People who live near major roadways are at higher risk of developing dangerous blood clots in the veins of the legs, according to a study published June 23, 2009 in Circulation, the Journal of the American Heart Association.
Deep vein thrombosis (DVT) is a blood clot in a vein deep in the body, usually in the leg. DVTs may cause pain, swelling, and skin redness or warmth, and can even be deadly if part of the clot breaks off and travels to the lungs (called a pulmonary embolism). DVTs occur in 1 in 1000 people every year and affect as many as 600,000 Americans annually. Factors that are known to increase your risk of developing a DVT include:
- recent surgery
- immobility (e.g. in a cast or on a long airplane flight)
- heart failure
Increasingly, research shows that small-particle air pollution (such as motor vehicle exhaust) can contribute to heart and blood vessel disease, including DVT. One German study (click here for more) found that people who lived near high-traffic roads were more likely to have hardening of the arteries, as measured by coronary artery calcification scores.
In the present study, Italian researchers investigated 663 patients (more than half were women) with DVT in their legs, and compared them with 859 healthy people who were similar in age other characteristics. They also measured how close each person lived to the nearest major traffic road.
Compared with people who lived far away, people who lived closest to major roads were more likely to have a DVT, even after adjustment for age and other factors, including the background level of air pollution. The closer to a road a person lived, the higher their risk. People in the group living closest to a major road (within about 65 feet) were 50% more likely to suffer a DVT than people who lived farther away (500 feet or more).
The results of this study reinforce the growing awareness that environmental factors can play a significant role in our cardiovascular health. While it's probably not practical to avoid traffic altogether, there are steps you can take to educate yourself and prevent DVT. To learn more about your DVT risk and what to watch for, visit the Coalition to Prevent Deep Vein Thrombosis at www.preventdvt.org.
Source: Bacarelli A, Martinelli I. Living near major traffic roads and risk of deep vein thrombosis. Circulation. 2009;119:3118-24