Testing reveals that at least 46 million Americans are affected by trace amounts of pharmaceuticals in drinking water. That's five million more people than originally thought.

Associated Press stories earlier this year led to legislative hearings and calls for mandatory testing of water supplies.

Drinking water has now been analyzed in 27 more metropolitan areas. And 17 of them show drug-contaminated drinking water.

Among the communities is Colorado Springs.

The majority of U.S. cities have not yet tested their drinking water, including the country's largest water provider in New York.

Tests showed no drugs in the water of eight cities, including Boston, Phoenix, and Seattle.

Drugs are flushed into sewers and waterways through human waste. Researchers are finding evidence that even very diluted drug residue may harm aquatic animals and the workings of human cells.