Which man-made source is the largest contributor to human radiation exposure?

The largest contributor to human radiation exposure from man-made sources is indeed medical procedures. This is primarily due to the widespread use of diagnostic imaging technologies, such as X-rays and CT scans, which deliver doses of ionizing radiation to patients.

Medical procedures are essential for diagnosing and treating various health conditions, and their accessibility has increased significantly over the years. As a result, the cumulative exposure from these procedures can surpass that from other sources like nuclear weapons testing, nuclear power plants, and industrial sources combined.

While nuclear power plants have robust safety protocols and are designed to limit radiation exposure, and industrial sources also contribute, their overall impact is considerably lower than that of medical imaging practices. Therefore, when considering overall human exposure to radiation from man-made activities, medical procedures stand out as the primary source.