Origin, Mobilization and Distribution of Selenium in a Soil/Water/Air System: A Global Perspective With Special Reference to the Indian Scenario

Abstract

Narrow tolerance limit of selenium (Se) brings serious concerns through deficiency as well as toxicity in the biological and environmental systems. Both geogenic and anthropogenic activities govern Se origin in nature, while its bioavailability is controlled by biogeochemical conditions and nature of Se species. Selenium hazards have drawn a special research interest globally, especially in USA, Canada and China, where large populations of aquatic life and human beings are being severely affected. Both Se deficiency and toxicity has been reported in India. Deficiency is shown to amplify arsenic (As) poisoning in As polluted regions. Industrial, mining, coal burns, and natural sources have been recognized as major causes of Se poisoning in soil, surface/groundwater and atmosphere. Besides local scale pollutions, the NW Indian state Punjab is known as the most alarmed region with >1000 ha of contaminated farm lands. Alkaline soil pH, cultivation of Se bioaccumulators, improper treatment of industrial effluents/emissions is responsible for Se mobilization and easy bioavailability. Acidification of soil pH, phytoremediation, application of excessive organic matters and sulfur‐rich minerals such as gypsum, changes in cultivation practices to non‐bioaccumulators, regulatory industrial effluent/emission treatment, and avoidance of Se‐rich fodders are considered to overcome Se‐toxicity, while Se supplements and/or Se‐rich fertilizers may resolve Se‐deficiency.

Geochemistry of Croatian superhigh-organic-sulphur Raša coal, imported low-S coal and bottom ash: their Se and trace metal fingerprints in seawater, clover, foliage and mushroom specimens

“…Also, Figures 2 and 3 show that these elements exhibited increased levels either in coal or ash material. Similarly, Paikaray (2016) reported that many areas in India show Se toxicity having resulted from coal mining and coal-fired power plants. The author emphasised that the problem can be regarded as being even more serious when taking into account that India is the third largest global coal producer.…”

Selenium–Fascinating Microelement, Properties and Sources in Food

“…In water, selenium is present in trace quantities, and mainly in the form of selenates and selenites [16]. The amount of selenium in groundwater is much higher than that in seawater [13] because of selenium elution from the parent rocks and excessive fertilization of soils with mixtures rich in selenium compounds [17]. The selenium content determined in groundwater in Poznań (Poland) is 0.17–0.44 µg/L [18].…”

“…It penetrates the soil as a result of anthropogenic activity through the combustion of coal and lignite, crude oil, and the use of agrotechnical processes—fertilization or liming [14]. These treatments are being done for example in Hubei Province, an area of Enshi in China, where the selenium content in coal oscillates at the level of 6–8.4 g/kg [17]. However, the greater part of China surface exhibits a very low content of this element in the soil (<0.1 mg/kg).…”

Effective Immune Functions of Micronutrients against SARS-CoV-2

“…So, the amount in similar food item varies in different geographical locations. However, the primary sources for this element are meat, bread, mushrooms, dairy products, fish, seafood, and nuts [ 49 , 50 , 51 ]. It acts as an enzyme cofactor that takes part in mammalian redox reactions [ 52 ].…”