The conversation explores the radiation doses associated with different types of X-rays and medical imaging, highlighting that larger individuals may receive more radiation due to the need for higher energy to penetrate their bodies. The discussion differentiates between localized doses, such as those used in cancer treatment, and whole-body doses, explaining that localized doses can be high but are concentrated in small areas, minimizing overall risk. For example, a prostate cancer treatment might involve 80 gray to a small area, which would be lethal if applied to the whole body. The conversation also addresses common diagnostic procedures like chest X-rays and CT scans, noting that these typically involve very low doses of radiation, often less than one millisievert, which is considered negligible compared to therapeutic doses. The principle of ALARA (As Low As Reasonably Achievable) is emphasized, suggesting that while it's important to minimize exposure, the risks at low doses are often overstated. The discussion also touches on the linear no-threshold model, which assumes any radiation dose carries risk, but recent evidence suggests low doses may not cause harm and could even have beneficial effects, a concept known as hormesis. Practical advice includes not avoiding necessary diagnostic imaging like dental X-rays or mammograms due to their low risk and significant benefits.