Estimating risk of radiocesium presence at levels exceeded the permissible amount of the radionuclide in forage and milk from the south-west part of Bryansk region long after the Chernobyl accident

The study was carried out in the south-west part of Bryansk region from 2010 over 2017. It was aimed to assess the risk associated with 137Cs contamination of forage and milk above the permissible limit in the third decade after the Chernobyl accident. The risk was assessed with account of soil conditions in that area. Annual data on contamination of milk and fodder provided by the Bryansk Interregional Veterinary Laboratory were used for analysis. The risk of radiocesium high-level contamination of the fodder and milk was estimated by the ratio of the products contaminated with the radionuclide (from the south-west part of the region) to the total amount of the products from all areas of the Bryansk region. Calculated risk values varied. The highest risk associated with 137Cs contamination of milk from public economies that exceeded the permissible level by 24.7% was found in Gordeevsky rayon. In Klintsovsky, Novozybkovsky, Krasnogorsky and Zlynkovsky rayons the content of the radionuclide was lower, however, it exceeded the permissible level. The risk associated with radiocesium contamination of milk from private farms was higher than in public economies. In some farms the risk was twofold or more than double as compared with risks in the public economies. The difference was due to the higher level of soil contamination in pastures for privately owned livestock. No any remedial measures were implemented in these pastures. The highest risk associated with radiation contamination of roughage and succulent fodder was in Gordeevsky rayon. Though remediation measures were implemented in radioactively contaminated areas in the Bryansk region after the accident, the livestock and lea management situation in those areas, especially in pastures for privately owned livestock, is still complicated. The study shows that there is the necessity to continue remediation measures in public economies and, particularly in privately owned farms.