Alpha Particles and Lung Cancer: Understanding the Risk

Alpha particles are large, heavy, and have a positive charge. They are unable to penetrate the skin and can be stopped by a few centimetres of air. However, if an alpha-emitting source is inhaled, ingested, or injected, the alpha particles can cause damage to the cells of the lungs, stomach, or bone (depending on the point of entry), leading to cancer. Because of the large size and charge of alpha particles, the damage occurs over a short range, and the cells most at risk are those close to the source.