Studies indicate an urgent need to map areas that have selenium-rich soil because the element has been linked to aridity there. A study published in the September issue of Journal of Environmental Management revealed that food grains from some arid regions in Northern India had high selenium.
For the study, researchers from the National University of Singapore and Maharshi Dayanand University in Haryana collected food grains from Rajasthan, Punjab, Himachal Pradesh and Haryana and tested the selenium content in them. They found that while extremely dry areas like Rajasthan and southern parts of Haryana had relatively higher selenium in food grains, the amount in Punjab, Himachal Pradesh and northern parts of Haryana was normal and grains from areas that were affected by floods along the Yamuna had lower levels of selenium. Estimations of selenium levels in food grains and soil showed that while the problem is intense in some pockets of Punjab and Haryana, in most parts of northern India, it is within safe limits. According to the study, the highest level of selenium detected was 0.272 mg/kg in wheat from Jind in south Haryana.
These levels are lower than those found by K S Dhillon, retired professor of Punjab Agricultural University, who has studied selenium content in soil in Punjab for about three decades. He detected up to 4.5 mg/kg of selenium in soil in some villages. Soil samples containing more than 0.5 mg/kg selenium lead to plants with more than 5 mg/kg selenium, he says. Plants containing more than 5 mg/kg are considered toxic.
Dhillon says,