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
What are 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)
What are the health effects of traffic pollutants?
- 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
Who is at risk?
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.
Measures of traffic pollutants
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