USGS Tests New Technology in Ohio Streams for Detecting Pharmaceuticals,
Other Low-Level Contaminants

By John Tertuliani and Diane Noserale

March 30, 2007

USGS scientist David Alvarez developed and patented the Polar Organic
Chemical Integrated Sampler, one of the newest tools to increase the
knowledge and understanding of emerging contaminants. POCIS is a portable
device so sensitive that if you breathe on it, it can detect the coffee you had
for breakfast. POCIS is becoming an important tool in learning more about
water quality.

Forgoing their morning coffee and bug spray last spring, USGS scientists, led
by John Tertuliani, set the POCIS devices at 18 sites on Tinkers Creek, the
largest tributary to the Cuyahoga River, which is the second largest tributary
to Lake Erie in Ohio.

Tinkers Creek was chosen as a study site after biological surveys by the Ohio
Environmental Protection Agency indicated that the numbers of fish in the
population did not match the available habitat. When fish are not abundant
enough to use the habitat available, it is normally a sign of harmful chemical
compounds in the water. But chemical surveys done in conjunction with the
biological surveys did not identify the usual chemical suspects. The Ohio
Environmental Protection Agency then asked Tertuliani for help investigating
whether emerging contaminants were having an effect on the fish population.

The POCIS device is designed to mimic the exposure to chemicals that aquatic
organisms, such as fish, would experience while living in the stream. It can
accumulate trace to ultra-trace concentrations of chemicals over a long-term
exposure, which is proving to be a more effective approach for these kinds of
studies than traditional monitoring methods such as grab sampling. By sampling
over an extended period, chemicals in the water are eventually captured in the
POCIS device. The membranes in the device are able to accumulate the
emerging contaminants in concentrations high enough to be identified.