Distribution of mercury in the soft tissues of the Blue Tilapia Oreochromis aureus (Steindachner) after acute exposure to mercury (II) chloride
Mercury has no known biological functions in the animal body and is described as an ultratrace element. Consequently, there is no well defined regulatory mechanism present in the animal body and it tends to accumulate readily if available in an animal's environment. Sources of mercury include the chloroalkali industry, the manufacture of electrical equipment, paint, fungicides and dentistry. The use of mercury in the gold mining industry has caused extensive pollution in the Amazon Basin. Whether fish take up organic or inorganic mercury, most of it accumulates in the tissues in the organic form. Most cases of mercury poisoning arising from fish consumption are due to methylmercury because mercury entering the aquatic system rapidly becomes methylated. Minamata disease in humans was first reported in 1956 due to consumption of contaminated fish and shellfish from Minamata Bay. Therefore it is important to monitor the mercury content of fish which are caught or farmed for human consumption. Since many commercial animal feeds contain a fish meal component, monitoring is important from the aspect of contamination of farm animals intended for human consumption. Oreochromis aureus (Steindachner) is a species of tilapia often cultured in ponds and also in cages in North and Latin America. Therefore, it is a suitable model to use for studying the effects of mercury exposure on the distribution of mercury in different tissues of fish. Distribution is important, because different cultures consume different fish organs, not just the muscle portion alone. The tissues which have a high content of mercury will be most dangerous from a toxicological viewpoint. Removal of the tissues known to contain the highest concentrations of mercury would reduce the mercury content of fish meal. Since fish are often species-specific in their responses to heavy metals, it is important to study a species which is actually farmed and cultured as a food fish. 20 refs., 2 tabs.
- OSTI ID:
- 6610785
- Journal Information:
- Bulletin of Environmental Contamination and Toxicology; (United States), Vol. 53:5; ISSN 0007-4861
- Country of Publication:
- United States
- Language:
- English
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