Fish located near coal-fired power plants have lower levels of mercury than fish that live much further away, a new study from North Carolina State University has found.
The surprising finding appears to be linked to high levels of another chemical, selenium, found near such facilities, which unfortunately poses problems of its own.
"We found that fish in lakes located at least 30 kilometers (km) from a coal-fired power plant had mercury levels more than three times higher than fish of the same species in lakes that are within 10 km of a plant," says Dana Sackett, a Ph.D. student at NC State and the lead author of a paper describing the study. "This information will inform health and wildlife officials who make determinations about fish consumption advisories and wildlife management decisions."
The findings are surprising because coal-fired power plants are the leading source of mercury air emissions globally, and a significant amount of that mercury is expected to settle out of the air within 10 km of a plant's smokestacks. Mercury is a bioaccumulative toxin that builds up in animal tissues - including fish - and can pose public health problems related to fish consumption.