Karta radiat︠s︡ionnoĭ obstanovki na territorii evropeĭskoĭ chasti SSSR po sostoi︠a︡nii︠u︡ na dekabrʹ 1990 goda : plotnostʹ zagri︠a︡znenii︠a︡ mestnosti stront︠s︡iem-90 : masshtab 1:500 000 (part 1: Gomel')
This map shows the spread of Strontium-90 contamination in the area of eastern Belarus and western Russia surrounding Gomel' in December 1990. It is one of a set of four Soviet-produced maps showing strontium contamination from the same point in time. They were produced by the State Committee for Hydrometrology and Control of Natural Resources of the Soviet Union, which was in charge of producing contamination maps twice a year.
An earlier version of the map served as the basis for the IAEA's map, in terms of contamination data. However, the two maps are very different in their portrayals of natural features, roads, and other basic elements of the map. In the process of verifying Soviet environmental monitoring data, the IAEA scientists instead often were faced with the task of reconciling two (or more) different basic accounts of the territory itself, and the level of contamination it contained.
Institut prikladnoĭ geofiziki imeni akademika E.K. Fedorova
GUGK SSSR
1991
Karta radiat︠s︡ionnoĭ obstanovki na territorii evropeĭskoĭ chasti SSSR po sostoi︠a︡nii︠u︡ na dekabrʹ 1990 goda : plotnostʹ zagri︠a︡znenii︠a︡ mestnosti t︠s︡eziem-137 : masshtab 1:500 000
This key refers to other maps that depict the extent of contamination from the Chernobyl disaster. Interestingly, it indicates that maps of Cesium-137 distribution were much more detailed than those of Strontium-90 from the same month and year; while only four maps were used to represent the contaminated territory, this document suggests that many more were produced to cover the same area for the Cesium maps.
While it does not itself provide this information, it points to two important things: first, the state of published knowledge about contamination from the accident at a pivotal historical moment; and second the extent of relevant territory for those who made the maps. While I have not (yet) located the other maps, this document serves as a baseline for further research.
GUGK USSR
GUGK SSSR
1991