Choosing Fish To Protect Health
Most health scientists agree that eating fish once or twice a week is good for our health as long as the fish are low in contaminants. The Minnesota Department of Health's updated fish consumption guidelines provide consumers and anglers with the information to help them make choices about the fish they eat.
"Most people can benefit from including more fish in their diet," said Pat McCann, MDH fish advisory coordinator. "Fish are a great source of low fat protein. Eating fish contributes to brain and eye development in the growing fetus. The Omega-3 fatty acids found in fish promote heart health for all adults."
MDH's guidelines provide clear, simple advice for two groups of people: children and women who are or may become pregnant; and all other people. Children and women who are or may become pregnant are more vulnerable to health effects from the contaminants in fish. MDH has advice for these groups that applies statewide and also specific advice for lakes and rivers where contaminants have been measured. The department's updated site-specific advice includes new data on mercury and levels of the perfluorochemical PFOS in fish. Both kinds of advice are available at: www.health.state.mn.us
A common misconception is that fish from wilderness lakes have lower levels of contaminants than fish from city lakes. Likewise, people think fish from clean-looking lakes and rivers have fewer contaminants than fish from dirty-looking lakes and rivers. Years of sampling fish from waters across the state show this is not correct, especially for mercury, the contaminant of most concern in Minnesota. Fish from city lakes are generally lower in mercury than fish from some lakes in the northeastern part of the state. In any lake, mercury levels are higher in older fish and in fish that eat other fish.
Watersheds in Minnesota receive mercury from the atmosphere rather than soil or rock. About 90 percent of the mercury in Minnesota lakes comes from outside the state and can originate from anywhere in the world. The amount of mercury moving from air into lakes is fairly even across the state. Differences in mercury levels in Minnesota fish are a result of how the individual watersheds and lakes process mercury.
Regarding perfluorochemicals in fish, MDH and its partners now have data from the Mississippi and St. Croix Rivers, a number of metro area lakes and two lakes near Duluth. The pattern and sources of contamination are not yet clear or well understood. While most of the data leads to unrestricted or one fish meal a week advice, four metro area lakes (Twin Lakes, Calhoun, Johanna and Lake Elmo) have levels of one perfluorochemical, PFOS, that require the more restrictive advice of only one fish meal per month. The Minnesota Pollution Control Agency is investigating the sources of perfluorochemicals in fish and determining if there is a pattern to the findings. MDH will continue to work with MPCA and the Department of Natural Resources to learn more about PFCs in fish.
While contaminants in fish are cause for concern, the fish consumption advisory helps Minnesotans obtain the benefits from eating fish while keeping their health risks from contaminants as low as possible.