By Shereen Siewert

Toxicologists with the Wisconsin Department of Health Services is recommending Wausau take steps to keep children away from city-owned property where high concentrations of heavy metals were detected earlier this year.

Test results at 1300 Cleveland Ave., once targeted for potential redevelopment, show high concentrations of substances including thallium, which is now banned in the U.S. due to its extreme toxicity to humans. Portions of the property are not fenced and can be easily accessed by the public.

In their letter to the city, DHS toxicologists also caution that residents living adjacent to the property should implement urban gardening practices and avoid tracking soil into their homes to avoid potential exposure. Among their recommendations: create a raised bed garden with store-bought soil, wear gloves while gardening or handling soil, wash hands to prevent hand-to-mouth exposure, wash produce thoroughly before eating, peel vegetables, remove outer layers of leafy vegetables and monitor children to ensure they are following proper techniques while gardening.

Peer-reviewed World Health Organization reports show thallium is especially toxic to children; single doses of as little as 4 mg/kg thallium sulphate have caused toxicity in a child.

A Phase II environmental study at the property collected subsurface soil samples from 22 locations at two different depths per location. Of the 44 soil samples, thallium was detected in 21 locations in concentrations ranging from 0.8 to 1.7 milligrams per kilogram, the report shows. Thallium is found at hazardous waste sites at an average of 1.7 milligrams per kilogram, according to the federal Agency for Toxic Substances and Disease Registry.

Acute thallium poisoning is primarily characterized by gastrointestinal, neurologic, and dermatologic symptoms, while neurologic findings predominate with chronic exposure and tend to progress, even despite decreasing blood thallium levels, said Dr. David Verrier, a physician and researcher at Johns Hopkins University.

According to an analysis by the Center for Health and Environmental Justice, thallium can be released into the environment by combustion or improper disposal of combustion waste. The Cleveland Avenue property, acquired by the city in 1986, was the former site of Connor Forest Industries, a wood manufacturing plant that was the subject of several Wisconsin Department of Natural Resources investigations. The property later became the site of Wausau’s business incubator.

Dist. 1 Alderman Pat Peckham, during a city meeting earlier this month, said Wausau officials contacted DHS to assess the level of risk the contamination detected on the property poses to residents. Peckham previously requested similar assessments for Riverside Park when residents were fighting for soil testing in the area. Later, testing performed at the park, at 132 River St., showed multiple exceedances of state Department of Natural Resources soil standards.

In their response, DHS acknowledged the agency does not have enough sampling data to calculate the potential risk to surrounding residential properties. Dist. 3 Alderman Tom Kilian, who represents the district in which the property lies, said that needs to change, as some residents are increasingly concerned about whether or not they have been impacted.

The parcel lies within a neighborhood with one of the highest concentrations of Southeast Asian residents, many of whom do not speak English, Kilian said.

One such family, the Yangs, say they are especially concerned because they maintain a garden abutting the southern portion of the Cleveland Avenue property – an area in which an alleged illegal dump site for toxic chemicals was located, DNR records show. There, the family grows the vegetables they sell at local farmer’s markets, a key portion of their income.

“I can’t sleep at night wondering if what I’m feeding my family is safe,” Ya Yang said. “And I’m worried about what I’m selling, too.”

DNR sketch of alleged dumping site on former Connor property. Source: Wisconsin Department of Natural Resources

Now, Kilian is requesting off-site testing for thallium and and PAHs on certain properties in close proximity to the former Connor propety to help protect the public. Additional on-site testing is already planned, part of a directive by the state Dept. of Natural Resources in response to the January findings.

“Plainly put, the levels of thallium and other compounds exceeding state standards pose a risk to individuals that may come into contact with them at the site,” Thompson told Wausau Pilot & Review in February. “State standards are calculated using compound specific toxicological data, similar to how the US E.P.A. establishes their cleanup standards.”

“The Wisconsin Department of Health Services (DHS) provided its public health conclusions regarding the onsite contaminants and neighboring residential areas based on the first round of environmental testing done by the City and GEI in October 2020 at 1300 Cleveland Avenue,” Kilian said. “The letter is a public record available for public review. In it, residents will find a summary of DHS findings on page 1, and both conclusions and recommendations from DHS on page 5.”

See the full letter, below.