Women Living Near Major Roads May Face Greater Risk of Sudden Cardiac Death, Says Study
A large study published in October, 2014 in the American Heart Association’s journal Circulation found that women who live near roads with heavy traffic may be at higher risk for sudden cardiac death. More than 107,000 American women, average age 60, were included in the study. The women participated in the Nurses’ Health study from 1986 to 2012.
The study, conducted by Harvard Medical School, was the first to measure risk of sudden cardiac death in relation to proximity of a busy road to the person’s residence. The increased risk is believed to be from the greater amounts of air pollution in the vicinity of such roads.
Researchers found that 523 of the women died from sudden cardiac death. The risk for this death was 38 percent greater for women living within 50 meters (164 ft) of a main road, compared to those living 500 meters (0.3 miles) or more from such a road. The risk for sudden cardiac death increased 6 percent with each 100 meters of proximity to the busy road.
In 1,159 deaths from coronary artery disease, risk increased by 24 percent for women living within 50 meters of a main road, compared to those living 500 meters or more from it.
Living close to a busy road is as big a risk factor for sudden cardiac death as smoking, obesity or poor eating habits, according to study author Jaime Hart, ScD, instructor of medicine at Brigham and Women’s Hospital and Harvard Medical School in Boston. She further stated that health care providers should recognize the fact that environmental exposures to toxins may be “under-appreciated risk factors” for diseases like sudden cardiac death and fatal coronary artery disease.
About 35 million Americans lived within 300 meters of a busy road in 2009, according to the Environmental Protection Agency.
Researchers noted that regardless of where a person lives, having heart-healthy habits, such as keeping a healthy weight, being physically active, eating balanced and nutritious foods, not smoking, not abusing alcohol and managing stress can help lower a person’s risk of heart and blood vessel diseases.
The study did not prove that traffic pollution was responsible for the higher incidence of heart and vascular diseases; however, it added to the number of studies that also found a link between traffic pollution and a greater risk of death from cardiovascular diseases (CVD).
A study by the University of British Columbia in Vancouver, Canada, published in the journal Epidemiology in 2010, found that middle-aged and older adults who lived near a busy highway or major road had a 29 percent greater risk of dying from CVD than people who did not live close to a high-traffic road.
More than 450,000 Vancouver-area residents between the ages of 45 and 85 were studied during a 9-year period. Study subjects had no known CVD at the start.
Over the 9 years, people who consistently lived within about 500 ft of a highway or within 165 ft of a major road were more likely to die from CVD than those who lived farther from busy roads.
Researchers in that study found that risk of CVD death increased for people who moved close to a busy road during the 9 years, while it decreased for those who moved farther from heavy traffic. However, the risks of CVD death were still greater for those who moved close to a busy road or moved away from one, compared to people who had not lived near a busy road.
The research team found that even when factors such as age, neighborhood income levels and pre-existing major lung disease were accounted for, people who lived close to high-traffic roads still had a 29 percent greater risk of CVD death than those who did not live near a busy road.
The AHA periodically publishes scientific statements aimed at giving researchers, health care providers and regulatory agencies comprehensive reviews of the latest study and clinical evidence linking air pollution to CVD and cardiovascular deaths.
The main two sources of air pollution are vehicle exhaust (including motor boats) and coal-burning power plants.
For the past decade, the AHA has been sounding increasingly stronger alarms about the apparent link between air pollution and cardiovascular disease and deaths. In its most recent Scientific Statement, published online in 2010 in Circulation, the AHA makes the following points:
- Exposure to particulate matter smaller than 2.5 micrometers in diameter over a few hours or weeks can produce CVD-related deaths and non-fatal events
- A few years’ exposure increases risk of cardiovascular death even more than exposure during a few days; in more polluted areas, years’ long exposure can reduce life expectancy from several months to a few years
- Reductions in particulate matter (PM) levels are associated with fewer CVD deaths in a time frame of a few years