The radioecology of the grapevine. 1. The transfer of nuclear weapons fallout from the soil into wine

In a field investigation (1983-1985) comprising eight places of the most important viticultural regions in the Federal Republic of Germany, the contents of the radionuclides tritium (3H), carbon-14 (14C), strontium-90 (90Sr), and cesium-137 (137Cs) in air, soils, leaves of the vine, grapes and wine were measured and site-specific transfer factors were calculated. Data concerning soil parameters, climatic conditions, cultivation and vinification were collected. The tritium content of all samples was 10 Bq/l water of combustion, independent of location and year. The specific activity of 14C in the atmosphere and in biological material was 0.22 Bq/g carbon, independent of site and year. 90Sr contents of soils fluctuated between 0.7 and 3.5 Bq/kg dry matter. The mean content of leaves was 2 Bq/kg fresh material, of grapes 0.035 Bq/kg and of wine 0.008 Bq/l. 137Cs content of soils fluctuated between 1.3 and 7.9 Bq/kg dry matter. The mean content of leaves was 0.098 Bq/kg fresh material, of grapes 0.021 Bq/kg and of wine 0.0085 Bq/l. A relation between transfer of radionuclides and soil parameters and between the contents of grapes and wine was not recognizable. While cultivar-specific differences were not observed in grapes, red wines contained somewhat more 137Cs than white wines. Transfer factors soil grapes were 0.027 for 90Sr and 0.0057 for 137Cs. Site-specific influences such as soil parameters, climate, cultivation, vinification and differences between years led to a relatively small fluctuation of values. An influence of the nuclear power station Neckarwestheim has not been found in any of the radionuclides.