Be wary of fishing at these 13 waterbodies found to have ‘forever chemicals,’ Mass DPH says

Recent testing found fish from ponds, reservoirs, and lakes in select state parks have levels of the substances above levels recommended for consumption.

Walden Pond in Concord
Walden Pond in Concord Cody O'Loughlin/The New York Times

Henry David Thoreau once wrote extensively about fishing in his beloved Walden Pond, with some of his catch likely serving as dinner for the famed writer from time to time.

This week though, the Massachusetts Department of Public Health wrote a different takeaway on fishing at the storied pond: Be careful.

The pond is among the 13 lakes, ponds, and reservoirs within state parks where the department is advising the public to either refrain from fishing entirely, or to use caution when catching and consuming freshwater fish.

Recent testing revealed fish harvested from their waters contained levels of per- and polyfluoroalkyl substances — or PFAS, better known as “forever chemicals” — higher than what public health officials recommend for regular consumption.


PFAS are man-made chemicals commonly used in consumer products around the globe. As implied by their nickname, PFAS do not break down in the environment over time.

PFAS exposure has been linked to changes in liver and kidney function, “changes in thyroid hormone and cholesterol levels, and immune system effects,” according to the DPH.

“In addition, PFAS exposure has been shown to cause developmental effects to fetuses during pregnancy,” officials said in a news release. “Some studies also suggest an increased risk of developing cancer following long-term exposures to elevated levels of some PFAS.”

Elevated levels of PFAS were found in fish sampled from these bodies of water:

  • Ashland Reservoir in Ashland
  • Chicopee Reservoir in Chicopee
  • Lake Cochituate in Natick
  • Dennison Lake in Winchendon
  • Dunn Pond in Gardner
  • Fearing Pond in Plymouth
  • Houghton’s Pond in Milton
  • Pearce Lake in Saugus
  • Pequot Pond in Westfield
  • Lake Quinsigamond in Worcester
  • Walden Pond in Concord
  • Wallum Lake in Douglas
  • Watson Pond in Taunton

Notably, PFAS were not detected from surface water sampled at these locations at levels unsafe for swimming or other recreational activities, the DPH said.

The department’s fish consumption advisories for each site vary, and can range from a recommendation of consuming no more than two meals per week to no fish at all.

“The fish consumption advisories for the 13 waterbodies include guidance on the amount of fish that can be safely consumed from each individual location. This varies depending on the levels of PFAS found in the fish, other contaminants that have been evaluated in the past, and who might consume the fish,” officials said. “Advisories were developed for sensitive populations (including children under 12, people who are or may become pregnant, and nursing people) and for all others in the general population.”


According to the DPH, the advice applies to the consumption of all native game fish but does not apply to the state’s stocked trout.

“Stocked fish are raised in fish hatcheries and then released,” the department said. “Therefore, they are unlikely to spend enough time in a lake or pond to become contaminated.”

Public health officials said they prioritized testing at the 13 waterbodies because of their popularity for fishing and swimming, and because of the fact that they are located in or near communities with environmental justice populations.

These are areas where “the existing burden of disease and exposure to sources of pollution are greatest,” according to the DPH.

“Surface water testing at seven marine beaches, including Carson, Constitution, Savin Hill, and Tenean beaches in Boston Harbor; Revere Beach in Broad Sound; Kings Beach in Nahant Bay; and Wollaston Beach in Quincy Bay showed that these beaches are safe for swimming,” the DPH noted.


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