"Chronic exposure to air pollution has been associated with various health-related illnesses, however few studies have related air pollution to cardiovascular disease," said lead author Demosthenes B. Panagiotakos, Ph.D., a biostatistician and epidemiologist at the First Cardiology Clinic at the University of Athens School of Medicine in Athens, Greece.
The researchers conducted the study in the greater Athens area from 1992 to 1997. They collected daily values of primary air pollutants smoke, sulfur dioxide, nitrogen dioxide and carbon monoxide from eight stations of the Ministry of Environment (Directorate of Air and Noise Pollution Control). They also collected data about the number of deaths due to heart disease and stroke.
They found a significant positive association between cardiovascular disease (CVD) deaths and several air pollutants. In particular, for every 10 micrograms per cubic meter (mg/m3) increase in black smoke, they observed a 4 percent increase of CVD deaths. Similarly, a 10-mg/m3 increase in sulfur dioxide was associated with a 5 percent increase of CVD deaths.
"The most important finding is that a 10-unit increase in carbon monoxide (CO) was associated with a 46 percent increase in CVD deaths," Panagiotakos said.
On further analysis, the researchers found that the average number of CVD deaths in the Athens area during the study period was 35 deaths each day.
Panagiotakos said the increase of 1-unit in CO levels might lead to two more deaths each day or more than 700 a year. In addition, CO levels roughly explained 3 percent of the observed CVD deaths during the investigated period.
The researchers said the values of the investigated air pollutants reached very high levels many times during the
Contact: Carole Bullock
American Heart Association