Recent mercury contamination from artisanal gold mining on Buru Island, Indonesia – Potential future risks to environmental health and food safety

In November 2011 gold was found at Mount Botak, Buru Island, Mollucas Province, Indonesia. Since 2012 mercury has been used to extract the gold requiring large volumes of water and resulting in deposition of mercury into Wamsait River and Kayeli Bay. Total mercury in waste ponds was over 680 mg/kg. In sediments at the mouth of the local river and a small feeder creek >3.00 mg/kg and >7.66 mg/kg respectively. River and bay sediments were proportionately higher in available mercury than elemental mercury and more strongly bound mercuric sulfide compared to that in trommel waste. This preliminary investigation raises concerns about the long term distribution and speciation of mercury. The floodplain is an important agricultural resource, and Mollucas Province is recognised nationally as the centre for Indonesian fish stocks. Challenges for management include communicating the potential future risks to the community and leaders and identifying mechanisms to reduce mercury waste.