proxy for exposure to traffic-related pollutants
What does this measure tell us?
- This measure can be used to provide an indication of potential exposure to pollutants such as PM2.5, NOx, and VOCs
- This measure can be used to estimate the proportion of the population at a greater risk for a variety of health outcomes, including heart disease, asthma, and reproductive outcomes
What can't this measure tell us?
- This measure cannot tell us how much of any pollutant people living near busy roadways are exposed to
- This measure cannot tell us about other important factors related to exposure, such as upwind/downwind location
- This measure cannot tell us about a person’s total individual exposure, which depends on where they work, go to school, walk, drive, and play