The Baltimore-Washington area made some improvements in air quality since last year, according to new rankings from the American Lung Association's State of the Air 2010 report.
The rankings find that a decade's worth of clean-up efforts, which include emissions reductions at coal-fired plants and a transition to cleaner diesel fuels, have made the nation's air better in general. That helped this area reduce its levels of smog and soot.
The report says, however, that more than half the U.S. population suffers pollution levels that are often dangerous.
"State of the Air 2010 proves with hard data that cleaning up air pollution produces healthier air," said Mary H. Partridge, the American Lung Association's national board chair, in a statement. "However, more needs to be done."
The Baltimore-Washington area had the 16th worst air by ozone, or smog. And it had the 18th worst by short-term particle pollution, or soot. It had improvements in short-term level of particle pollution and smog, according to the report. Air pollution data was collected in 2006-2008 around the nation.