Selenium Content and Uptake in Crops as Affected by Soil Selenium Content and Implications on Human Health

Abstract

The selenium contents of soil and its uptake by a wide variety of crops are analyzed along a transect, with the sampling stations located at Mawkyrwat, Upper Shillong, Pynthormukrah, and Nongpoh. Each site is successively farther away from uranium deposits, with the closest being Mawkyrwat (50 km). Leafy vegetables had greater selenium content than tubers and fruits. The concentrations of selenium in soil ranged from 70 μg g⁻¹ to 296 μg g⁻¹ and in vegetables varied from 26 μg g⁻¹ to 225 μg g⁻¹. Selenium is known to be a decay product of uranium, and the results indicate that the selenium content of soil and vegetables of Mawkrywat is greater than the other three sampling sites. This can be attributed to the proximity of this site to uranium deposits of Domiasat. The possible implications of selenium on human health are discussed.

Keywords:

• Selenium
• soil
• vegetables

Acknowledgments

The authors are grateful to Defense Research and Development Organization, government of India for funding part of the work; the principal and co-investigators of the project of Department of Atomic Energy and Board of Research in Nuclear Science for sharing their data on the health status of population of Domiasiat; U. K. Mishra, senior scientist, Geological Survey of India, for his valuable suggestions in the review process and for providing the geological map of Meghalaya; and Amir Ali, junior research fellow, Department of Environmental Studies, NEHU, for help in modifying the geological map.