Mercury content in agricultural soils and field crops of central Serbia

Abstract

Mercury (Hg) is a heavy metal, designated as a pollutant in the environment, due to its harmful effects on biota. Mercury pollution is a significant global concern, not only due to its increased levels in the environment, but also due to its toxic effect on human health across the food chain. The aim of this study was to determine the content of Hg in agricultural soils and main field crops. Total number of 84 bulked soil samples were taken (0-30 cm depth) from agricultural land. At the same plots, 84 plant crops (11 species – used as food and feed) were taken during the vegetation season 2018. The samples were analyzed for total Hg content using Direct Mercury Analyzer DMA 80 Milestone. The obtained results of Hg content in soil were within interval 0.003-0.37 mg kg-1 . The average concentration of Hg was 0.08, with median 0.06±0.06 mg kg-1 . Obtained values of Hg in soils were below maximum allowable concentration (MAC) and this interval is complied with the most cited range in soils up to 1 mg kg-1 without known nearby contamination sources. It was found that Hg content is positively correlated with pH value, slit soil fraction, and CaCO3. The obtained results of Hg content in plant – field crops, were within interval 0.0001-0.9087 µg kg-1 . Obtained maximum value is still far lower than MACs for feed and food. According to the average Hg content in plant species, obtained results were classified from highest to lowest, respectively: bean, alfalfa, maize, soybean, rapeseed, sunflower, barley, pepper, wheat, rye and tomato.