Mammography

"1 mammography screening exposes the patient to 1-4 RADS of radiation (2 views of each breast). If a woman age 55-75 has annual mammograms, she will receive a minimum cumulative exposure of 20 RADS of radiation over that period. Comparison: women who survived the atomic bomb in hiroshima and nagasaki received a dose of 35 RADS of radiation. One big dose all at once is worse, but there's no doubt that significant damage is caused by a cumulative dose as well."