Researchers at the University of North Dakota say there's new evidence that mercury levels in fish are not as dangerous as previously thought.
Researchers at the Energy and Environmental Research Center in Grand Forks say the trace mineral selenium is just as important as the amount of mercury in fish.
Research Scientist Nick Ralston said brain damage from mercury poisoning happens when mercury depletes selenium in the body. He said if fish contain more selenium than mercury, they are safe to eat.
He wants to see a new standard for fish consumption advisories.
"I think one of the most urgent things is we have to start looking into the lake mercury-selenium ratios," Ralston said. "We have to see what the selenium health benefit values are for fish from various locations to establish which fish are safe and if there are places where fish are not safe to make sure people are very aware of that."
Ralston said it's urgent to conduct research that identifies which lakes have low levels of selenium so fish from those lakes can be identified as the most dangerous for human consumption.
He said his examination of selenium levels in fish shows most Minnesota lakes are likely to be rich in selenium, except in the northern part of the state where he believes many lakes have low selenium levels.
Minnesota's fish consumption advisory coordinator is not convinced. Patricia McCann said the new research is not definitive and will not affect how Minnesota establishes fish consumption advisories.