Environmental Science & Technology Letters

Pharmaceuticals in surface water of lakes and streams are a real concern. They are capable of causing developmental and other health issues in aquatic life. Scientists consider treated wastewater released into the environment as the main source.

But now one team reveals in ACS’ journalEnvironmental Science & Technology Letters that other important factors are also contributing to the problem.

One diabetes drug, metformin, has been widely detected in treated wastewater, in naturally occurring water bodies and even in tap water. Some researchers have shown that the drug can cause genetic changes in fish. Similar studies have found that other pharmaceuticals can also have various health effects on aquatic life. While treated wastewater that is introduced back into the environment is an obvious route for drugs to enter waterways, Paul M. Bradley and colleagues wanted to see whether other sources might be involved.

His researchers tested water from 59 streams across 4 states in the South Eastern U.S., both close to and far away from wastewater treatment plants. The samples contained a wide range of pharmaceuticals and other active compounds, including metformin, nicotine and the anti-seizure medication carbamazepine, at varying concentrations. Their results confirmed that wastewater plants are important sources of pharmaceuticals, but they also demonstrated that these compounds are common in streams that aren’t fed by wastewater plants. This suggests that urban run-off and the below-surface movement of water could be important contributors to the flow of drugs into streams.