Investigation of water pollution in dairy cattle farms in Qazvin province to some heavy metals (lead, cadmium, chromium, nickel and mercury)

the aim of this study was to evaluate the concentration of some heavy metals in the drinking water consumed by dairy farms in Qazvin province. For this study, water samples of 35 industrial dairy herds under the auspices of the Livestock Breeders Union of Qazvin province in different cities including Abyek, Qazvin, Takestan, Buin Zahra and Alborz were collected by direct reference and the concentration of heavy metals including lead, cadmium, chromium, nickel and mercury were determined. Then, the obtained data were analyzed in a completely randomized design. The concentrations of lead and cadmium in the sampled water were 0.67± 0.98 and 0.42±0.11 μg/kg respectively and there was no significant difference in the concentration of these elements among different cities. The mean concentrations of chromium in the water samples from Buin Zahra city was more than other areas of the province (P ≤ 0.05). The mean concentrations of nickel and mercury in the water consumed in dairy farms were 0.65± 0.79 and 0.38± 0.33 μg/kg respectively. There was no significant differences in nickel and mercury concentrations among different cities.In general, since the concentrations of heavy metals are less than the minimum hazardous levels, water consumed in industrial farms in Qazvin province in terms of impact on animal health and product quality can be consumed without any worries.