Scientists Find Link Between Air Pollution And Blood Clot Formation
Reported May 13, 2008
Rome, Italy (AHN) – Scientists have found a link between long-term exposure to air pollution and the development of blood clots in the legs. Dirty particles in polluted air appeared to increase the risk of deep vein thrombosis (DVT) or “economy class syndrome”, which are blood clots in the thighs or legs, an Italian study finds.
Risk factors for deep vein thrombosis include sitting for a long period of time, injury to the lower leg, obesity and taking birth control pills. Nearly 900 people in Italy were studied for exposure to particulate air pollution in the year prior to diagnosis of a blood clot in the leg, known as deep vein thrombosis.
Particulate air pollution comes from very small particles of solid and liquid chemicals that come from burning fossil fuels and other sources. Particulate air matter has been linked to the increased risk of developing or dying from heart disease and stroke, according to background information in the article.
When scientists, led by Dr. Andrea Baccarelli of the Harvard School of Public Health, compared this data to 1,200 study subjects who had not been diagnosed with blood clots, they found that those with deep vein thrombosis had a 70 per cent increased risk of developing the condition.
DVT was present for every increase of particulate matter of 10 micrograms per square metre. In addition, the blood of patients in both the case and control groups with higher levels of exposure to particulate matter took less time to clot, as measured by a test given in the clinic.
Risk factors for deep vein thrombosis include sitting for a long period of time, injury to the lower leg, obesity and taking birth control pills.
In their study, the authors call for tighter standards and continued efforts aimed at reducing the impact of urban air pollutants on human health. The study was published Monday in the Archives of Internal Medicine.
The link between particle exposure and blood clots was stronger in men than in women, and disappeared among women taking oral contraceptives or hormone therapy.
Previous studies have linked air pollution to heart disease and stroke. It is also a known contributor to respiratory problems, especially during the smoggy summer months.