The heavy pollution in Beijing might increase the risk of cardiovascular events in spectators. This warning adds to previous concerns that Olympic competitors have had about the heavily polluted air in Beijing.

 

For certain individuals, exposure to heavy pollution, followed by a plane flight within one day, can greatly increase the risk of blood clots. This could lead to serious cardiovascular events, such as heart attack and stroke.

 

The explanation for this increased risk was explained in past research, which focused on "microscopic air pollution," which accounts for very tiny particles unable to be seen with the naked eye. It was shown in this research that these microscopic air pollutants thicken the blood, increasing the risk of clots.

 

Those with high blood pressure, diabetes, history of cardiovascular problems, smokers, obese individuals, and those with family history, are believed to be at highest risk from pollution exposure. These are all major risk factors for cardiovascular disease outside of pollution as well, suggesting pollution has the ability to "trigger" these events in people already at risk. Researcher Dr. Gokhun Mutlu warns though that "being exposed to higher levels of pollution may unmask heart disease even if you've never had any symptoms."