Kidney Cancer Rates in Merrimack: A Growing Concern
A new study shows that kidney cancer rates in Merrimack are about 38% higher than expected. It also suggests another possible cluster in Manchester, as reported by Dartmouth researcher Megan Romano to a state commission on October 10.
Study Overview
These findings come from a preliminary study on kidney cancer needs in Merrimack. Romano, an Associate Professor at the Dartmouth Geisel School of Medicine, presented at the Commission on Environmental and Public Health Impacts of Perfluorinated Chemicals. The data can’t identify specific causes or confirm links to high kidney cancer rates in the two towns. However, Romano believes this study opens the door for further investigation, particularly into environmental contaminants like PFAS.
Key Quotes
“Ultimately, we hope future research will clarify…” “Verify links between environmental exposures and health outcomes in this region,” Romano said. “This will help inform public health initiatives.”
Data Sources
The study used data from the New Hampshire State Cancer Registry. This registry tracks cancer cases diagnosed or treated in New Hampshire. Researchers looked at kidney cancer rates in Merrimack and eight nearby towns compared to the rest of the state. They divided the data into three periods:
- 1995-2003
- 2004-2012
- 2013-2021
Findings
Most towns did not show high kidney cancer rates during these periods. However, from 2013 to 2021, Merrimack had 38% more kidney cancer cases. This aligns with a 2021 state report estimating that kidney cancer was 42% higher than expected in Merrimack.
The data also revealed:
- An 18% excess of cases in Manchester during the same period.
- More cases in women than expected.
Romano cautioned against “over-interpreting” the Manchester data until more information is available.
Additional Findings
The report noted a third finding:
- An 83% excess of kidney cancer cases in Hudson during 1995-2003, with the rate returning to normal in later years.
Romano also mentioned that the data did not show unusual cancer rates in people under 20.
“The very young folks are not seemingly getting excess kidney cancer in this area,” she said.
Community Concerns
In 2021, after the initial state report was published, Merrimack residents noted that the statistics reflected their concerns about high cancer rates. Many linked these rates to high levels of environmental PFAS contamination.
Testing shows that soil and groundwater in Merrimack and nearby towns are contaminated with PFAS. These toxic chemicals, called “forever chemicals,” last a long time in the environment. The New Hampshire Department of Environmental Services links high PFAS levels in Merrimack to the former Saint-Gobain Performance Plastics plant, which allegedly released PFAS emissions for decades.
In Merrimack and Manchester, the study shows that high cancer rates mainly come from clear cell renal carcinoma. Researchers connect different types of PFAS to cancers in humans, including renal cell carcinoma. The International Agency for Research on Cancer has labeled PFOA, a common PFAS, as carcinogenic. They also consider PFOS as possibly carcinogenic.
Ongoing Research Needs
However, Romano noted that the research team does not yet have enough data to identify causes for the cluster. While they confirmed elevated kidney cancer rates in Merrimack and Manchester, researchers still need more information to explore contributing factors.
Romano states that this investigation needs:
- More research
- More participants
- Expert input
They plan to work with the Department of Environmental Services, which can offer a database of water testing histories. By cross-referencing this data with participants’ residential histories, they hope to map exposure to possible contaminants.
Challenges Ahead
Romano acknowledged that this work requires significant effort. She anticipates that securing funding will be a major challenge.
“The current climate for federal research funding is very uncertain,” she said. “… It is admittedly a difficult funding climate for biomedical research.”
Despite these challenges, Romano emphasized that both residents and researchers are eager to continue this project. A poll during the study showed that residents are motivated to find answers. Researchers involved over the years also hope to keep moving forward.
“We all remain very excited about this work,” she said. “… We are acutely aware of the importance of this work and are committed to doing our best.”