New analysis shows higher cancer risk for Merrimack residents between 2005 and 2014
Residents of Merrimack learned they were exposed to PFAS chemicals from emissions at the Saint Gobain manufacturing facility in 2016. This month, a paper on cancer risks in the town from 2005 to 2014 shows residents had a significantly higher risk for some kinds of cancer than the national average.
The study uses the same data as a 2018 state report on cancer risk in Merrimack, which concluded that residents didn’t have higher rates than in New Hampshire in general.
But authors of the recent paper instead compared Merrimack’s data to national averages and to similar New England towns without documented PFAS exposure, finding there was a significantly higher risk of certain cancers, including thyroid and bladder cancer.
Another analysis of cancer rates in Merrimack released by New Hampshire’s Department of Health and Human Services found that more people than expected had kidney and renal cancers between 2008 and 2018.
The department’s Comprehensive Cancer Control Program has resources for residents looking to learn more about PFAS and cancer or speak with state officials.
Scientists are still studying how PFAS is related to cancer, but the most well-studied PFAS chemical has been classified as a possible human carcinogen, and the Agency for Toxic Substances and Disease Registry says PFAS exposure may lead to increased risk of some cancers.
Mindi Messmer, an author on the study and a co-founder of the nonprofit NH Science and Public Health, said the state’s 2018 study did not provide the full picture; New Hampshire’s population already has elevated levels of cancer, and much of the southern part of the state, where most of the state’s population lives, has been exposed to PFAS chemicals.
“I hope that this method will sort of provide a roadmap for the state of New Hampshire to conduct additional studies,” she said, noting that other communities, including Litchfield, Bedford, and Londonderry were affected by PFAS exposure but haven’t been studied.
She also said she hopes the paper is a step towards limiting environmental exposures to industrial emissions.
“There's enough evidence here to know that these people are experiencing higher rates of cancer than they should be. And so let's do something to prevent that,” she said.
Saint Gobain installed a treatment device on its Merrimack facility to manage PFAS emissions last year, but a November letter of deficiency from state regulators regarding the device added to the distrust of the company some residents and advocates continue to feel.
In 2021, the Environmental Protection Agency released a new plan for handling PFAS contamination.
The study on cancer risk in Merrimack said blood serum levels of one main PFAS chemical, PFOA, were more than two times higher in the community exposed to PFAS chemicals from Saint Gobain than average levels in the United States.
For the community in Merrimack that has been dealing with the effects of contamination for years, the recent paper is meaningful, said Laurene Allen, who co-founded the advocacy group Merrimack Citizens for Clean Water.
Allen said she received lots of messages from residents in the days after the paper was published. She added 130 people to her mailing list, she said.
“This is validation. It's a small piece of validation, but it's sadly a very powerful one,” she said.