Chronic exposure to ground level ozone, a powerful greenhouse gas and a widespread air pollutant in many major cities, is linked to premature death from cardiovascular disease, finds a new study led by University of California, Berkeley, researchers.
The analysis, funded by the California Air Resources Board and published in the current issue of American Journal of Respiratory and Critical Care Medicine, also found a strong link between nitrogen dioxide, a marker for traffic pollution, and increased risk of death from lung cancer.
Numerous studies have connected air pollution to a higher risk of mortality, but until now, the extent of the impact had been uncertain.
For the new paper, researchers developed individualized air pollution exposure estimates of more than 73,000 California residents. They used a combination of home addresses, government air monitors and statistical models to obtain monthly averaged values of exposure to ozone, nitrogen dioxide and fine particulate matter pollution. Researchers tracked mortality from 1982-2000 to link the deaths to air pollution exposure.
"Ozone has already been linked to respiratory problems, but this is the first study to show that it also increases the risk of death from ischemic heart disease, which accounts for more than 7 million deaths worldwide each year," said study lead author Michael Jerrett, professor and chair of environmental health sciences at UC Berkeley's School of Public Health. "Our findings will likely up the total deaths due to air pollution by hundreds of thousands per year in the next World Health Organization assessment."