SOUTHWICK — Congamond Lake has high enough PFAS contamination that the state recently issued an advisory recommending that individuals should eat fish caught in the three ponds no more than once a week.

Swimming poses no significant pollution risk, the state Department of Public Health advisory says.

“There was no recommendation related to the lake’s water if you’re just swimming,” said town Health Director Thomas Hibert.

Drinking a large amount of the water could be a risk, he said. But getting some pond water in one’s mouth while swimming isn’t considered a health hazard.

“That’s not really a concern,” Hibert said, adding the PFAS level measured in the ponds was 17.3 nanograms per liter, which is below the 20 nanograms per liter that would trigger having the waters posted as potentially hazardous.

Hibert noted that while the state asks most people to consume no more than one fish per week from Congamond, there is a stricter recommendation for children under 12 and for people who are nursing, pregnant, or who may become pregnant. These people shouldn’t eat any fish from the ponds.

When conducting the survey at the lake, researchers sampled the water in various locations, primarily those considered swimming areas, and caught three different fish types: brown bullheads — a type of catfish — bluegills, and pumpkinseeds, also known as pond perch.

The highest concentrations of PFAS in the fish tissues sampled was in bluegills, while pumpkinseed had the lowest. Largemouth bass sampled, but not caught in the ponds by the researchers, had the largest amount of PFAS contamination, according to the report.

The fish sampled from the ponds exceeded the PFAS limit of 0.22 parts per billion, which the DPH considers an “action level” advisory.

The advisory will remain in effect unless further research indicates that concentrations have declined, according to the DPH.

In the summer and fall of 2022, surface water and fish tissue samples were collected from 52 water bodies throughout the state, including Congamond Lake, according to a report issued by the state’s Department of Environmental Protection.

While these efforts focused on water bodies near known or suspected sources of PFAS that were expected to have high PFAS concentrations, samples were also collected at six water bodies in rural areas for comparison, according to the report.

It’s unclear in the report if Congamond was one of the rural area bodies of water sampled. The closest known area of high PFAS concentrations is the North Side of Westfield, around Westfield-Barnes Regional Airport, which is over seven miles away.

Hibert acknowledged that it would seem unlikely that Congamond Lakes would have a PFAS contamination problem, given there are no former or current industrial sites in town which have been identified as contaminated.

However, Hibert said, “We’re learning it’s in everything and everywhere.”

The DEP report also said PFAS contamination is a widespread problem.

“PFAS concentrations in surface water and fish tissue in many states and countries continue to be a major concern for human health and the environment. Although limited to freshwaters, findings from this study add to the growing body of evidence that PFAS are ubiquitous in the environment,” according to the report.

In fact, according to the DEP report, every body of water tested had measurable levels of PFAS contamination in the waters and in fish caught.

PFAS, short for per- and polyfluoroalkyl substances, are a group of chemicals used since the 1950s to manufacture stain-resistant, water-resistant and non-stick products, and are widely used in common consumer products such as food packaging, outdoor clothing, coatings, carpets, leather goods, and other products. They have also been used in firefighting foam, as well as in other industrial processes. Runoff from firefighting foam at Barnes is believed to have caused the high levels of PFAS contamination in the groundwater in Westfield.

According to a fact sheet from the DPH, studies of laboratory animals and people indicate that exposure to PFAS can cause adverse health effects.

In humans, PFAS have been associated with increased levels of cholesterol and liver enzymes, increased risk of high blood pressure or pre-eclampsia during pregnancy, slightly decreased birth weights, and decreased response to vaccines in children.

There is also evidence that long-term exposure to elevated levels of PFOA — a component or “analyte” of PFAS — may increase the risk of both kidney and testicular cancer in humans.

The DPH also advised that the likelihood of experiencing health effects associated with PFAS increases with exposure to higher amounts of PFAS.

“It’s also important to keep in mind that health effects associated with PFAS are not specific to PFAS — they can also be caused by many other factors. As a result, it is not possible to link a person’s PFAS exposure to any previous, current, or future health effects,” according to the DPH fact sheet.

Despite extensive research, there are still some gaps in scientists’ understanding of PFAS toxicity. Currently, scientists are still learning about the health effects of exposures to mixtures of types of PFAS and about differences in how laboratory animals and humans respond to PFAS, according to the DPH fact sheet.