The Proceedings of The 2nd Annual International Conference Syiah Kuala University 2012 & The 8th I T-GT Uninet Biosciences Conference Banda Aceh, 22-24 November 2012 Mercury in sediment and freshwater organisms from Kr. Sikulat River around the artisanal gold mining plants in Sawang, Aceh Province, Indonesia Suhendrayatna and 2Elvitriana 1Department of Chemical Engineering, Syiah Kuala University, Banda ceh 23111, Indonesia$ 2Department of Environmental Engineering, University of Serambi Mekkah, Banda ceh 23111, Indonesia. Coorresponding uthor: suhendrayatna*unsyiah.ac.id Abstract. rtisanal gold miners in Sawang use mercury in gold separation process. ,he workers put gold ore and mercury into the tumblers to e-tract gold and silver by amalgamation method. fter gold and silver are isolated from the ore as amalgam, mercury is vapori.ed by burning with an oil burner. /urthermore, wastewater containing mercury is discharged at landfills and Kr. Sikulat 0iver stream. 1ith the purpose of knowing the impact of small2scale gold mining plant in Sawang, the concentrations of mercury in Kr. Sikulat 0iver sediment and the accumulation of mercury in tissues of freshwater organisms from Kr. Sikulat 0iver were investigated. Sediments were taken from locations near the gold mining plant and freshwater organisms were caught in the estuary from Kr. Sikulat 0iver. Samples were transported live to the laboratory and sampled dissected after death. ,issue from each organism were removed and grained after dried. ,otal mercury analy.ed using an tomic bsorption Spectrometry 3 S4, 25300 Shimad.u. ,he results showed that the concentration of mercury in sediment found 0.0339 mg27g8kg, while the concentration of mercury in the water phase were found 0.005 9 0.047 mg27g8L. Mercury was also found in the concentration of 0.1903 mg27g8kg accumulated in the shellfish, but it was not found accumulated in other freshwater organisms such as fish and shrimp. Based on these results, a regular monitoring program in Kr. Sikulat 0iver is necessary conducted in order to better elucidate the rate of bioaccumulation and biomagnification by organisms. Keywords: mercury$ artisanal gold mining$ bioaccumulation$ and Kr. Sikulat 0iver. Introduction rtisanal gold mining is one of the major sources of mercury 37g4 contamination in many developing countries 3United Nations Environment Programme, 20024. ,hese activities relies mainly on manual labor and makes use of simple methods. It offers poor people an important means of livelihood and has served as a safety net in times of economic distress 3Limbonga, et al., 20034. In artisanal gold mining practiced in many developing countries, especially in Indonesia, gold is separated from ore by the use of mercury, which forms an amalgam with gold. ll related processes are undertaken with a low level of technical knowledge and skills, no regulation, and with disregard for the safety of human and environment health. ,he amalgamation method of artisanal gold mining causes mercury emissions to leak into the environment in several different ways. /or e-ample, when Mercury is unintentionally spilled onto the ground. tmospheric transport and deposition at normal temperature is the pathway delivering mercury to rivers, lakes, and oceans. Moreover, mercury is often discharged together with other wastes into inadequate tailings ponds, or is disposed of directly into rivers and waterways. nother means of introducing mercury into the environment take place when purifying the amalgam by burning and vapori.ed mercury is released into the atmosphere. Many researchers have been reported contamination of mercury in environment from gold mining activities. Bose2AB0eilly, et al. 320104 reported clinical e-aminations and mercury levels in people living and working in the Indonesian gold mining areas. ,he primary result is that mercury is a serious health ha.ard in the small2scale gold mining areas of ,atelu 3North4 and Kerang Pangi 3Central Kalimantan4. 1orking for many years in the amalgamation or burning process, especially amalgam2burning has resulted in severe 159 )olume 2 Number 2, 2012 The Proceedings of The 2nd Annual International Conference Syiah Kuala University 2012 & The 8th I T-GT Uninet Biosciences Conference Banda Aceh, 22-24 November 2012 symptoms of mercury into-ication. Limbong et al., 2003 observed the emissions of mercury from artisanal gold mining in North Sulawesi and indicated that an increase took place along the three main rivers in the watershed. Natural process also causes the entering of mercury in aquatic ecosystem such as mineral deposits, volcanoes, forest fires, oceanic emission, and crust degassing. It also could be released by human activities such as smelters processing sulfide ores 3i.e., in the production of metals such as gold, copper, iron, lead and .inc4 and cement kilns, roasting of sulfide ores for production of sulfuric acid 37ylander and Meili, 20034. Mercury contamination in some rivers in Indonesia mosly caused by the gold mining activities, such as Ciliunggunung 0iver in Sukabumi 0egency 31idodo, 200C4, ,awalaan, Bailang, and Kima 0iver in North Sulawesi 3Limbong et al., 20034, and Barito, Kahayangan, 0ungan 0iver in Central Kalimantan 3Dumiri et al., 20094, and Kr. Meureubo 0iver in 1est ceh 3Suhendrayatna et al., 20104. ,he gold ore from the mining is processed with a direct amalgamation method and produces low gold concentrate, but the concentrate of mercury discarded to the river is high enough. /urthermore, low levels of technical knowledge and skills and no regulation are also applied in all related gold mining processes in Indonesia 3Limbong et al., 20034. In the last three years, our peer group focussed study on the emissions and environmental implications of mercury from artisanal gold mining in ceh. In 2010, we reported that high concentration of mercury was detected in main tissues of freshwater fish and shellfish from Kr. Meurebo 0iver, 1est ceh and the accumulated mercury in organisms were significantly greater in shellfish than in fish which mean concentrations were 2.CC2E14C and 0.321E1C.7 mg8kg2dry weight, respectively. 7igh mercury levels in organism samples provided strong indication of a high bioaccumulation from the Kr. Meurebo 0iver 3Suhendrayatna, et al., 20104 and also Kr. Sabe 0iver area in ceh Faya 3Suhendrayatna, et al., 20114. Bioaccumulation of mercury by fish from Kr. Sabe 0iver was found minimum in head 30.045E10.0 mg8kg2dry weight4, whereas ma-imum bioaccumulation founded in the gill 30.399E1.5 mg8kg2dry weight4. Mercury concentrations varied in the order: Dill G Muscle G Bone G Eye G 7ead 3Suhendrayatna, et al., 20114. Solutions to these problems must be formulated as soon as possible in order to avoid a major health, economic, and ecological disaster arising from the continuing discharge of mercury in ceh. 1ith the purpose of knowing distribution of mercury in sediment and freshwater organisms from river around the artisanal gold mining plants, this study investigated in the watershed of Kr. Sikulat 0iver. Kr. Sikulat 0iver is located in Sawang Sub2district, the south part of ceh, Indonesia and only 2 9 4 m deep on average. ,he major source of pollution is predicted by the waste effluents from the artisanal gold plant lies in the upstream of the river as parts of Sikulat Mountain. ,he gold separation processes are undertaken with a low level of technical knowledge and skills, no regulation, and with disregard for the safety of human and environment health. ,he situation is generating serious potential health and environmental risks in that area. s part of an ongoing monitoring program, total mercury concentrations were e-amined in the organismHs samples from the Kr. Sikulat 0iver, which receives drainage from gold plant practices. ,his study assessed the levels of mercury concentration in biological samples from organisms such as fishes and shellfishes in a watershed of Kr. Sikulat 0iver. Materials and Methods Study area Study area focused on the Kr. Sikulat 0iver watershed near to gold processing activities centered on the Panton Luas village, Sawang Sub2District, South ceh District which selected sampling locations are as follow. 314 . 1 Kr. Sikulet watershed near housing area 3N : 03o23H2C,2I E : 097o07H14,9I4 324 . 2 1atershed near artisanal gold mining effluent 3N:03o23H41,5I E:097o07H53,7I4 334 . 3 1atershed near artisanal gold mining effluent 3N:03o23H3C,2I E:097o07H54,1I4. ,he sampling site illustrated in /igure 1. 150 )olume 2 Number 2, 2012 The Proceedings of The 2nd Annual International Conference Syiah Kuala University 2012 & The 8th I T-GT Uninet Biosciences Conference Banda Aceh, 22-24 November 2012 Reagents 2E 7g standard solution 31000 mg8L, 7gCl2 in 0.02 M 7Cl4, methylmercury 3II4 chloride, and hydrochloric acid were purchased from 1ako Pure Chemical Industries, Ltd. ll chemicals used were analytical grade quality. ll solutions were prepared in ultrapure water prepared by a Purelab Ultra Ionic 3Argano Co., Ltd.4. Experimental Procedure /ish and shellfish were caught in the estuary from Kr. Sikulat 0iver and sampling sites were selected in the downstream of river that correlated to the contaminant sources as illustrated in /igure 1. ll organisms were transported live to the laboratory and sampled dissected after death. Argans from each organism were removed and grained after constant dried at 35oC. /igure 1. Sampling site area Analysis procedure Dried fish tissue samples were digested using nitric acid and hydrogen pero-ide along with hotplate heating, and the Mercury concentrations of fish tissues were e-amined. ,otal Mercury for all samples were determined by the cold vapor technique using an tomic bsorption Spectrometry 3 S4, 25300 Shimad.u, according to the method suggested by kagi and Nishimura 319914. Juality control was monitored for all chemical analyses. Instrument calibration was verified by analy.ing certified calibration solutions during each instrumental run. Results and Discussion Mercury levels among the three sampling phases were variable at sampling sites 1, 2, and 3 as shown in ,able 1. ,he mercury concentration in water phase was found in the ranged between 0.001 and 0.047 mg27g8L.