Effort targets mercury levels in newborns

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• Where mercury comes from

State and federal officials on Thursday announced a $1.4 million grant aimed at cutting the amount of toxic mercury passing through pregnant mothers to newborn babies in Minnesota’s portion of the Lake Superior region.

The Minnesota Department of Health will partner with the Grand Portage and Grand Marais locations of the Sawtooth Mountain Clinics and the Grand Portage Chippewa Tribe.

Cook County was targeted because newborns tested in that area had disproportionately high levels of mercury in their blood, said Seth Moore, tribal wildlife biologist for the Grand Portage band. Tribal members also tend to eat more fish than the general population, he said.

The grant from the Environmental Protection Agency is intended “to reduce mercury exposure risk for women and children who live along the North Shore of Lake Superior,” said Susan Hedman, Midwest region director of the EPA. “We want to help women along the North Shore reduce their exposure to mercury and avoid the health risks.”

The money comes from the federal Great Lakes Protection Fund and will pay for a combined study and education effort for patients at the Sawtooth clinics — namely, women of child-bearing age in Cook County — to find out how much fish they eat and to educate them on how much and what kinds of fish are safe to eat.

Officials said existing advisories about limiting fish consumption simply aren’t reaching enough women.

“We need a better strategy to solve this problem,” said Linda Bruemmer, director of the Minnesota Department of Health’s environmental division. “This is a pilot program that, we hope, can be rolled out throughout the Great Lakes basin.”

Alarming study

The effort, funded for four years, is a direct response to a study released in February by the Minnesota Department of Health that showed one of every 10 babies born in the Lake Superior region of Minnesota has unsafe levels of toxic mercury in his or her bloodstream.

Researchers looked at blood samples from 1,465 newborns in the Lake Superior area of Minnesota, Wisconsin and Michigan from 2008-10 for the study, which was paid for by the federal Environmental Protection Agency and the Minnesota Department of Health.

The results showed the highest levels of babies affected in Minnesota, at 10 percent, with 3 percent in Wisconsin and none in Michigan. Across the three-state region, 8 percent of babies tested had levels above the 5.8 micrograms per liter that the EPA considers safe. Some children tested showed levels as high as 211 micrograms per liter.

Fetuses, infants and children are most at risk from mercury exposure because even small amounts can harm the developing brain and nervous system.

“This means that some pregnant women in the Lake Superior region have mercury exposures that need to be reduced,” the study concluded.

It’s been known for decades that too much mercury can cause severe developmental problems in children and fetuses and neurological damage in adults.

Many studies have looked at the amount of mercury in fish, and some studies have looked at adult blood samples. But health officials said in February that it was the first study of its kind to measure and report mercury in newborn blood-spot samples and it wasn’t clear how dangerous the high levels of mercury were for babies.

Big fish to blame?

The report said the mercury exposure probably came late in pregnancy, close to the time of birth, and probably from the mothers eating fish or shellfish contaminated with methyl mercury. Other sources could be dental fillings or broken thermometers.

There was no difference in mercury levels between male and female babies, but babies born in the summer had higher levels of mercury.

“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,” the study concludes.

Health officials 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 trout, walleye or northern from Northland lakes or yellowfin tuna, shark, mackerel or orange roughy from the ocean. The state warns women and children not to eat any walleye over 20 inches or northern pike over 30 inches.

“Large lake trout (from Lake Superior) are an especially bad choice” because they are high in mercury, said the Grand Portage band’s Moore.

The mercury exposure from fish could lead to lower developmental levels as children grow.

Minnesota, Wisconsin and Michigan already have posted advisories for people — especially pregnant women and children — to limit the size and number of meals they eat of fish caught from many lakes and rivers. But the study suggests that information may not be reaching enough people.

Women “need more information on how to select fish low in mercury,” the February report concluded.

When in doubt, think smaller fish. Some of the best choices from Northland waters are smaller game fish, panfish, stream trout and salmon.

For more information on mercury in fish, including guidelines on which fish to eat, which fish to avoid and how often it’s safe to eat fish, go to www.health.state.mn.us/fish.

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