A recent study on Air pollution reported in the Journal of Clinical Investigation may explain how small particles in air pollution might trigger blood clots and cause heart attacks and strokes. While there is a known link between particulate air pollution and elevated risk of cardiovascular events, the underlying mechanism remains a mystery. Recent studies on animals and humans found that the small particles in air pollution may disrupt hemostasis - the methods allowing blood to be maintained in a fluid state.

Using lab mice, researchers examined how small particles may accelerate blood clotting. The results found that mice injected with particles smaller than 10 micrometers (one tenth the thickness of a strand of hair) had increased levels of clotting agents like fibrinogen and factor X. Within 24 hours of the injection there was also a coinciding 15 fold increase of a clot causing immune system agent known as interleuken 6 (or IL-6). Mice that had their immune systems suppressed so that they could not produce IL-6 were protected against particle triggered blood clots, suggesting that IL-6 was the driving force.

Researchers are now studying to see if the clotting effect caused by IL-6, could be counteracted by low dose aspirin. Aspirin has already been found to thin blood and is currently used to treat people with heart conditions.