Quantitative assessment of the radon (222Rn) decay product 210Pb in human toenails as a sensitive measure of personalized long-term radon gas exposure history https://www.sciencedirect.com/science/article/pii/S016041202500532X Radon is the second leading cause of lung cancer after tobacco smoking https://medicalxpress.com/news/2025-10-scientists-toenail-reveal-radon-exposure.html Toenails hold long-term information about our exposure to radioactive toxicants in our environment, such as radon gas. They are one of our body's archives of past exposure. Measuring radioactive lead in toenails is a promising way to estimate a person's long-term radon exposure