Abstract

Gills and muscles of Tilapia fish from Naik lake of Nagpur city were estimated for heavy metals (Zinc, Lead, Nickel, Copper and Cadmium) using inductively coupled plasma optical emission spectrometry (ICP-OES). Results showed higher concentrations of heavy metals in gills than in muscles of tilapia fish. Trends of heavy metal concentrations in gills and muscles of tilapia fish were found Zn > Pb> Ni> Cu >Cd.  Highest lead and cadmium levels in muscles of the fish were 83±0.07 µg/g dw and 13±0.21 µg/g dw respectively. These levels were above the maximum permissible limits of Food and Agriculture Organization (FAO)/World Health Organisation (WHO). The results confirmed that tilapia fish from Naik lake are not safe for human consumption. Further, the health risks related to Zn, Pb, Ni, Cu and Cd were assessed based on target hazard quotients (THQ). The health risks from lead and cadmium were found to be the highest among all heavy metals in the study. THQ values of lead and cadmium were 4.0108, and 2.450, 0.818 and 2.57, 1.53 and 0.513 for person who eat tilapia fish from Naik lake five times, three times and once a week respectively. Maximum allowable daily consumption rate (CRlim) for lead and cadmium in tilapia fish from Naik Lake was 0.0015 kg/day and 0.0024 kg/day respectively. Highest allowable weekly (CRwm) and monthly (CRmm) consumption rates for lead and cadmium in tilapia fish from Naik Lake were 0.0105 kg/week , 0.0168 kg/week and 0.198 kg/month, 0.318 kg/month respectively. Above these values of highest allowable daily, weekly and monthly consumption rates for lead and cadmium are unsafe for inhabitant who eats tilapia fish from Naik lake. Health risk assessment of lead and cadmium in tilapia fish from Naik lake suggests that consumption of fish from Naik lake might be unsafe for humans. Regular assessment of heavy metals in fish in Naik lake must be conducted to assure food safety.

Key words: Health risk estimation, heavy metals, tilapia fish, allowable daily consumption, target hazard quotients.