Analysis of Selected Heavy Metals in Fresh Cow milk, drinking water, grass and soil of dairy farms in Saki East local Government area of Oyo State, Nigeria

Abstract

Urbanization and industrialization have increased in recent times and these have caused increase in the inorganic contaminants present in the air, food items, water and soil. Soundness of agricultural processes is a matter of concern and safety of the food produced for both animal and human consumption. Twenty-nine fresh milk samples, composite soil, grass and drinking water samples were collected from three dairy farms in Saki East Local Government area of Oyo state, Nigeria. These were analyzed for the concentration of selected heavy metals (copper, cadmium and lead) using Atomic Absorption Spectrometry. The mean concentrations of copper in milk, drinking water, soil and grass were 1.33 mg/L, 0.03 mg/L, 0.11 mg/Kg and 0.16 mg/Kg respectively. The mean concentrations of cadmium in milk, drinking water, soil and grass were 0.12mg/L, 0.13mg/L, 0.1 1mg/Kg, and 0.10mg/Kg respectively. The mean concentrations of lead in milk, drinking water, soil and grass were 0.77 mg/L, 0.85 mg/L, 0.5 mg/Kg and 0.20 mg/Kg respectively. Mean concentrations of cadmium in water, lead in milk and lead in water were above the permissible standard limits and therefore were not fit for human or animal consumption. Advocacy for organic dairy is highly recommended as one of the standards required for certification is proper analysis of the soil and drinking water sources for heavy metal contaminants. The result of such analyses would guide the prospective farmers in the choice of farm sites and paddocks. Routine analysis for heavy metal concentration in fresh milk, drinking water, grass/feed and soil of dairy farms is strongly recommended.