With smog season rapidly approaching, Baltimore-area residents who hate yardwork soon may have a good excuse -- and advance warning -- to skip mowing their lawns on certain hot, sunny days.
Maryland environmental officials yesterday disclosed plans for an early alert system this spring and summer that will forecast high levels of smog a day ahead so that the many people affected by ozone pollution can restrict their outdoor exertions.
And when the state predicts a "bad air" day, it also intends to ask the public to help fight ozone by avoiding polluting activities, such as using gasoline-powered lawn mowers, driving alone to work and taking the family motorboat out for a cruise.
Most smog-forming pollutants come from automobiles. But gasoline-powered mowers and outboard engines also are major sources.
For example, an hour cutting grass is like driving 50 miles. And a 60-minute cruise on a motorboat can produce as many hydrocarbons as driving 800 miles.
Merrylin Zaw-Mon, director of air and radiation management for the Maryland Department of the Environment, outlined the smog-forecasting plans at a briefing yesterday on air pollution arranged by the American Lung Association of Maryland.
Details remain to be worked out, but state officials say they intend to provide Baltimore area news organizations with a forecast of what the next day's air quality is likely to be.
The predictions will be announced in time for use on evening radio and television broadcasts and for publication in the next morning's newspapers.
More than 4 million Marylanders breathe unhealthy levels of ozone at least occasionally each spring and summer. The Baltimore area, with the sixth-worst smog among the nation's urban areas, had 16 days last year when ozone levels exceeded the safety threshold set by the federal government.
The Washington area, the country's 10th-smoggiest, had eight bad ozone days.
The main component of smog, ozone is an invisible, odorless gas formed when pollutants from cars and trucks, power plants and a host of other sources combine in the air on hot, sunny days.
Ozone levels begin to build in the late morning after rush hour and peak in midafternoon to late afternoon.
Though many Marylanders consider smog a downtown problem, the highest ozone levels often are recorded in suburban counties.
The gas can reduce a person's breathing ability and cause chest pains, coughing and wheezing. It may even weaken the lung's defenses against disease, some research shows.
The elderly and the very young are especially sensitive to ozone, as are 600,000 Maryland residents with lung disease -- mainly asthma, emphysema and bronchitis.
But even healthy people can suffer ill effects if, while exercising vigorously, they inhale even moderate amounts of ozone. The inner lining of their lungs can become inflamed, in a manner similar to that of a sunburn or skin abrasion. Some people may notice a tightness in their chests and may be unable to catch their breath.
"The problem with ozone is you can't see it, and you can't really smell it," said Dr. Rebecca Bascom, an associate professor of medicine at the University of Maryland.
"There is no way for someone with a [breathing] problem or who wants to be healthy to get out of the way."
Washington-area residents already have an early warning system for smog. The Washington Council of Governments has been issuing same-day air quality predictions since the 1970s and began making next-day and weekend forecasts last summer, said Sherry Conway Appel, the council's director of public affairs.