Researchers from the Johns Hopkins Bloomberg School of Public Health have found a link between higher levels of a specific kind of air pollution in major urban areas and an increase in cardiovascular-related hospitalizations such as for heart attacks in people 65 and older.
The findings, published in the November issue of Environmental Health Perspectives, are the strongest evidence to date that coarse particulate matter – airborne pollutants that range in size from 2.5 to 10 microns in 
diameter and can be released into the air from farming, construction projects or even wind in the desert – impacts public health. It has long been understood that particles smaller in size, which typically come from automobile exhaust or power plants, can damage the lungs and even enter the bloodstream. This is believed to be the first study that clearly implicates larger particles, which are smaller in diameter than a human hair.
“We suspected that there was an association between coarse particles and health outcomes, but we didn’t have the research to back that up before,” says study leader Roger D. Peng, PhD, an associate professor of biostatistics at the Bloomberg School. “This work provides the evidence, at least for cardiovascular disease outcomes. I don’t feel like we need another study to convince us. Now it’s time for action.”
The researchers also studied respiratory diseases but did not find a correlation between high levels of coarse particles and hospitalizations for those illnesses.
For the national study, Peng and his colleagues studied data from an air monitoring network set up by the U.S. Environmental Protection Agency (EPA) in 110 large urban counties in the United States and linked it to Medicare data on hospitalizations in those same areas from 1999 to 2010. The hospitalizations covered people ages 65 and older.