Distribution and mobility of toxic metals in Thymus alsarensis Ronniger in the Allchar As–Sb–Tl mine, Republic of Macedonia

Abstract

The Allchar district is an abandoned antimony–arsenic–thallium deposit located in the north-western region of Kožuf mountain in the Republic of Macedonia. The locality of Allchar has a complex and unique mineral composition. The current study sought to investigate the levels of uptake and distribution of different heavy metals, such as As, Sb and Tl, in the different organs of Thymus alsarensis Ronniger, an endemic plant species of the area. Root, stem, leaf and flower samples, as well as corresponding soils, were processed, digested and then analysed by inductively coupled plasma atomic emission spectrometry. Significant accumulation of As, Sb and Tl in this endemic species was observed. Total As content in the soil ranged from 34.7 to 5288 mg kg–1, and the content of As in plants ranged from 0.25 to 140 mg kg–1. The content of Sb in soil and plants ranged from 6.3 to 130 mg kg–1 and 0.25 to 1.51 mg kg–1, respectively. Lastly, the content of Tl in soil and plants ranged from 2.0 to 330 mg kg–1 and 0.10 to 496 mg kg–1, respectively. Similar results were obtained from extraction tests of soil samples using various solvents.