Mercury pollution in the aquatic system near of Urban Artisanal Gold Mining (UAGM) activity in Makassar, South Sulawesi, Indonesia

The Urban Artisanal Gold Mining (UAGM) in Makassar, South Sulawesi, Indonesia, has been run by a number of goldsmiths with gold jewelry manufacture as its core activity. The urban artisanal gold mining process has been existing and also using mercury in the process of gold production. The amalgamation, smelting, and refining are the processes in which Hg may release into the environment. This research aimed to assess Hg environmental pollution in the Tello river near the UAGM area. In UAGM workers use drainage or canal to discharge waste from their tailing reservoirs or some of them directly discharge to drainage. The results showed that the Hg concentration in the drainage sediment was found very high in the spot C3 and C7, reaching 627 and 79 μg/g, respectively. On the other drainage spots, mercury concentration average 16 μg/g (0–30.5 μg/g). On the other hand, the canal sediments in the inside UAGM site showed an elevated concentration of heavy metals due to contaminant enrichment. This is because the discharged wastes taken from the goldsmith’s area were already contaminated by heavy metals. This was because burning goldsmith’s wastes were commonly conducted in an open space using kerosene, gasoline, or firewood as a fuel. The aquatic system such as rivers, fishponds, and beaches have been polluted by heavy metals. This is due to heavy metals in the tailing of UAGM flow and contaminates the river and fishpond around it.