At least 271 million pounds of pharmaceutical ingredients have been legally released into U.S. lakes, rivers and streams, many of which are sources of drinking water, says the Associated Press.
These ingredients are used to make drugs and various other products. For example, nitroglycerin is used in explosives and in a heart drug, while lithium is used to treat bipolar disorder and to make ceramics.
The federal government and industry officials say the amount of such compounds released into waterways isn't known because they're not tracked, at least not as drug ingredients. But the AP analysis of 20 years of federal records identified 22 compounds that show up on two lists.
The U.S. Food and Drug Administration monitors these ingredients as active pharmaceutical agents, while the Environmental Protection Agency classifies them as industrial chemicals.
The AP analysis didn't determine how much drug makers and other manufacturers each contribute to the 271 million pounds. The news agency also said limited federal monitoring means that figure is well below what's actually released into U.S.