MILLBROOK, N.Y., Aug. 25 (UPI) -- Both prescription and illegal drugs can become concentrated in local waterways. New research shows amphetamine levels can become high enough in some urban streams to alter the base of the food chain.
As part of an ecological monitoring project, researchers at the Cary Institute of Ecosystem Studies measured the levels of several drug types in streams in and around Baltimore, Md. A mix of urban and rural sites within the Gwynns Falls watershed were tested.
Traces of several drugs, including amphetamines, were found at all of the sites. The highest concentrations of illegal drugs were measured at stream sites closest to the city of Baltimore.
"Around the world, treated and untreated wastewater entering surface waters contains pharmaceuticals and illicit drugs that originate from human consumption and excretion, manufacturing processes, or improper disposal," lead researcher Sylvia S. Lee said in a news release.
In follow-up tests, researchers built an artificial stream and studied the effects of amphetamines -- found in drugs for ADHD as well as illicit drugs like cocaine and ecstasy -- on small aquatic plants and animals.
"We have every reason to suspect that the release of stimulants to aquatic environments is on the rise across the globe, yet little is known about the ecological consequences of this pollution," said Emma J. Rosi-Marshall, a freshwater ecologist at the Cary Institute. "We found that when artificial streams were exposed to amphetamine at a concentration similar to what we found in parts of the Gwynns Falls watershed, there were measurable and concerning effects to the base of the aquatic food web."
Test streams were high concentrations of amphetamines were released featured less biofilm growth, altered bacterial and diatom communities and early-emerging aquatic insects.
"As society continues to grapple with aging wastewater infrastructure and escalating pharmaceutical and illicit drug use, we need to consider collateral damages to our freshwater resources," Rosi-Marshall added. "More work is needed on the ecological fate of these pollutants and the threat they pose to aquatic life and water quality. Ultimately, solutions will lie in innovations in the way we manage wastewater."
The results of the experiments and field work were detailed in a new paper published this week in the journal Environmental Science and Technology.