Submitted to: Selenium Deficiency, Toxicity and Biofortification for Human Health
Publication Type: Book / Chapter
Publication Acceptance Date: 12/1/2009
Publication Date: 12/31/2009
Citation: Banuelos, G.S., Lin, Z., Yin, X. 2009. Selenium deficiency, toxicity and biofortification for human health. Selenium Deficiency, Toxicity and Biofortification for Human Health. 21-23. Interpretive Summary: Worldwide, interest in the biological impacts of Selenium (Se) on the environment and food chains is increasing because it is an essential micronutrient for many organisms, including humans and other animals. For this reason there is the urgent need to synthesize, critically analyze information on selenium research conducted world-wide into an updated perspective for preserving the health of the environment, livestock, and humans provided the impetus for the development of this book. The book contains critical parts of the lectures held at the First International Conference on Selenium in the Environment and Human Health that was held in Suzhou China. Chapters will include the impact of selenium contamination and deficiency on the environment, domestic animal-crop-human accumulation, biochemical metabolism processes and further on human health. The importance of these topics clearly shows why selenium is arguably one of the natural-occurring trace elements of greatest impact worldwide in the 21st century.
Technical Abstract: The melatloid selenium (Se) is ubiquitous in the environment and its concentrations vary from below 0.1 to 10 µg/g or above; although Se concentrations as high as 1200 mg/kg have been reported in some seleniferous regions soil Se concentrations and bioavailability vary with parent material and environmental conditions, and the distribution of Se in soils is usually heterogeneous and site-specific. However, se bioavailability to plants can vary substantially for reasons that are still poorly understood. At low intake levels, Se is an essential micronutrient for both human beings and animals, but high levels of dietary intake or ingestion can result in Se toxicity. Selenium is toxic to animal and human in sufficient quantities. Selenosis was manifest as deformities mainly in fish and birds, but had been known earlier in grazing animals as well as in humans living in Se-rich areas who suffered from Se toxicity ingesting high quantities of Se-laden food. Chronic Se toxicosis on the other hand, has been implicated in causing hair and nail loss, skin lesions, liver enlargement in addition to gastrointestinal and neurological pathologies. Selenium has a regulated metabolism that serves to supply it to tissues that have special need for it and to excrete excess amounts of the element that have been ingested. The overall goals of this homeostasis are to avoid Se toxicity and to support the synthesis of selenoproteins and thereby maintain Se functions. In this book, we intend to highlight the key developments made on Se research during the past years at the molecular, cellular, environmental, animal and human health areas, and aim at identifying new research directions.