Exposure to radiation at the workplace-assessing radiation risks

On a daily basis people are exposed to naturally-occurring radioactive materials (NORM) found in soil, water and air and to natural radiation coming from cosmic rays. Human exposure to radiation also comes from man-made sources ranging from nuclear power generation to medical applications. Medical uses of radiation for diagnosis and treatment represent today the largest human-made source of radiation exposure. Radiation risks became apparent by the end of the 19th century and soon later the discipline called Radiological Protection was started, with the ultimate purpose of ensuring an adequate level of protection by controlling risks without unduly limiting the benefits. Radiation damage to tissue and organs depends on the dose of radiation received. In addition to the amount of radiation (dose), also the rate at which this dose is delivered (dose rate) influences the response. Beyond certain thresholds, radiation can impair the functioning of tissues or organs and can produce acute effects such as skin redness, hair loss, radiation burns, or acute radiation syndrome. These effects are more severe at higher doses and higher dose rates. If the dose is low or delivered over a long period of time (low dose rate), there is greater likelihood for damaged cells to successfully repair themselves but long-term effects such as cancer may still occur. Effects of this type will not always occur, but their likelihood is proportional to the radiation dose. This presentation reviews possible health risks associated with radiation exposure in the workplace, with particular focus on situations in which these risks may be significant (e.g. radiation risks in interventional cardiology, radiological protection of pregnant workers). The steps of the health risk assessment process and its application to assess radiation risks in the work place are discussed.