Effective and Ecological Half-lives of 137Cs in Cow's Milk in Alpine Agriculture

Alpine regions have been heavily affected by the Chernobyl fallout depositing 137Cs activities up to more than 100 kBq/m². To a large extent, alpine ecosystems are semi-natural environments and vulnerable to radioactive contaminants with respect to their long persistence in the ecosystem. Since 1988 a continuous monitoring of 137Cs in milk on different seasonally used alpine production sites in Austria has been carried out and ecological half lives have been calculated. With good agreement the decrease of 137Cs in milk follows a simple exponential decay with ecological half-lives between approximately 6 y and 15 y depending on the site of the alpine pasture. However, from the decay curve of some sites there are good hints of more than one ecological half life controlling the decay and of a long lived component which may have an ecological half-life longer than 15 y. The differences are systematic and ecological half-lives are positively correlated with the altitude above sea level. Alpine sites on elevated altitudes show a marked tendency to longer ecological half-lives which corresponds with higher soil to plant transfer of 137Cs and lower migration rates in the soil.

LETTNER Herbert;  HUBMER Alexander;  BOSSEW Peter;  STREBL Friederike;  STEINHÄUSLER Friedrich; 

2009-01-26

SPRINGER

JRC45500

0301-634X,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC45500,   

10.1007/s00411-008-0192-X,