Levels of Lead (Pb), Cadmium (Cd) and Cobalt (Co) in Cow Milk from Selected Areas of Zanzibar Island, Tanzania

Abstract

Milk is one of the very important nutrients of human diet. The presence of toxic elements in milk may threaten the public health. This study reports the levels of Cadmium (Cd), Cobalt (Co) and Lead (Pb) in raw cow’s milk collected from different areas of Zanzibar Island during March - May 2016. The samples of raw milk were analyzed by Thermo Scientific-Atomic Absorption Spectrophotometer for quantitative determination of the metals in the matrix. The concentration of Co in this study ranged from ND at Mwanakwerekwe (MK1 and MK2) to a maximum of 0.004 mg/L at Mshelishelini (MS5) and Fuoni (F5) sites with mean concentration of 0.020 ± 0.003 mg/L for all sites. Concentration of Pb ranged between 0.05 - 0.51 mg/L at Fuoni (F7) and Mwanakwerekwe (MK1) respectively, with mean concentration of 0.263 ± 0.031 mg/L for all sites. However, Cd was only detected in one sample collected at Fuoni (F3) with a concentration of 0.001 mg/L. The results revealed that cow’s milk is contaminated with toxic metals, particularly Pb which exceeded the WHO maximum permissible level of 0.02 mg/L. The study furthermore sheds light on possible consequences to public health. It is recommended that, stakeholders especially in Zanzibar such as Zanzibar Food and Drug Authorities (ZFDA) and Zanzibar Bureau of Standards (ZBS) as well as researchers, use the findings of this study for policy making, future study plans, formulation of technical strategies to control milk contamination, risk assessment and develop new alternative methods to measure milk contamination even at a low detection limit for the sake of the consumers’ welfare before posing any serious effects to their health.