EMPLOYMENT PRACTICES AND BREAST-CANCER AMONG RADIOLOGIC TECHNOLOGISTS

A case-control study of breast cancer and employment practices among f emale radiologic technologists was conducted. The cohort from which ca ses and controls were derived included over 105,000 female medical rad iation workers certified by the American Registry of Radiologic Techno logists during 1926-1980. Breast cancer cases (n = 528) were individua lly matched to an average of five control subjects (n = 2628) based on year of birth, year of certification, and length of follow-up. Proced ures most commonly performed by controls included fluoroscopy (93%), p ortable radiographs (92%), routine radiographs (92%), multifilm proced ures (87%), dental x-rays (46%), radium therapy (31%), orthovoltage (2 3%), and cobalt-60 (21%). Breast cancer was not significantly increase d with occupational experience with any of these procedures. Furthermo re, risk was not related to number of years worked with a particular p rocedure. This study is reassuring in indicating that medical radiatio n workers are not at substantial risk for developing radiation-induced breast cancer. However, because only surrogate measures of radiation exposure were available, possibility of a small risk cannot be discoun ted. Ongoing follow-up of this cohort for incident cancers will incorp orate detailed exposure assessment schemes, providing additional infor mation on effects of long-term low-dose radiation, through occupation.