Assessment of the water quality, the human health risk, and heavy metal accumulation in Nile tilapia and African catfish collected from the Kitchener Drain-Egypt

Abstract

The water running in Kitchener Drain, the longest in Egypt, is sourced from agriculture and industries with many pollutants such as toxic minerals, chemicals, pesticides, and insecticides. This study assesses the water quality, human health risk, and heavy metal accumulation in Nile tilapia and African catfish from the Kitchener Drain-Egypt over the four seasons. Water and fish samples were collected from the Kitchener Drain during four seasons from April 2021 to March 2022. Markedly higher levels of Fe, Cu, Zn, Pb, Cr, and Mn were detected in the water samples during summer than in winter, spring, and autumn. Further, the presence of heavy metals in the water samples followed the sequence of Fe > Mn > Zn > Pb > Cu > Cr regardless of seasonality. In Nile tilapia, the sequence of heavy metals collected from the Kitchener Drain during the four seasons is Fe > Zn > Cu > Pb > Cr > Mn. In African catfish, all detected heavy metals in the muscle vary significantly during the different seasons and follow the sequence of Fe > Zn > Pb > Cr > Mn > Cu. Consequently, Fe, Cu, Zn, Pb, Cr, and Mn were present in African catfish >Nile tilapia. The estimated daily intakes (EDI) for Nile tilapia followed the sequence of Fe > Zn > Cu > Pb > Mn > Cr and for African catfish Fe > Zn > Pb > Cu > Cr > Mn regardless of seasonality. Based on the target hazard quotients (THQ) and hazard index (HI) of Nile tilapia and African catfish, it is evident that consuming their flesh may cause a health risk. Further, the differences in the levels of detected heavy metals in Nile tilapia and African catfish during the four seasons indicate that these results depend on the fish species and seasonality.