Breathing in air pollution from traffic fumes can raise the risk of potentially deadly blood clots, a US study says.
Exposure to small particulates - tiny chemicals caused by burning fossil fuels - is known to increase the chances of heart disease and stroke. But the Harvard School of Public Health found it also affected development of deep vein thrombosis - blood clots in the legs - in a study of 2,000 people. Researchers said the pollution made the blood more sticky and likely to clot.
The team looked at people living in Italy - nearly 900 of whom developed DVT. Blood clots which form in the legs can travel to the lungs, where they can become lodged, triggering a potentially fatal pulmonary embolism.
The risk of DVT is known to be increased by long periods of immobility. In particular, passengers on long-haul flights have been shown to be vulnerable, but so are people who spend long periods of time sitting at their office desk without exercising, or walking around. Researchers obtained pollution readings from the areas they lived and found those exposed to higher levels of small particulates in the year before diagnosis were more likely to develop blood clots.
The Archives of Internal Medicine report said for every 10 microgrammes per square metre increase in small particulates, the risk of developing a DVT went up by 70%. Air quality guidelines generally state that small particulate concentrations should not exceed 50 microgrammes.
Source - BBC