A new Harvard School of Public Health (HSPH) air pollution study of millions of deaths from heart disease, lung disorders, and other causes in 75 American cities found that the effect of particles on mortality rates was about 75 percent higher in cities with a high proportion of sulfates from coal burning power plants than in cities with little sulfate pollution. It was about 50% higher in cities with a higher proportion of particles from road dust.

The researchers found that air pollution effects were highest when the temperatures were mild, and windows are most likely to be open. For each 10 micrograms per cubic meter of air particles, city death rates increased by over 1 percent. Moreover, the concentration of fine particulate matter in the air fluctuated with changing seasons and weather.

“These findings confirm the large number of studies showing airborne particles kill, and provide insight into which types are most toxic,” said Dr. Joel Schwartz, professor of environmental epidemiology at HSPH, senior author. “This study provides vital information to the U.S. Environmental Protection Agency that may help it decide which sources of air pollution are most critical to control.”

Read more on the Harvard website.