More than 65,000 women from 36 different U.S. cities were taken as a subject. They were between the ages of 50 to 79. The time period of study was 9 years. When the study began, none of the woman had any signs of heart disease.A new study published in the New England Journal of Medicine has discovered a significant correlation between the air pollution around a woman's home and her risk of heart disease. At the end of the study, researchers compared heart disease patients among participants in different cities with the quality of air. A strong correlation was noticed between the density of particulate matter in the air and presence of cardiovascular disease.

"These soot particles ... are typically created by fossil-fuel combustion in vehicles and power plants, " said lead researcher Joel Kaufman of the University of Washington. "The tiny particles — and the air pollutant gases that travel along with them — cause harmful effects once they are breathed in."

"In the meantime," he said, "when localized air pollution is particularly high, people with ... coronary heart disease should avoid staying outside for long periods."

Researchers think that air pollution has the same effect on men.