By Shereen Siewert
Wisconsin Department of Natural Resources officials agree with health department recommendations for a Wausau park with toxic compounds that pose an unacceptable cancer risk, but city officials have so far not said whether they’ll comply.
An updated risk assessment for Riverside Park was released last week by the Wisconsin Department of Health Services, outlining a serious concern for children and adults who use the space. Health officials are recommending Wausau take immediate steps to limit exposure to the toxic soil by covering the area with wood chips and posting warning signs. The DNR concurs with those recommendations.
“Removing the impacted soil is an ideal solution in this area given its accessibility to park users,” said DNR hydrogeologist Matt Thompson, in an email to Wausau Pilot & Review. “The act of covering and signage has been implemented elsewhere in the state and can be an effective means of deterring individuals from digging in contaminated soils.”
Soils in the affected area will eventually be excavated, but Thompson said he does not know the city’s timeline. City officials including Public Works Director Eric Lindman have not responded to questions submitted last week about the status of the park’s remediation plan, which has been delayed several times.
The most recent DHS report was summarized by Dr. Jeremiah Yee, a toxicologist with the Bureau of Environmental and Occupational Health, in response to a request from Dist. 3 Alder Tom Kilian.
“Our health assessment…suggests that the dioxin is at high enough of a level to cause unacceptable cancer risk,” Yee said.
A nationally-known toxicologist who played a key role in the historic Love Canal cleanup, Stephen Lester, toured the park and the Thomas Street neighborhood on Sunday, one day after appearing at Wausau’s first-ever environmental health summit. Lester, who is now the director of the Center for Health, Environment and Justice, was sharply critical of a 2018 study that did not include cancer risk in its assessment that was used by prior administration officials in Wausau to deny repeated requests for action.
Kilian, who is a founding member of the grassroots advocacy group Citizens for a Clean Wausau, said Lester’s appearance as he toured the area was especially meaningful to the group and the residents in the neighborhood who have fought the city for years in their quest for environmental safety.
Dioxins are highly toxic and can cause cancer, reproductive and developmental problems, damage to the immune system, and can interfere with hormones, according to the Environmental Protection Agency. They are persistent organic pollutants that take a long time to break down once they are in the environment.
The DHS employs a “toxic equivalency factor” risk assessment approach that compares the toxicity of different combinations of dioxins and dioxin-like compounds. Cancer risk is estimated by calculating a dose of a chemical received and multiplying that dose by the cancer-causing potential of that chemical, Yee said. That is also known as the “cancer slope factor” or “cancer potency” factor in such calculations.
“In brief, there is assumed to be no ‘safe dose’ of a chemical that can cause cancer,” the DHS assessment letter reads.
The analysis, first reported last week by Wausau Pilot & Review, is the latest development in a years-long fight to protect the public from cancer-causing chemicals on the city’s near-west side, where decades of manufacturing activities have resulted in contamination and cleanup efforts.
Wausau Pilot & Review reached out last week to Lindman, along with Parks Director Jamie Polley and Wausau Mayor Katie Rosenberg with questions about whether the city will heed the DHS warning. No one has responded.
