TRADESCANTIA STAMEN-HAIR MUTATION BIOASSAY ON THE MUTAGENICITY OF RADIOISOTOPE-CONTAMINATED AIR FOLLOWING THE CHERNOBYL NUCLEAR ACCIDENT AND ONE YEAR LATER

This paper presents results of the research on the mutagenic effect of ambient air in the Cracow area. Initial studies were conducted in May 1986, following the Chernobyl accident. Other studies were performed at various sites within the Cracow area in the Spring of 1987. Counts were made of stunted hairs and pink cells in the stamen hairs of Tradescantia clone 4430. Mutations scored from the 11th day after the beginning of exposure were used as a measure of the mutagenic effect. The mean mutation frequencies measured in 1986 and 1987 were 0.43 and 0.21 per 100 hairs respectively. The time-dependent development of mutation frequencies observed after the Chernobyl accident showed a correlation with the time-dependent development of total radioactivities measured in the air at that time. The results obtained in 1987 showed on average a significant decrease of ambient air mutagenicity. Still, the variation of mutation rates observed during the investigated period at different sites in the Cracow area was rather high (0.09-0.38 mut/100 hairs). Only the highest frequencies observed in the Spring of 1987 were comparable to the level detected after the Chernobyl accident.