Lead content in plant materials in the buffer zones of surface water bodies of Northwestern and Central regions of Lithuania

Abstract

The lead (Pb) is a heavy metal, which causes severe disorders in humans and other organisms. Recently, the item of wetland buffer zone has emerged as an integrated development approach to nature conservation including buffer zone pollution by Pb. The main sources of Pb pollution in Lithuania are Pb ammunition used by hunters and natural and anthropogenic activities. Considering plant capability to accumulate Pb, they are used for bioindication. The objective of the study was to determine Pb content in the aboveground biomass of vegetation collected from the reference sites in the buffer zones of wetlands. The research was conducted in three localities of the different wetland buffer zones – drying ditch, natural pond, and stream, in the three parts of Lithuania: in the Northwestern part of Lithuania in the territory of the Žemaitija National Park, in the northern part of the Žemaitija Upland at the border of Latvia, and in the Central Lithuania, in the vicinity of the largest artificial waterbody – Kauno Marios and the Nemunas River. The content of Pb in the working solutions was determined by the atomic absorption method on an atomic absorption spectrometer at a wavelength of 283.0 nm. Significant differences were calculated using the three-way ANOVA (Tukey’s HSD test). The relationships were calculated using a regression analysis, the data were significant at P ≤ 0.01 and P ≤ 0.001. The data of the research show that the content of Pb corresponds to the background content of uncontaminated sites, the values of which are reported by other scientists and is equal to 0.95–6.84 mg kg −1 . The average content of Pb in the buffer zones of various surface water source types was 3.75–3.76 mg kg −1 . The content of Pb in the plants at 20–30 m from the surface water bodies increased by 1.3–1.5 times, and then at 40 m it decreased by the same indicator.