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Near-Source Air Pollution Research

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Living and working near sources of air pollution can lead to higher exposures to air contaminants, many of which contribute to adverse health effects including:
  • reduced lung function,
  • asthma,
  • cardiovascular disease and
  • premature death.
Some communities are more impacted than others, making air pollution an environmental justice concern. Children, older adults, people with preexisting cardiopulmonary disease, and people of low socioeconomic status are among those at higher risk for health impacts associated with living near:
  • busy highways
  • rail yards
  • marine ports
  • industries where pollutants are emitted from multiple sources

Smoke from wildfires is another close-by source of air pollution that is becoming more common as a result of the impacts of a changing climate.  As a result, some populations who live in areas prone to wildfires are more vulnerable to the effects of wildfire smoke. Wildfires can become a regional air pollution concern as well since smoke can travel many miles to other locations.

Research is conducted to:

  • Assess near-source impacts for single source and complex multi-source environments
  • Understand factors influencing adverse health effects attributed to near-source impacts.
  • Develop models and tools to quantify near-source emissions and exposures to guide community planning
  • Develop mitigation strategies to reduce emissions, exposures and health effects
The research includes:
  • field studies
  • computer modeling
  • analytical methods development
  • epidemiological and toxicological studies to evaluate exposures and health effects of air pollutant emissions

Findings provide important information to:

  • Develop and implement the National Ambient Air Quality Standards (NAAQS)
  • Develop emissions standards and control strategies
  • Assist states, communities and local groups with planning for roads, schools, and other land-use decisions as well as regional wildfire smoke overdrafts.  


With more than 45 million people in the U.S. living within 300 feet of a major transportation facility or infrastructure, notably busy roads, there is concern about the potential health impacts from air pollutants emitted from cars, trucks and other vehicles.  Research has demonstrated that exposure to pollutants emitted from motor vehicles can cause lung and heart problems and premature death.

To reduce the impact of living near busy roads, researchers are evaluating how roadway design, including noise barriers and roadside vegetation, can help to reduce exposure to air pollutants.

Researchers continue to study the health effects of single and multiple pollutants and are examining specific components of emissions that are associated with the effects. In addition, EPA supports the Health Effects Institute, an independent nonprofit organization that provides science on the health effects of pollutants from motor vehicles and other sources. Supported jointly with industry, HEI has produced important research findings on the health effects of air pollutants related to motor vehicle emissions.

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Ports and Rail Yards

Ports and rail yards are another source of air pollution from locomotives, transport trucks, loading and unloading equipment, and ships. The many different types of traffic and activity at rail yards and ports generates a variety of pollutants that can impact nearby communities and neighborhoods. Research is conducted to better understand near-rail and near-port air emissions and air quality including how pollutants from these sources impact areas surrounding these facilities and nearby freight movement corridors. Studies are examining the sources of emissions, how emissions are dispersed to surrounding areas, and ways to improve modeling to evaluate near-source impacts and control strategies.

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Research has found that wildfire smoke can increase health risks and leads to lung and heart problems and premature death. Climate-related changes and land-use practices are expected to increase the risk of wildfires in the coming decades, pointing to a growing need for more information on the health and economic impacts.

Researchers continue to focus on understanding the health effects from wildfires, identify the most susceptible populations, learn more about the economic effects in terms of health care costs, lost revenues, and loss of environmental resources. Research is also pursuing ways to mitigate the health effects from wildfires.

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