Care about air: Pollution exposure may boost death risk from heart disease

You may want to start caring about the air you breathe, as a new study has linked air pollution to increased deaths from heart disease.

In what is believed to be the largest, most detailed study of its kind in the United States, scientists at NYU Langone Medical Center and elsewhere have confirmed that the tiny chemical particles in the air we breathe are linked to an overall increase in risk of death.

The researchers say this kind of air pollution involves particles so small that they are invisible to the human eye (at less than one ten-thousandth of an inch in diameter, or no more than 2.5 micrometers across).

The scientists conclude that even minuscule increases in the amount of these particles (by 10 micrograms per cubic meter of air, for example) lead to an overall increased risk of death from all causes by three percent and roughly a 10 percent increase in risk of death due to heart disease. For nonsmokers, the risk increase rises to 27 percent in cases of death due to respiratory disease.

The data adds 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 non-smokers, said lead investigator George Thurston.

According to Thurston, fine particles can contribute to the development of potentially fatal heart and lung diseases because they slip past the body's defenses and can be absorbed deep into the lungs and bloodstream. They are not sneezed or coughed out the way larger natural particles, like airborne soil and sand, are removed from the body's airways.

Moreover, Thurston says, fine particles are usually made of harmful chemicals such as arsenic, selenium, and mercury, and can also transport gaseous pollutants, including sulfur and nitrogen oxides, with them into the lungs.

Senior author Richard B. Hayes said researchers need to better inform policy makers about the types and sources of particulate pollution so they know where to focus regulations. It is especially important to continue monitoring health risks as national standards for air pollution are strengthened.

The study is published online in the journal Environmental Health Perspectives.