Data comprise water chemistry measurements (major alkali and alkali-earth element water concentrations and trace element concentrations) recorded over two years at seven lakes in Belarus and Ukraine at distances from 1.5 to 225 km of the Chernobyl Nuclear Power Plant (CNPP). The lakes include Glubokoye, Yanovsky lakes and Cooling Pond (high (H) contaminated lakes), Svyatoye Lake (medium (M) contaminated lake) and Stoyacheye, Dvoriche and Gorova lakes (low (L) contaminated lakes). Full details about this dataset can be found at https://doi.org/10.5285/b29d8ab8-9aa7-4f63-a03d-4ed176c32bf3

Data comprise radionuclide deposition, radioactivity dose measurements, radioactive particle activity and physical characteristic information from soil samples collected within and around the Chernobyl Exclusion Zone (CEZ) following the Chernobyl nuclear accident in 1986. Data include radiocaesium, radiostrontium and soil chemistry parameters from soils collected in 1997, plutonium isotope measurements in soil samples and soil layers collected in 2000 and 2001, 'Hot particle' dataset presenting radionuclide activity and some physical characteristics of 'hot particles' extracted from soils collected in the Ukraine and Poland between 1995 and 1997; and Ivankov region data (radionuclide activity concentrations and natural background dose measurements) from a survey of the Ivankov region, immediately to the south of the CEZ conducted in 2014. Funding for preparing this data set was provided by the EU COMET project (http://www.radioecology-exchange.org/content/comet) and TREE (http://www.ceh.ac.uk/tree) project funded by the NERC, Environment Agency and Radioactive Waste Management Ltd. under the RATE programme. Full details about this dataset can be found at https://doi.org/10.5285/782ec845-2135-4698-8881-b38823e533bf