Spectrophotometric Quantification of Trace Elements and Toxic Metals in Raw Milk Samples of Peshawar City, Pakistan

Abstract

The present study focused on the physicochemical characterization and spectrophotometric determination of
the concentrations of trace elements (Zn, Cu, Fe and Mn) and toxic heavy metals (Cd and Pb) in raw milk samples
collected from various commercial sites of Peshawar city, Pakistan. Evaluation of the nutritional values as well as the
possible health concerns associated with the consumption of contaminated milk shown the average percentage
composition of protein, fats, solid non-fats, lactose, salts and added water in the milk sample as 2.78, 4.81, 6.41, 3.05,
0.47 and 31.1 %, respectively. The values of pH, conductivity, density and freezing point were observed as 6.59, 3.51
mS/cm, 1.04 g/mL and -0.3674 ºC at 26 ºC. The physicochemical characteristics such as percentage protein, fat,
lactose, salts, water, solid not fat, total solids, pH, conductivity and density were evaluated and found in the safe limits
of the WHO/FAO. The average concentration of trace elements such as zinc and copper were found to be 1.4035 mg/L
and 0.2588 mg/L, respectively. The concentration of Zn and Cu was found within permissible limits suggested by
WHO. However, the average concentration of Fe, Mn, Cd and Pb were found higher than the permissible limits of
WHO. The observed concentrations were: Fe = 1.5553, Mn = 0.4354, Cd = 0.1865 and Pb = 1.1162 mg/L. The
presence of the non-essential and hazardous Cd and Pb in milk samples even in lower concentrations may cause severe
health problems since these are the most noxious pollutants due to their non-biodegradable and bio-accumulative
nature. Over-dose of Fe and Mn also leads to several health issues. A thorough and more precise investigation of raw
milk consumption in Peshawar is highly recommended to ascertain the actual reasons and sources in the larger public
interests.