Researchers at MIT have found that young mice exposed to the carcinogen NDMA develop significantly more DNA damage and cancer than adult mice, despite equal exposure levels. The study highlights how rapid cell division in juveniles amplifies risks from the chemical, present in contaminated water, medications, and processed foods. Findings urge changes in safety testing to include younger animals.
A new MIT study demonstrates that NDMA, or N-Nitrosodimethylamine, poses a heightened cancer risk to children compared to adults. In experiments, juvenile mice aged three weeks drank water with five parts per million of NDMA for two weeks, matching exposure for six-month-old adults. Young mice showed initial DNA adducts similar to adults but developed double-strand breaks, mutations, and liver tumors, while adults largely avoided these outcomes, researchers reported. Some juveniles also developed lung cancer and lymphoma. Bevin Engelward, an MIT professor of biological engineering and senior author, 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.' Lead author Lindsay Volk, an MIT postdoc, noted that standard toxicological tests using adult mice miss vulnerabilities in younger groups due to slower cell division in adults. Rapid proliferation in juvenile livers turns damage into mutations before repairs complete. The study links to past NDMA contamination in Wilmington, Massachusetts, where wells polluted by Olin Chemical were shut in 2003 after 22 childhood cancer cases from 1990 to 2000. Engelward called for paradigm shifts in safety testing: '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.' NDMA appears in industrial byproducts, cigarette smoke, processed meats, and drugs like valsartan, ranitidine, and metformin. The team, funded partly by the National Institutes of Environmental Health Sciences, published results in Nature Communications.
