Mercury levels high in North Shore babies

(Click on audio mp3 above to hear an interview with study author and lead research scientist Pat McCann of the Minnesota Department of Health)

One in 10 babies along Minnesota's North Shore are born with unhealthy levels of mercury in their bodies. That, according to a new report on contamination around Lake Superior.

Researchers at the Minnesota Department of Health said they found that some of the 1,465 children they tested had very high concentrations. Mercury is a pollutant that can cause neurological damage and is distributed around the world, primarily by coal-fired power plants.

Researchers also found that the Minnesota infants were more likely to have unhealthy mercury levels in their blood than their counterparts in Wisconsin and Michigan.

According to Pat McCann, the research scientist who conducted the study for the Health Department and the Environmental Protection Agency, babies born in the summer months, had more mercury than those born in winter. “This seasonal effect suggests that increased consumption of locally caught fish during the warm months is an important source of pregnant women’s mercury exposure in this region,” said McCann.

"People could be eating enough fish to cause exposures that we are concerned about," she said. A mother eating as few as two meals per week of fish high in mercury could cause newborn blood levels to reach unacceptable levels. That includes large walleyes or northerns from Northland lakes. The state warns women and children not to eat any walleye over 20 inches or northern pike over 30 inches.

Mercury goes into the air when coal and other fossil fuels are burned and then falls back to Earth. In the U.S., about half of all mercury emissions come from coal-fired power plants. In Minnesota, taconite plants also are a large source.

Between 2008 and 2010 blood samples were taken from infants born around the Lake Superior basin. The majority by far were from Minnesota, where the basin extends from Duluth to Hibbing and up along the shore to the Canadian border. In all, 8 percent of the babies had blood concentrations above the EPA health standard -- up to a thousand times higher. In Minnesota, 10 percent of the blood samples had mercury levels above the healthy standard.

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