4. Conclusions
The results obtained for trace elements (essential and toxic) in
analyzed fish species were acceptable to human consumption at
nutritional and toxic levels except O. mossambicus in case of arsenic
content. In Bangladesh 35 million people are believed to be
exposed to As concentration in drinking water exceeding
0.05 mg L1 especially in rural areas. In rural areas people consume
tilapia fish and arsenic contaminated water. In that case the total
daily intake of arsenic for a rural people would be 0.239 mg d1
exceeding the FAO limit by a factor of two. Therefore, O. mossambicus
would be considered as a potential threat to human health in
terms of arsenic toxicity in the rural areas of Bangladesh.
In this study only fish consumption was considered which
constitutes only 3% of per capita per day calorie intake by food
items. It may be concluded that other food sources and particularly
dietary staple rice as well as vegetables, fruits, cereals,
piscine and non-piscine protein sources need to be evaluated to
determine the exact health risks due to intake of trace metals
from such foods.