Human Health Risk Assessment of Heavy metals in Cow Milks from Selected Local Government Areas of Kano state, Nigeria

Environmental pollution is a problem that has emerged due to increased industrialization with its attendant effects on well-being of people. This study determined the contamination level of cow milk by the heavy metals (Pb, Cr, Cd, Cu, Zn, Mn and Fe) from three local governments (Bichi, Rano and Nassarawa) in Kano state. The results obtained showed that, the concentration of Pb, Cd, Cu, Zn and Mn were below permissible limits in milk. Whereas, moderate contamination by Fe and Cr were also observed. The data obtained were used to calculate some risk indices such as daily intake of metals (DIM), and total hazard index (THI). The DIM in the three local governments was within the range of 3.4 × 10^-4 – 6.8 × 10^-3 μg l^-1. b.w/day for Cr and 0.367 – 1.55 μg/l. b.w/day for Fe. Lead (Pb) was only detected in Rano local government within the range of 0.104 – 0.117 μg/l. b.w/day, while Zn was detected in Bichi and Rano within the range of 0.048 – 0.113 μg l^-1. b.w/day. All hazard indices calculated for metals were found to be below 1. The result therefore, showed tolerable risk in consumed milk at the aforementioned locations. However, risk assessment should be carried out at intervals as a form of environmental assessment to assess the general health of the public, to prevent buildup of environmental pollutants and consequent consequences.