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PubMedDate not supplied

Late progression of radiographic changes in Canari chrysotile mine and mill exworkers.

The present radiological status of 133 exworkers (mean age: 58 +/- 0.7 yr) of the chrysotile mine of Canari (Corsica) was compared to that recorded in 1965, when the mine was closed. The mean time since first exposure is 27 +/- 0.4 yr, and the mean time since termination of asbestos exposure equals 16 +/- 0.3 yr. This study showed an evolution of radiographic changes: in 1965 only 14% of the subjects had grade 1/1 or more parenchymal fibrosis, and 6% had bilateral pleural lesions; in 1979 these percentages reached 40% and 27%, respectively. Subjects who had a given parenchymal change in 1965 (e.g., 1/1 grade lesions) were older and had a more intensive dust exposure and tobacco consumption than exminers who developed the same parenchymal changes much later. A progression of parenchymal changes was observed in 39% of the subjects with normal findings in 1965, and in 63% of the subjects with grade 1/1 or more changes in 1965. Those who progressed (46% of the cohort) were older, had a longer exposure, and a more intensive dust exposure and cigarette smoking than nonprogressors.

Age Factors↗
PubMed1992

Acceptable workloads for three common mining materials.

A series of psychophysical lifting studies was conducted to establish maximum acceptable weights of lift (MAWL) for three supply items commonly handled in underground coal mines (rock dust bags, ventilation stopping blocks, and crib blocks). Each study utilized 12 subjects, all of whom had considerable experience working in underground coal mines. Effects of lifting in four postures (standing, stooping under a 1.5 m ceiling, stooping under a 1.2 m ceiling, and kneeling) were investigated together with four lifting conditions (combinations of lifting symmetry and lifting height). The frequency of lifting was set at four per min, and the task duration was 15 min. Posture significantly affected the MAWL for the rock dust bag (standing MAWL was 7% greater than restricted postures and kneeling MAWL was 6.4% less than stopped); however, posture interacted with lifting conditions for both of the other materials. Physiological costs were found to be significantly greater in the stooped postures compared with kneeling for all materials. Other contrasts (standing versus restricted postures, stooping under 1.5 m ceiling versus stopping under 1.2 m ceiling) did not exhibit significantly different levels of energy expenditure. Energy expenditure was significantly affected by vertical lifting height; however, the plane of lifting had little influence on metabolic cost. Recommended acceptable workloads for the three materials are 20.0 kg for the rock dust bag, 16.5 kg for the ventilation stopping block, and 14.7 kg for the crib block. These results suggest that miners are often required to lift supplies that are substantially heavier than psychophysically acceptable lifting limits.

Accidents, Occupational↗
PubMed2006

Impact of coal mine dump contaminated soils on elemental uptake by Spinacia oleracea (spinach).

The elemental uptake and the growth response of Spinacia oleracea (spinach) to the soil contaminated with the South African bituminous coal mine dump soil, viz. 0%, 5%, 15%, and 25% w/w, was investigated. The contaminated soils were analyzed for pH, cation exchange capacity (CEC), soil organic matter (SOM), and concentrations of selected heavy metals. The pH, SOM, and CEC decreased with an increase in contamination indicating the acidic nature of coal mine soil and the raise in the soil binding sites. The distribution of Fe, Mn, Ni, Cd, and Pb in the in roots and leaves of the plants was determined in two stages of plant growth. Spinach showed high accumulation of Fe and increased levels of Ni and Cd with an increase in contamination. No plant growth was recorded with 25% contamination.

Cadmium↗
PubMed2001

Transport, fate and speciation of heavy metals (Pb, Zn, Cu, Cd) in mine drainage: geochemical modeling and anodic stripping voltammetric analysis.

The maximum concentrations (ppb) of heavy metals in the mine drainage (pH: down to 3.3) of Chonam-ri creek in the abandoned Kwangyang gold-silver mine, South Korea, are 22600 Zn, 2810 Cu, 182 Cd, and 109 Pb. A small, limestone-infused retention pond, about 440 meters downstream from the waste dump, plays an important role in the removal of heavy metals: the factors of reduction for Zn, Cu, Cd, and Pb are 12, 24, 14, and 14, respectively. This is due to the pH increase (up to >5.4) accompanying adsorption onto and/or coprecipitation with Fe- and Al-hydroxides (goethite and gibbsite). From the waste dump to the pond, heavy metal concentrations also progressively decrease due to pH increase. Geochemical modeling (using the computer code WATEQ4F) predicts that free aqueous metal ions are dominant (mostly >70% for Cu and Zn, and >60% for Pb and Cd) in samples collected upstream from the pond, whereas complexing with sulfate, carbonate and hydroxyl ions becomes important in the samples collected downstream. The comparison between the concentrations of electrochemically labile species (determined by Anodic Stripping Voltammetry) and the result of computer modeling shows that Cd and Zn are present predominantly as labile inorganic species throughout the whole range of the creek. However, Cu and Pb in the samples collected downstream from the pond largely form electrochemically inert species (possibly, metal-organic complexes). The above results indicate that the retention pond is effective in reducing the toxicity of heavy metals, especially Cu and Pb.

Electrochemistry↗
PubMed2006

Airborne total gaseous mercury and exposure in a Venezuelan mining area.

This paper presents a short-term monitoring study of total gaseous mercury (TGM) in air, and exposure to airborne mercury. The evaluation was carried out in polluted mining sites (El Callao, Venezuela), where for decades mercury has been used in diverse stages of gold mining activities. The contamination is mainly due to emission of Hg0 during gold amalgamation and burning, which can cause direct human health risks. Total gaseous mercury (TGM) in air was analysed in mill, jewellery and indoor house sites, and at different heights (height profiles near the surface) at polluted and not polluted sites. Mercury concentration in air was measured with a portable mercury analyser (Lumex Ra-915+). Time weighted average mercury (TWA) was calculated for the evaluation of mercury exposure. TWA values ranged between 0.28 microg m(-3) and >100 microg m(-3). These measurements were done during sunny and dry days. In the case of mills and gold workshops, the values were over the limit recommended by the World Health Organization to exposure (25 microg m(-3)) and NIOSH limit (50 microg m(-3)). Indoors in a house, the air Hg average value was 2.58 microg m(-3) exceeding EPA (0.3 microg m(-3)) and ATSDR (1 microg m(-3)) guidelines. The mercury concentration at different height profiles, varied between 1766 microg m(-3) and 0.014 microg m(-3). Mercury height profiles were described by a power function model of the form c(Hg) = ah(-b), where a parameter describes the magnitude of Hg emission. For polluted sites there was a significant correlation between a and Hg in soil or Hg emission from soil to air, while b is only significantly correlated with air temperature. An air and soil mercury measurement transect was carried out at a mill site up to a distance of 1000 m, and it was observed that the air mercury concentration decreases with increasing distance from the mill site, and inversely to Hg soil content.

Air Pollutants↗
PubMed2002

Gas forming processes within lignite mining dumps.

Gas analyses of the soil atmosphere of lignite mining dumps yielded increased contents of carbon dioxide. To get information about the potential sources and the carbon dioxide releasing capacity of the dumps, samples of dump material were investigated for their contents and isotopic compositions of organic and inorganic carbon as well as the carbon dioxide in the soil atmosphere. The contents of organic and inorganic carbon were found to vary depending on type of dump material. The isotopic composition of the organic carbon ranges between -24.5 and -26.5 per thousand, which is typical for humous materials. The carbonates are found to be of marine origin (delta13C: +0.5 to -1.1 per thousand). By means of the isotope investigations it could be shown that the carbon dioxide in the lignite mining dump arises from these two different sources. Mixing ratios can be calculated using the isotope balance equation. Both reaction paths are associated with oxygen consumption and do not result in an increased gas pressure within the dump.

Carbon Dioxide↗
PubMed2006

Flooding of lignite mines: isotope variations and processes in a system influenced by saline groundwater.

The quality of both groundwaters and surface waters that arise during flooding of abandoned lignite open pits are influenced by regional and local factors. A typical regional factor is due to oxidised sedimentary sulfides. A more local factor is the interaction of shallow water with highly saline groundwater, which is important in Merseburg-Ost (Germany). Investigation of this system is aided by the use of many environmental isotope tracers but special problems can arise. In order to reveal processes in the mine environment (shallow groundwater, lake water) and to characterise mixtures with saline groundwater results are described using the tracers deltaD, delta18O, delta13C, delta34S, 87Sr/86Sr, 3H, 14C, 39Ar, and 222Rn. Deep highly saline groundwater had a radiocarbon concentration typically below 10 pMC. The values of delta13C(DIC) are around-5 per thousand. As delta13C of the aquifer rock samples (Permian, Zechstein carbonates) was in the range of-6...+5 per thousand, residence time corrections based on delta13C are questionable. Additional checks with 39Ar, as well as results from the variationof delta18O (or deltaD) with respect to the salinity, emphasise a Holocene age; as is also the case for most mineralised groundwaters and also for water having a low delta18O (and deltaD). For saline groundwater residing in the Zechstein aquifer the measured delta34S values of about 12 per thousand are close to those expected from the literature. In contrast, the 87Sr/86Sr ratio of dissolved strontium is far from the values anticipated for the aquifer rocks despite there being proportionality between the chloride concentration and the strontium concentration. Furthermore, the proportionality is not valid in lower mineralised water. The 87Sr/86Sr ratio can, therefore, hardly be used as a tracer for the distribution of ascending saline water. The amount of salt-water coming from below into the residual quarry basins is an essential contribution to the lake inventories. Therefore, 222Rn was used to assist in determining the renewal of salt-water layers that formed in deep lake locations. In the deep zones 222Rn concentrations up to 6 Bq/l were measured but were dominantly in equilibrium with 226Ra, which was found in all higher mineralised groundwater samples. Excess radon was limited to just a few decimetres above the lake sediment surface but does not appear to be caused by continuous groundwater discharge. Hydrochemical investigations of groundwater from the Quaternary aquifer were carried out over the last six years before flooding was complete. Apart from a slight downward shift of the average sulfate concentration, other changes showed virtually no trends. An increase of the sulfate concentration was mostly correlated with a decrease of delta34S for individual sites only, but not for the whole ensemble of sampling locations. Sulfate from pyrite oxidation plays an important role but cannot be attributed unequivocally to coal mining. There are hints that the conditions closer to the basin edges may differ from those remoter parts of the flood plain.

Coal↗
PubMed2000

Virtual reality for mine safety training.

Mining has long remained one of America's most hazardous occupations. Researchers believe that by developing realistic, affordable VR training software, miners will be able to receive accurate training in hazard recognition and avoidance. In addition, the VR software will allow miners to follow mine evacuation routes and safe procedures without exposing themselves to danger. This VR software may ultimately be tailored to provide training in other industries, such as the construction, agricultural, and petroleum industries.

Computer-Assisted Instruction↗
PubMed2002

Levels and composition of atmospheric particulates (PM10) in a mining-industrial site in the city of Lavrion, Greece.

The present work focuses on the characterization of air quality and the identification of pollutant origin at a former mining site in the city of Lavrion, Greece. A historical metallurgy complex is reused for establishing the Lavrion Technology and Cultural Park (LTCP). A serious problem with this is the severe soil contamination that resulted from intensive mining and metallurgical activities that has taken place in the greater area for the past 3,000 years. Among other consequences, surface-polluted depositions, rich in heavy and toxic metals, are loose and easily wind-eroded, resulting in transportation of particulate matter (PM) in the surrounding atmosphere. On the other hand, there are a number of industries relatively close to the site that are potential sources of PM air pollution. The current study deals with the collection and analysis of PM10 samples with respect to their concentration in heavy metals, such as Pb, Cd, Cu, Fe, Zn, Mn, Cr, and Ni. Though not a heavy metal, As also is included. Furthermore, the source of these elements is verified using statistical correlation and by calculating enrichment factors (EFs), considering that some substances are certainly of contaminated soil origin. Results show that PM10 and element concentrations are relatively low during winter but significantly increase during summer. Fe, Pb, Zn, Mn, and Cu may be considered of contaminated soil origin, while As, Ni, Cd, and Cr are very much enriched with respect to contaminated soil, indicating another possible source attributed to the adjacent industrial plants.

Air Pollutants↗
PubMed2001

Heavy mining vehicle controls and skidding accidents.

This paper examines various control locations in heavy mining vehicles. Three trucks have been tested on a skid pad in both clockwise and anticlockwise directions. The skid lengths were measured after each trial. The primary focus of the study was the positioning of various controls and their relevance to various skid lengths. Some additional measures such as NASA-TLX scales were also used to make subjective evaluations. The results are presented in this paper. The findings clearly indicate the relevance of control locations to actual skid lengths. The poorly located controls resulted in greater skid lengths. This is an important finding as skid lengths are related to greater reaction times in a skidding situation and hence greater risk of accidents on relevant trucks. Such accidents can incur large repair bills for damaged equipment whereas more importantly, jeopardizing the life and safety of heavy mining vehicle drivers.

Accidents, Occupational↗
PubMed2006

Treatment of acid mine drainage with fly ash: removal of major contaminants and trace elements.

Acid mine drainage (AMD) has been reacted with two South African fly ashes in a batch setup in an attempt to evaluate their neutralization and major, trace elements removal capacity. Different fly ash: acid mine drainage ratios (FA: AMD) were stirred in a beaker for a set time and the process water analyzed for major, trace elements and sulphate content. The three factors that finally dictated the nature of the final solution in these neutralization reactions were the FA: AMD ratio, the contact time of the reaction and the chemistry of the AMD. Efficiency of the elements removal was directly linked to the amount of FA in the reaction mixture and to the final pH attained. Most elements attained approximately 100% removal only when the pH of minimum solubility of their hydroxides was achieved (i.e., Mg = 10.49-11.0, Cu(2+) = 6, Pb(2+) = 6-7). Dissolution of CaO and subsequent precipitation of gypsum and formation of Al, Fe oxyhydroxysulphates, Fe oxyhydroxides with subsequent adsorption of sulphate contributed to the sulphate attenuation. Significant leaching of B, Sr, Ba and Mo was observed as the reaction progressed and was observed to increase with quantity of fly ash in the reaction mixture. However B was observed to decrease at high FA: AMD ratios probably as result of co-precipitation with CaCO(3(s)).

Acids↗
PubMed2004

The causes and control of loader- and truck-related fatalities in surface mining operations.

At surface mining operations throughout the world, loaders and trucks are a primary means of material loading and haulage. As the size, use and technological complexity of these units have increased, so has the concern regarding loader and truck safety. The severity and number of accidents involving loaders and trucks is higher when compared to all other mining accident types. In this paper, an analysis of loader and truck-related fatalities over the last 8 years is performed, the fatality categories and causes of accidents are established and control strategies are discussed and evaluated in an effort to increase hazard awareness by emphasizing safe loading, hauling and maintenance practices, as well as the value of traditional and innovative miner training programmes.

Accidents, Occupational↗
PubMed2004

Capacity of Lemna gibba L. (duckweed) for uranium and arsenic phytoremediation in mine tailing waters.

The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface waters was investigated in wetlands of two former uranium mines in eastern Germany and in laboratory hydroponic culture. Water and plants were sampled and L gibba growth and yield were monitored in tailing ponds from the field study sites. Contaminant accumulation, growth and yield experiments were conducted in the laboratory using synthetic tailing water. Mean background concentrations of the surface waters were 186.0+/-81.2 microg l(-1) uranium and 47.0+/-21.3 microg l(-1) arsenic in Site one and 293.7+/-121.3 microg l(-1) uranium and 41.37+/-24.7 microg l(-1) arsenic in Site two. The initial concentration of both uranium and arsenic in the culture solutions was 100 microg l(-1). The plant samples were either not leached, leached with deionized H2O or ethylenediaminetetracetic (EDTA). The results revealed high bioaccumulation coefficients for both uranium and arsenic. Uranium and arsenic content of L gibba dry biomass of the field samples were as follows: nonleached samples > deionized H2O leached (insignificant ANOVA p = 0.05) > EDTA leached. The difference in both arsenic and uranium enrichment were significantly high between the nonleached and the other two lead samples tested at ANOVA p > 0.001. Estimated mean L gibba density in surface water was 85,344.8+/-1843.4 fronds m(-2) (approximately 1319.7 g m(-2)). The maximum specific growth rate was 0.47+/-0.2 d(-1), which exceeded reported specific growth rates for L gibba in the literature. Average yield was estimated at 20.2+/-6.7 g m(-2) d(-1), giving approximately 73.6+/-21.4 t ha(-1) y(-1) as the annual yield. The highest accumulations observed were 896.9+/-203.8 mg kg(-1) uranium and 1021.7+/-250.8 mg kg(-1) arsenic dry biomass for a 21-d test period in the laboratory steady-state experiments. The potential extractions from surface waters with L gibba L. were estimated to be 662.7 kg uranium ha(-1) yr(-1) and 751.9 kg arsenic ha(-1) yr(-1) under the above conditions.

Araceae↗
PubMed2003

Pollution of coastal region impacted by acid mine drainage in Morphou bay, northern Cyprus.

Abandoned copper mines, located in Lefka-Xeros area by the Morphou bay were primarily producing copper. Secondary products, such as silver and gold were also produced for a century by cyanide leaching method. The residues of mining processes were deposited in large tailing ponds that were constructed with primitive technology. In this research, water samples from several different points of tailing ponds, Lefka river and coast of Morphou bay are collected. The laboratory analysis of the samples is then carried out, considering basic pollutant parameters such as copper. The cross-shore and Longshore numerical modelling technique is applied associating the wave climate and the morphologic characteristics of the Morphou bay with the laboratory results to measure long-term effects of the pollution, diffused into the Mediterranean sea.

Copper↗
PubMed2003

Ambient concentrations of total suspended particulate matter and its elemental constituents at the wider area of the mining facilities of TVX Hellas in Chalkidiki, Greece.

To assess ambient air quality at the wider area of TVX Hellas mining facilities, the Total Suspended Particulate matter (TSP) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn are being monitored for more than thirty months as part of the established Environmental Monitoring Program. High Volume air samplers equipped with Tissue Quartz filters were employed for the collection of TSP. Analyses were effected after digestion of the suspended particulate with an HNO3-HCl solution and determination of elemental concentrations with an Atomic Absorption Spectroscopy equipped with graphite furnace. The sampling stations were selected to record representatively the existing ambient air quality in the vicinity of the facilities and at remote sites not affected from industrial activities. Monitoring data indicated that the background TSP concentrations ranged from 5-60 microg/m3. Recorded TSP concentrations at the residential sites close to the facilities ranged between 20-100 microg/m3, indicating only a minimal influence from the mining and milling activities. Similar spatial variation was observed for the TSP constituents and specifically for Pb and Zn. To validate the monitoring procedures, a parallel sampling campaign took place with different High Volume samplers at days where low TSP concentrations were expected. The satisfactory agreement (+/- 11%) at low concentrations (50-100 microg/m3) clearly supported the reproducibility of the techniques employed specifically at the critical range of lower concentrations.

Air Pollutants↗
PubMed1998

Genetic characterization of HIV type 1 from migrant workers in three South African gold mines.

The phylogenetic relationships between 44 HIV-1 isolates from 43 infected subjects employed by three adjacent South African gold mines were investigated. The patients were migrant workers originating from rural areas of South Africa and the neighboring countries of Lesotho, Botswana, Swaziland, and Mozambique. Proviral HIV-1 DNA was subtyped using a heteroduplex mobility assay (HMA) based on the 700-bp V3-V5 region of the env gene. DNA sequence analysis was used to confirm the subtype designation and to determine phylogenetic relationships between isolates. All 44 HIV-1 isolates were identified as env subtype C using both HMA and phylogenetic analysis. These isolates did not show a distinct phylogenetic relatedness based on the geographic origins of the migrant workers or show close homology to other subtype C sequences from southern Africa or India. However, five clusters of closely related sequences were identified, mainly involving miners of disparate geographic origins, suggesting possible epidemiological linkage in these few cases. The characteristic tetrapeptide sequence, GPGQ, at the tip of the V3 loop of subtype C viruses was conserved in the predicted amino acid sequences of most isolates. The heterogeneity of HIV-1 sequences among migrant workers in a mining cohort suggests multiple introductions of HIV-1 subtype C into this population that are not apparently linked to the geographic origins of the patients.

Adolescent↗
PubMed1990

Fibres in Lower Silesia hard coal mines respirable dusts.

The paper describes the presence of fibres in respirable coal dust in high rank coal mines in Lower Silesia. The amount of fibres in dust particles is about 1.5% (by count). Testing by the incineration test, the lack of atomic number contrast in electron back-scattering imaging in SEM and X-ray microanalysis allow the fibres to be identified as coal. The authors suggest the possible role of coal fibres in the increased fibrogenic activity of the dusts in coal mines in Lower Silesia.

Air Pollutants, Occupational↗
PubMed2002

Mortality among workers at a talc mining and milling facility.

BACKGROUND: This study evaluated mortality among workers at a talc mining and milling facility. METHODS: Subjects were white men actively employed between 1948 and 1989 and known to have been alive in or after 1950. Analyses assessed cancer mortality during the period 1950-89 (809 subjects) and non-cancer mortality during 1960-89 (782 subjects). RESULTS: Comparisons with regional general population death rates for 1960-89 indicated that the workers had more than expected deaths from all causes combined [209 observed/160 expected, standardized mortality ratio (SMR) = 131, 95% confidence interval (CI) = 114-150], due mainly to increased mortality from lung cancer (31/13, SMR = 232, CI = 157-329) and non-malignant respiratory disease (NMRD) (28/13, SMR = 221, CI = 147-320). The lung cancer excess was concentrated in miners (18/4.6, SMR = 394, CI = 233-622); millers had only a small increase (7/5.5, SMR = 128, CI = 51-263). An excess of NMRD occurred both in miners (10/4.2, SMR = 241, CI = 116-444) and in millers (11/4.8, SMR = 227, CI = 113-407). The median estimated exposure to respirable dust was 511 mg/m(3)-days for all exposed employees, 739 mg/m(3)-days for mine workers and 683 mg/m(3)-days for mill workers. Employees with high, compared with low, estimated exposure to dust had a rate ratio of 0.5 (CI = 0.2-1.3) for lung cancer and of 11.8 (CI = 3.1-44.9) for pulmonary fibrosis. CONCLUSIONS: Exposure to talc ore dust may not have been responsible for the lung cancer excess among these workers but probably contributed to the elevated rate of NMRD, particularly pulmonary fibrosis.

Dust↗