Concentration of Some Selected Heavy Metals as Contaminants and Associated Potential Health Risks in Raw Milk in Birnin Kebbi Metropolis, Kebbi State, Nigeria

Abstract

Raw milk is a vital component in the human diet due to its complete nutritional contents. This study was 
carried out to investigate the concentrations of cadmium, chromium, arsenic, mercury, lead and copper in 
the raw milk of camel, cow, goat and sheep from different dairy farms in Birnin Kebbi and environs and 
evaluate the potential health risks of metals to humans via consumption of raw milk. A total of two hundred 
(200) samples of raw milk 50 each of camel, cow, goat and sheep were collected from the dairy farms 
directly using the established protocol of random sampling and analysed using Atomic Adsorption 
Specctrophotometer. The concentrations (mg/kg wet weight) of Cd, Cr, As, Hg, Pb and Cu detected in raw 
milk were in the range: 0.001 - 0.038, 0.022 – 0.314, ND – 0.00002, 0.001 – 0.005, 0.021 – 0.330 and 0.021 – 1.077 respectively. The prevalence of the metals in the various samples are in the order: Cu > Pb > Cr > 
Cd > Hg > As. Cow milk has the highest number of samples (52%) above the Maximum Permissible Limit 
(MPL), sheep milk has the least number of samples above the MPL. It was concluded from this study that 
although the maximum limit of Cu, Pb and Cr have been exceeded by 52%, 48% and 42% respectively in 
the dairy products tested, the health risk assessment indices comprising Estimated Daily Intakes, 
Provisional Tolerable Daily Intakes, Target Hazard Quotient, and Hazard Index indicated no potential 
health risk upon consumption of such dairy products analyzed.