Insecticides, polychlorinated biphenyls and metals in African lake ecosystems. I. Hartbeespoort Dam, Transvaal and Voëlvlei Dam, Cape Province, Republic of South Africa

Abstract

Concentrations and distribution of chlorinated hydrocarbon insecticides, polychlorinated biphenyls (PCB's) and some metals were determined in two South African lakes, Hartbeespoort Dam and Voëlvlei Dam. Water, bottom sediments, aquatic plants, aquatic insects, fish, fish-eating birds and their eggs were collected. Insecticides and PCB's were analyzed by thin layer and gas chromatography and mass-spectrometry. Analysis of metals was accomplished with atomic absorption spectrophotometry. Metals included arsenic, cadmium, copper, mangenese, lead, zinc, and mercury. The insecticide residue most commonly found in both dams were DDE, DDD, DDT, and dieldrin. Hartbeespoort had higher levesl than Voëlvlei of insecticides and PCB's in all types of samples common to both lakes. Concentrations of PCB's in all types of samples common to both lakes. Concentrations of PCB's having six or more chlorines increased with an increase in the trophic level. Concentrations of PCB's in the brains of the African birds were greater than the average total concentration of insecticides while the opposite was true for carcasses. Biological magnification of insecticides and PCB's occurred in both lakes. Hartbeespoort Dam had higher levels than Voëlvlei for all metals examined in bottom sediments and birds, except for copper in bird carcasses. Mercury levels in bird carcasses ranged from 2- to 5-fold greater than in fish while lead concentrations ranged from 2- to 10-fold greater.

Characterization of polychlorinated biphenyls in surface sediments of the North End Lake, Port Elizabeth, South Africa

“…Grobler (1994) also checked for the presence of PCBs (Aroclor 1254 and 1260) in the sediment of the Olifants River in Mpumalanga, but the levels were below the detection limit. The levels reported by Greichus et al (1977) were two-fold greater in magnitude compared to the levels detected in the present study. Compared to the concentrations reported from other developing and industrially developed countries around the world, PCB concentrations measured in the present study were similar to those reported by Guzzella et al (2005), Rajendran et al (2005), He et al (2006), El-Khady et al (2007), and Verhaert et al (2013) (Table 3).…”

“…In South Africa, the literature indicates little research on PCB content in sediments. Greichus et al (1977) ) and the Hartbeespoort dam, North-West Province (0.32 ng·g -1 dw). Grobler (1994) also checked for the presence of PCBs (Aroclor 1254 and 1260) in the sediment of the Olifants River in Mpumalanga, but the levels were below the detection limit.…”

Heavy Metals Pollution in Water, Sediments and Fish of Léré Lake, Western Mayo Kebbi (Chad)

“…These concentrations were quite lower compared to those obtained by other authors: 255 mg/kg [19], 125mg/kg [16] and 131.95 mg/kg [7].…”

“…These values were higher than those fixed by WHO (0.20 µg/g). In water of the Harbestport lake in South Africa, [19] found a lead content of 0.42 mg/kg in fish. A comparable rate of 0.48 mg/kg was also reported by [25] for fish of the delta of Niger in Nigeria.…”

“…Other researchers found values more raised: 2.9 mg/kg in the Harbestport Dam Lake in South Africa [19] and 12 mg/kg in Bay of Abou-Kir in Egypt [40].…”