If you have heart problems, you might want to roll up those windows as you sit in traffic.
A new study suggests that breathing in the fumes from heavy traffic can hike up your risk of heart attack for the following six hours.
The heart attack risk goes down gradually after that time frame, according to the British Medical Journal study. Researchers said it's not that the air pollution causes people to have heart attacks who wouldn't otherwise have them, but rather could hasten heart attacks in people who would have had one anyway, Medical News Today reported.
"We know that pollution can have a major effect on your heart health, possibly because it can 'thicken' the blood to make it more likely to clot, putting you at higher risk of a heart attack," study co-funder Jeremy Pearson, associate medical director of the British Heart Foundation, told BBC News.
Therefore, people who have heart disease should avoid highly polluted areas because of this increased risk, BBC News reported.
To find this increased risk, researchers from the London School of Hygiene and Tropical Medicine looked at health data from 79,288 people in the United Kingdom who have had a heart attack between 2003 and 2006, noting the exact time of the day of their heart attack. They also looked at the traffic pollution (like carbon monoxide and ozone) in different parts of the UK, and found that the people's likelihood of having a heart attack was the highest in the six hours after they'd been exposed to traffic fumes.
BBC News reports that the risk of heart attack differs by level of pollution; for example, heart attack risk goes up by 5 percent when going from low pollution to medium-level pollution.
The findings are similar to that of a 2009 study, which showed that fumes from heavy traffic triple the risk of heart attack within the hour, Fox News reported.
LiveScience also reported another congestion-related aspect that seems to be linked with heart attack risk: the noise. They reported that people who live in noisier neighborhoods (with lots of traffic noise) have more heart attacks than people in quieter neighborhoods.