Dr. Simmons questions whether the epidemiological literature supports the existence of radiogenic cancer risks for dose increments below about 200 mGy.

As noted in my Commentary (1), however, prenatal X-ray examinations delivering 5–10 mGy have been associated with an increase in childhood leukemia and solid tumors (2). Moreover, several studies of medically irradiated cohorts have shown clear evidence of increased cancer due to multiple X-ray exposures of the order of 10 mGy, administered at least a day apart. This would include studies of breast cancer induction in patients receiving diagnostic X rays for TB or scoliosis (3 ,4) as well as of thyroid cancer resulting from childhood irradiation for ringworm (5).

A major point of the Commentary was that studies of occupationally and environmentally exposed cohorts, who received their doses chronically, might be...

You do not currently have access to this content.