Читать книгу Selenium Contamination in Water - Группа авторов - Страница 41
3.4.1 Human Population
ОглавлениеSe is an essential micronutrient required for the human body. It is an important part of selenoproteins which will be required for various biological functions such as antioxidants defense, thyroid hormone formation, DNA synthesis, fertility, and reproduction. In organisms Se is converted into different metabolites. Se plays an important role in slowing down the aging process and improvement of endurance of muscles besides vitamin E. Methylselenol also plays a part in cancer prevention (Papp et al. 2007).
Table 3.1 Drinking water and surface water limits of different countries (EPA 2020; WHO 2012).
| Country | Limit (μg/l) | |
|---|---|---|
| Drinking water | Surface water | |
| United States | 50 | 5 |
| Canada (British Columbia, Ontario, Quebec) | 10 | – |
| Canada (Alberta, Nova Scotia, Prince Edward Island) | 50 | – |
| South Africa | 20 | – |
| Germany | 10 | 3 |
| Ireland | 10 | – |
| Japan | 10 | – |
| India | 10 | – |
| Malaysia | 10 | – |
| Russia | 10 | – |
| Abu Dhabi | 40 | – |
| New Zealand | – | 10 |
| Australia | – | 10 |
The deficiency of Se causes biochemical changes which may lead to additional stress in humans and causes certain type of illness (Du et al. 2012). A combination of Se deficiency and another stress such as viral infection can cause Keshan disease. A disease, namely cardiomyopathy, (also termed as Keshan disease) occurred in China during 1970 due to deficiency of Se. It was recommended that a daily intake of 20 mcg can protect the adults from this disease. Kashin–Beck disease is a type of osteoarthritis which is associated with male infertility due to Se deficiency (Sanmartin et al. 2012).
Se supplementation has an antiviral effect in the human body which lowers the risk of autoimmune thyroid disease. Excessive Se can generate reactive oxygen species which may leads to carcinogenesis. A few pieces of research also specify that high Se concentration may develop tumorigenesis by uplifting TR 1 expression and to diabetes. Besides a close relation with carcinogenesis, Se is related to development of chronic degenerative diseases such as cardiovascular disease and amyotrophic lateral sclerosis (Ralston et al. 2008). Se is 40 times more neurotoxic in inorganic form than in organic form.
