Sources, exposures, intakes and ontakes, and irradiation: Careful use of language is the key to successful communication

Too often in communicating information about radiation and radioactive materials, we encounter difficulties in conveying some of the most fundamental concepts, such its the distinction between radiation and contamination. These difficulties are caused in part by fuzzy thinking due to the imprecise or inappropriate use of language in our profession. In this paper, I disaggregate several concepts that are often lumped together, examining along the way, why we have come to use words the way we have. By separating source, exposure, intake or open-quotes ontakeclose quotes of the source, and irradiation, I illustrate why phrases like open-quotes internal exposureclose quotes should be abandoned in favor of clearer terminology that communicates to non-experts and scientists outside of health physics. Four sources are identified: airborne, food- and drink-borne and surface- and liquid-borne radioactive materials, and penetrating radiation sources (machines and radioactive materials) that remain at a distance from the body. Five kinds of exposures are identified: person encounters contaminated air; person consumes contaminated food or drink; person's skin is penetrated by contaminated material; persons skin contacts contamination or contaminated surface; and person comes in proximity to source of penetrating radiation. The processes of intake and open-quotes ontakeclose quotes (material contacting skin) of the sources, as being distinct frorn the exposures, are discussed. Finally, the time course and process of irradiation in each case is described. The fact that exposure and irradiation are essentially the same for external sources has muddied the essential distinction between these concepts for materials that get on or in the body and only then begin to irradiate a person