Air Pollution Linked to Increased Death from Heart Disease

One of the most comprehensive studies of its kind in the United States has revealed that tiny chemical particles in the air are linked to an increased risk for death, even at lower air pollution levels than have been seen in the United States since 2000.

Findings published in Environmental Health Perspectives showed that even a slight increase in exposure to these particles, by just 10 μg/m³ of air, can result in a 3% overall increased risk for death and a 10% increased risk for death from heart disease.

The study showed no significant differences in mortality rates by sex, age, or education. There was, however, a 27% increased risk for death due to respiratory disease for nonsmokers.

“Our data add to a growing body of evidence that particulate matter is really harmful to health, increasing overall mortality, mostly deaths from cardiovascular disease, as well as deaths from respiratory disease in nonsmokers,” said lead study investigator and health epidemiologist George Thurston, ScD, a professor of population health and environmental medicine at NYU Langone.

Unlike larger natural particles such as airborne soil and sand that are sneezed or coughed out, fine particles can contribute to heart and lung disease because they slip past the body’s defenses and can be absorbed deep into the lungs and bloodstream, Thurston said in a press release. Fine particles are also usually composed of harmful chemicals such as arsenic, selenium, and mercury and can transport gaseous pollutants such as sulfur and nitrogen oxides into the lungs.

Scientists at NYU Langone Medical Center examined detailed health and diet questionnaire responses from 517  041 participants in a National Institutes of Health (NIH)-AARP study. To calculate the participants’ risk for death from exposure to particulate matter in the atmosphere, researchers cross-referenced the responses with information from the Environmental Protection Agency’s (EPA) Air Quality System and other databases.

The participants were aged 50 to 71 years old, were from 6 states (California, Florida, Louisiana, New Jersey, North Carolina, and Pennsylvania) and 2 cities (Atlanta and Detroit), and responded to a mailed questionnaire in 1995 and 1996. The questionnaires gleaned information on demographic and anthropometric characteristics, dietary intake, and numerous health-related variables at enrollment, including marital status, body mass index, education, race, smoking status, physical activity, and alcohol consumption. Contextual environmental characteristics, such as median income, for the census tract of each participant were also compiled in the NIH-AARP Study and allowed the researchers to incorporate contextual socioeconomic variables.

“Our study is particularly notable because all the data used in our analysis comes from government and independently held sources,” Thurston said.