BALTIMORE, March 7 (UPI) -- A particular type of air pollution -- fine particle pollution -- raises the risk of heart and lung-disease hospitalization.
That according to researchers at Johns Hopkins University who said this week that being exposed to "fine particle matter" air pollution increases a person's risk for hospital admission for cardiovascular and respiratory disease.
"In the lung, particulate matter may promote inflammation and thereby exacerbate underlying lung disease and reduce the efficacy of lung-defense mechanisms. Cardiovascular effects may reflect (nerve tissue-related) and inflammatory processes," the researchers said.
They found that the biggest impact of fine-particle pollution was on cardiac-failure risk, for which the pollution raised the risk by 1.28 percent.
The higher heart risk tended to be centered in counties located in the eastern United States, including the Northeast, the Southeast, the Midwest and the South, the scientists noted, and was hardest on the elderly.
However, they observed a short-term increase in hospital-admission rates linked to the fine air particles for all of the health outcomes studied except injuries.
The researchers said their study calls for limits on air pollution that is comprised of small particles, or those in the diameter range expressed as "PM2.5."
This size particle poses the greatest risk to human health because the particles' smaller size makes it easier for them to invade the tiny airways and air sacs in the lungs, they said.
"Evidence is limited on the health risks of this size range of particulate matter," the researchers noted.
The Johns Hopkins team analyzed data from a national database for 1999 through 2002 on hospital-admission rates constructed from the Medicare National Claims History Files for cardiovascular and respiratory outcomes and injuries for 11.5 million Medicare enrollees.
The enrollees lived in 204 U.S. urban counties with populations of more than 200,000 and also resided an average of 5.9 miles from a PM2.5 monitor.
The findings appear in the March 8 issue of Journal of the American Medical Association.
