Retired Maine Mine Causing Widespread Contamination [VIDEO]

Toxic metals from an open pit mine in Maine are causing widespread contamination in nearby sediment, a Dartmouth study reveals.

The Callahan Mine Site located in the Goose Pond estuary was once a hard-rock mine, but has since retired and is currently being cleaned up by the Environmental Protection Agency (EPA).

While many studies have been done regarding the effects of mining contamination on human health and wildlife, the paper, published in the journal Archives of Environmental Contamination and Toxicology, is one of the first to examine the impacts of an open pit mine on a estuary and the coastal marine food web.

The scientists worked as part of Dartmouth's Toxic Metal Superfund Research Program studying metal concentrations in the sediment, water and Atlantic killifish, the latter of which represents a key food for larger fish species consumed by humans.

In doing so, the researchers discovered elevated levels of copper, zinc, cadmium and lead in all three. And while this was largely expected, the scientists were surprised by the high concentrations in distinct areas of the marsh -- an observation indicating metals are constantly seeping from the mine's waste rock piles and debris. In fact, the study revealed the site is leaking copper, zinc and lead into the Gulf of Maine at rates only surpassed by some areas of the Boston Harbor, the study found.

Exactly how far spread the effects of this contamination reach is unclear, though the results showed they have the potential to affect the region's fish and birds. For this reasons, the researchers warn that humans who consume seafood from the area may be putting themselves at risk of contamination.

Going forward, the scientists say they hope their findings will inform the EPA's cleanup efforts as well as provide a baseline for future site evaluations.