The AP investigation discovered traces of everything from sex hormones to drugs used to treat heart conditions and epilepsy. Experts say the majority of this contamination is most likely due to the body's natural excretion of the medication. Sewage treatment plants often fail to remove the drugs. They end up flowing into rivers and lakes, and then into drinking water plants.
"The amount found in our drinking water is minute...it is changing our environment and might be difficult to reverse," said Dr. Michael Wahl, Metropolitan Chicago Healthcare Council.
Studies have shown that pharmaceuticals are present in our nation's water bodies. The presence of these prescription and over-the-counter drugs has scientists concerned about the long-term effects on human health.
"Still do not know the long term effect it will have on humans," said Wahl ."More studies need to be done."
Further research suggest that certain drugs may cause ecological harm and may harm the environment.
"Male fish are now developing female sex characteristics, and that's not normal, and that happens because of the hormones and other medications that are in the environment," said Gary Gulezian, EPA Great Lakes Program.
The drugs that we take are not entirely absorbed by our bodies and are excreted and passed into wastewater and surface water. Experts say technology is not advanced enough to remove the chemicals.
"We're seeing the chemicals at extremely well levels and it's difficult to treat water when things are at that low a level," Wahl said.
AP tested 28 major water providers. Thirty-four remain to be tested, including Chicago. Tom LaPorte, the water department spokesperson, said, "We are confident our purified water is safe and meets all standards established for safety. Lake Michigan is a vast and stable fresh water source. We would also note that most pharmaceuticals enter water through waste streams. Chicago does not return treated water to the lake."
"People continue to drink the water that's coming from their taps and we're looking into it and would be taking steps to the extent those steps are warranted," said Wahl.
The AP report also disclosed that even users of bottled water do not avoid exposure. They says some bottlers simply repackage tap water and do not treat or test for pharmaceuticals. They also say home filtration systems can not remove the trace amounts of drugs. The experts ABC7 talked with said it is important to dispose of unwanted or expired medication to an approved medication disposal site in your community.