Remediation strategies for rural territories contaminated by the Chernobyl accident.

The objective of the present paper is to derive remediation strategies for rural settlements contaminated by the Chernobyl accident in which annual doses to a critical group still exceed 1 mSv. Extensive radioecological data have been collected for 70 contaminated settlements. A dose model based on these data resulted in estimates that are on average close to and a bit less than the official dose estimates ('catalogue doses') published by the responsible Ministries of Belarus, Russia and Ukraine. For eight remedial actions that can be applied on a large scale, effectiveness and costs have been assessed in light of their dependence on soil type, contamination level and on the degree of previous application of remedial actions. Remediation strategies were derived for each of the 70 settlements by choosing remedial actions with lowest costs per averted dose and with highest degree of acceptability among the farmers and local authorities until annual doses are assessed to fall below 1 mSv. The results were generalised to 11 contamination/internal-dose categories. The total numbers of rural inhabitants and privately owned cows in the three countries distributed over the categories were determined and predicted until the year 2015. Based on these data, costs and averted doses were derived for the whole affected population. The main results are (i) about 2000 Sv can be averted at relatively low costs, (ii) the emphasis on reducing external exposures should be increased, (iii) radical improvement of hay-land and meadows and application of Prussian blue to cows should be performed on a large scale if annual doses of 1 mSv are an aim to be achieved, (iv) additional remedial actions of importance are fertilising of potato fields, distribution of food monitors and restriction of mushroom consumption, and (v) for inhabitants of some settlements (in total about 8600) annual doses cannot be reduced below 1 mSv by the remedial actions considered.