THE ARGUS EYE: A long-overdue D.P.H. report on PCBs and cancer delivers no surprises
PCBs may play a role, the agency says, but the mix of diffuse exposures, data limitations, and many other cancer risk factors leaves no clear culprit.
∎ ∎ ∎
Last week, the Massachusetts Department of Public Health finally released a long-promised update on cancer in five Berkshire County communities along the Housatonic River.
The state’s screening-level review—formally titled Updated Cancer Incidence Evaluation in Response to Community Concerns about PCB Contamination in the Housatonic River Area—arrives nearly five years after the Pittsfield City Council requested it, and after years of lawsuits and bitter debate over additional Housatonic River clean-up. That debate has, in recent years, focused on plans for a new engineered landfill in the Town of Lee that will permanently store PCBs, a toxic chemical manufactured by Monsanto and left behind after G.E.’s half-century of transformer production in Pittsfield.
The D.P.H. report’s conclusions will surprise no one familiar with the history of cancer-cluster investigations in Massachusetts and across the country, because it is vanishingly rare to tie cancers, conclusively, to a single industrial source in the environment. (See the recent Argus report, The Uncertainty Machine: A Story of PCBs, Cancer, and Doubt.)
Using data from the state’s cancer registry, D.P.H. examined cases from 1995 through 2019 in Pittsfield, Lenox, Lee, Stockbridge, and Great Barrington, focusing on cancers that past research has tied—strongly or weakly—to PCB exposure. Breast cancer, liver and intrahepatic bile duct cancers, and non-Hodgkin lymphoma top the “stronger evidence” list. Colorectal, prostate, gallbladder, stomach, and a few others fall into the “less certain” category. Bladder cancer was included because of earlier elevated findings in Pittsfield.
The data analysis found no consistent elevations in the cancers most strongly linked to PCBs. Instead, the standout finding is a persistently higher rate of colorectal cancer in Pittsfield, Lee, and Lenox, stretching across multiple five-year intervals. Pittsfield men also showed sustained elevations of bladder cancer.
D.P.H. attributes much of this to smoking, diet, and other familiar risk factors. Still, the agency noted that it “cannot completely rule out the possible contribution of PCB exposure from fish consumption or frequent contact with contaminated floodplain soil or river sediments,” but also found “no unusual spatial clustering of cancer diagnoses … near the former G.E. facility or downstream portions of the Housatonic River.” In other words, the new report does not depart from D.P.H. findings in reports the agency issued in 2002 and 2008.
David Carpenter, the SUNY-Albany public-health scientist known in the Berkshires for his many decades of PCB research—including a focus on dangers from airborne PCBs—told me last week that the report appears “thoughtful and accurate.” Colorectal cancer, he added, is common and has many risk factors. “Cancer has many causes,” he wrote in an email, “and without question exposure to PCBs adds to the risk.”
Bill Shein
Still, the limitations of this type of study are worth recalling. Cancer registries record only where someone lived at the time of diagnosis, not where they grew up or what exposures accumulated across a lifetime. Residents who moved away vanish from the data. Family history, occupation, and other exposures are unknowable without a far more searching investigation. And the numbers, sliced by town and cancer type, are often too small in low-population communities to provide meaningful results.
(Melanoma, though linked to PCB exposure, was left out. The state cancer registry doesn’t capture it well since many cases are diagnosed in dermatologists’ offices.)
The report is a reminder that environmental carcinogens seldom announce themselves in tidy geographic clusters—at least in ways that statistics can detect with certainty. The chemical age, and the country’s uneven record of regulating it, has ensured that toxins are diffuse. PCBs have been found in the blood of nearly everyone; by the time we look for a specific cause of a specific cancer in a specific place, the evidence has often dissolved into that larger background haze.
Meanwhile, the timing of the study and its release is notable. As this final report languished for several years, residents of Lee and neighboring towns fought over the new landfill, and Pittsfield residents near the Allendale School and G.E. campus in 2023 brought suit against G.E. and Monsanto for allegedly causing their cancers. Now, with construction of the Lee landfill set to begin in the coming months, and nine PCB-related lawsuits mired in a legal venue dispute, the state has produced a study that underscores the challenge of linking one community’s cancers to one industrial source.
Armed with its updated analysis, a D.P.H. spokesperson told me the agency will work with local officials to expand colorectal-cancer screening in Pittsfield, Lee, and Lenox, and “support targeted tobacco-cessation efforts” as well. It will also re-evaluate colorectal and bladder cancer incidence when the next five years of data are available from the cancer registry in 2027.
How these results will impact public debate over the Rest of River cleanup, expected to continue well into the 2030s, remains to be seen. Bob Jones, a member of Lee’s Select Board and a leader of community efforts to oppose the new landfill, told me that he is still reviewing the D.P.H. findings.
But as several epidemiologists told me this year, retrospective studies like this may, in the end, matter far less than ongoing clean-up and reducing our reliance on chemicals linked to environmental damage and human illness.
D.P.H. will present the report’s findings at an upcoming meeting of the Pittsfield City Council’s Public Health and Safety Committee, the spokesperson said.
∎ ∎ ∎
