Radiation Exposure in the United States

RACE has always been exposed to some ionizing radiation of cosmic origin and from natural sources in the environment and within the body.During a lifetime, a person who lives to be 70 years of age is exposed, on the average, to about 9 roentgens.ofradiation from these sources.Today, however, radiation from these sources comprises only a small portion of the total exposure received by man.Radiation-generating machines and radioactive materials, which are being employed in nearly all phases of the environment, constitute the principal sources of radiation.Knowledge of the wide variety of sources and of the levels of radiation exposure is essential to the planning and conducting of a sound radiological public health program.Data available in the literature on the extent of radi- ation exposures in the United States are re- viewed here to aid the many State and local health departments engaged in determining and evaluating radiation sources affecting public health in their areas.Neither the control of radiation exposure nor specific public health effects of the exposure are discussed in this paper.Mr. Moeller, a sanitary engineer, is an environ- mental radiation specialist with the radiological health branch, Division of Engineering Re- sources,