This is Gwen Outen with the VOA Special English Health Report.
Researchers say people traveling in traffic are three times more likely to suffer a heart attack whether driving in a car, riding a bus or bicycling. They say the risk of a heart attack is greatest within an hour of being in traffic. Researchers believe the main reason is polluted air.
The findings are based on a German study of almost seven hundred people who suffered heart attacks. The patients described their activities during the four days before their heart attack. Researchers found that those who had been in traffic were three times more likely to have a heart attack within one hour, compared to those who had not been in traffic.
Most of those in the study had been traveling by car. But some had been on bicycles and others were on buses. Women, people over the age of sixty and those already at risk for heart problems were most at risk.
Research shows that people in cars and buses are exposed to ten times the amount of pollutants as people walking on the street. That is largely because they breathe in the particles and gasses released from the vehicles in front of them.
Over time, these small particles speed the buildup of a sticky substance in the blood. This can cause blockages to form in the arteries around the heart and lead to a heart attack.
Earlier studies have linked traffic, air pollution and heart disease. They found that people who live near major roads are at greater risk of dying from heart and lung problems.
Other studies have also linked heart trouble to stress, similar to the kind that people face while driving in heavy traffic. But the researchers of the latest study say they do not know whether the increased heart attack risk was the result of stress or pollution. They suggest it may be a combination of stress, noise and pollution.
The study found that traffic was linked to eight percent of heart attacks. But experts note that the overall risk of having a heart attack after being in traffic is still very low.
Annette Peters led the research. She is with the National Research Center for Environment and Health in Neuherberg, Germany. She said the research shows the need for cleaner vehicles and better city planning.
The research was done from nineteen ninety-nine to two thousand one. The study was published in the New England Journal of Medicine.
This VOA Special English Health Report was written by Cynthia Kirk. This is Gwen Outen.