Air pollution leads to blood clot in veins

Air pollution heavy in small particles may alter coagulation function and increase the risk for deep vein thrombosis. Deep vein thrombosis (DVT) refers to the formation of a blood clot or thrombus within a vein commonly in the thigh or calf. The blood clot can either partially or completely block the flow of blood in the vein. Previous research has related air pollution from automobiles and industry, containing tiny particles of carbon, nitrates, metals and other materials, to a variety of health problems. While lung diseases were the initial concern, later research has indicated it may cause heart disease and stroke, possibly because it increases the rate at which blood can coagulate. Until now particulate pollution had not been linked to blood clots in the veins. The mechanism that causes problems for some air travellers is related not to the blood itself, but to impaired circulation when sitting in one place without exercise for long periods of time. To investigate, researchers in America studied 870 people in Italy who had developed DVT between 1995 and 2005. When compared with 1,210 others living in the same region who did not have the problem, it was found that for every increase in particulate matter of 10 micrograms per square metre the previous year, the risk of DVT increased by 70 per cent. On top of that, the blood of those with higher levels of exposure to particulate matter was quicker to clot when tested at a clinic. The findings indicate that prolonged exposure to air pollution is related to DVT. This calls for tighter standards and continued efforts aimed at reducing the impact of urban air pollutants on human health.