Review on environmental selenium: Occurrence, public …
Several studies confirmed that organic selenium compounds undergo photo-oxidation in water, and that their mineralization eventually yields inorganic Se species and volatile species of Se, H 2 Se, CH 3 SeH, (CH 3) 2 Se and (CH 3) 2 Se 2 (He et al., 2020; Amouroux et al., 2001; Diaz et al., 2009). In sediments, species are controlled by their ...
اقرأ أكثر
Selenium contaminated waters: An overview of analytical …
For reasons of human health and ecotoxicity, selenium concentration has to be controlled in drinking-water and in wastewater, as it is a potential pollutant of water bodies. …
اقرأ أكثر
Selenium Compounds in the Waste Water | SpringerLink
The bulk of solid selenides are intermetallic compounds. There are also many organic selenium compounds, and their nomenclature is expanding from year to year. Various methods of analysis are used from all currently available groups. Spectroscopic methods based on the interaction of selenium or its compounds with electromagnetic radiation include:
اقرأ أكثر
Selenium in the Environment, Metabolism and Involvement …
Selenium in Water. Selenium is also found in water. It originates from atmospheric deposits or soil drainage and sub-soils which are naturally rich in selenium. ... Three groups of selenium compounds can be distinguished in the atmosphere according to their behaviour: volatile organic compounds (DMSe, DMDSe and methaneselenol), volatile ...
اقرأ أكثر
Selenium Public Health Goal, December 2010
The primary water-soluble selenium forms in aqueous media that are bioavailable to humans are inorganic selenate (SeO 4-2) and selenite (SeO 3-2) ions. Compared to drinking water, food is the major overall source of selenium for humans. Moderately water-soluble organic selenium compounds such as selenomethionine and selenocysteine are
اقرأ أكثر
Technical Factsheet on: SELENIU
This amount is around 50,000 times greater than the selenium found in seawater. Selenium dioxide is the primary source of problems from industrial exposures since the dioxide forms selenious acid with water or sweat, and the acid is an irritant. Selenium compounds released during coal or petroleum combustion may be a significant source of exposure.
اقرأ أكثر
Selenium–Fascinating Microelement, Properties and Sources …
Selenium in the forms of both inorganic compounds (Na 2 SeO 3 and Na 2 SeO 4) and organic ones (selenocysteine, selenomethionine, and selenoglutathione) introduced into the organism through food or drinking water results in a significant reduction of chemically induced cancers . Protective effect of selenium occurs after crossing a threshold ...
اقرأ أكثر
Technical Factsheet on: SELENIU
Selenium concentration in fresh water is usually around 0.02 ppm. The selenium content of surface water is greatly influenced by pH, being high in acidic (pH < 3.0) and in alkaline waters …
اقرأ أكثر
ATSDR Selenium ToxFAQs
This selenium dust will eventually settle over the land and water. ' It also enters water from rocks and soil, and from agricultural and industrial waste. Some selenium compounds will dissolve in water, and some will settle to the bottom as particles. ' Insoluble forms of selenium will remain in soil, but soluble
اقرأ أكثر
Biogeochemistry of selenium compounds in the water …
The biogeochemistry of dissolved selenium (Se) was investigated over 3 years (2015–2017) in the subtropical, warm monomictic and meso-eutrophic Lake Kinneret (Sea of Galilee, Israel). We monitored seasonal variation and vertical distribution of dissolved total Se (T.Se), inorganic oxyanions (Se(IV) & Se(VI)), reduced Se fraction (Red.Se), organic (Org.Se) …
اقرأ أكثر
Selenium Compounds
Water The levels of selenium in groundwater and surface water range from 0.06 to about 400 µg/litre (5–7); in some areas, levels in groundwater may approach 6000 µg/litre (8). …
اقرأ أكثر
Final Public Health Goal for Selenium
The PHG for selenium is established at 30 parts per billion (ppb) for water-soluble and bioavailable selenium compounds in drinking water. The health-protective level is based …
اقرأ أكثر
HEALTH EFFECTS
Because of greater bioavailability, water-soluble selenium compounds are probably more toxic than elemental selenium by any route. Selenium is found in nature complexed with multiple compounds, and although various forms are discussed in the profile, many others exist. Some plants, such as alfalfa, yeasts, white grain, and cruciferous species ...
اقرأ أكثر
Selenium Compound
The reduced form of selenium (selenide) may be formed from water-soluble selenium compounds under acid conditions or in biological systems. The formal oxidation state is –2, and of biological interest are hydrogen selenide, dimethylselenide and trimethylselenonium ions, and selenosugars. The reduced form may also be found in the place of ...
اقرأ أكثر
Selenium in Drinking-water
See more on cdn.who.int
Selenium | Public Health Statement | ATSDR
Selenium levels are less than 10 parts of selenium in a billion parts of water (10 ppb) in 99.5% of drinking water sources tested. People may be exposed to higher-than-normal levels of …
اقرأ أكثر
A Review of Human Health Impacts of Selenium in …
selenium in all its forms and attributed risk of harm to organisms and biodiversity resulting from selenium and its compounds (ECCC and Health Canada, 2017). In response to numerous health risks, public health agencies have developed screening values for selenium in ambient water and fish potentially impacted by elevated selenium of geologic or
اقرأ أكثر
Basic Information about Selenium in Drinking Water
The major sources of selenium in drinking water are discharge from petroleum and metal refineries; erosion of natural deposits; and discharge from mines. A federal law called the …
اقرأ أكثر
Selenolanthionine is the major water-soluble selenium compound …
The Cardamine violifolia sample did not contain in considerable amount any of the organic selenium species that are often formed in hyperaccumulator plants; the inorganic selenium content (mostly as elemental selenium) accounted only for <20% of total Se. The most abundant selenium compound, accounting for about 40% of total Se was proved to be …
اقرأ أكثر
Selenium Compounds as Novel Potential Anticancer Agents
Chemical structure of inorganic selenium compounds (1—selenite, 2—sodium selenite, 3—selenate, and 4—sodium selenate).During the metabolism of SS in vivo, the formation of hydrogen selenide (H 2 Se) occurs [5,24], which is then methylated forming methylselenol [25,26].The in vivo study concluded that SeL (3 mg/kg body weight (b.w.)) was well tolerated …
اقرأ أكثر
Selenium
The 4 natural oxidation states of selenium are elemental selenium (0), selenide (-2), selenite (+4), and selenate (+6). Inorganic selenate and selenite predominate in water whereas organic selenium compounds (selenomethionine, selenocysteine) are the major selenium species in cereal and in vegetables.
اقرأ أكثر
PUBLIC HEALTH STATEMENT
Selenium compounds that can dissolve in water are sometimes very mobile. Thus, there is an increased chance of exposure to these compounds. Selenium may enter surface water in irrigation drainage waters. Some evidence indicates that selenium can be taken up in tissues of aquatic organisms and possibly increase in concentration as the selenium ...
اقرأ أكثر
A review on environmental selenium issues | Discover …
This process leaches natural soluble selenium compounds (such as selenates) into the water, which may then be concentrated in emerging wetlands. Selenium pollution of waterways also occurs when selenium is leached from coal flue ash, mining and metal smelting, crude oil processing, and landfill.
اقرأ أكثر
Selenium Distribution and Chemistry in Water and Soil
The soluble forms of selenium compounds are mobile and their speciation in soil and water is highly dependent on conditions of specific location, however SeO 4 − has been reported as a major species in oxygenated agriculture water. In past few decades the elevated concentration of selenium in soil and water has been reported as a serious ...
اقرأ أكثر
Synthesis Strategies for Organoselenium Compounds and Their Potential
The selenium (Se) element was discovered by a Swedish chemist J. J. Berzelius (1817) in the reddish deposits appeared in the lead chambers in a sulphuric acid plant [].It was named as selenium in honour of Greek Goddess 'Selene' meaning The Moon.Initially, it was thought to be tellurium; but subsequently, it was observed that even though it exhibited very …
اقرأ أكثر
Selenium, Chemical Element
Compounds Very few compounds of selenium have any important practical applications. One exception is selenium sulfide (SeS 2 ). This compound is used to treat seborrhea, or "oily skin." It is sometimes added to shampoos for people with especially oily hair. ... They traced the problem to high levels of selenium in the water. A large artificial ...
اقرأ أكثر
Biogeochemistry of selenium compounds in the water …
incoming water, while direct precipitation contributes only * 10% of the total water input to the lake and the rest is supplied by other small streams (Rimmer and Gal 2003). Notably, during the 3 years of this study (2015–2017), the annual minimum lake water level dropped by 1.34 m as a result of continuous drought, with below average annual ...
اقرأ أكثر
Selenolanthionine is the major water-soluble selenium compound …
The most abundant selenium compound, accounting for about 40% of total Se was proved to be selenolanthionine, a selenium species that has never been unambiguously identified before from any selenium containing sample. The identification process was completed with chemical synthesis too. ... The molar ratio of lanthionine:selenolanthionine in ...
اقرأ أكثر
Selenium in freshwater and marine water
Three oxidation states may occur in the water column, selenium (VI), selenium (IV) and selenium (II). Elemental selenium may also occur in reducing sediments (Maier & Knight 1994). ... (VI) and inorganic selenium compounds. Data were available for total selenium on four taxonomic groups (12 data points), as follows (the pH range was 7.30 to 7.98):
اقرأ أكثر
National Primary Drinking Water Regulations | US EPA
Long Term 1 Enhanced Surface Water Treatment: Surface water systems or groundwater under the direct influence (GWUDI) systems serving fewer than 10,000 people must comply with the applicable Long Term 1 Enhanced Surface Water Treatment Rule provisions (such as turbidity standards, individual filter monitoring, Cryptosporidium removal ...
اقرأ أكثر
Biogeochemistry of selenium compounds in the water …
The biogeochemistry of dissolved selenium (Se) was investigated over 3 years (2015–2017) in the subtropical, warm monomictic and meso-eutrophic Lake Kinneret (Sea of Galilee, Israel).
اقرأ أكثر