Traffic Triples Heart Attack Risk
Study Shows Even Passengers Risk Heart Attack in Heavy Traffic; Exhaust Fumes Blamed
March 13, 2009 -- Whether you drive, take the bus, or bicycle, being in
heavy traffic triples your risk of heart attack within one hour.
Air pollution from car fumes is the likely culprit, suggest Annette Peters,
PhD, and colleagues at the Institute of Epidemiology, Helmholtz Center, Munich,
In a previous study, Peters and colleagues found that a sizeable proportion
of heart attacks -- about 8% -- could be attributed to being in traffic.
To follow up, the researchers interviewed 1,454 people who survived heart
attacks. In the hour before their heart attack, many of the survivors had been
in heavy traffic.
Analysis of the data showed that these heart-attack-vulnerable people were
3.2 times more likely to suffer a heart attack if they'd been in heavy traffic
in the previous hour.
"One potential factor could be the exhaust and air pollution coming from
other cars," Peters says in a news release. "But we can't exclude the
synergy between stress and air pollution that could tip the balance."
Making it less likely that stress was involved was the fact that patients
didn't have to be driving; the risk was the same whether they were driving or
taking the bus.
Traffic appeared to be five times more dangerous to women than to men in the
study, although the relatively small number of women in the study (325) may
have made this calculation less accurate.
To nail down the true culprit, Peters and colleagues are working with
University of Rochester researchers to determine exactly what it is about
traffic that raises heart attack risk.
In that study, 120 healthy volunteers are driving to work and running
errands wearing heart monitors, while other instruments measure their exposure
to air pollution and to noise. The data and findings from this trial are not
Peters reported the current findings at this week's American Heart
Association (AHA) meeting in Palm Harbor, Fla.