Mercury contaminations from gold mining using amalgamation technique in Xiaoqinling Region, Shanxi Province, PR China

摘要

In China, rudimentary procedures (gold extraction using amalgamation technique) are still used, especially in Xiaoqinling region of Shanxi Province. Gold was discovered in Tongguan County in Xiaoqinling region about 900 years ago, and almost every family has been involved in small-scale gold mining activities for a long time. This region lies in a semiarid zone, and gold mining activities are distributed along several streams that are up reaches of Yellow River. Every year about 120 t mercury are released into environment due to gold extracting, with 38.0% released into atmosphere, 62.0% into solid tailings and 0.003% into river directly with the tailing water. In this paper, different mercury species in water samples collected in this area were measured. The results indicated that the average dissolved mercury concentration in water was 0.74ug/l, varied from 0.11 to 3.10ug/l, and the particulate mercury concentrations were much higher (0.10 ～ 258.62ug/l). In filtered water, the reactive mercury was predominant, ranged from 7.76% to 62.68%. Our preliminary study indicated that the study area is seriously contaminated by mercury due to gold extraction activities, and further study is on-going to evaluate ecological and human health effects from mercury contamination in this area.