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After decades of study, state officials link drinking water contamination with elevated rates of childhood cancer in Wilmington

Nicole Raso in 2001, a year after her cancer diagnosis. She was diagnosed with leukemia when she was 3 years old. State officials on Wednesday issued a long-awaited report that linked her cancer and those of 21 other children in Wilmington to contaminated drinking water.Greg Raso

In 2000, Greg Raso began to notice his 3-year-old daughter had become unusually lethargic and had small blood clots beneath her eyes. She was hospitalized with a common bacterial infection that rarely sickens people, and a few months later was diagnosed with leukemia.

While undergoing chemotherapy during a two-month stay at Boston Children’s Hospital, their daughter had a roommate who had also been diagnosed with cancer. The young girl, it turned out, also lived in Wilmington, a suburb north of Boston.

“This was the scariest thing in the world for us, and then we began to realize it was happening to other families in our town,” said Raso, whose family moved soon afterward to Stoneham. “We felt there was something going on, but nobody knew what.”


More than two decades later, the state Department of Public Health on Wednesday released a report that lent credence to the Rasos’ fears. The results “strongly suggested” a link between elevated rates of childhood cancer in Wilmington in the 1990s and prenatal exposure to contaminated water during that time.

Between 1990 and 2000, at least 22 local children contracted cancer. Two of them have died.

“Despite limitations, including a small sample size and modeled exposure estimates, study results show an association between childhood cancer and prenatal exposure to NDMA,” DPH officials said in announcing the findings.

In an initial study in 2000, state officials identified an unusual pattern of children with cancer who lived on the west side of Wilmington. Those findings led the Legislature to fund a broader epidemiological study to determine if they were the result of environmental factors.

In 2003, regulators identified a known carcinogen called n-nitrosodimethylamine, or NDMA, that was contaminating drinking water from one of the town’s aquifers, which was shut down. They determined the contamination came from a large chemical manufacturing facility in town that had been operated by a series of companies between 1953 and 1986.


The 53-acre site was last purchased by Olin Chemical Co. in 1980 and is now managed by the Environmental Protection Agency as a Superfund site. The EPA recently issued a $48 million plan to clean up the area.

The study also investigated whether the cancers were associated with exposure to trichloroethylene, or TCE, a solvent also present in the water that has been linked to cancer. DPH officials said the results were “statistically significant.”

“The results remained consistent even after statistical adjustment for other possible cancer risk factors, such as maternal pregnancy exposures, household and occupational exposures, family history of cancer, and childhood medical history,” health officials said in a statement. “There was no evidence of increased odds of cancer for children who were exposed to NDMA or TCE during childhood.”

Officials at Olin Chemical Co. said in a statement that they were “in the process of reviewing the study and its findings.”

“Olin was not asked to participate in, or contribute information to the Massachusetts Department of Public Health or others in connection with the study,” said Ed Kral, a company spokesman. “We continue to work cooperatively with, and under direct oversight of the US EPA and the Massachusetts Department of Environmental Protection to investigate and remediate the Wilmington site.”

Kathleen Barry, a spokeswoman for 18 of the families whose children were diagnosed with cancer in the 1990s, said many of the parents were relieved to finally have answers.


“We’re all struggling to make something good out of such a bad situation,” she said.

Many families were stunned to learn that the exposure was prenatal.

“They were shell-shocked by this,” she said. “Even though they expected the link, they were dumbfounded with how the department figured it out.”

The study required researchers to develop computer models and reconstruct historical concentrations of the chemicals at the homes of each study participant, which is part of the reason it took so long to complete, DPH officials said. The study was slated for release last year but was delayed by the pandemic.

Only two cases of childhood cancer were diagnosed in Wilmington between 1982 and 1989, likely before the chemicals penetrated the aquifer, the report found. The 22 cases in the 1990s included eight cases of leukemia and three lymphomas. Since 2001, local childhood cancer incidence returned to expected rates, about one case per year, state officials said.

In the study, researchers wrote that while the “presence of these contaminants cannot definitively explain the pattern of childhood/adolescent cancer,” the risks of exposure offered “what we believe is a plausible explanation.”

Barry said the families are unlikely to file a lawsuit against Olin, which has already established a trust to pay for the health care, education, and other financial needs of their children.

It was unclear how the town would respond, given its long-term loss of a vital and lucrative aquifer that provided about 3.5 million gallons of drinking water a day to the town’s 22,000 residents.


“I wish to express my deepest sympathies to the families,” said Jeffrey M. Hull, the town manager. “There is no more terrifying diagnosis for anyone to receive, and particularly a parent, than to be told that their child has cancer.”

He said town officials are taking the findings “very seriously” and will be conferring with an environmental consultant to determine their next steps.

When asked if the town would sue Olin, Hull said: “I cannot offer further comment pending a detailed review of the study.”

He said the town’s water supply is now safe, meeting state and federal requirements and undergoing regular testing.

“Providing residents and businesses with safe and clean water is a core priority of the town,” he said.

Local environmental advocates, who long expressed frustration with the town’s lack of action, said they thought residents deserve to be compensated.

“That aquifer was a revenue generator for the town, and that resource has been damaged, possibly irreparably,” said Martha Stevenson, president of the Wilmington Environmental Restoration Committee.

She said many local residents felt vindicated that their suspicions had merit.

“It was really frustrating to have to wait so long and to have the families in limbo for two decades,” Stevenson said.

For the Rasos, whose daughter Nicole is now a healthy 24-year-old preschool teacher, the report left them with mixed emotions.

“We’re satisfied that we’re validated, but it doesn’t make us feel any better that our kids were sick, and some of them died,” Raso said. “There’s definitely some lingering anger.”


David Abel can be reached at david.abel@globe.com. Follow him on Twitter @davabel.