Thallium pollution and potential ecological risk in the vicinity of coal mines in henan province, china

Abstract

This study was aimed to analyze the thallium pollution and assess the potential ecological risks in the vicinity of coal mines in Henan province, China. We studied 90 surface farmland soil samples from 9 representative coal mines. The Tl concentrations were determined and the potential ecological risks were evaluated. Investigations revealed the farmland soils were modestly contaminated and the trace elements in coal mining areas transferred to the surface soils. Soil Tl contents and potential ecological risks in coal mining areas were significantly increased compared with the original soils which came from the villagers’ mud houses built 40 years ago. The soil Tl concentrations ranged from 0.25 to 0.77(mean = 0.46) mg∙kg −1 , which were higher than the original level (0.42 mg∙kg −1 ). The potential ecological risk index of Tl ranged from 24.00 to 73.2 (mean 44.08), representing a moderate pollution level as a whole of the soils in Henan. In general, high Tl concentrations and high potential ecological risk were found around SHQ and DTG. The soil Tl concentrations exceed the original level and pose noticeable ecological risks.