Exposure to high levels of air pollution has been linked with increased risk for heart attacks and stroke.

Dr. Scott Budinger, associate professor in medicine-pulmonary and cell and molecular biology, in collaboration with Dr. Gokhan Mutlu, chief of Pulmonary and Critical Care at the University of Chicago, showed that exposure to air pollution causes a stress response in the body characterized by an elevation in the levels of the stress hormone adrenaline.

The paper was recently published in the Journal of Clinical Investigation.

The team has previously shown that exposure to air pollution increases the tendency to form blood clots.

In the current study, the scientist used mouse models to demonstrate how increased adrenaline activates beta-2 adrenergic receptors on immune cells and promotes lung inflammation and a tendency to form blood clots. Similar to the effects of adrenaline, inhalers called beta-2 agonists that are used for conditions such as asthma or chronic obstructive pulmonary disease further worsen the air pollution-induced lung inflammation and clot formation.

“Our findings show that stress can make existing lung inflammation worse and increase the tendency to form clots in the body,” said Dr. Budinger. “Enhancing the response to infection and clotting the blood was likely helpful during evolution when stress was commonly induced by attacking predators. In our modern world, this protective mechanism becomes harmful when activated by air pollution, increasing the risk of heart attacks and strokes.”

Journal article: http://www.jci.org/articles/view/75157

Read more: http://www.feinberg.northwestern.edu/news/2014/07/Budinger_air_pollution.html