For the first time, a population-based study has shown a relationship between living near heavily-trafficked roads and atherosclerosis (hardening of the arteries) according to a study published online July 16, 2007 in Circulation.
Researchers in Germany evaluated 4494 residents (51% were women) aged 45 to 74 from the densely populated and industrialized Rhur area and studied their exposure to fine particulate matter based on the distance the resident lived from a major freeway or a heavily-trafficked highway. Residents included in the study were also evaluated for personal risk factors such as family history of cardiovascular disease, diabetes, and smoking.
Results showed that the closer an individual lived to a high-traffic road the more likely they were to have atherosclerosis. The chance of having high coronary artery calcification scores (one measure of hardening of the arteries) was increased by 63% for those living within 50 meters of a major road when compared with those living more than 200 meters away. The results also suggested that traffic had a slightly greater effect on atherosclerosis in men compared with women, although the difference was small enough that is could have been due to chance.
In addition, fine particulate matter was measured in individuals who had not been working full-time for at least five years. The researchers found that there was a stronger link between the amount of fine particulate matter and high coronary artery calcium measurements in these people compared with people who had been working full time. Researchers assumed the association was due to the fact that the elderly and the unemployed spend more hours at home, thus increasing their exposure to traffic, a major source of air pollution.
Previous studies have shown that short-term exposure to the toxic air pollutants produced by traffic can cause inflammation of the blood vessels and make clots more likely to form. This study extends this interaction to the real world, and may give doctors a reason to consider a patient's proximity to heavy traffic when evaluating them for coronary artery disease. However, the researchers cautioned that the findings of their study will need to be confirmed in prospective trials. A five-year follow-up analysis is expected next year.
Hoffmann B, Moebus S. Residential exposure to traffic is associated with coronary atherosclerosis. Circulation 2007; DOI: 10.1161/circulationaha.107.693622.