Influence of Earthworms on Cesium-137 Migration in Soil and Bioaccumulation by Vegetable Plants

The explosion at the Chernobyl Nuclear Power Plan was one of the greatest known nuclear disasters of the 20th Century. The Chernobyl accident can be differentiated from other radiation accidents not only by its magnitude, but also by its transcontinental impact and the unique patterns of radionuclide fall-out. It is estimated that more than 16 million people in Russia, Ukraine and Belarus were exposed. Unfortunately, the majority of people in this region rely on farming of vegetables grown in the radioactively contaminated soil as their main food supply.

Our research project is being conducted in the Bryansk (west-central) region of Russia. The study is focused on the role of earthworms in reducing the amount of Cesium-137 in soil. In our research we have compared the soils of polluted and non-polluted territories; in regions populated by earthworms and in areas where earthworms are not present. In the first part of our study, we have studied the migration of Cesium-137 radionuclides within a soil profile, and in the second part, we will attempt to determine factors causing their movement.

Our research to date shows that earthworms are capable of decreasing the accumulation of radionuclides in plants by a statistically significant factor of 1.5 to 1.7. As a result of this research project, we hope to provide scientific proof that earthworms can be used for bioremediation of soils contaminated with radionuclides. In other words, through the use of earthworms, it will be possible to reduce the migration of radionuclides from soil to plant to people, thereby improving the health of individuals living in radioactively polluted regions.