There's a new reason to worry about air pollution. Known for many years to harm the lungs, air pollution also damages the circulatory system, a study now suggests.
A reexamination of data collected for various health care trials in the Los Angeles area indicates that the more air pollution there is around a person's home, the thicker the walls of his or her carotid artery become. Thickened artery walls are a leading risk factor for heart attacks and strokes.
Nino Künzli of the University of Southern California in Los Angeles and his collaborators carried out the study, scheduled for an upcoming Environmental Health Perspectives.
Animal studies have previously shown that air pollution—specifically small dust particles less than 2.5 micrometers across—irritates the lungs and provokes inflammation of the blood vessels. Over time, inflammation of the arteries leads to the thickening and hardening of the artery walls, or atherosclerosis.