Estimation of Cadmium in Muscles of Five Freshwater Fish Species from Manzalah Lake, and Possible Human Risk Assessment of Fish Consumption (Egypt)

The Egyptian government devised a plan in 2016 to improve the unique ecological significance of northern lakes, which mentioned Manzalah Lake in the Egypt Vision 2030. In this regard, this study investigated cadmium (Cd) content in five freshwater fish species collected from Manzalah Lake in Egypt at 2018 by local fishermen. According to the findings, Clarias gariepinus recorded the highest concentration of Cd (1.40 +/- 0.2 mu g/g) and the lowest concentration was recorded in O. aureus (1.19 +/- 0.2 mu g/g). Cadmium contents of all species were largely above the permissible level of the Food Agricultural Organization (FAO)/World Health Organization (WHO) and Commission Regulation (EC). The estimated daily intake (EDI), the estimated weekly intake (EWI), and the percentages of provisional tolerable weekly intake (PTWI %) values for Cd in the C. gariepinus> Sarotherodon galilaeus> Tilapia zillii> Oreochromis niloticus> Oreochromis aureus which consumed by children, teenagers, and adults were much higher than the PTWI values established by FAO/WHO. In addition, C. gariepinus consumed by children showed the highest value of the target hazard quotient (THQ) (5.83 a day or 40.81 a week) while O. aureus that ingested by adults showed the lowest level (1.06 a day or 7.42a week). The target carcinogenic risk (TCR) of C. gariepinus in children had the greatest level (2.21 x 10(-3) a day or 1.55 x 10(-2) a week), whereas O. aureus in adults had the lowest level of TCR (4 x 10(-4) a day or 2.81 x 10(-3) a week). THQs values of Cd in the five studied species were found higher than one. Moreover, TCRs values of Cd in the five species were exceeded the US Environmental Protection Agency guideline USEPA permissible limits suggesting that a daily or weekly consumption of these species could lead to a high risk non-carcinogenic and carcinogenic for humans.

Automated summary

This study investigated the cadmium content in five freshwater fish species collected from Manzalah Lake in Egypt and found that all species had cadmium levels that exceeded the permissible limits. Additionally, the consumption of these fish species could pose a high risk, both non-carcinogenic and carcinogenic, for humans.