Of X rays, viruses, and cooked meat

The psychology of risk is a tricky business. That’s why the American Association of Physicists in Medicine (AAPM) in College Park, Md., worries that many people might react with undue alarm to the Jan. 31 announcement by the government that the National Toxicology Program (NTP) has added ionizing radiation, including X rays and neutrons, to its list of human carcinogens.