Source of cat-urine smell unknown

NEW CASTLE, Pa. -- Pennsylvania environmental officials can't explain why residents of one city thought part of their town smelled like cat urine last year. The New Castle News reports a state Department of Environmental Protection report was inconclusive. The department said it's likely some kind of waste containing mesityl oxide mixed with some kind of sulfur compound to create the smell. But air samples and testing of substances at the city's sewage treatment plant didn't turn up a source of the substances.