May 3, 2018
State issues updated fish consumption guidelines for 2018
New advice to not eat largemouth bass from Lake Harriet or any fish from Lake Elmo
The Minnesota Department of Health (MDH) today released new recommendations on how often to eat fish from certain Minnesota waters. These guidelines are updated as new monitoring data become available and are developed in collaboration with the Minnesota Department of Natural Resources (DNR) and the Minnesota Pollution Control Agency (MPCA).
This year’s guidance includes updated advice for six Twin Cities area lakes — Bde Maka Ska (formerly Calhoun), Elmo, Harriet, Lake of the Isles, Johanna and Twin – and the Mississippi River between the Ford Dam and the lock and dam at Hastings based on their levels of one type of contaminant known as perfluorooctane sulfonate (PFOS). In the past, these waters had levels of PFOS contamination that prompted a guidance limit of one meal per month for certain fish species. Fortunately the PFOS levels in the fish from five of these six lakes declined over the last decade, but the levels in fish from Washington County’s Lake Elmo remained high.
Based on updated scientific evidence and risk assessment for PFOS, MDH last month changed the level at which it begins to advise to not eat the fish at all – from 800 ng/g (nanograms per gram) to 200 ng/g – adding greater health protection. Applying this new threshold led to more restrictive fish consumption advice for some species in the six identified lakes, including advice to not eat any fish from Lake Elmo and to not eat largemouth bass from Lake Harriet in Minneapolis.
In some studies, higher levels of PFOS in a person’s body have been associated with higher cholesterol, changes to liver function, changes in thyroid hormone levels and reduced immune response. Given the potential health effects of long-term exposure at elevated levels, MDH Assistant Commissioner Paul Allwood said the new guidance applies to everyone, not just higher risk populations.
“We recognize that some people may like to eat the fish they catch from these lakes, but this recommendation is prudent based on the available information,” said Allwood. “It’s important to note that our guidelines are based on long-term exposure, not the kind of short-term exposure you might have from a few meals.”
Allwood emphasized that the fish consumption guidelines are intended to help people make healthy and well-informed choices about the fish they eat. While fish can contain some contaminants posing health risks at high levels, fish consumption also can have health benefits.
“Most people can benefit from including more fish in their diet,” he said. “Fish are a great source of low-fat protein, and omega-3 fatty acids found in fish may promote heart and overall health. Our goal is to provide Minnesotans with the information they need to make informed choices.”
MDH’s site-specific meal advice helps people limit exposure to contaminants like PCBs, mercury and PFOS by choosing fish lower in contaminants. MDH also offers more general statewide safe-eating guidelines for avoiding exposure to contaminants in fish from all sources. Information on fish contamination in local lakes and waters also can be found on the DNR LakeFinder web app.
T.J. DeBates, the DNR’s east metro fisheries supervisor, said fishing is a fun activity enjoyed by nearly 1.4 million licensed anglers in Minnesota. He pointed out that even with the new recommendations, fishing can still be done in Lake Elmo and Lake Harriet on a catch-and-release basis.
“Even if you don’t eat the fish you catch, fishing is still a great outdoors activity, with many anglers participating in catch and release,” DeBates said.
MDH and MPCA officials say the most likely source of the elevated levels of PFOS in Lake Elmo is surface and groundwater contaminated by the former 3M disposal site in Oakdale. The recent 3M settlement will allow further investigation and action as warranted to reduce the contamination. PFOS levels in Lake Harriet have been declining since the source of the PFOS – the nearby Douglas Corporation plating facility – was addressed starting in 2010. If PFOS levels in Lake Harriet continue to decline, the advice to avoid eating largemouth bass from the lake is likely to change as well.
The guidance released today focuses on fish from those six lakes and from the Mississippi River between the Ford Dam and the Hastings lock and dam because those were the bodies of water for which recent fish tissue data (from within the past five years) were available. This is because water contamination levels can drop quickly as contaminant sources are eliminated or mitigated. Over the next year, state agencies will collect and analyze fish from other waters to update the data and guidance. In the coming months, MDH also will complete a more in-depth assessment of the potential benefits and risks of consuming fish containing PFOS at low levels.