PITTSBURGH — Mine Safety Appliances Co., a maker of protective equipment, is replacing 200,000 filter cartridges in gas masks primarily used by law enforcement because of a design defect.

The cartridges contain carbon that could shift — if handled roughly or in transportation — and reduce the masks' service time, company spokesman Mark Deasy said.

The Pittsburgh-based company issued an advisory and will replace the cartridges for free.

A customer doing routine testing alerted MSA to the problem and the company followed up with its own tests, Deasy said.

Law enforcement agencies are the primary buyers of masks using the cartridges, Deasy said. They are designed to protect against tear gas and other chemical agents.

The New York Police Department said it had replaced nearly 24,000 masks — designed to protect officers during a terrorist attack — after the defect was discovered. The masks have become standard equipment for New York City patrol officers.

PITTSBURGH — The state Department of Environmental Protection fined FirstEnergy Corp. $25,000 for residue from a power plant smokestack that covered more than two dozen properties in June.The fine, the maximum allowed under the state's Air Pollution Control Act, is the second issued this year. The DEP fined the Akron, Ohio-based company $25,000 for a similar release in July 2006.The June incident at a coal-fired power plant in Shippingport, about 30 miles northwest of Pittsburgh, left gray, gritty material on 28 homes and properties in Beaver County.The problem was caused by a malfunction with the scrubbers, which clean emissions.

WILKES-BARRE — A 7-year-old girl and her 5-year-old brother drowned in a neighbor's backyard pool.The children, whose names were not immediately released pending notification of relatives, had been missing from their home nearby for a few hours when their bodies were found Monday evening, Luzerne County District Attorney David Lupas said.The in-ground pool was in the fenced-in backyard of a city police officer, Wilkes-Barre Detective Capt. Wayne Cooney confirmed, though authorities did not release the officer's name. Lupas said there was no indication of foul play.

HARRISBURG — An insect-borne virus has killed more than 100 deer in southwestern Pennsylvania, state wildlife officials said.Tests confirmed that the deer in Greene and Washington counties died of epizootic hemorrhagic disease, Dr. Walter Cottrell, wildlife veterinarian for the state Game Commission, said Monday.EHD is a common, seasonal virus among white-tailed deer, contracted by the bite of insects called biting midges. The virus, which does not spread from deer to deer by contact, can kill the animal in five to 10 days."Hunters need to know that EHD cannot be contracted by humans, furthermore it is extremely rare — and highly unlikely — for this variant to cause clinical signs in traditional livestock, such as cattle, sheep or goats," Cottrell said.The virus, which was found in the same area in 2002, should stop spreading after the first hard frost, which will kill the insects, Cottrell said.While EHD is not infectious to humans, deer displaying severe symptoms of the virus might not be suitable to eat, officials said. Symptoms include excessive drooling, weakness and a loss of fear of humans.