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PubMed2001

Resistance to copper toxicity in populations of the earthworms Lumbricus rubellus and Dendrodrilus rubidus from contaminated mine wastes.

Two arsenic and heavy metal-contaminated mine spoil sites, at Carrock Fell, Cumbria, United Kingdom, and Devon Great Consols Mine, Devon, United Kingdom, have been found to support populations of the earthworms Lumbricus rubellus Hoffmeister and Dendrodrilus rubidus (Savigny). Lumbricus rubellus and D. rubidus collected from the Devon site and an uncontaminated site were kept for 28 d in uncontaminated soil and in soil containing 750 mg/kg CuCl2, the state of the specimens being recorded using a semiquantitative assessment of earthworm health (condition index). The condition index remained high for all specimens except those of L. rubellus and D. rubidus from uncontaminated sites, which displayed 100% mortality. Bioavailability of Cu in the soils from one uncontaminated and two contaminated sites and in the uncontaminated soil treated with CuCl2 was determined using sequential extraction. Soils from Devon Great Consols had the greatest availability of Cu, Carrock Fell the lowest. Total tissue Cu for L. rubellus and D. rubidus from the contaminated sites did not change significantly for each species during the experiment. Total tissue concentrations of Cu for L. rubellus and D. rubidus from uncontaminated sites increased significantly during the first 7 d, after which mortality was 90%, making it impossible to continue the analysis.

Animals↗
PubMed1983

Fatality rates and regulatory policies in bituminous coal mining, United States, 1959-1981.

In the eleven years prior to the passage of the Federal Coal Mine Health and Safety Act of 1969, fatality rates changed little for underground miners and were increasing for surface miners. Following implementation of the 1969 Act, both rates decreased. Beginning in 1979, and continuing into the first six months of 1982, both rates increased. These associations suggest that current relaxation of regulations and policies for coal mine safety are unwarranted.

Accident Prevention↗
PubMed1991

Costs and benefits of implementing child survival services at a private mining company in Peru.

Costs and savings of child health services were studied in a private mining company in Peru. Despite considerable outlays for medical services, few children under age 5 were vaccinated, and half of their illnesses went untreated. Children who were attended at the company clinic usually received unnecessary medication. As a result of the study, the company hired additional staff to provide integrated maternal-child preventive health care and family planning and contracted for intensive training and periodic on-site supervision. In less than 2 years, vaccination coverage reached 75%, and virtually all children under age 1 were enrolled in growth monitoring. Prescriptions were reduced by 24%, including a 67% drop in antimicrobials. The cost of the new services was $13,200 for the first 2 years. Approximately $6800 has been saved in pharmaceuticals prescribed for respiratory infection and diarrhea. Recently, two more mines adopted maternal and child health and family planning services. It is hoped that cost-benefit arguments will encourage other companies to incorporate aggressive child survival measures into their health plans.

Child Health Services↗
PubMedDate not supplied

Sources of salinity near a coal mine spoil pile, north-central Colorado.

A small (1 km2) salt-affected stream drainage on the High Plains north of Denver, Colorado was sampled to determine the near-surface dispersion of soluble salts and metals from low-sulfur coal mining waste (spoil). Surface waters collected along the 0.8-km stream reach, and aqueous leachates of spoil and naturally saline local soil, were analyzed for chemical constituents and sulfur isotopes. In this semiarid setting with abundant carbonate-bearing surficial sediments, the limited, mildly acidic drainage from the spoil pile is quickly neutralized, restricting the mobility of many elements. However, some spoil-derived constituents were clearly traceable within the upper 0.4 km of the stream reach. Spoil leachates and surface water near the spoil pile have distinctive compositions of major anions and cations, and elevated levels of dissolved nitrate compared with downstream waters. Spoil-derived sulfate was traceable because it has generally positive values of delta34S that contrasted with generally negative values of delta34S in soil leachates and evaporite salts from the surrounding area. Spatial-chemical sampling of surface water showed an abrupt increase in dissolved U, Se, B, Li, and Mn in the lower 0.4 km of the stream reach where shallow ground water from surrounding irrigated fields contributed to surface flow. The downstream evolution of surface water chemistry and sulfur isotopic composition is consistent with mixing between spoil-affected upstream water and irrigation-return water. The methods described should be applicable at other sites in similar settings where the environmental effect of low-sulfur coal mining waste must be assessed and where access to samples of shallow ground water is limited.

Coal↗
PubMedDate not supplied

Cottongrass effects on trace elements in submersed mine tailings.

Phytostabilization may limit the leakage of metals and As from submersed mine tailings, thus treatment of acid mine drainage with lime could be reduced. Tall cottongrass (Eriophorum angustifolium Honckeny) and white cottongrass (E. scheuchzeri Hoppe) were planted in pots with unlimed (pH 5.0) and limed (pH 10.9) tailings (containing sulfides) amended with sewage sludge (SS) or a bioashsewage sludge mixture (ASM). Effects of the amendments on plant growth and plant element uptake were studied. Also, effects of plant growth on elements (Cd, Cu, Pb, Zn, and As), pH, electrical conductivity (EC), and concentrations of SO4(2-), in the drainage water as well as dissolved oxygen in tailings, were measured. Both plant species grew better and the shoot element concentrations of white cottongrass were lower in SS than in ASM. Metal concentrations were lowest in drainage water from limed tailings, and plant establishment had little effect on metal release, except for an increase in Zn levels, even though SO4(2-) levels were increased. In unlimed tailings, plant growth increased SO4(2-) levels slightly; however, pH was increased and metal concentrations were low. Thus, metals were stabilized by plant uptake and high pH. Amendments or plants did not affect As levels in the drainage water from unlimed tailings. Thus, to reduce the use of lime for stabilizing metals, phytostabilization with tall cottongrass and white cottongrass on tailings is a sound possibility.

Arsenic↗
PubMedDate not supplied

Soil and plant selenium at a reclaimed uranium mine.

Selenium (Se) associated with reclaimed uranium (U) mine lands may result in increased food chain transfer and water contamination. To assess post-reclamation bioavailability of Se at a U mine site in southeastern Wyoming, we studied soil Se distribution, dissolution, speciation, and sorption characteristics and plant Se accumulation. Phosphate-extractable soil Se exceeded the critical limit of 0.5 mg/kg in all the samples, whereas total soil Se ranged from a low (0.6 mg/kg) to an extremely high (26 mg/kg) value. Selenite was the dominant species in phosphate and ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extracts, whereas selenate was the major Se species in hot water extracts. Extractable soil Se concentrations were in the order of KH2PO4 > AB-DTPA > hot water > saturated paste. The soils were undersaturated with respect to various Se solid phases, albeit with high levels of extractable Se surpassing the critical limit. Calcium and Mg minerals were the potential primary solids controlling Se dissolution, with dissolved organic carbon in the equilibrium solutions resulting in enhanced Se availability. Adsorption was a significant (r2 = 0.76-0.99 at P < 0.05) mechanism governing Se availability and was best described by the initial mass isotherm model, which predicted a maximum reserve Se pool corresponding to 87% of the phosphate-extractable Se concentrations. Grasses, forbs, and shrubs accumulated 11 to 1800 mg Se/kg dry weight. While elevated levels of bioavailable Se may be potentially toxic, the plants accumulating high Se may be used for phytoremediation, or the palatable forage species may be used as animal feed supplements in Se-deficient areas.

Adsorption↗
PubMed2005

Effect of water table on willows grown in amended mine tailing.

Survival and growth characteristics of two montane riparian willow species, Geyer willow (Salix geyeriana Andersson) and mountain willow (Salix monticola Bebb), grown in amended fluvial mine tailing were investigated in a greenhouse study. Willow stem cuttings were planted in lysimeters that simulated a 60-cm amended tailing profile with three static water depths (20, 40, and 60 cm) and a fluctuating water table for a total of four water table treatments. Species and water table treatments affected plant biomass and chemical composition of the soil and plant tissue. Mountain willow leaf, stem, and root biomass were 62, 95, and 164% greater, respectively, than for Geyer willow. Averaging across species, the fluctuating water table negatively affected leaf and stem biomass compared with the 20- and 60-cm water table treatments. Manganese was the only metal in plant tissue to strongly respond to water table treatments. Manganese concentrations in mountain willow leaf tissue were approximately twofold higher in the two most saturated water table treatments (20 cm and fluctuating) than in the least saturated water table treatment (60 cm). This trend was consistent with chemical analyses of the growth media, which reflected higher bioavailable Mn in the saturated tailing profile compared with the unsaturated profile. Results from this study indicate that mountain willow is a more vigorous and possibly more metal-tolerant species than Geyer willow when grown in amended mine tailing and that a fluctuating water table negatively affects willow growth.

Adaptation, Physiological↗
PubMed2006

Nutrient and trace element leaching following mine reclamation with biosolids.

Mine reclamation with biosolids increases revegetation success but nutrient addition well in excess of vegetation requirements has the potential to increase leaching of NO3 and other biosolids constituents. A 3-yr water quality monitoring study was conducted on a Pennsylvania mine site reclaimed with biosolids applied at the maximum permitted and standard loading rate of 134 Mg ha(-1). Zero-tension lysimeters were installed at 1-m depth 1 yr before reclamation: three in the biosolids application area, one in a control area (no biosolids). Before reclamation, all water samples had pH in the range 4.7 to 6.2, acidity < 20 mg L(-1), and very low levels of all other measured parameters. Following reclamation, percolate water in the biosolids-treated area had lower pH and greater acidity than the control area. Acidity was greatest during the first winter following biosolids application, decreased during the spring, and showed a similar pattern but with much smaller concentrations the second year. Maximum first- year leachate NO3 concentrations were approximately 300 mg L(-1) and half as large the second year. Estimated inorganic N leaching loss during the first 2 yr after biosolids application was 2327 kg N ha(-1). Aluminum, Mn, Cu, Ni, Pb, and Zn followed similar leaching patterns as did acidity, and their mobilization appeared to be the result of the increased acidity. These results indicate that large applications of low-C/N-ratio biosolids could negatively impact area water quality and that biosolids reclamation practices should be modified to reduce this possibility.

Environmental Monitoring↗
PubMed2006

Risk assessment test for lead bioaccessibility to waterfowl in mine-impacted soils.

Due to variations in soil physicochemical properties, species physiology, and contaminant speciation, Pb toxicity is difficult to evaluate without conducting in vivo dose-response studies. Such tests, however, are expensive and time consuming, making them impractical to use in assessment and management of contaminated environments. One possible alternative is to develop a physiologically based extraction test (PBET) that can be used to measure relative bioaccessibility. We developed and correlated a PBET designed to measure the bioaccessibility of Pb to waterfowl (W-PBET) in mine-impacted soils located in the Coeur d'Alene River Basin, Idaho. The W-PBET was also used to evaluate the impact of P amendments on Pb bioavailability. The W-PBET results were correlated to waterfowl-tissue Pb levels from a mallard duck [Anas platyrhynchos (L.)] feeding study. The W-PBET Pb concentrations were significantly less in the P-amended soils than in the unamended soils. Results from this study show that the W-PBET can be used to assess relative changes in Pb bioaccessibility to waterfowl in these mine-impacted soils, and therefore will be a valuable test to help manage and remediate contaminated soils.

Animals↗
PubMed2007

Passive treatment of acid mine drainage in bioreactors using sulfate-reducing bacteria: critical review and research needs.

Acid mine drainage (AMD), characterized by low pH and high concentrations of sulfate and heavy metals, is an important and widespread environmental problem related to the mining industry. Sulfate-reducing passive bioreactors have received much attention lately as promising biotechnologies for AMD treatment. They offer advantages such as high metal removal at low pH, stable sludge, very low operation costs, and minimal energy consumption. Sulfide precipitation is the desired mechanism of contaminant removal; however, many mechanisms including adsorption and precipitation of metal carbonates and hydroxides occur in passive bioreactors. The efficiency of sulfate-reducing passive bioreactors is sometimes limited because they rely on the activity of an anaerobic microflora [including sulfate-reducing bacteria (SRB)] which is controlled primarily by the reactive mixture composition. The most important mixture component is the organic carbon source. The performance of field bioreactors can also be limited by AMD load and metal toxicity. Several studies conducted to find the best mixture of natural organic substrates for SRB are reviewed. Moreover, critical parameters for design and long-term operation are discussed. Additional work needs to be done to properly assess the long-term efficiency of reactive mixtures and the metal removal mechanisms. Furthermore, metal speciation and ecotoxicological assessment of treated effluent from on-site passive bioreactors have yet to be performed.

Acids↗
PubMed2006

Biological treatment of heavy metals in acid mine drainage using sulfate reducing bioreactors.

The uncontrolled release of acid mine drainage (AMD) from abandoned mines and tailing piles threatens water resources in many sites worldwide. AMD introduces elevated concentrations of sulfate ions and dissolved heavy metals as well as high acidity levels to groundwater and receiving surface water. Anaerobic biological processes relying on the activity of sulfate reducing bacteria are being considered for the treatment of AMD and other heavy metal containing effluents. Biogenic sulfides form insoluble complexes with heavy metals resulting in their precipitation. The objective of this study was to investigate the remediation of AMD in sulfate reducing bioreactors inoculated with anaerobic granular sludge and fed with an influent containing ethanol. Biological treatment of an acidic (pH 4.0) synthetic AMD containing high concentrations of heavy metals (100 mg Cu(2+)l(-1); 10 mg Ni(2+)l(-1), 10 mg Zn(2+)l(-1)) increased the effluent pH level to 7.0-7.2 and resulted in metal removal efficiencies exceeding 99.2%. The highest metal precipitation rates attained for Cu, Ni and Zn averaged 92.5, 14.6 and 15.8 mg metal l(-1) of reactor d(-1). The results of this work demonstrate that an ethanol-fed sulfidogenic reactor was highly effective to remove heavy metal contamination and neutralized the acidity of the synthetic wastewater.

Acids↗
PubMed2006

Physiological strain of miners at hot working places in German coal mines.

As the percentage of shifts in hot working conditions in German Coal mines had increased to more than 50% during the last decade, a study was carried out to record the physiological strain of miners. Thirty-eight miners participated during 125 shifts. Heart rate and rectal temperature were measured continuously. Sweat losses as well as food and fluid uptake were estimated from measurements before and after shifts. During all shifts mean heart rates resulted in 102.8 min(-1), mean rectal temperature was 37.7 degrees C. Mean sweat loss per shift was 3,436 g; mean sweat rates resulted in 494 g/h. Rehydration during the shift at high climatic stress decreased to about 60% of sweat losses. In order to state the organizational frame of work at hot working places in German coal mines, the main features of regulations of work at hot working places are presented.

Adult↗
PubMed1993

Blood lead concentrations of Swedish preschool children in a community with high lead levels from mine waste in soil and dust.

The lead concentration in capillary blood was investigated in 49 preschool children (0.7-7.4 years of age) visiting a day-care center in a Swedish community with high lead contamination from mining and milling in soil and dust in populated areas [up to 1400 and 14,000 micrograms.g-1 (6.76 and 67.63 mumol.g-1) of dry weight, respectively]. The blood lead levels were examined twice (in April and in September) in 33 of the children. The lead levels were low on both sampling occasions [arithmetic mean 31 (SD 13, median 30, range 13-79) micrograms.l-1, ie, arithmetic mean 0.15, (SD 0.06, median 0.14, range 0.06-0.38) mumol.l-1]. Whereas children up to four years of age showed significantly increased levels from April to September, a significant decrease was seen in older children. The level of lead in soil at home, gender, smoking habits at home, and estimated level of hand-to-mouth activity did not appear as strong determinants of lead in blood. The results indicate that lead from mine waste in soil and dust fallout does not constitute a significant health hazard for preschool children in Falun.

Child↗
PubMed1989

Nonmalignant respiratory disease among hematite mine workers in China.

The mortality risk of nonmalignant respiratory disease among hematite workers in the Longyan and Taochong mines of China was investigated in a retrospective cohort study covering the period 1970-1982. The cohort was limited to men and consisted of 5406 underground miners, of whom 1335 (25%) were diagnosed as having silicosis. Among those with silicosis, 560 (42%) were diagnosed as having silicotuberculosis. Among the 490 underground miners who died, 278 (57%) died of nonmalignant respiratory disease. The relative risk for death due to nonmalignant respiratory disease for stage III silicotics compared to nonsilicotics was almost 100-fold. High dust exposure was associated with a statistically significant increase in risk of death due to nonmalignant respiratory disease (relative risk 5.3). The relative risk associated with jobs with high dust exposure before the introduction of industrial hygiene controls was 7.7, and the corresponding value for after their introduction was 2.3. There is a need for continued close monitoring of industrial hygiene in these mines.

Adult↗
PubMed1985

Cancer incidence among workers exposed to radon and thoron daughters at a niobium mine.

The aim of this study was to investigate the incidence of cancer among 318 male employees of a niobium mining company which was only operated between 1951 and 1965. Many of the workers, especially underground miners, were exposed to the daughters of radon and thoron and also to thorium. The accumulated doses to the workers from short-lived radon and thoron daughters in the mine atmosphere were assessed to be relatively low; up to 300 working-level months. During the follow-up period 1953-1981, 24 new cases of cancer were observed compared to an expected number of 22.8. Twelve cases of lung cancer had occurred versus 3.0 expected. Among the 77 miners, 9 cases of lung cancer were observed against 0.8 expected. Associations between the occurrence of lung cancer and exposure to alpha radiation and smoking were found. For the radon and thoron daughter exposure, about 50 excess cases per million person-years at risk per working-level month were observed.

Adult↗
PubMed1976

[The struggle against dust in the Belgian coal mines. Situation at the beginning of 1976].

The present communication gives a general view of the methods of dust control in the Belgian coal mines at the beginning of 1976. The statistical data received from the mines are presented in tabular form. The length and the output of coal faces treated by the classical methods of pre-spraying of the wall, wet cutting, water infusion and wet pneumatic picks, are given separately; in some cases two or more of these technics are used together on the same coal face. The number of stone drivages in which different methods of dust control are used, is also given.

Air Pollutants↗
PubMed1999

Heat stress and flame protective clothing in mine rescue brigadesmen: inter- and intraindividual variation of strain.

A climatic exposure was conducted for the 52 rescue brigadesmen of a mine while they wore flame protective clothing. We looked for individual parameters allowing prediction of tolerated exposure times in the climate tested. Of all individual parameters, only body temperature at the end of the Stoklossa heat tolerance test and physical fitness showed significant influence on the tolerated exposure time, although not very strongly. Age, body mass, and Body Mass Index showed no significant influence on the tolerated exposure time. It was found during a longitudinal study that the tolerance time within the climate for four subjects showed considerable variations, and so it was decided neither to take the result of the heat tolerance test as admittance criterion for the mine rescue service nor to perform a ranking of brigadesmen with respect to heat tolerance by this test.

Adult↗
PubMed2000

[Characteristics of occupational factors and the workers' health state in strip mining of tungsten and molybdenum ores].

Ores extraction in Tyrnaouz tungsten-molybdenum pool is conducted in specific climate and geologic conditions that considerably influence aimbient dust levels in open pit and mining workplaces, levels of exhaust, radioactive and explosive gases and lower those levels to the MACs or below. With regular mining equipment used, noise and vibration levels are the same as at other open pits. The stated occupational hazards could induce vibration disease and deafness in the workers.

Adult↗