Hygienic Assessment of Heavy Metal Levels in Biological Samples of the Population of Baku

Abstract

The aim of the study was to determine some heavy metals in human biological samples and to establish the hygienic significance of the obtained data in order to identify possible risks of adverse exposures and to assess the level of environmental pollution of the observed districts with heavy metals. Materials and methods. The studies were conducted in different areas of Baku. Concentrations of some heavy metals (Pb, Cd, Cr, Ni, Cu, and Zn) in human blood and hair, as well as in soil samples of residential, industrial and suburban areas were determined by atomic absorption spectrophotometry. Results. Different levels of heavy metals in the studied biological samples were established depending on the area of residence. The highest concentrations were registered in the people dwelling in the industrial area. At the same time, blood concentrations of metals did not exceed corresponding permissible values, regardless of the area of residence. Yet, metal concentrations in human hair with respect to the area of residence of our subjects followed a different pattern: concentrations of Pb, Cd, and Cr in hair exceeded the minimum values of their reference levels in the residents of all study areas while the concentrations of Ni, Cu, and Zn in hair turned out to be significantly higher than the regulatory levels in those living in the residential and industrial districts of the city. Consequently, the concentrations of all heavy metals measured in human hair of the people dwelling in the urban residential and industrial areas significantly exceeded the corresponding reference levels and correlated (r = 0.90-0.99) with high concentrations of those metals in local soils. Conclusions. The study results enabled us to conclude that a significant excess of the relevant hygienic standards for heavy metals both in human hair and soil in the study areas posed a certain risk of developing environment-related diseases from high outdoor exposures to toxic metals. They also proved the priority importance of testing hair as a reliable diagnostic medium for biological monitoring in hygienic studies.