[en] The environmental and atmospheric samples i.e. surface water, ground water, surface soil, sediment, rain and fog from various sites of contaminated environments of central India were collected in year, 2000-2001. The concentration levels of total-Hg in these samples were analyzed by using techniques i.e. cold vapor- atomic absorption spectrophotometer (CV-AAS), X-ray fluorescence spectrophotometer XFS). Further, the data base of total Hg in the environmental samples would be validated in other laboratories i.e. Prof Dr. Klaus Heumann (Johannes Gutenberg-University, Mainz, Germany), David Amouroux (University of Pau, France) and Dr Joerg Feldmann (University of Aberdeen, Scotland, UK) for exploration of the Hg-contaminated environments by using techniques i.e. ICP-MS/GC, gas chromatography-induced couple atomic emission spectrophotometer (GC-ICP-AES), neutron activation analysis (NAA). (author)

[en] Mercury pollution in most parts of the regions in the world are caused by release into the environment of metallic mercury used in the recovery of gold by an amalgamation technique with subsequent mercury emission into the atmosphere by blowtorching operations. Significant small-scale gold mining operations in other countries such as Tanzania, Philippines, Indonesia, China and Vietnam have been reported with roughly 10 million people estimated to be involved in these activities Artisanal gold mining activities using mercury has proliferated in various parts of the country since the early 1980's. In Southern Philippines, it is estimated that a small-scale gold processor utilizes one kilogram of mercury every week or an average of fifty-two kgs/1yr. Production is estimated at 30 kilograms of gold per day. It has been estimated that 140 tons of mercury flux has been dumped directly into the river systems from small-scale gold mining operations in one of the gold rush areas in the country. In the 1980's, gold rush activities intensified in Northeastern Mindanao providing livelihood opportunities to about 80,000-120,000 people at the height of mining activities in the area. In gold mining areas it should be noted that transformation in the natural environment of inorganic mercury to methylmercury occurs which can easily bio-accumulate in fish and other organisms through the aquatic food chains. Therefore, there are two main exposure pathways of mercury contamination that can affect the human population in gold mining areas. First, gold miners and workers are exposed to inorganic mercury due to direct inhalation of mercury during gold recovery processes and second, people living along the river systems and depending on riverine products for food sources can be exposed to methylmercury mainly through fish consumption. Presently, environmental and health monitoring conducted by several government agencies in the recent past were limited to the determination of total mercury only. Previous studies undertaken focused mainly on the exposure of adults and workers to mercury during mining/processing operations. Fifty-three (53) research subjects were selected by stratified random sampling in a mining community in Sibutad, Zamboanga del Norte, Philippines. There were 40 (75.47%) adults aged from 26 to 50 years and 13 children aged 6 months to 11 years. Environmental monitoring results showed that ambient air monitoring of three sampling station exceeded the standards for mercury in ambient air. Water quality monitoring of a drinking water source showed a slightly higher level than that obtained from a nearby river. Mercury levels in marine/aquatic samples ranged from 4.03-62.97 ng/g for total mercury and 3.75-35.98 ng/g in 9 species. These levels were below the recommended USFDA standard of 500 ng/g. The proportion of methylmercury ranged from 22.98%-89.78%. Hair samples in 51 respondents showed total mercury and methylmercury levels which ranged from 0.95-68.68 ng/g and 0.73-5.81 ng/g. The proportion of methylmercury in hair ranged from 2.66-99.98%. 10 had elevated total mercury levels and 23 with elevated methylmercury levels. Blood samples from 50 respondents showed total mercury and methylmercury levels ranged from 2.74-29.47 ug/L and 1. 63-23.11 ug/L. A total of 23 blood samples from the 50 tested showed total mercury values will be followed up for possible detoxification while 10 had elevated methylmercury levels. (author)

[en] This is the first comprehensive health evaluation made by the Department of Health of the mining community's exposure to total and methyl mercury. Previous studies have mainly focused more on the health risks associated with occupational exposure to mercury. Other sources of mercury exposure such as diet and other environmental media was not investigated and the population studied did not include high risk groups such as pregnant women and children

[en] The dispersion and transformation of mercury in the southwest Lake Victoria gold fields was investigated through field and laboratory studies in order to evaluate the environmental impact and human health risks due to mercury pollution from small-scale gold mining in Tanzania. River sediment, gold-ore tailings, fish, and lichens were analyzed for their mercury content to determine mercury contamination levels. Mercury concentrations in the tailings from Rwamagaza mine were in the range of 165 to 232 mg/kg while at the Mugusu mine the maximum concentration was 6 mg/kg in the river sediment contaminated by the tailings. The dispersion of mercury along the Mabubi River downstream of the gold-ore processing site at the Mugusu mine decreased rapidly to less than 0.5 mg/kg at a distance of 4 km, and less than 0.1 mg/kg at 9 km. Granulometrical analysis of mercury distribution indicated highest mercury concentrations to be associated with the grain size fraction <212 mm in the sediment. Total mercury concentrations in eight fish species from the Lake Victoria at Nungwe Bay were generally very low and varied from 2 to 34, μg/kg (w.w). The lowest concentrations were found in Tilapia and the highest in Nile perch. The percentage of methylmercury in the fish muscle ranged from 65 to 97%. These results suggest that mercury contamination from gold mining operations in the southwest Lake Victoria goldfields has not led to any significant increase in environmental methylmercury levels that could be reflected in high mercury concentrations in the fish. Based on these results, fish consumption from the Nungwe Bay area of the Lake Victoria does not pose any human health risks on account of very low mercury levels in the fish at present. Mercury concentrations in two lichen species, Parmelia and Usnea, in the Geita Forest Reserve around the Mugusu mine ranged from 0.10 to 3.10 μg/g (d.w.). The mercury concentration in the lichens decreased away from the mine village, indicating the fall of mercury levels in the air away from the source of emission. The presence of the mercury gradient in the lichens around the mine, make the lichens suitable as a bioindicator for the assessment of air mercury pollution from gold-ore processing operations. Results of the laboratory experiments on mercury absorption by laterite and bauxite and mercury transformation and uptake by fish in an aquatic system contaminated by gold-ore tailings are also discussed. (author)

[en] Full text: Highlights and achievements: Relationship between atmospheric mercury and plant leaves mercury content Hg in plants came both from soil and the atmosphere. On the whole, Hg contents in plant leaves increased with the increase of air-Hg, the correlation equation was: y = 0.0173x-0.3204. Calculation from this equation showed that the accumulation of Hg in plants stemmed mainly from soil rather than atmosphere when air-Hg was lower than 18.5 ng/m³, however contribution of air-Hg to plant Hg accumulation was increasing with the increase of Air-Hg when its concentration was higher than 18.5 ng/m³. (author)

[en] Full text: Scientific background and scope of the project: A well planned field campaign is a highlight for any researcher working in the field. Correctly sampled and identified samples are the true base for high quality research. Poorly collected samples can never be corrected, no matter how much resources are spent on sample preparation and analysing equipment. With experience from several field campaigns, I think the following points might be helpful to achieve scientific results worth publishing: Information. INFORM all participants in a field campaign on their area of responsibility, material to bring, dates and times, etc. The coordinator has the main responsibility for informing the participants. And the participants should confirm received information. Make a detailed research plan and do not expect anybody to perform sampling if this has not been combined, preferably written to avoid misunderstandings due to expected tacitly implied agreements. The coordinator may delegate to another person to compile the plan, in which case it certainly should bear the name of that person; Make a PLAN with aim, objectives, and expected outcomes. Search for existing data and literature from the area and identify where additional research is needed. Compile then a scheme with methods to use, relevant to the objectives and existing funds. High quality research can be done with limited funds! Continue with a list on materials to bring with you to the field and a realistic time schedule. (Since I am a time optimist I never realize that research always lasts twice as long as expected.); Get hold of a topographic MAP, e.g. at the National Survey, and identify suitable sampling points (incl a few alternative ones); Organize a PLANNING MEETING with participating persons to discuss the plan and define the area of responsibility for each one; Take short and concise NOTES from all meetings, which relate treated matters and made agreements and decisions. The one writing the notes and two additional persons selected at the meeting should sign the notes, thereby confirming that they are adequately relating/referring to the matters discussed. The notes should be sent to ALL participants within 3 days; Taking care of obtained DATA is as important as taking care of samples and analyses. Enter obtained data in Excel files as soon as possible and control their reliability, while it still is possible to track any abnormalities; Final points: Anybody able to write can produce data. The goal must be to get data possible to publish. and then PUBLISH them! Good luck!

[en] Lichens have long been regarded as a suitable tool for monitoring the relative levels of atmospheric pollutants. Lichens have neither roots, a waxy cuticle nor stomata: hence, for mineral nutrition they are largely dependent on wet and dry deposition from the atmosphere. Moreover, lichens are perennial and can accumulate elements over long periods of time. Therefore, concentrations of elements in lichens represent the average levels of elements in the atmosphere for a long period of time. The epiphytic lichen Hypogymnia physodes is a good bioindicator of air pollution with total mercury (THg). In addition, it contains small amounts of methylmercury (MeHg⁺). The first aim of our work was to test analytical techniques for determination of MeHg in lichens taken from different locations in Idrija and reference locations

[en] Tanzania experienced unprecedented rush for gold mining in late 1980s and early 1990s when a similar gold rush was taking place in Latin America and other developing countries because of good gold market prices. The gold rush in Tanzania was also prompted by the socioeconomic and political transformations that were taking place in the country. The liberalization of mining policy and regulations by the government allowed foreign and local private investment in mining and encouraged small-scale mining and gold trade. Because of the liberalization, thousands of local miners, mostly from rural communities, rushed to gold mining for subsistence income. The use of mercury in gold recovery became widespread in Tanzania as a result of the gold rush. From 1992/93, the Department of Geology of the University of Dar es Salaam (UDSM in collaboration with the National Environment Management Council (NEMC) initiated studies to assess the extent of mercury pollution in the country. Further studies on mercury and other heavy metal pollution were undertaken between 1993 and 1997 by UDSM, under a broader project on 'Environmental Aspects of Mining and Industrialization in Tanzania', supported by the Swedish Agency for Research Cooperation with Developing Countries SAREC (Sida/SAREC). The above studies revealed the presence of elevated mercury concentrations in gold-ore tailings and river sediment in several gold mining areas. Studies to evaluate environmental transformation, partition and bioaccumulation of mercury in different environmental matrices and the long-term impact of mercury pollution have not been done. The present research project was initiated to provide scientific database necessary to better understand the environmental behaviour and cycling of mercury in the southwest Lake Victoria goldfields. Such data are necessary in the evaluation of environmental impacts of mercury pollution and in the mitigation of adverse impacts on the ecosystems and human health

[en] Increased awareness about the toxicity of mercury (Hg) has during the latest decades resulted in reduced use of Hg in industrialised countries. Developing countries, on the contrary, have largely increased their anthropogenic Hg emissions caused by its use in gold mining, transfer of Hg emitting factories from developed countries, and increased burning of coal without appropriate flue gas cleaning. The contribution of global Hg sources and the importance of other parameters to increased Hg levels encountered in hydroelectric reservoirs and other areas after flooding is not well understood, especially not in the tropics. The aim of the present study is to increase the knowledge about Hg transformations in tropical areas. Total Hg content in water, biota, and sediment will be determined by atomic absorption and fluorescence spectrophotometry and methyl Hg content in biota by gaschromatography after extraction with acids, hydroxides, and organic solvents. Mercury methylation capacity in sediments, water, and selected biota will be determined with ²⁰³Hg and subsequent radiological measurements of insitu incubations. Factors affecting the methylation and demethylation rates will be identified with laboratory incubations with ²⁰³Hg at varying environmental conditions such as organic matter, pH, redox potential, conductivity, light, temperature, geochemical factors and populations of bacteria. The populations of bacteria will be determined to quantity by isotope techniques. The first experiments indicate markedly larger methylation capacity as well as bacterial production of incubated samples of Eichhornia crassipes, originating from Brazil, compared to Myriophyllum spicatum from Sweden. The results are the first step to better understand the importance of environmental parameters and bacterial production for methylation of Hg. (author)

[en] In the reservoir Guri located at the south of Venezuela in Bolivar State has occurred the bioaccumulation process. Several studies have demonstrated it. In samples of 42 specimens of carnivorous trophic level, the average value of total mercury was 1.90 mg/g with a maximum of 6.04 mg/g. As first job it was necessary to identify and classify the infrastructures of each town according to their use due to the lack of updated demographic information. In this investigation is described the home characteristics with relation to its residence conditions and work status of home bosses through the design and application of a survey by home in two communities nearby reservoir Guri: 'La Paragua' and 'El Manteco'. A simple questionnaire was also designed and applied where home bosses were asked for the weekly frequency of consumption of fish, especially those of carnivorous habits as well as the quantity in grams consumed per week. Homes were better structured at 'La Paragua' than at 'El Manteco' but in the latest the monthly income by home was bigger nevertheless, it does not meet the requirements of the basic basket in Venezuela of US $ 323 for a four people family. The overall consumption of fish per week was twice higher at 'El Manteco' (1,485 kg) than at 'La Paragua' (678 kg). The fish specie consumed as first priority at 'La Paragua' was Prochilodus rubrotaeniatus ('Coporo') which is of detritivorous alimentary habits while the second more consumed was Cichla ocellaris ('Pavon') of carnivorous alimentary habits. On the opposite side, at 'El Manteco' the first priority of fish was Cichla ocellaris ('Pavon') while the second one was for Prochilodus rubrotaeniatus ('Coporo'). Next step will be the organic mercury analysis in hair samples and the nutritional profile in individuals from the selected homes: 36 at 'La Paragua' and 50 at 'El Manteco' towns. (author)