Sample results from Pennsylvania's two longest-running mercury collection sites reinforce other state and national studies that show the toxin tends to concentrate around local emission sources, creating "hot spots" of contamination.

Data collected over eight years by Penn State University for the Department of Environmental Protection show mercury levels 47 percent higher in areas closer to power plants, according to results released today.

"The data show that if Pennsylvania wants to protect the unborn, young children and other vulnerable populations, mercury needs to be controlled at its source," DEP Secretary Kathleen A. McGinty said.

The data were collected at two sites -- Cresson in Cambria County and Wellsboro in Tioga County -- between 1997 and 2004. The sites were selected because of their significantly different profile relative to locations to nearby coal-fired electric generating stations.

The Cresson site, which is fairly close to and downwind of a number of large coal-fired electric utilities in southwestern Pennsylvania, reported an average mercury deposit rate that was 47 percent higher than results collected at Wellsboro.

Wellsboro is at a much greater distance from any coal-fired utilities, the DEP reported.

More details in tomorrow's Pittsburgh Post-Gazette.