Metal contamination of commercial fish feed and quality aspects of farmed tilapia (Oreochromis niloticus) in Bangladesh

In this study, we evaluated the heavy metal load of the formulated commercial fish feeds and heavy metal burden in cultured tilapia (Oreochromis niloticus) in Muktagacha, Mymensingh, one of the concentrated aquaculture regions of Bangladesh. Three of the most commonly used commercial fish feeds namely Quality, Mega, Rupshi, manufactured by Quality feeds limited, Spectra hexa feeds limited., and Rupshi fish feed limited respectively and tilapia were collected from nine aquaculture farms selected randomly from the Muktagacha, Mymensingh region. Heavymetal (Cu, Fe, Pb, Cd, Na, Cr, Ni) concentrations were measured using Atomic Absorption Spectrometer (AAS) in edible muscle from fish and in fish feeds. We observed higher concentrations of Cd, Fe, Na and Pb in fish feeds and in fish muscles, all of which exceeded the World Health Organization's or other standard limits for food safety. The highest target hazard quotient (THQ) value was estimated for Na (1.51) followed by Cd (1.45), which were higher than the acceptable guideline of US Environmental Protection Agency (USEPA). In case of target cancer risk (TR), consumption of tilapia at current accumulation level is safe but continuous and excess consumption for a lifetime of more than 70 years are in risk of cancer.