By Robbie Webber
A paper published in Circulation, the journal of the American Heart Association, outlines the dangers for women’s health of living near major roadways. Researchers following a group of nurses since 1976 found that those living within 50 meters of major roadways—defined as U.S. Census Feature Class Codes A1, A2, and A3, both limited- and full-access roads, generally with more than two lanes—had a 38 percent greater risk of sudden cardiac death (SCD) than those living more than 500 meters away. Each 100 meters closer to the roadway showed a six percent increased risk of SCD. Living close to a major road was found to be as important a risk factor for sudden cardiac death as smoking, obesity, and poor eating habits.
Although this is thought to be the first study to examine the impact of residential roadway proximity on the risk of SCD, the authors acknowledge that there are many unanswered questions. The exact cause of the higher incidence of SCD was not clear from this study; but based on previous studies linking localized pollution with other cardiac symptoms, they speculate that air quality and particulate matter exposure are the culprits. Also mentioned was previous research finding that traffic noise can affect blood pressure and other health indicators associated with cardiac disease.
The findings are based on health surveys of nurses that have filled out questionnaires and detailed health reports for almost 30 years. The study results are based on participants who are a middle-aged and elderly population of mostly white, middle- or upper-income women. Researchers would like to see if the results can be generalized to other populations.
In addition, residential proximity to a major roadway neither indicates how much time is spent in that location nor the actual amount of traffic exposure since roads of the same size can have significantly different traffic volumes.
However, due to the long-term and detailed health and demographic data gathered about the participants—including residence and, therefore, proximity to roadways—the study authors felt the findings were significant. Although the risk elevations are modest, given that the EPA estimates that 35 million Americans lived within 300 meters of a major roadway in 2009, the overall effect on national health could be comparable to other SCD risk factors.
Robbie Webber is a Senior Associate at SSTI.
By Robbie Webber