WASHINGTON -- The Environmental Protection Agency will officially designate today about 470 of the United States' 2,700 counties as having air with unhealthy levels of ozone or smog, EPA officials said yesterday.
The designation coincides with a new, more protective standard that today becomes the country's primary gauge for judging smog levels.
The ozone levels in many of the designated counties, which include 100 metropolitan areas and at least eight popular national parks, have dropped in recent years, EPA Administrator Michael O. Leavitt said in remarks to the National Press Club. But, he added, there are still days when the levels are higher than is considered safe.
"This isn't about the air getting dirtier; the air is getting cleaner," Leavitt said. "It's about our standards getting tougher and our national resolve to meet them."
In 1997, the EPA decided that it needed to set a more protective standard for ozone because scientific research showed that even at low levels, ozone pollution was causing acute respiratory problems, aggravating asthma and impairing immune systems. Children, older individuals and people with fragile immune systems are most vulnerable. The standards were designed to reduce asthma attacks, hospital stays and chronic illness.
Old standard
Under the old standard, air was considered unhealthy when it measured above 120 parts per billion of ozone over a one-hour period. Now air is considered unhealthy if it measures an average of above 85 parts per billion over an eight-hour period. Ozone is the primary component of smog.
Today's announcement will more than double the number of counties considered to have harmful levels of ozone. Currently, 221 counties -- home to more than 110 million people -- violate the one-hour standard, according to EPA officials. The states suggested last July that 412 counties deserved to be on the new list, but in December the EPA proposed naming 506 counties. EPA officials refused to specify which counties fell off the agency's list or why.
Leavitt described the new ozone policy as a key part of the Bush administration's strategy to launch "one of the most productive periods of air quality improvement in our ... nation's history."
