The haze hovering over a wilting Baltimore region reached an unhealthy level yesterday for the 12th day this year, making this summer one of the smoggiest since 1983.
Soaring temperatures that reached 103 at 2 p.m. and stagnant air combined with the vapors from cars and trucks to create low-lying ozone, an air pollutant that can make even healthy adults feel short of breath, cough and wheeze their way through a day.
The heat wave set new records in the area yesterday for both peak power usage and the high temperature. The Baltimore Gas and Electric Co. said the load caused numerous power outages throughout the metropolitan area.
But a long-awaited cold front from Canada is finally due to arrive today, and is expected eventually to bring lower temperatures and lower humidity.
The high of 103 degrees recorded yesterday in downtown Baltimore broke the old record of 101 degrees for the same date in 1988, according to the National Weather Service. The prediction is that temperatures will be in the low 90s today, with cooler air -- highs in the high 80s -- following the cold front tomorrow.
Last night, scattered thunderstorms brought some relief in several parts of the state. Showers were reported around Easton and in Anne Arundel County, where lightning set fire to utility poles and high winds felled trees onto power lines, cutting power to 13,000 households.
BG&E said power was quickly restored to 2,000 customers but the remainder would probably be without power until later this morning.
About 745 customers in downtown Baltimore lost power last night, including the Downtown Athletic Club, where a fire alarm was set off by the outage.
The Bermuda high pressure system sitting over the Southeast coast, which has been responsible for nine days of temperatures over 90 degrees, is breaking down, said meteorologist Fred Davis of the National Weather Service at Baltimore-Washington International Airport.
The hottest spot in the state yesterday was Waldorf, where the high was 104 degrees. It was 103 degrees in Annapolis, Bel Air and Hagerstown, and 101 degrees in Westminster, Frederick and Easton. But temperatures only reached the high 80s in Garrett County.
The hottest areas did not have the unhealthiest air. The worst places to be in Maryland -- for breathing that is -- were not the steamy pavements of downtown Baltimore but Millington, a small rural town in Kent County, and Edgewood.
"The concentrations of ozone are high downwind because it takes time for the chemical reactions to occur," explained Susan Wierman, deputy director for the state's Air Management Administration.
This did not mean Baltimore's air was not bad, she said, because readings at one station usually reflect a wide area. "You can't tell where the good air begins and the bad air stops." And the ozone can often circulate back over a metropolitan area.
During periods of high ozone readings, the state cautions people with heart or respiratory ailments to reduce their physical activity and stay inside.
People who spend a lot of time outside, such as construction workers, children at play or people jogging or bicycling also are at risk. "Even healthy people experience a reduction in their lung capacity," Ms. Wierman said.
The past week has been particularly smoggy. Five of the past eight days have registered ozone levels above federal standards. "This is definitely not a good year," Ms. Wierman said.
However, the air quality has not been as bad as the summer of 1988, when ozone levels were above the standard for 36 days.
Yesterday's highest bad-air reading, in Millington, reached 128 parts per billion for ozone. The air is considered unhealthy at 120 ppb.
BG&E reported record power usage yesterday, breaking the previous record of 5,490 megawatts set just last Friday. Beginning at 1 p.m., when peak usage hit 5,582 megawatts, the record was broken every hour, until it reached a high of 5,910 megawatts at 6 p.m., said BG&E spokesman John A. Metzger.
About 13,000 customers who were without power for various periods during the dayyesterday had it restored by evening. All these outages were believed to be heat-related "due to the tremendous strain put on the various components in the electric system," Mr. Metzger said. "Wires, transformers, fuses, capacitors, they all get hot."
Water system managers, concerned about lowering water pressure, are asking customers to cut back on water usage.
The dawn-to-dusk ban on outdoor watering in the city and three of the metropolitan counties continues, while administrators in Harford County urged its 23,000 water customers to begin conserving water voluntarily by taking shorter showers and using other water-saving techniques.
The conservation plea came after Harford County was forced to shut down its new water treatment plant in Havre de Grace Monday because of the Susquehanna River's unusually shallow low tides.
"These are the lowest low tide levels in the Susquehanna River since
1965," said Jackie Ludwig, a civil engineer with the county's Department of Public Works.
"We're at Mother Nature's mercy. Right now, we're just asking people to become aware of how much water they're using. If everybody conserves it is a manageable situation," she said.
The hot weather has caused short tempers. A dispute over turning on a fire hydrant erupted in gunfire Monday. A South Baltimore man who was shot was reported in satisfactory condition at University Medical Center last night, according to a spokeswoman.
Police said Donald Craig Arnold, 21, of the 1000 block of Wilmington Avenue, had turned on a fire hydrant about 4 p.m. Monday in an apparent attempt to gain some relief from the heat when he was confronted by a man who ordered him to turn it off.
When Mr. Arnold refused, the man shot him in the right arm with a handgun. Terry Lee Looney, 29, of the 1200 block of James Street, was charged with assault with intent to murder and a handgun violation, police said.