The scientific evidence linking air pollution to heart attacks, strokes and cardiovascular death has substantially strengthened, and people, particularly those at high cardiovascular risk, should limit their exposure, according to an updated American Heart Association scientific statement. Drs. Joel Kaufman and David Siscovick of the UW were among the co-authors of the statement, which was released May 10 and published in Circulation, a journal of the American Heart Association.
Kaufman said researchers reviewed all available literature over the last five years to draw the conclusion. “Research confirmed what we were suspicious of before,” he said. “This really nailed it down.” Evidence is strongest for fine particulate matter having a causal relationship to cardiovascular disease, according to the statement. The major source of this particulate matter is fossil fuel combustion from industry, traffic and power generation. Biomass burning, heating, cooking, indoor activities and forest fires may also be relevant sources, particularly in certain regions.
How does pollution lead to heart disease? Kaufman said air pollution causes blood pressure to go a little higher. If a person is living in a polluted area — within a football field’s distance to a major highway — he or she could have increased blood pressure all of the time. In addition, when pollution becomes worse, this could trigger an electrical level in the body that leads to a heart attack.
Spending time outside in a polluted area or during high pollution days can be a risk, said Kaufman, a UW professor of medicine, epidemiology and environmental and occupational health sciences. “Have a conversation with your doctor” if you are concerned, he said. “Most people with heart disease are recommended to be more active. But don’t exercise outdoors on days when the air quality index says you shouldn’t do so.”
Siscovick is a UW professor of medicine and epidemiology.