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PubMed2006

Lead and cadmium exposure in children living around a coal-mining area in Yatağan, Turkey.

The study was designed to determine asymptomatic lead poisoning prevalence and cadmium exposure of preschool children living in a coal-mining area in Yatağan, Mugla, Turkey. The research was conducted between May and June 2002. The study included 236 children (53.4% female and 46.6% male) who were identified among the healthy children between the ages of 6 months and 6 years, using a systematic sampling method, from the records of the local medical centre of Yatağan. Assessments of the levels of blood lead and cadmium were performed by an atomic absorption spectrophotometer, in the Department of Biophysics, Cerrahpaşa Medical Faculty. The mean age of females and males were 49+/-18 and 43+/-19 months, respectively. The mean blood lead level was 33.8+/-15.6 microg/dL in females and 38.8+/-16.0 microg/dL in males. The mean blood lead level of the males was significantly higher than the females (P<0.05). Correlation analysis showed a statistically significant negative correlation between blood lead level and age in both sex groups (r= -0.367, P<0.001). The blood lead level was found to be > 10 microg/dL in 95.7% and >20 microg/dL in 87.6% of all children. The mean blood cadmium level of all children was 1.31+/-0.72 microg/dL. The blood cadmium level was found to be >0.5 microg/dL, which is considered to be toxic, in 85% of all children. The difference in blood cadmium levels between sexes was not significant. A statistically significant negative correlation was found between blood cadmium level and age of all children (r= -0.382, P<0.001). Although it is not possible to understand from this study what proportion of the biological lead and cadmium burden results from mining waste and what proportion comes from other sources, such as paint and gasoline residue deposited in soil and air, these results do indicate that asymptomatic lead poisoning and cadmium exposure are significant problems in children living in the Yatağan area. In conclusion, environmental lead measurements (house dust, soil, drinking water and air) must be performed, the results must be compared with the normal limits, and precautions must be taken if necessary in the Yatağan area. Future public health research efforts should focus on reducing the excessive levels of lead and cadmium in the environment.

Age Factors↗
PubMed1989

Production of free radicals arising from the surface activity of minerals and oxygen. Part I. Iron mine ores.

The excess incidence of lung cancers observed in many metal mines probably is not only correlated with radioactivity but also with the inhaled dusts. In an attempt to determine a possible mechanism of carcinogenicity related to the surface activity of dusts, using the spin-trapping agent and ESR spectroscopy, one can demonstrate that some mineral dusts from iron ore mines are very active in an oxidative process in aqueous medium, implying the formation of radical oxygen species on reducing surface sites of the solid. This reducing surface activity of the dusts depends on the presence of Fe2+ ion in the lattice and on the process of activation and passivation of the surface sites. The more simple process of activation is the dissolution of the oxidized coating on the particle surface. Among the oxides, oxyhydroxides, carbonates, and silicates, the magnesium-iron phyllosilicates (chlorite, biotite, berthierine) appear the most active. The siderite FeCO3 is also active, but the iron oxides and oxyhydroxides are generally nonactive.

Free Radicals↗
PubMed2000

Sporotrichosis infection on mines of the Witwatersrand.

BACKGROUND: Our knowledge of skin disease is often based on fortuitous situations that have provided opportunities for observation and study of the disease. One of these diseases is sporotrichosis. OBJECTIVE: This article examines a symposium published in 1947 by the Transvaal Chamber of Mines in South Africa. It reviews the approach taken in the investigation of a large outbreak of sporotrichosis in the mine workers. CONCLUSION: The investigation of this outbreak has contributed significantly to our present day knowledge of sporotrichosis, the causative organism, its mode of spread, and its clinical features. It is also a striking example of meticulous scientific research and observation.

Disease Outbreaks↗
PubMedDate not supplied

Creating alliances for disease management in industrial settings: a case study of HIV/AIDS in workers in South African gold mines.

The epidemic of HIV/AIDS is at an advanced stage in many African countries, but little attention has been given to the impact that this will have in industrial settings. Using the Southern African mining industry as a case study, the authors consider the state of the HIV epidemic and discuss programs that have been undertaken to manage HIV. They critically analyze the reasons current interventions have had little impact on HIV among mine workers, tracing the lack of success to neglect of the social and community contexts within which HIV transmission takes place, as well as the lack of attention to the psychosocial processes and mechanisms underlying disease transmission. Finally, they present an intervention that aims to address the limitations of existing industrial programs and improve the management of sexually transmitted diseases (STDs), including HIV, in a particular occupational setting through creating alliances between a wide range of community stakeholders. The intervention aims not only to reduce STDs, promote awareness of HIV risks, and distribute condoms, as existing programs have done, but also to address the broader social, cultural, and community contexts that facilitate HIV transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Micronodules and emphysema in coal mine dust or silica exposure: relation with lung function.

The aim of this study was to investigate the respective effects of micronodules and pulmonary emphysema, detected by computed tomography (CT), on lung function in workers exposed to silica and coal mine dust. Eighty-three subjects exposed to silica (n=35) or to coal mine dust (n=48), without progressive massive fibrosis, were investigated by high-resolution and conventional CT scans to detect micronodules and to quantify pulmonary emphysema by measuring the relative area of the lung with attenuation values lower than -950 Hounsfield units. Sixty-six (54.5%) subjects had evidence of micronodules on CT scans. Smokers had micronodules more rarely than nonsmokers. Significant correlations were found between the forced expiratory volume in one second (FEV(1); % predicted) (r=-0.41, p<0.001), FEV1/vital capacity (VC) (r=-0.61, p<0.001), diffusing capacity of the lung for carbon monoxide (DL,CO) (r=-0.36, p<0.001) and the extent of emphysema. No difference was demonstrated in the linear relationships between the extent of emphysema and the pulmonary function according to the type of exposure or the presence of micronodules on CT scans. This study suggests that micronodules detected by computed tomography have no influence, by themselves, on pulmonary function and that they should only be considered as a marker of exposure.

Adult↗
PubMed1979

Health effects of coal mining and combustion: carcinogens and cofactors.

Some polynuclear aromatics (PNA) have been found to be potent carcinogens for all tissues and organs of experimental animals that have been exposed to them, but different dose levels are needed for these effects. They have been known for decades to cause cancer at the site of application but also at certain sites distant from the area of contact. Although some hydrocarbons are potent and complete carcinogens, the majority of related hydrocarbons was originally found to be inactive. Since they generally appear together, it was important to know more about their interaction, particularly whether they would synergize, or antagonize. The polycyclic hydrocarbons have been studied by subcutaneous injection, where they prove very potent carcinogens. They are also very active on the skin of mice where they produce cancer on prolonged application. Inhalation studies, require larger doses yielded negative results until particulate matter was introduced which facilitated the development of lung tumors. Although iron oxide dust was used initially, other dusts were also capable of enhancing the response of the tissue to benzo(a)pyrene carcinogenesis. This point is of importance, particularly since the inhalation of PNA in situations of air pollution or coal mining involves particulates, although of a different type. Soot is not a homogenous substance and several factors determine its properties. Soots will lose some of the absorbed chemicals during their residence in air, but they retain their PNAs for long periods of time when they reach the soil. The carcinogenicity of PNAs in the adsorbed state may be completely absent, depending on particle size of the soot and availability of eluting capability of the tissues or cells in contact with the soot. Whenever the carcinogenic polynuclear aromatics can be eluted they will be active in producing cancer if their residence is adequate. There seems to be no reason to assume that a large increase in coal combustion in the future will by necessity lead to greater risks of cancer to the coal miners or the general urban dweller, because activities to be started now can take into consideration the requirements necessary for control of air pollution in mines as well as in cities. If new uses of coal will be developed, it will be a completely different situation, and statements about the carcinogenic risk from coal utilization do not apply there. Although some of the same carcinogenic PNAs are involved in the health hazards from those processes, other carcinogens and also cocarcinogens will be present, and the exposed workers will not have the apparent benefits of adsorption of PNAs on soot.

Air Pollutants↗
PubMed1994

Biopersistence of the mineral matter of coal mine dusts in silicotic human lungs: is there a preferential release of iron?

Toxic potency of quartz-containing dusts, including coal mine dusts, is usually inhibited by protective clay mineral layers on the surface of quartz particles. This investigation of 11 dusts recovered from lungs of coal miners with different silicosis grade shows that such layers persist during long-term contact with human lung tissues. On the other hand, the results suggest that an apparently preferential release of iron occurred in lungs with massive fibrosis. These preliminary results support the hypothesis of an iron-related harmfulness of coal mine dusts.

Coal Mining↗
PubMed2025

Genome mining based on transcriptional regulatory networks uncovers a novel locus involved in desferrioxamine biosynthesis.

Bacteria produce a plethora of natural products that are in clinical, agricultural and biotechnological use. Genome mining has uncovered millions of biosynthetic gene clusters (BGCs) that encode their biosynthesis, the vast majority of them lacking a clear product or function. Thus, a major challenge is to predict the bioactivities of the molecules these BGCs specify, and how to elicit their expression. Here, we present an innovative strategy whereby we harness the power of regulatory networks combined with global gene expression patterns to predict BGC functions. Bioinformatic analysis of all genes predicted to be controlled by the iron master regulator DmdR1 combined with co-expression data, led to identification of the novel operon desJGH that plays a key role in the biosynthesis of the iron overload drug desferrioxamine (DFO) B in Streptomyces coelicolor. Deletion of either desG or desH strongly reduces the biosynthesis of DFO B, while that of DFO E is enhanced. DesJGH most likely act by changing the balance between the DFO precursors. Our work shows the power of harnessing regulation-based genome mining to functionally prioritize BGCs, accelerating the discovery of novel bioactive molecules.

Deferoxamine↗
PubMed1991

Serum angiotensin-converting enzyme is elevated in association with underground coal mining.

Serum angiotensin-converting enzyme activity (SACE) and lysozyme activity were measured in a group of 40 underground coal miners and two control groups, 20 subjects with sarcoidosis and 15 normal non-dust-exposed volunteers. The miners were grouped first according to whether they had recent exposure (still actively mining or retired three years or less prior to measurement) or temporally more distant exposure (retired more than three years prior to measurement). Secondly, they were grouped as to whether or not they had coal workers' pneumoconiosis (CWP). The subjects with sarcoidosis were grouped according to disease activity. As expected, the subjects with active sarcoidosis had elevated SACE activity compared with normal subjects. The coal miners as a group did not have elevation of their SACE activity. However, the coal miners with recent exposure had elevated SACE activity (57.1 +/- 3.9 U/ml) compared with normal controls (43.8 +/- 1.5 U/ml, p = 0.007). The SACE activity in miners without recent exposure was not elevated (39.8 +/- 1.3 U/ml) compared with the normal controls. No increase in SACE activity was found when the miners were grouped according to the presence or absence of CWP. In contrast, the miners' serum lysozyme activity was not elevated. Since alveolar macrophages are a potential source of SACE, elevation of SACE activity in underground coal miners may reflect alveolar macrophage activation caused by increased pulmonary mixed coal mine dust burden. Furthermore, since both SACE and serum lysozyme are elevated in association with silicosis, these findings may confirm that the macrophage responses to inhaled silica and coal dust differ.

Coal Mining↗
PubMed1984

Estimation of the exertion requirements of coal mining work.

The work requirements of coal mining work were estimated by studying a group of 12 underground coal miners. A two level (rest, 300 kg X m/min) test was performed to estimate the linear relationship between each subject's heart rate and oxygen consumption. Then, heart rates were recorded during coal mining work with a Holter type recorder. From these data, the distributions of oxygen consumptions during work were estimated, allowing characterization of the range of exertion throughout the work day. The average median estimated oxygen consumption was 3.3 METS, the average 70th percentile was 4.3 METS, and the average 90th percentile was 6.3 METS. These results should be considered when assessing an individual's occupational fitness.

Adult↗
PubMed2003

[Association between reported annual gold mining extraction and incidence of malaria in Mato Grosso-Brazil, 1985-1996].

A secondary data analysis was performed using an ecological design to study the association between malaria incidence rates, the reported annual production of gold mining extraction and monetary investments for the control of malaria from 1985 to 1996 in Mato Grosso, Brazil. A positive and statistically significant (p<0.001) association between the amount of gold extracted and MIR was obtained in multivariate regression analysis, even after allowing for financial investments in malaria control activities. This finding contributes to an understanding of the decrease observed in malaria incidence in Mato Grosso during the last decade, in view of the significant decrease in gold mining within the region during this period.

Brazil↗
PubMed2006

Field demonstration of reduction of lead availability in soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings using phosphorus fertilizers.

A field demonstration of reduction of lead availability in a soil and cabbage (Brassica Chinensis L.) contaminated by mining tailings, located in Shaoxing, China was carried out to evaluate the effects of applications of phosphorus fertilizers on Pb fractionation and Pb phyto-availability in the soil. It was found that the addition of all three P fertilizers including single super phosphate (SSP), phosphate rock (PR), and calcium magnesium phosphate (CMP) significantly decreased the percentage of water-soluble and exchangeable (WE) soil Pb and then reduced the uptake of Pb, Cd, and Zn by the cabbage compared to the control (CK). The results showed that the level of 300 g P/m(2) soil was the most cost-effective application rate of P fertilizers for reducing Pb availability at the first stage of remediation, and that at this P level, the effect of WE fraction of Pb in the soil decreased by three phosphorus fertilizers followed the order: CMP (79%)>SSP (41%)>PR (23%); Effectiveness on the reduction of Pb uptake by cabbage was in the order: CMP (53%)>SSP (41%)>PR (30%). Therefore our field trial demonstrated that it was effective and feasible to reduce Pb availability in soil and cabbage contaminated by mining tailings using P fertilizers in China and PR would be a most cost-effective amendment.

Biodegradation, Environmental↗
PubMed2004

A comparison of the sensitivity of stream benthic community indices to effects associated with mines, pulp and paper mills, and urbanization.

This study examined the relative sensitivities of seven commonly used indices of stream benthic community composition and three multivariate indices to effects associated with mines, pulp and paper mills, and urbanization. The indices included total abundance, number of taxa, diversity (H'), evenness, Hilsenhoff's biotic index (HBI), the BioMAP water quality index (WQI), the percent model affinity (PMA), and the first three ordination axes from a correspondence analysis. The second objective of the study was to determine the degree of redundancy among these indices. Six data sets (two from each of the three types of development) were used to address the objectives. In each data set, replicate benthic samples were collected from reference areas as well as one or more downstream areas exposed to a point-source or non-point-source discharge. The PMA approach and the ordination axes indicated significant differences between the reference and downstream communities for all six data sets (p < 0.05). With the exception of H', each of the other metrics revealed significant effects associated with one or two, but not all three, types of development. For example, the HBI and WQI indicated significant effects associated with pulp and paper mills and urbanization, but not mining. In all studies, effect sizes (i.e., the standardized difference between means for the reference and exposed areas expressed in units of standard deviations [SDs]) exceeded 2 SDs. However, effect sizes for the PMA and the first or second ordination axis scores were generally larger than effect sizes for the other metrics, indicating that these indices were often the most sensitive indicators of development. In addition, a high degree of redundancy was found among the various metrics, perhaps because the effects were large (i.e., >2 SDs). The greater sensitivity of the ordination axes and the PMA approach emphasizes their value as indices of benthic community composition. As a result, we recommend that any suite of indices used for assessing benthic communities should include these types of multivariate metrics.

Animals↗
PubMed2004

Effects of acid mine drainage on larval Chironomus (Diptera, Chironomidae) measured with the Multispecies Freshwater Biomonitor.

The abandoned Säo Domingos mine (Portugal) offers a pH and metal gradient of acid mine drainage (AMD), and is an ideal model for ecotoxicological studies. Short-term 24-h bioassays with water from the AMD (pH 3.3, 4.4, and 5.5, and control) were performed with fourth instars of Chironomus in the laboratory and in situ (AMD at pH 5.5) in artificial flow-through channels. This was compared to reference water acidified to the respective pH values (acid only). Behavioral stress responses were monitored online with the Multispecies Freshwater Biomonitor (MFB). The exposure to AMD and acid only was in the sublethal range (mortality 0-20%). The use of MFB chambers did not affect survival. Stress behavior of Chironomus consisted mainly of decreased locomotory activity in AMD and increased activity in acid-only tests, indicating that the metals in the AMD played a role as stress factor. Field exposure in the AMD mixing zone (pH 5.5) generated similar activity as in the corresponding laboratory exposure.

Acids↗
PubMed2004

Using artificial streams to assess the effects of metal-mining effluent on the life cycle of the freshwater midge (Chironomus tentans) in situ.

In 2002, we developed an in situ life-cycle bioassay with Chironomus tentans in artificial streams to evaluate the effects of a complex metal mine effluent under ambient environmental conditions. The bioassay was tested in the field using effluent from the Copper Cliff Waste Water Treatment Plant at INCO (Sudbury, ON, Canada). Chironomus tentans were exposed throughout the life cycle to 45% Copper Cliff effluent, which is the average effluent concentration measured in Junction Creek (ON, Canada), the natural receiving environment. Chironomus tentans in the effluent treatment exhibited reduced survival (p = 0.001), reduced total emergence (p = 0.001), increased time-to-emergence (p = 0.001), and reduced hatching success (p = 0.001) relative to animals in the reference water treatment. Chironomus tentans in the effluent treatment were not significantly different from the reference in terms of growth, sex ratio, number of egg cases/female, and number of eggs/egg case. This research showed how a life-cycle bioassay could be used in situ to assess metal mine effluent effects on a benthic invertebrate.

Animals↗
PubMed2004

Wastewater treatment polymers identified as the toxic component of a diamond mine effluent.

The Ekati Diamond Mine, located approximately 300 km northeast of Yellowknife in Canada's Northwest Territories, uses mechanical crushing and washing processes to extract diamonds from kimberlite ore. The processing plant's effluent contains kimberlite ore particles (< or =0.5 mm), wastewater, and two wastewater treatment polymers, a cationic polydiallydimethylammonium chloride (DADMAC) polymer and an anionic sodium acrylate polyacrylamide (PAM) polymer. A series of acute (48-h) and chronic (7-d) toxicity tests determined the processed kimberlite effluent (PKE) was chronically, but not acutely, toxic to Ceriodaphnia dubia. Reproduction of C. dubia was inhibited significantly at concentrations as low as 12.5% PKE. Toxicity identification evaluations (TIE) were initiated to identify the toxic component of PKE. Ethylenediaminetetraacetic acid (EDTA), sodium thiosulfate, aeration, and solid phase extraction with C-18 manipulations failed to reduce PKE toxicity. Toxicity was reduced significantly by pH adjustments to pH 3 or 11 followed by filtration. Toxicity testing with C. dubia determined that the cationic DADMAC polymer had a 48-h median lethal concentration (LC50) of 0.32 mg/L and 7-d median effective concentration (EC50) of 0.014 mg/L. The anionic PAM polymer had a 48-h LC50 of 218 mg/L. A weight-of-evidence approach, using the data obtained from the TIE, the polymer toxicity experiments, the estimated concentration of the cationic polymer in the kimberlite effluent, and the behavior of kimberlite minerals in pH-adjusted solutions provided sufficient evidence to identify the cationic DADMAC polymer as the toxic component of the diamond mine PKE.

Acrylic Resins↗
PubMed2005

Biofilm formation by algae as a mechanism for surviving on mine tailings.

Photosynthetic biofilms successfully colonize the sediments of a mine tailings reservoir (Guanajuato, Mexico) despite the high metal concentrations that are present. To elucidate the mechanisms of biofilm survival despite metal ores, experiments were performed to evaluate the response of seminatural biofilms to Cu, Zn, and a combination of both metals at concentrations observed in the field. The biofilms were composed mostly of the chlorophyte Chlorococcum sp. and the cyanobacterium Phormidium sp., and their response to the two added metals was described by measurements of extracellular polymeric substances (EPS) and in vivo fluorescence. The photosynthetic efficiency and the minimal chlorophyll fluorescence of dark-adapted cells were measured by multiwavelength pulse amplitude-modulated fluorometry. The photosynthetic efficiency of light-adapted cells (phi(PSII)) also was measured. Metal exposure increased the EPS production of biofilms, as visualized with confocal laser-scanning microscopy. Extracellular polymeric substances enhanced the extracellular metal accumulation from the first day of metal exposure. Metals provoked changes in the relative abundance of the dominant taxa because of a species-specific response to the metals when added individually. Metals affected the phi(PSII) less than the total biomass, suggesting ongoing activity of the surviving biofilms. Survival of individual biofilm photosynthetic cells was found to resume from the embedding in the mucilaginous structure, which immobilizes the metals extracellularly. The survival of biofilms under mixed-metal exposure has practical applications in the remediation of mine tailings.

Biodegradation, Environmental↗
PubMed2006

Evaluation of genotoxic effects of heavy metals and arsenic in wild nestling white storks (Ciconia ciconia) and black kites (Milvus migrans) from southwestern Spain after a mining accident.

Studies of birds from Doñana (southwestern Spain) after the Aznalcóllar mining accident (April 1998) have reported high levels of genetic damage when compared to conspecifics from reference areas. However, potential relationships between DNA damage and metal pollution have not yet been reported. The aim of the present study was to investigate the current levels of Zn, Pb, As, Cu, and Cd and to determine if they were associated with the genetic damage observed in free-living, nestling white storks (Ciconia ciconia) and black kites (Milvus migrans) born in the Doñana area after the mining spill. Blood concentrations of heavy metals and of As were quantified and DNA damage (comet assay) was determined in 258 storks and 132 kites monitored during a four-year period (1999-2002). Correlations between these elements and genetic damage varied between species and throughout years within species. Some elements did not show any relationship with DNA damage (e.g., Pb), whereas others had a significant correlation (e.g., As in storks, and Cu and Cd in kites) or only marginal statistical effects (e.g., Zn and Cd in storks, and As in kites) in some years but not in others. These results suggest that nestling white storks and black kites were affected, in part, by the elements studied, but they alone do not satisfactorily explain the observed DNA damage. Moreover, our results show that species-specific differences should be carefully considered when planning schemes for pollution monitoring, and highlight the need for including the temporal scale into the study of the pollutants effects in the wild.

Animals↗