THE NATURAL RADIATION ENVIRONMENT - FUTURE PERSPECTIVE

The need to control the exposure of man to the natural radiation environment (NRE) is increasingly recognised. The main NRE sources and exposure situations warranting intensified efforts in the future are: exposure to radiation in space (astronaut: less-than-or-equal-to 1 mSv.d-1), technologically enhanced natural radiation (TENR; global impact: 400,000 man.Sv.y-1) and populations living in high background radiation areas (resident: less-than-or-equal-to 360 mGy.y-1). Data on NRE-TENR-induced biological effects are scarce and inconclusive, such as increased frequency of chromosome aberrations and mental retardation from environmental gamma radiation, but there are contradictory results for thorium and radon exposure induced lung cancer risk. Four coordinated actions are proposed, i.e. international standardisation of methods, coordination of multidisciplinary health effect studies, development of principles for NRE/TENR control, and establishment of an international clearing house for all NRE-related topics.