Metal bioaccumulation in the fish of the Olifants River, Limpopo province, South Africa, and the associated human health risk: a case study of rednose labeo Labeo rosae from two impoundments

Abstract

The Olifants River, Limpopo River system, is now one of the most polluted rivers in South Africa. The concentrations of metals in fish muscle tissue from two impoundments on the Olifants River, Flag Boshielo Dam and Phalaborwa Barrage, were measured and a human health risk assessment conducted to investigate whether it was safe to consume Labeo rosae from these impoundments. Labeo rosae is one of the most common pan-fish in these impoundments and is frequently available to rural communities. Metals are accumulating in the muscle tissue of L. rosae even though the populations appear to be healthy. At Flag Boshielo Dam the recommended hazard quotient (HQ) of 1 was exceeded for lead and chromium in all L. rosae analysed, and 53% exceeded that for antimony. At Phalaborwa Barrage almost all L. rosae analysed exceeded the recommended HQ for lead, and <25% exceeded that for arsenic. Weekly consumption of 150 g of L. rosae muscle tissue from these impoundments may pose an unacceptable health risk to rural communities.