Heart Facts
•Heart disease and stroke are the first and fourth leading causes of death in the U.S.
•Air pollution can affect heart health and can trigger heart attacks and strokes that cause disability and death.
•One in three Americans has heart or blood vessel disease and is at higher risk from air pollution.
Since passage of the Clean Air Act in 1970, EPA scientists have been at the forefront of air pollution research to provide the scientific foundation for the nation’s air quality standards. The research has helped to save lives and improve health. One focus of that research is to better understand the effects of air pollution on the heart, nervous, and vascular systems.

A significant body of research has shown that long-term exposure to fine particulate matter, known as PM2.5, can impact heart disease. Particles are emitted year-round in exhaust from motor vehicles and smoke from power plants, industries, and forest fires. PM also develops from chemical reactions in sunlight from vapor and gaseous pollutants.

Research is now focusing on ozone, a widespread pollutant that peaks during the summer. Ozone is formed when exhaust and other emissions from the same sources are exposed to sunlight. Clinical and animal studies are indicating that ozone has similar effects as PM2.5 on the heart, nervous and vascular systems. Research continues on these and other air pollutants, including mixtures of pollutants.

The many pollutants in the environment may have a greater health impact than individual pollutants. For example, when diesel exhaust combines with ozone, the health impact from the combination of pollutants may be greater than the impact from each separately.

Sensitive Groups
Some people may be more sensitive to air pollution’s impact on the heart. EPA scientists are studying groups and individuals who may be at increased risk due to air pollution exposure. Genetic characteristics may be a risk factor for health problems from air pollution exposure. EPA is studying people with heart disease and looking at their exposure to sources of pollutants and the potential that their genetic makeup affected their response to pollutants and the development of their heart disease.

EPA researchers are also studying groups who may be at increased risk of heart problems as a result of exposure to air pollution and, such as those with hypertension, diabetes or obesity.

Sources
Do some sources of air pollution cause a greater threat? What sources of pollutants are you exposed to throughout your day?

To understand the impacts of air pollution on health, including the cardiovascular system, scientists are studying sources of pollutants, where they travel and how they may impact the health of those in their path. They are assessing exposure levels of people who live near sources of pollution such as major roadways, ports, and railways to determine the link between exposure and health impacts.

Intervention Strategies
EPA is also testing tools and methods to control and reduce air pollution. Research found that barriers such as retainer walls reduce pollutants by up to 50 percent from nearby major roads.

Individuals can also prevent air pollution from affecting their heart. One EPA study found that omega-3 fatty acids in dietary supplements block some of the effects of PM2.5 on the cardiovascular system.

EPA’s research contributed to the development of the federal government’s Air Quality Index, an online tool that can be used to reduce personal exposure to air pollutants and promote health.