Radiation from radiological events can damage cells and DNA, potentially causing harmful effects in tissue and interfering with cellular processes. Effects may be immediate or take years to appear, and can impact future generations through genetic effects. Radiation exposure can come from radioactive materials used in dirty bombs designed to disseminate radiation or from accidents involving nuclear materials. The Chernobyl disaster exposed many people to different types of radiation from the explosion and fire. Radiological events pose hazards through radiation sickness and increased cancer risks.