By Julia Munemo
Juniors Linda Shin ’17 and Matthew Goss ’17 spent this summer measuring polychlorinated biphenyl (PCB) levels in crayfish and trout from the Hoosic River. Their goal was to help determine if levels of the synthetic chemical compound have decreased in recent years.
The production of PCBs, which cause cancer in animals and is a probable human carcinogen, was banned in 1979. Before that date, however, PCBs were used at Sprague Electric in North Adams, and from that site they leaked into the Hoosic River. As a result, fishing in the river is limited to catch and release, and swimming is unadvised.
While it’s too early to say conclusively if it’s now safe to swim in or eat fish from the river, the students are proud of their contribution to this long-term research project. “As a chemistry major with an interest in the environment, I was excited for the opportunity to spend the summer doing environmentally focused chemistry,” says Goss, who is a member of the Outing Club and has taken several courses in environmental science.
The project started when Kris Hansen ’91 conducted research on PCB levels near the former Sprague site for her honors thesis. Chemistry professor David Richardson, who teaches the course Toxicology and Cancer, got involved 15 years later, when Elaine Denny ’04 wanted to revisit the question. Their findings—which showed spikes in PCB levels near Sprague—were published in the journal Northeastern Geology & Environmental Sciences in 2005.
Research into PCB levels in the Hoosic has continued ever since. Several years ago, chemistry professor Jay Thoman ’82—who has experience teaching Introduction to Environmental Science and conducting research on chemical pollutants in soils and drinking water—joined the team.
“We’ve been trying to determine just how polluted is the river and if it’s trending downward,” says Richardson. Student researchers work in the lab each summer, and in 2014, Allie Rowe ’15 and Marissa Shieh ’14 collected crayfish and established a system for local anglers to donate trout to the project. Those are the samples Shin and Goss spent the summer processing.
“After freeze-drying and dissecting each sample, we end up with a couple teaspoons of a powder-like substance that you can compare to coffee grounds,” Goss says. “We run hexane through the ‘grounds’ to extract the PCBs into the organic solvent.” The pair then conducts a series of chemical processes to separate the PCBs from any other compounds present in the resulting liquid. Finally, they analyze the sample with a tool called a gas chromatagraph mass spectrometer, which helps them determine the concentration of PCBs present.
“While more data need to be analyzed and our results are preliminary, we found PCB concentrations in small trout to be lower than EPA guidelines,” says Thoman. The team presented those findings to the Hoosic River Watershed Association at their recent State of the River Conference. “One man at the meeting suggested that because the river is deemed unfishable due to contaminants, in some ways it’s actually healthier than many other rivers,” says Goss. “He was speaking about how you find such big fish in the river, which I understand is really unusual.”