For the first time in 1998, the Baltimore-area forecast calls for unhealthy levels of smog, as pollution percolates in the still air under cloudless skies.
The Maryland Department of Environment has issued a "code orange" smog watch for today, predicting moderately unhealthy levels of air pollution.
Forecasters blame the smog on a noxious brew of chemicals -- emissions from cars, lawn mowers, industrial smokestacks and even paint fumes -- that simmers under hot, clear skies to form potentially harmful ozone.
The hazy smog is the downside of this week's unseasonably hot weather.
"It's the concentration of pollutants with bright, hot sunlight that causes the problem," said MDE spokesman Quentin Banks. "On a clear, cloudless day, they mix together and just cook in the heat."
The pollution probably won't be bad enough to cause healthy people's eyes to water and throats to catch, as the "code red" smog levels of midsummer often do. But it could cause difficulty for people with heart conditions or chronic breathing problems such as emphysema or asthma.
About 600,000 Marylanders have health problems that make them "susceptible" to ozone pollution, Banks said. They're advised to limit outdoor activities today, and to go indoors if they feel short of breath.
To help reduce the amount of pollution-forming chemicals in the air, MDE is asking Marylanders to try to minimize their driving by sharing rides, taking public transportation or combining several errands into one car trip. The state also urges residents not to use gasoline-powered lawn mowers, which emit as many pollutants in one hour as the average car does on a 50-mile drive.
MDE also recommends waiting until after dark to refuel cars, to minimize the volatile vapors emitted to the air.
Code orange pollution levels range from 110 to 124 parts per billion of ozone, just below the Clean Air Act's air quality standard of 125 parts per billion. Levels that high trigger code red health alerts.
Yesterday, the region's ozone levels fell between 63 and 109 parts per billion, with the highest levels found at an air monitor in Davidsonville in central Anne Arundel County, Banks said.
The "ozone season" runs from the end of May through September, Banks said, and it's a little unusual to see smog alerts this early. Last year, the area's first smog-related health warning came in mid-June.
By summer's end last year, the region had accumulated 14 "code red" days, when ozone levels were high enough to violate federal air quality standards set under the Clean Air Act.
Pub Date: 5/19/98