Mercury toxicity potential from artisanal and small scale gold mines in Lebong Regency, Bengkulu Province

摘要

Artisanal and small scale gold mining (ASGM) is considered as the largest source of mercury pollution worldwide. The ASGM has been practiced for years in the area of Lebong Regency of Bengkulu Province. To extract gold from the ores, miners use a simple technique called Gelondong. This practice involves amalgamation process which forms amalgam, a mixure composed of mercury and gold. These amalgamation generates liquid and solid wastes (tailings) which still contain significant amount of mercury. Consequently, ASGM activities can potentially create mercury contamination of the environment, especially aquatic ecosystems. This study was aimed to investigate the concentration and distribution of total mercury in rivers to which wastes from ASGM communities in three villages of North Lebong District were dumped. Water and streambed sediments along the rivers were collected and brought to the laboratory for total mercury analysis. Data showed that total mercury was not detected in the river water but high in the river sediments with high variations among lactions from 0.11 to 110.37 mg kg~(-1). Apparently, total mercury tended to decrease with the distance from it source. High amounts of mercury in the river sediments could potentially spread to wider area and cause bioaccumulation in aquatic organisms, especially fish which can be dangerous to consume.