The effect of bauxite mining on soil and dominant plant pollution in arid rangelands of Taft in Yazd Province

Environmental contaminations resulting from mining operations play an important role in the collapse of ecosystems balance. In order to measure vegetation characteristics and to study soil and plant contamination in rangelands surrounding bauxite mine, a systematic random sampling was done according to physiognomy and homogeneity of vegetation cover. Sampling was performed using a 50-meter transect in three areas including near the mine (0-200 m), medium distance from the mine (200 to 500 m) and long distance from the mine (500 to 1000 m). Soil sampling sites were systematically selected from the middle of transects. In each region, three samples of the aerial parts and leaveswere randomly taken from Zygophyllum eurypterum plant with three replications. Then the concentration of heavy metals in soil and plant samples was evaluated using X-ray Fluorescence Spectroscopy, S4-Explorer model. The results showed that the highest and lowest metals concentrations in all soil and plant samples were obtained at a distance of 200 and 1500 meters from the mine, respectively. The overall evaluation results based on the integrated pollution index and mean of pollution degree showed that the pollution potential of the study area is low to moderate. The findings also indicated that the soil surrounding the mine is contaminated with aluminum, titanium, antimony and iodine.