Research in Action
Air pollution near roads and highways
Air pollution comes from many sources, including industrial smoke stacks, motor vehicles, and even forest fires and volcanoes. Recent research suggests that tiny bits of particulate matter (PM or soot) from diesel-burning cars and trucks can have serious health effects if inhaled deeply into the lungs, especially by those with other health problems and living near heavily traveled roadways.
Air pollution effects on children are of special concern to EPA because schools, child care centers, and shopping centers are frequently built near major roads for ease of access. Especially in large cities, these same children may also be exposed to additional pollution because they live in heavily congested areas near major highways.
As part of a larger EPA research program to study the impact of air pollution near roadways, EPA researchers are partnering with the University of Michigan (U-M) on a study of the impact of vehicle emissions on near-road air quality, human exposures, and potential health effects in asthmatic children.
The Near-Road Exposures to Urban Air Pollutants Study (NEXUS) is being conducted in Detroit, Mich., as part of EPA’s larger research program on roadway air pollution and its potential health effects. Approximately 100 children, 6 to 16 years old, with persistent asthma and living close to specific kinds of roadways are participating in the study. Roadway types included in the study are:
- High traffic/high diesel;
- High traffic/low diesel; and
- Low traffic/low diesel
The study design will help tease out the health effects of particulate matter from diesel-burning truck and car exhaust. Researchers are also measuring levels of traffic-related air pollution near roadways in the neighborhoods of the study participants, and inside and outside of up to 30 homes in the study. University of Michigan researchers are collecting information on changes in the children’s respiratory health, which will then be correlated with the exposure measurements to determine how exposure to traffic-related air pollutants affects changes in the health of asthmatic children.
Particulate matter and other pollutants are being measured immediately next to the roadways and at various distances from them, to study how pollutant concentrations decrease as distance from the roadway increases. EPA modelers will then compare the actual exposure and health data collected for the children to that predicted by existing air quality and exposure models. Then the existing models can be fine-tuned to give even better predictions of the health effects of air pollutants.
Results and Impact
Results of this NEXUS research on the interactions between air pollution and health effects can have wide-ranging importance. State highway planners and environmental agencies can assess the current vehicle emissions and project the impacts of future road construction projects. Federal, state, and local governments and organizations can make better public health decisions on siting major community developments near roadways. Policy makers can develop better plans to reduce exposures to air pollution for people living near roadways. Even individuals can use these results to make more informed decisions on where they may wish to live.