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S17 Mercury in artisanal and small-scale gold mining

Thursday, 28 July, 2011

RS17-P2 — 11:00-12:00 and 17:30-18:30
MERCURY DISTRIBUTION IN THE SEDIMENT OF TALAWAAN RIVER, WHERE MANY SMALL-SCALE GOLD MINES ARE OPERATING IN ITS UPSTREAM REGION, IN NORTH SULAWESI, INDONESIA
Authors: MORI, Keisuke1, LASUT, Markus T.2, YASUDA, Yoshiaki1
(1) National Institute for Minamata Disease, morik@nimd.go.jp; (2) Marine Science Department, Faculty of Fisheries and Marine Science, Sam Ratulangi University;

A new gold ore deposit was found in the Talawaan region, North Sulawesi, Indonesia, in 1996, which was followed by establishment of a great number of small-scale gold mines upstream in the Talawaan river from 1998 to 2000. The gold mines distribute in a triangular-shaped region around Dimembe, Talawaan and Tatelu Villages, which we named AT (auriferous triangle). In order to evaluate mercury behavior in the environment after release from each mine, we determined the methylmercury (MeHg) as well as total mercury (THg) levels in sediments at more than 10 stations along the Talawaan River.

Geometric means of sediment THg and MeHg concentrations in the river were 0.31 µg/g and 0.92 ng/g, respectively. The maximum THg and MeHg levels were both detected inside AT, as 3.25 µg/g and 9.20 ng/g. MeHg distributions were highly correlated with those of THg, which implies that MeHg was generated from the elemental mercury derived from the artisanal gold mining waste materials. In addition, MeHg concentrations in sediment samples were correlated with amounts of ignition loss. Moreover, the accumulation of MeHg in fishes in this area in the food web was observed. Thus, we infer that metallic mercury diffusion from mining into the environment causes bio-accumulation of MeHg in the Talawaan watershed.

RS17-P3 — 11:00-12:00 and 17:30-18:30
WHAT DO GENES MEAN FOR THE SUSCEPTIBILITY TO MERCURY-RELATED NEUROTOXIC EFFECTS AMONG GOLD MINERS?
Authors: ENGSTRÖM, Karin1, BÖSE-O’REILLY, Stephan2, DRASCH, Gustav3, AMEER, Shegufta1, SKERFVING, Staffan1, BROBERG, Karin1
(1) Occupational and environmental medicine, Lund university, karin.engstrom@med.lu.se; (2) Institute of Public Health, Medical Decision Making and Health Technology Assessment, UMIT – University for Health Sciences, Medical Informatics and Technology, Hall i.T., Austria; (3) Institute of Forensic Medicine, Ludwig-Maximilians-University, Munich, Germany;

Background:
Elemental mercury (Hg0) has a high neurotoxic potential due to its ability to pass the blood-brain barrier. Hg0 is used in artisanal and small-scale gold mining. Earlier studies, conducted in Indonesia (Böse-O’Reilly et al. Sci Total Environ 2010), Philippines (Drasch et al. Sci Total Environ 2001), Tanzania (Böse-O’Reilly et al. Sci Total Environ 2010) and Zimbabwe (Lettmeier et al. Sci Total Environ 2010), showed that individuals working with gold mining or living in areas highly exposed to Hg from the mining had a high prevalence of neurotoxic symptoms and signs. However, there were large differences in neurotoxic effects among individuals with similar exposure. These differences may be due to genetic factors.

Aim:
The aim of this study is to identify genetic variants that affect the susceptibility to Hg-related neurotoxic effects among gold miners.

Materials and methods:
Study subjects were the participants from the above-mentioned studies in Indonesia, Philippines, Tanzania and Zimbabwe (N=1113). Sampling was done as a part of the Global Mercury Project. Individuals were classified as controls (no specific Hg exposure), or with low (living in a Hg-contaminated mining area) or high (working with Hg) exposure. Urine, hair, and blood were collected for analysis of Hg by cold-vapor atomic absorption spectrometry (CV-AAS). Anamnestic data was evaluated by a health assessment questionnaire, and participants were examined neurologically for ataxia, tremor, and motor coordination. Genotyping was done for 106 polymorphisms selected from approximately 30 genes in three groups of genes potentially involved in Hg-induced neurotoxic effects: antioxidative defense, neurotoxicity and apoptosis.

Preliminary results:
Preliminary results indicate genetic effect modification of Hg-related neurotoxic effects.

Conclusions:
This is, to our knowledge, the largest study to evaluate potential impact of genetic factors on Hg-induced neurotoxic effects. By taking into account influential genetic polymorphisms, susceptible groups can be identified and more relevant health risk assessments can be made.

RS17-P4 — 11:00-12:00 and 17:30-18:30
MERCURY EXPOSURE MONITORING IN GOLD SHOPS OF THE ITAITUBA CITY, AMAZON
Authors: SOUZA, Terezinha M. Cid1, BASTOS, Wanderley R.2, ANJOS, José Raimundo1, OLIVEIRA, Ronaldo C.2
(1) National Department of Mineral Production-DNPM, ttcid@yahoo.com; (2) Federal University of Rondonia-UNIR;

Itaituba City, where are located the gold shops, is the main center of gold commercialization from Tapajós region. In those shops, the gold sold by the mining workers still contains up to 5% of mercury, that is burned again releasing the vapor in the environment, provoking pollution. This research aimed to investigate the mercury vapors inside the gold shops and if this mercury is reaching the workers. The study was accomplished through the mercury analysis in the air inside the shops using the biomonitorr Tillandsia usneoides and mercury analysis in the workers’ urine, in two periods. They were registered 17 shops and applied a questionnaire in 97 workers. The biomonitor was exposed at the shops by periods of 15 and 30 days. The mercury analyses were accomplished by 2 analytical systems cold vapor atomic absorption spectrophotometry. The Hg concentrations in the plants exposed by 15 and 30 days showed growing values in function of the exposure time, presenting a very good correlation between Hg concentration and the period of exposure. The Hg concentration in the plants with 15 exposure days presented average of 1.04 mg/Kg and 0.44 mg/Kg, representing 104 and 12 times above the Hg found in the control sample, respectively for the first and second period. The plants exposed for 30 days, presented average of 1.66 mg/Kg and 0.86 mg/Kg, corresponding to 55 and 23 times above the control sample, respectively for the first and second period. 80% of the workers are men (18 to 59 years old). The activities were arranged in two categories: burner (63%), other functions (27%). The average of Hg in the workers’ urine was of 15.5 µg/L and 30.34 µg/L, respectively for the first and second period. The highest values of Hg were found in the burner’s group with average of 16.6 µg/L and 45.47 µg/L. 51% of the workers presented Hg above 10 µg/L and 3% Hg above 50 µg/L, considered biological limit of tolerance. It was verified that the workers that presented the highest concentrations of Hg in the urine worked at the shops that presented the highest Hg values in the biomonitor. This study suggests that the Hg vapors are being spread in the atmosphere and reaching the workers.

RS17-P5 — 11:00-12:00 and 17:30-18:30
APPLICABILITY OF TWO MOBILE ANALYSERS FOR MERCURY IN URINE IN SMALL-SCALE GOLD MINING AREAS
Authors: BAEUML, Jennifer1, BOESE-O’REILLY, Stephan1, LETTMEIER, Beate 1, MAYDL, Alexandra 2, MESSERER, Katalin 2, ROIDER, Gabriele 2, DRASCH, Gustav 2, SIEBERT, Uwe1
(1) Department of Public Health, Information Systems and Health Technology Assessment, UMIT University for Health Sciences, Medical Informatics and Technology, Hall i.T., Austria, jennifer.baeuml@umit.at; (2) Institute of Forensic Medicine, (LMU) Ludwig Maximilians-University, Nussbaumstrasse 26, D-80336 Munich, Germany;

Background: In artisanal and small-scale gold mining (ASGM) in developing countries, mercury is still frequently used to extract gold from ore. The resulting mercury vapor from melting the amalgam is toxic. Inhabitant’s intake of the vapor via different pathways, like air, water and food is a serious health hazard. Mercury vapor is a neurotoxic substance.

Methods: The concentration of mercury in urine was analyzed in different mining areas in Zimbabwe, Indonesia and Tanzania. During the field projects, the urine samples were first analyzed by the CV-AAS (cold vapor atomic absorption spectrometry) with a mobile mercury analyzer (Lumex® or Seefelder®) and second, in a laboratory with a stationary CV-AAS mercury analyzer (Perkin Elmer®).

Results: In the first analysis with the mobile mercury analyzer, only the amount of inorganic mercury in urine was obtained and in the second analysis the total amount of mercury was detected. Afterwards, the test results obtained by the mobile analyzer were compared to the data from the stationary analyzer. There were no significant differences detectable between the results maintained with the two different ways of analyzing mercury in urine.

Discussion: Comparing the characteristics of the different analyzers, the advantages of the mobile analyzers are the lower operating costs and that they do not need gas for operating, therefore they are easier to use in remote areas. In contrast, the advantage of the stationary analyzer is that it is more precise (lower limits of detection).

Conclusion: To identify increased inorganic mercury levels in urine in artisanal and small-scale gold mining (ASGM), mobile mercury atomic absorption analyzers are useful.

RS17-P6 — 11:00-12:00 and 17:30-18:30
HAIR MERCURY LEVELS IN RELATION TO FISH CONSUMPTION AT INHABITANTS OF THE VILLAGE ALONG RIVERS WITH SMALL SCALE GOLD MINING
Authors: KAWAKAMI, Tomonori 1, INOUE, Takanobu2, ELVINCE, Rosana2, , Ardianor3
(1) Toyama Prefectural University, kawakami@pu-toyama.ac.jp; (2) Toyohashi University of Technology; (3) University of Palankaraya.

Inhabitants with high freshwater fish consumption in the Central Kalimantan have a significant exposure to dietary methyl mercury, and areas where environmental mercury pollution is an issue due to gold mining activities are of special concern.

Hair mercury levels were determined in 77 individuals from inhabitants along the rivers that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methl mercury. The mean mercury concentration of Bakut, Tapah and Baung was approximately0.3µg/g. Almost inhabitants consumed these freshwater fish at least once a week or more. As could be expected, there was a clear increase in hair Hg with reported freshwater fish consumption. The average mercury level in hair was 6.8 µg /g for the whole group. The highest hair mercury level was 94µg/g, in a woman who may consumed fish several time per week. Men had higher hair Hg than women except two women of high concentration, that is 94, 40mg/g. The median hair mercury level in 77 inhabitants was 3.9 µg/g for the men and 2.7µg/g for women. All inhabitants had hair mercury exceeding 1µg/g, corresponding to the reference dose by the US Environmental Protection Agency. The most at-risk group at these levels women of fertile age and infant. Hair mercury concentrations of all of these people had exceeding 1µg/g, especially woman for 27years old had 10µg/g and man for 2yeas old had 3.3years old. However, since fish is rich in many important nutrients, it is unsatisfactory that fish consumption must be restricted, and thus there is a need to reduce mercury levels in fish.

RS17-P7 — 11:00-12:00 and 17:30-18:30
ATMOSPHERIC MERCURY MONITORING IN AN ARTISANAL SMALL SCALE GOLD MINING COMMUNITY IN INDONESIA
Authors: ROSSIN, Ricardo1, TELMER, Kevin1
(1) University of Victoria, rossin@uvic.ca

The significance and fate of mercury released from gold mining, particularly artisanal and small scale (ASGM), remains poorly understood - despite the fact that ASGM is now the largest anthropogenic release of mercury to the environment. Together with partners, a Tekran atmospheric mercury monitoring system was installed in the ASGM community of Timika, Papua, Indonesia. The concentrations of gaseous elemental mercury (GEM), particulate mercury (Hg-P), and reactive gaseous mercury (RGM) in the air have been continuously recorded from June 2008 to present date. Meteorological data such as wind speed and direction, temperature, relative humidity, and solar radiation are also being simultaneously collected. The monitor was tested in one location and then moved to another closer to the gold shops and the Timika community. Data from the initial test site shows dominantly two sources of mercury: (i) regional background; (ii) an urban influence (Timika). The mean value of atmospheric mercury (GEM) including the urban influence is 2.4 ng/m3. The mean value for other wind directions is 1.4 to 1.5 ng/m3 and is therefore lower than the mean northern hemisphere background and near that recorded for the southern hemisphere (1.1 to 1.3 ng/m3). However, the southern hemisphere value is poorly constrained in general (mainly from the southern pole and ocean cruises), and particularly for Southeast Asia due to a paucity of data. As such these are some of the first results for the South East Asian region and so contribute to the understanding of mercury in ASGM communities but also on a more regional or global level. They are the first long-term continuous and speciated measurements for this region. Concentrations and ratios of the other species of mercury (RGM and Hg-P) indicate similar results. The percentage of total mercury in the atmosphere represented by RGM varies between 0.002% to 9.37%, with a mean of 0.57% while Hg-P varies between 0.004% and 4.24%, with a mean of 0.40%. Rural and pristine sites typically have maximum values of around 2% whereas urban areas can have higher RGM values (Detroit, 11%). Marine halogens - a potential factor in forming RGM may influence mercury in Timika. Results from the new location in the vicinity of gold shops are recent as of this January 2011 and will be reported at the ICMGP conference.

RS17-P8 — 11:00-12:00 and 17:30-18:30
EMISSION AND DISPERSION OF GASEOUS MERCURY FROM ARTISANAL SMALL-SCALE GOLD?MINING PLANTS IN THE POBOYA AREA OF PALU CITY, CENTRAL SULAWESI, INDONESIA
Authors: SERIKAWA, Yuka1, INOUE, Takanobu 2, KAWAKAMI, Tomonori1, CYIO, Basir 3, NUR, Isrun3, ELVINCE, Rosana 2
(1) Toyama Prefectural University, serikawa@pu-toyama.ac.jp; (2) Toyohashi University of Technology; (3) Tadulako University;

In the northeastern part of Palu City (Poboya), Indonesia, it is estimated that more than 760 artisanal and small-scale gold mining (ASGM) plants are operating. In the ASGM plants in Poboya, about 180 tons of mercury is estimated to be consumed to produce gold amalgam every year, leading to a yield of 45kg of purified gold. In the gold purification process, gaseous mercury is emitted into the atmosphere without treatment. Despite the fact that local residents around the gold mining site could face health risks as a result of the mercury contamination in the air, the atmospheric mercury concentration in the vicinity of the gold mining area has rarely been measured. The objective of the present study was to investigate the space distribution and daily change of the mercury concentration in Palu City in order to evaluate the degree of exposure of the residents to gaseous mercury. The concentration of the atmospheric gaseous mercury in Palu City was measured using passive samplers that do not require a power supply and are suitable for multi-point sampling. Twenty-two samplers were distributed in the Poboya area and in Palu City on August 3 and October 28, 2010. The samplers were exposed to the atmosphere for about 24 hours until they were retrieved on August 4 and October 29. In addition, an active sampler, with which the air is aspirated by an air pump to absorb mercury to an absorber, was used to measure the daily change of the gaseous mercury concentration in the center of the city from October 27 to 29, 2010. Both active and passive samples were taken to Japan, and the mercury concentration was measured. The mercury concentration in the center of Poboya, was 47,000ng/m3, which was 47 times higher than that shown by the WHO guidelines. Moreover the results from the active sampler, the mercury concentration fluctuated between 100 and 600ng/m3 during the measurement, indicating that meteorological conditions could bring a high mercury concentration to the center of the city. The potential damage to the health of the residents as a result of exposure to mercury is a serious threat.

Thursday, 28 July, 2011