A groundbreaking study from the Massachusetts Institute of Technology (MIT) reveals that a carcinogen commonly found in contaminated water and certain medications may pose a significantly greater health risk to young children than to adults. The chemical, N-Nitrosodimethylamine (NDMA), is a byproduct of many industrial processes and has been detected in drinking water and some pharmaceuticals, including valsartan, ranitidine, and metformin. The research, published in Nature Communications, shows that NDMA exposure early in life leads to dramatically higher rates of DNA damage and cancer in juvenile mice compared to adults.
The Hidden Threat of NDMA
NDMA is generated as a byproduct of industrial chemical processes and can contaminate drinking water near chemical plants. It is also present in cigarette smoke and processed meats. The MIT study found that NDMA causes DNA adducts—methyl groups attached to DNA bases—that can lead to mutations. In juvenile mice, these adducts resulted in significant double-stranded DNA breaks, which are precursors to cancer. In contrast, adult mice showed few such breaks and fewer mutations, even with similar initial DNA damage.
Lead author Lindsay Volk, an MIT postdoc, explained: “The initial structural changes to the DNA had very different consequences depending on age. The double-stranded breaks were exclusively observed in the young.” This difference is attributed to higher rates of cell proliferation in juvenile livers, which increases the chance of mutations. The study emphasizes that standard toxicological testing using adult mice may underestimate risks to children.
Link to Childhood Cancer
The findings may explain elevated childhood cancer rates in Wilmington, Massachusetts, where NDMA contaminated drinking water in the 1990s. Between 1990 and 2000, 22 children in the area were diagnosed with cancer. The contaminated wells were closed in 2003. Senior author Bevin Engelward, an MIT professor of biological engineering, stated: “We really hope that groups that do safety testing will change their paradigm and start looking at young animals, so that we can catch potential carcinogens before people are exposed.”
Implications for Safety Testing
The researchers urge regulatory agencies to incorporate juvenile animals in carcinogen testing. Current standards often use adult mice, which may not reveal vulnerabilities in younger populations. Engelward added: “As a solution to cancer, cancer prevention is clearly much better than cancer treatment, so we hope we can spot dangerous chemicals before people are exposed.”
Risk in Adults
While the study highlights increased risk in children, adults are not immune. Factors such as viral infections, high-fat diets, or chronic alcohol consumption can increase liver cell proliferation and susceptibility to NDMA. The team is now investigating how a high-fat diet influences cancer development in NDMA-exposed mice.
This research underscores the need for age-specific risk assessments to protect vulnerable populations from environmental carcinogens.
