Levels of Some Selected (Essential-Mn, Zn and Toxic-Al, Sb) Metals in Clariasgariepinus(Cat Fish) Reared in Plastic Ponds in Benin City-Public Health Implication

Abstract

Increase in world dependence on fish and fish products as source of protein has caused a resultant increase in fish cultivation in artificial habitats including tarpaulin ponds. This may have potential health threat to fish consumers as certain trace and toxic elements have been implicated with such tarpaulin materials which are made from polyvinyl chloride stabilized with additives. This present study is aimed at evaluating the levels of some trace/toxic elements in African Catfish (Clariasgariepinus) and the health risk associated with these elements. Fish and water samples were obtained from tarpaulin fish ponds and Ikpobariver (control). The fish were dissected, blood samples were obtained and the tissues were digested with standard methodsand assayed for levels of manganese, zinc, aluminum and antimony using inductively coupled plasma mass spectrophotometer (ICP-MS). Results obtained showed that the mean concentration of the elements differed significantly in tissue and blood. Levels of manganese and zinc in tissues of fish from all the tarpaulin ponds were higher than those from the control river (P<0.01).The concentrations of manganese in blood and antimony in water of controls were higher compared with that of tarpaulin ponds. In general, the concentration of metals (manganese,zinc,aluminiumand antimony) were above the standard guidelines stipulated by the World Health Organization and the Food and Agricultural Organization (WHO/FAO). Consumption of Catfish reared and harvested from these sampled sites over a prolonged period might pose health threat to consumers in the sampled area, thus regular awareness campaigns for fish farmers on the impact of the bio-accumulation of trace and toxic metals on human health should be ensured.