The distribution and mobility of mercury from artisanal gold mining in river sediments and water, Banyumas, Central Java, Indonesia

Traditional gold mining, in which mercury is still used to process the ore, is widespread in Indonesia. The objective of this study was to investigate the distribution and mobility of mercury in river sediments and water in Banyumas, Central Java. River sediment and water samples were collected from several places, using a systematic random method, and then analyzed in the laboratory. The results showed that the mining activities in the study area were the main source of the mercury in the river water and sediments. The mercury concentrations in river water and sediments were high relative to those found in other areas, perhaps because there have been mining activities in this area for a long time and mercury had accumulated in the sediments. The high percentage of bioavailable mercury in the river sediments suggests that the mercury in the river sediments was relatively mobile and had the potential to directly pollute the environment when released into the river water and taken up by aquatic organisms.