This project aims to improve estimates of the risks of long-term health effects associated with protracted external and internal radiation exposures, through further studies of exposed populations in the Southern Urals (Russian Federation). Specific objectives of the project are as follows: 1. To develop improved modules for estimating external doses to exposed cohorts in the Southern Urals. It is anticipated that new dosimetry systems that come into use after the end of SOLO will incorporate these modules and support future epidemiological work. 2. To carry out epidemiological studies of morbidity and mortality from non-cancer diseases - specifically respiratory and circulatory diseases - and of cancer incidence among workers at Mayak Production Association, based on Mayak-Doses-2008. 3. To examine the feasibility of conducting a pooled epidemiological analysis of the Mayak and Sellafield plutonium worker cohorts. A common internal dosimetry protocol for assessing doses from plutonium exposures will be produced , with quantification of uncertainties. If judged feasible, doses will be calculated and an epidemiological analysis undertaken. 4. To analyse the feasibility of conducting a pooled analysis of cancer incidence and mortality following in utero irradiation among the offspring of Mayak female workers and of the Techa River female population, based on the estimation of doses to the embryo and fetus, and - if judged feasible - to undertake this analysis. The research will be coordinated with related research in the Southern Urals. The findings should provide a more robust scientific basis for underpinning radiation protection standards.