Striking at the heart
exposure to elevated levels of fine particles from automobiles for just two hours raises the likelihood of heart attack according to a recent study in the journal Circulation.
Murray Mittleman, director of cardiovascular epidemiology at Boston's Beth Israel Deaconess Medical Centre, us , who led the study said previous studies linked exposure to particulate air pollution to heightened risk of cardiovascular diseases, but the new study is the first to look at short-term effects of air pollution on the risk of heart attack.
This type of pollution is produced by combustion processes in automobile engines, power plants, refineries and smelters, added Douglas Dockery, professor of environmental epidemiology at the Harvard School of Public Health, usa . These particles are less than 2.5 micrometers (25/10,000th of a millimeter) in size. Dockery said larger particles such as airborne dust and debris from farming, construction work and mining are far less likely to trigger a heart attack.
These particles are so small that after being inhaled, they can evade the normal defense mechanisms in the lungs and penetrate deeply into the lung's air sacs and their presence there can