State health officials are warning residents against consuming native fish caught at 13 state parks because of elevated levels of PFAS in the water.

The Massachusetts Department of Public Health issued new health advisories this week after recent testing found wild fish in those parks contained higher than recommended levels of a group of synthetic chemicals known as PFAS. The fish tested contained varying levels of PFAS, so the advisories range from eating no native fish from some bodies of water to no more than two meals a week of native fish from others.

PFAS, an abbreviation for perfluoroalkyl and polyfluoroalkyl substances, are a group of synthetic chemicals manufactured and used in consumer products and industries worldwide. Exposure to certain PFAS have been linked to changes in liver and kidney function, changes in thyroid hormone and cholesterol levels, and immune system effects. Some studies also suggest an increased risk of developing cancer following long-term exposure to elevated levels of some PFAS.

Marc Nascarella, the director of the environmental toxicology program at the Department of Public Health, said other state and federal agencies have PFAS testing programs, but his department's testing prioritized areas that are popular for fishing and swimming. None of the bodies of water tested were deemed unsafe for swimming.

"We actually sampled 146 individual fish at each water body," Nascarella explained. "And we sampled it the way you would eat your dinner, not the whole fish, but the fillet."

Fish consumption guidelines to limit PFAS exposure

Click here to see all freshwater fish advisories, including those for mercury and other hazards.

  • Ashland Reservoir in Ashland: Limit all fish to one meal per month.
  • Chicopee Reservoir in Chicopee: Do not eat any fish.
  • Dennison Lake in Winchendon: Limit all fish to two meals per month.
  • Dunn Pond in Gardner: Limit all fish to one meal per month.
  • Fearing Pond in Plymouth: Limit all fish to two meals per week.
  • Houghtons Pond in Milton: Limit all fish to one meal per week.
  • Lake Cochituate in Natick: Do not eat any American eel, and limit other species to one meal per month.
  • Lake Quinsigamond in Worcester: Limit all fish to one meal per two-month period.
  • Pearce Lake in Saugus: Limit all fish to two meals per week.
  • Pequot Pond in Westfield: Limit all fish to one meal per two-month period.
  • Walden Pond in Concord: Limit all fish to two meals per month.
  • Wallum Lake in Douglas: Limit all fish to two meals per month.
  • Watsons Pond in Taunton: Limit all fish to one meal per week.

While the advisories apply to all native game fish, they do not apply to stocked trout, which are raised in one of five fish hatcheries and then released into roughly 500 bodies of water across the state. The Department of Public Health said stocked trout are not likely to spend enough time in a lake or pond to become contaminated.

Todd Richards, assistant director of fisheries at Mass Wildlife, said the state encourages people to fish and currently has about 200,000 licensed anglers. But he noted that while trout from the state's long-running stocking program may be safe, PFAS levels in wild fish aren't likely to go down anytime soon.

"The key to restoring these water bodies is pollution prevention and stopping the source," he explained. "We do know that once PFAS stop accumulating in the waters, over time those water bodies can be restored. It's taken decades for a lot of these water bodies to return to levels where fish are safe to eat because of mercury."

Deirdre Cummings, legislative director at MASSPIRG, said she's not surprised PFAS levels in wild fish exceed recommended levels in Massachusetts waters. She applauds the Department of Public Health for testing for the chemicals, calling it a step in the right direction.

"This is an urgent problem," she said, "and unless we can turn off the tap and stop these chemicals getting into our environment, this problem will get worse and escalate over time."

Cummings says MASSPIRG supports a bill that was recently filed by state Sen. Julian Cyr and state Rep. Kate Hogan, which calls for banning the use of PFAS statewide by 2030.