Dr Alice Mary Stewart was a physician and epidemiologist specialising in social medicine and the effects of radiation on health. Her study of radiation-induced illness among workers at the Hanford plutonium production plant, Washington, is frequently cited by those who seek to demonstrate that even very low doses of radiation cause substantial hazard. Wikipedia*
On the C-SPAN Networks:
Alice Stewart has one video in the C-SPAN Video Library; the first appearance was a 2011 Call-In.