Scientists at the University of Calgary are asking Canadians to send in their toenail clippings as part of a groundbreaking study into long-term radon exposure and its connection to lung cancer.Dr. Aaron Goodarzi, PhD, leads an interdisciplinary team at the Cumming School of Medicine examining environmental causes of lung cancer, including radon — a naturally occurring, odorless, colorless radioactive gas that is the second leading cause of the disease after tobacco. Traditional screening programs cannot yet account for radon exposure because few people can reliably track their exposure over decades.“Toenails hold long-term information about our exposure to radioactive toxicants in the environment such as radon gas,” said Goodarzi. “They are one of our body’s archives of past exposure.”.When inhaled, radon quickly decays into a specific type of radioactive lead that the body stores in slow-shedding tissues such as skin, hair, and nails. A pilot study published in Environment International showed that measuring these lead isotopes in toenails provides a promising method to estimate individual lifetime radon exposure.The new study, funded by the Canadian Cancer Society, aims to recruit up to 10,000 participants across Canada. Volunteers will collect toenail clippings monthly for four months and test their homes for radon. Samples are analyzed in a specially designed, contamination-free lab at the Arnie Charbonneau Cancer Institute using advanced mass spectrometry techniques capable of detecting ultratrace amounts of radioactive lead..Researchers say toenails are preferable to hair or fingernails because they are less exposed to chemical contaminants such as dyes or household chemicals. Lifestyle data — including time spent at home, work, other residences, or outdoors — is also collected to refine estimates of radon dose.“If this validation trial works, it could transform cancer prevention in Canada,” said Goodarzi. “The data could support early screening for patients whose lung cancer is not caused by tobacco smoke, potentially saving lives.”Two in five Canadians who develop lung cancer today do not meet current screening criteria, with half never having smoked. Patients like Emi Bossio and Tim Monds, both non-smokers, are advocating for greater awareness and research into environmental risks.Researchers say the study could provide one of the most comprehensive assessments of radon exposure in Canada, combining atomic markers from toenails with home radon testing and personal behaviour data to better predict lung cancer risk.
