Uptake of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead‐zinc mine in Kabwe, Zambia

Abstract

Concentrations of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe (Zambia), which is ranked among the 10 worst polluted places on earth, were compared with other Zambian towns. Metal concentrations were measured in the liver and kidneys of 51 cattle from Kabwe and other Zambian towns. The maximum metal concentrations, expressed in mg/kg and dry weight, in the liver or kidneys were 398.4 (Cu), 252.6 (Zn), 77.81 (Cr), 19.37 (Cd), 7.57 (Ni), 1.8 (Pb), 1.04 (Co), 0.112 (Hg), and 0.05 (As). Concentrations of Pb and Cd in Kabwe cattle were higher than levels in other Zambian towns. The mean concentration of Cd exceeded benchmark values in offal destined for human consumption. Levels of Ni and Cr may also pose public health concerns. Concentrations of Pb and Cr, Pb and Cu, Cd and Zn, Cd and Hg, Zn and Cu, Cu and Co, as well as Co and Ni were positively correlated. The present study also highlighted the dangers of exposure of animals and humans to a mixture of toxic metals.

Accumulation of Metals in the Liver and Kidneys of Cattle from Agricultural Areas in Lusaka, Zambia

“…The low levels of Hg and As in the present study agreed with findings in other studies [5,15], and they posed no immediate health risk to human consumers.…”

“…Although toxic metal concentrations in the current study were low and did not pose immediate health risks, the levels of Pb and Cd indicate potential for increased accumulation, if exposure is prolonged as these metals bioaccumulate and bioconcentrate in organs and tissues of animals [14]. The low levels of Hg and As in the present study agreed with findings in other studies [5,15], and they posed no immediate health risk to human consumers.Ni and Cr are considered as essential trace elements, and there are no benchmark values for cattle offal destined for human consumption. In the current study, median levels of 0.594 mg/kg wet weight Ni and 1.35 mg/kg Cr in the liver were comparable to the concentrations reported previously in cattle from polluted regions in Zambia [15].…”

“…Although toxic metal concentrations in the current study were low and did not pose immediate health risks, the levels of Pb and Cd indicate potential for increased accumulation, if exposure is prolonged as these metals bioaccumulate and bioconcentrate in organs and tissues of animals [14]. The low levels of Hg and As in the present study agreed with findings in other studies [5,15], and they posed no immediate health risk to human consumers.…”

“…Thus, the contribution of cattle offal to the total intake of Ni and Cr in human consumers should be monitored, as cattle offal are considered as delicacies and frequently consumed in Zambia and other countries. The median concentrations of Cu (40.9 mg/kg) and Zn (35.2 mg/kg) in the liver were similar to concentrations found in cattle from polluted environments [6,15].Cattle in the present study were reared on commercial farms away from industrial and mining activities. Therefore, commercial farming involving prolonged application of fertilizers and the natural presence of metals in soils could have contributed to metal accumulation either singly or combined.…”

Retrospective study of cattle poisonings in California: recognition, diagnosis, and treatment

“…74 Chronic exposure occurs from grazing on polluted pastures in the vicinity of lead mines or ingestion of forages harvested from such areas. 77 Only 2%-10% of the ingested lead is absorbed through the GI tract and rapidly distributed to kidney and liver. 74 Kidney tissue concentrations often reflect accurately the environmental level.…”