Assessment of Heavy Metals Migration in the Water - Soil - Fodder - Milk Food Chain in the Almaty Region

Abstract

This study presents the results of monitoring heavy metals (Cd, Pb, As and Hg) in the water - soil - fodder - milk food chain. The research aimed to study the effect of lead, cadmium, mercury and arsenic in soil, water and components of the diet of cattle on their bioaccumulation in livestock products (milk) in basic farms of the Republic of Kazakhstan. The possibility of obtaining ecologically safe livestock products in meat and dairy cattle breeding has also been scientifically substantiated. A total of 120 soil samples, 60 water samples, 212 fodder samples and 60 milk samples were analyzed. Samples for the research were taken in spring, summer and fall in 2018 and 2019. Analysis of samples for the content of heavy metals was performed in the laboratory of the Kazakh-Japan Innovation Center at the Kazakh National Agrarian University. Determination of residual amounts of heavy metals (cadmium, lead, arsenic and mercury) was carried out on a novAA350 atomic absorption spectrometer (Analytik Jena, Germany) with a TaLab voltammetric analyzer. The obtained data allow concluding the degree of environmental pollution (water bodies, soil, agricultural fodder) and, consequently, the environmental safety of milk. Considering the data obtained, the authors have found that in the studied administrative districts of the Almaty region, the calculated transition coefficients in the water-soil-fodder-milk system indicated that the largest transition of heavy metals was for lead and less migration was observed for mercury and arsenic. Fodders and feed additives preserved the tendency to accumulate trace elements. The analysis of heavy metals content in the study objects has shown that their distribution occurred in decreasing order: Lead > zinc > mercury > arsenic.