Streams across Pennsylvania and the United States are contaminated with a wide range of chemicals, according to a recent study by the Toxic Substances Hydrology Program of the United States Geological Survey.

The study, which sampled 139 streams in 30 states, found at least one or more chemicals in 80 percent of the streams sampled.

According to the report, the chemicals found include pharmaceuticals and hormones, but were generally found at low concentrations. However, little is known about the effects of these chemicals at low concentrations in humans and aquatic organisms.

"The concentrations were at a part per billion in most cases," said Herbert Buxton, one of the study's authors.

Although the concentrations were low, some of the compounds found in the streams are harmful in low concentrations.

"Some of the compounds that were found are hormonally active in amounts less that one part per billion," Buxton said.

The compounds, which include some antibiotics, are more harmful to the plants and wild life of the streams than to humans, Buxton said.

"We are talking about low concentrations, but they cause alarm," he said.

While the findings are startling, they are not representative of streams across the nation.

The streams selected were those Buxton and other members of his team felt were susceptible to contamination from human, industrial and agricultural wastewater.

As a result, the selected streams are "indicative of the worst case scenarios," Buxton said.

In addition, the selected streams are those with a history of infection by waste sources.

The streams studied in Pennsylvania were no exception.

The samples from Lebanon, Lancaster, Schuylkill and Cumberland counties showed similar results.

According to John Nantz of the USGS, nothing out of the ordinary was found.

"The streams were not at levels thus far that we should be concerned about," Nantz said.

The wastewater found in the Pennsylvania samples were all a result of agricultural and human influence, Nantz said.

For local residents, the contamination of the streams studied should not be a worry.

David Nebel, of the State College Borough Water Authority, said the water source for State College residents is a network of 23 wells and a reservoir. The reservoir, the only water that residents get from a stream, is filtered, he said. The well water does not go through the same filter.

The study, which was conducted between 1999 and 2000, is the result of newly discovered methods of water filtering analysis.

According to Buxton, the USGS hopes to perform similar studies on wells and source waters.

For researchers such as Buxton and Nantz, this study has been helpful.

"This report was very informative for scientists," Nantz said. "This whole report was to let people know we can do this."