Accidents radiologiques et santé publique : une étude d'évaluation des risques
Verger P, Charpin F., Mansoux H., Bard D.
Environnement, Risques et Santé 1(1), 15-21, in French
To examine how existing plans for the post-emergency phase assessment and management of the health consequences of a radiological accident could be improved, the Institute of Radiation Protection and Nuclear Safety (IRSN) assessed the health risks of an accidental release of radioactivity in the environment. The risk assessment was based on a core meltdown scenario for an experimental nuclear reactor. In this scenario, 1.6 10E13 Bq (400 Ci) of iodine 131 and 2.5 10E11 Bq (7Ci) of cesium 137 were released: the thyroid gland was the principal target organ. Estimates of doses in the absence of protective measures showed that they would be highest residents of the area close to the site (0-5 km) and younger than 25 years of age at the time of the accident: approximately 16mSv to the whole body and 135 mSv to the thyroid. Protective measures, if applied by 90 ù of the population concerned, would divide these doses by 10 for the thyroid gland and by 3 for the whole body. There would be no deterministic effects at any of these dose levels (with or without protective measures). Calculations showed that the excess number of cases of thyroid cancer and leukemia were very low compared with the number expected spontaneously, even in the absence of protective measures. The excess number of other solid cancers would be even lower. These excesses were calculated under conservative assumptions and would not be detectable by epidemiologic cancer surveillance or properly performed epidemiologic studies. The principal evaluation and health care actions necessary in such a situation are discussed, and improvements suggested for existing plans. Four themes are distinguished: information provided to the public, and the stake-holders, exposure and dose monitoring, screening and medical follow-up, and epidemiologic response.