Concentrations Of Hazardous Metals Research Articles

Experimental and theoretical investigation of the treatment of Cu-rich Acid Mine Drainage using iron oxide magnetic nanoparticles

Acid Mine Drainage (AMD) is a significant environmental problem in the mining industry due to its high concentration of hazardous metals and metalloids, sulfate compounds, and low pH levels. Despite the attention that iron oxide magnetic nanoparticles (MNP) have received for AMD remediation, there is still a lack of understanding of the physicochemical mechanisms behind their non-specific adsorption, particularly in distinct variations of AMD, such as Cu-rich AMD. In this study, we synthesized, characterized, and applied MNP to the two-step treatment of Cu-rich AMD. The chemical and physical properties of the MNP and magnetically separated sludges after AMD treatment are characterized. Additionally, the chemical species adsorbed onto the MNP, the oxidation state of the resultant sludge after Cu-rich AMD treatment, and the short-range ordering of metal contaminant species on the surface of the MNP are identified. Finally, first-principles calculations using Density Functional Theory were conducted to understand how different Cu ion species adsorb to the MNP surface depending on the pH of the Cu-rich AMD. The bonding between MNP and Cu species occurs primarily through metal cation-oxygen bonds on the surface of MNP, and this bonding is influenced by the pH of the solution. A combination of experimental and theoretical approaches was the key to arrive at this conclusion. This information can aid in the comprehension of how metal contaminants adhere to the surfaces of MNP and in the precise engineering of these nanoparticles.

Cadmium, lead, and mercury in two commercial squid species from the north Adriatic Sea (central Mediterranean): contamination levels and health risk assessment

In this study, lead (Pb), cadmium (Cd), and total mercury (Hg) concentrations in European squids (Loligo vulgaris) and flying squids (Todarodes sagittatus) from the northern Adriatic Sea (Italy) were analyzed. The risk of the Italian population being exposed to potentially hazardous metal concentrations through the consumption of these products was also assessed. Compared to European squids, flying squids showed three times higher total Hg concentrations and one hundred times higher Cd concentrations to the point that more than 6 and 25% of the samples exceeded the maximum Hg and Cd limits established by the current legislation. From the evaluation of dietary exposure levels, it emerged that the consumption of flying squids was associated with the highest Pb intake by children and, consequently, with the lower margin of exposure values in relation to the risk of neurotoxicity (margin of exposure=33). Consumption of flying squids, especially by children, was also associated with higher intakes of Cd, inorganic, and methyl-Hg, which, respectively, accounted for 156, 113, and 23% of the tolerable weekly intakes established for these contaminants at European level. The obtained results raise concern and it may be necessary to provide specific dietary advice on the moderate dietary consumption of some cephalopod species, especially to the youngest and most vulnerable segment of the population. However, besides the highly conservative deterministic method adopted in this study, a refined consumer exposure assessment should be performed through the probabilistic methodology, which is more suitable to represent the real exposure scenario.

Heavy Metals in Tattoo Inks: Developing an Analytical Methodology for Accessing Customer Safety

AbstractTattoo inks contains metal salts or different types of coloured organic molecules. To the best of our knowledge, there are few data on the concentration of hazardous metals in tattoo inks sold online or by makeshift hawkers. The aim of this work was to organize an analytical methodology to ensure the simultaneous quantitative determination of 18 elements in a complex matrix, like inks for tattooing, by Inductively Coupled Plasma Mass Spectrometry. The total concentrations of metals in the 16 analysed tattoo ink samples ranged from 0.060 to 16.9 g kg−1. Zinc is the most present metal in the samples, in fact it is in the range 3.4–13882 mg kg−1. In three of the 16 samples the zinc concentrations exceed those required by legislation (2000 μg g−1). Cr concentration in all cases is higher than allowed (0.5 μg g−1). The weight loss by heating the ink samples to 105 °C and, subsequently, to 550 °C showed that in all cases the volatile component (ethanol, solvents, etc.) varies from 48 (Wh1) to 95 %, while the percentages of the residue at 550 °C ranged from 0 % (BK0) to 47 % (Wh1). Considering values limit, four of analysed samples should not be used by tattoo artists.

Residual impacts of a wildland urban interface fire on urban particulate matter and dust: a study from the Marshall Fire

The impacts of wildfires along the wildland urban interface (WUI) on atmospheric particulate concentrations and composition are an understudied source of air pollution exposure. To assess the residual impacts of the 2021 Marshall Fire (Colorado), a wildfire that predominantly burned homes and other human-made materials, on homes within the fire perimeter that escaped the fire, we performed a combination of fine particulate matter (PM2.5) filter sampling and chemical analysis, indoor dust collection and chemical analysis, community scale PurpleAir PM2.5 analysis, and indoor particle number concentration measurements. Following the fire, the chemical speciation of dust collected in smoke-affected homes in the burned zone showed elevated concentrations of the biomass burning marker levoglucosan (medianlevo = 4147 ng g−1), EPA priority toxic polycyclic aromatic hydrocarbons (median Σ16PAH = 1859.3 ng g−1), and metals (median Σ20Metals = 34.6 mg g−1) when compared to samples collected in homes outside of the burn zone 6 months after the fire. As indoor dust particles are often resuspended and can become airborne, the enhanced concentration of hazardous metals and organics within dust samples may pose a threat to human health. Indoor airborne particulate organic carbon (median = 1.91 μg m−3), particulate elemental carbon (median = .02 μg m−3), and quantified semi-volatile organic species in PM2.5 were found in concentrations comparable to ambient air in urban areas across the USA. Particle number and size distribution analysis at a heavily instrumented supersite home located immediately next to the burned area showed indoor particulates in low concentrations (below 10 μg m−3) across various sizes of PM (12 nm–20 μm), but were elevated by resuspension from human activity, including cleaning.Graphical

Effect of SiO2/Al2O3 Ratio on the Crystallization and Heavy Metal Immobilization of Glass Ceramics Derived from Stainless Steel Slag

This study investigated the effects of the SiO2/Al2O3 mass ratio on the glass stability, crystallization and heavy metal immobilization of glass ceramics derived from stainless steel slag (SSS). When the SiO2/Al2O3 mass ratio decreased from 11.2 to 4.2, the glass stability and the depolymerization degree of the parent glass increased from 2.13 to 2.40 and subsequently decreased to 2.31. The predominant crystal phase of the resulting glass–ceramics changed from pyroxene and diopside to wollastonite, pyroxene, and diopside as the crystallization temperature of samples increased from 800°C to 860°C. The heavy metals, Cr and Mn, from SSS cured in the spinel of glass–ceramics, whereas the hazardous metal Ni was primarily found in pyroxene (CaNiSi2O6). In addition, the leached concentrations of hazardous metals, Ni, Mn, and Cr ions, in glass-ceramics were far below the national standard. The results showed that it is possible and safe to turn SSS into eco-friendly glass-ceramic.

Intrinsic characteristics of coal combustion residues and their environmental impacts: A case study for Bangladesh

This study has focused on petrography, geochemistry, radiochemical, and leaching properties of coal combustion residues (CCRs), their leachates and nearby waters from the Barapukuria coal-fired power-plant (BCPP) to evaluate the potential environmental impacts and human health hazards for the first in Bangladesh. The CCRs, used in this study are predominantly comprised of Al-Si-rich glassy materials (94.8%) followed by crystallites (3.6%), notably quartz, mullite, and spinel with rock-fragments (0.3%); and un-burnt organic constituents (1.3%) such as anisotropic coke (0.8%) and slightly altered inertinite (0.5%). Hematite, magnetite, cristobalite, monazite, zircon, rutile, tourmaline and sillimanite were also identified as trace minerals. Elemental contents are found to be elevated (2.1–14.2 times) in the fly ash (FA) and bottom ash (BA), as compared to world coal-ash average with the exceptions of Ni in FA; and of Zn, As, Cu, and Hg in BA. The sum of detected rare earth elements is significantly high as compared to the world FA, Indian and Chinese ash residues. The specific activities of CCR are comparatively higher by a factor of 3.7 (226Ra) to 6.2 (232Th) than those of the world average. The examined spheres, particles, and agglomerates of FA are predominantly comprised of C, Al, and Si as major while, K, Ca, Mg, Fe, W and Ti as minor elements. On the other hand, extractable amounts of soluble potentially toxic elements in FA leachates are 7.7% for Se, 4.8% for Zn, and in BA 5.7% for As and 3.1% for Se and others are < 1%. Metals are substantially released from FA in the range of 8.5 (for Cr) to 9650 (for Zn) ppb and 0.002% (for Cr) −7.7% (for Se), while from BA below detection level (for Cr) to 940 ppb (for Mn). The concentration of hazardous metals in the discharged waste water and water ash pond were higher than those were found in nearby pond- and ground-water sources around the BCPP. Ecological and radiological risk indices suggest moderate-risk derived from FA and low-risk from BA.

The use of contaminated soil and lithium slag for the production of sustainable lightweight aggregate

The contaminated soil (CS) and lithium slag (LS) contain amounts of hazardous ingredients which may move into the ground water and local cropland. In order to prevent CS and LS from damaging the environment, an investigation on the utilization of CS and LS for the production of lightweight aggregate (LWA) was presented in this article. The basic properties of LWA were evaluated. Furthermore, the crystalline phases of the produced LWA were analyzed, and the microstructure of LWA was analyzed by X-ray micro-tomography. The experimental results showed that the LWA produced from the CS and LS had good performances with density of 0.5–1.5 g/cm3 and compressive strength of 1.0–8.7 MPa, which met the required standard of LWA. Meanwhile, it can be revealed that the LS can reduce the sintering temperature of LWA, thus exhibiting low energy consumption. The analysis of crystal phases indicated that the mineral compositions of LWA contained spinel phases, which provided a possibility for the solidification of heavy metals. In addition, the evaluation of environmental effect revealed the leaching concentrations of hazardous metals were much lower than the critical limits of nonhazardous materials. Finally, the economic benefits were analyzed in the entire production process of LWA, which indicated that using CS and LS to produce LWA can lower the raw material cost by 85–98%. This work will create a more eco-friendly and economical method for the management of solid wastes (CS and LS). Meanwhile, this study can provide theoretical basis for the sustainable production of LWA.

Urban Soils and Road Dust—Civilization Effects and Metal Pollution—A Review

Urban soils have been changed much by human impacts in terms of structure, composition and use. This review paper gives a general introduction into changes from compaction, mixing, water retention, nutrient inputs, sealing, gardening, and pollution. Because pollutions in particular have caused concerns in the past, metal pollutions and platinum group metal inputs have been treated in more detail. Though it is not possible to cover the entire literature done on this field, it has been tried to give examples from all continents, regarding geochemical background levels. Urban metal soil pollution depends on the age of the settlement, current emissions from traffic and industry, and washout. It seems that in regions of high precipitation, pollutants are swept away to the watershed, leaving the soils less polluted than in Europe. Health hazards, however, are caused by ingestion and inhalation, which are higher in 3rd world countries, and not by concentrations met in urban soils as such; these are not treated within this paper in detail. With respect to pollutants, this paper is focused on metals. Contrary to many reviews of the past, which mix all data into one column, like sampling depth, sieved grain sizes, digestion and determination methods, these have been considered, because this might lead to considerable interpretation changes. Because many datasets are not Gaussian distributed, medians and concentration ranges are given, wherever possible. Urban dust contains about two to three fold the hazardous metal concentrations met in urban soils. Some data about metal mobilities obtained from selective and sequential leaching procedures, are also added. Soil compaction, pollution, sealings and run-offs cause stress situations for green plants growing at roadside locations, which is discussed in the Section 5. Environmental protection measures have led to decrease metal pollutions within the last decade in many places.

The Removal of Residual Concentration of Hazardous Metals in Wastewater from a Neutralization Station Using Biosorbent-A Case Study Company Gutra, Czech Republic.

This article deals with the possibility of using a biosorbent in the form of a mixture of cones from coniferous trees to remove the residual concentration of hazardous metals contained in hazardous waste, which is disposed of in a neutralization station. The efficiency of the tested biosorbent in removing Ni, Zn, Cu, and Fe was monitored here. Laboratory research was carried out before the actual testing of the biosorbent directly in the operation of the neutralization station. With regard to the planned use of the biosorbent in the operational test, the laboratory experiments were performed in a batch mode and for the most problematic metals (Ni and Zn). The laboratory tests with real wastewater have shown that the biosorbent can be used to remove hazardous metals. Under the given conditions, 96% of Ni and 19% of Zn were removed after 20 min when using NaOH activated biosorbent with the concentration of 0.1 mol L−1. The inactivated biosorbent removed 93% of Ni and 31% of Zn. The tested biosorbent was also successful during the operational tests. The inactivated biosorbent was applied due to the financial costs. It was used for the pre-treatment of hazardous waste in a preparation tank, where a significant reduction in the concentration of hazardous metals occurred, but the values of Ni, Cu, and Zn still failed to meet the emission limits. After 72 h, we measured 10 mg L−1 from the original 4,056 mg L−1 of Ni, 1 mg L−1 from the original 2,252 mg L−1 of Cu, 1 mg L−1 from the original 4,020 mg L–1 of Zn, and 7 mg L−1 from the original 1,853 mg L−1 of Fe. However, even after neutralization, the treated water did not meet the emission limits for discharging into the sewer system. The biosorbent was, therefore, used in the filtration unit as well, which was placed in front of the Parshall flume. After passing through the filtration unit, the concentrations of all the monitored parameters were reduced to a minimum, and the values met the prescribed emission limits. The biosorbent was further used to thicken the residual sludge in the waste pre-treatment tank, which contributed to a significant reduction in the overall cost of disposing of residual hazardous waste. This waste was converted from liquid to solid-state.

Nickel tolerance and toxicity mechanisms in the halophyte Sesuvium portulacastrum L. as revealed by Ni localization and ligand environment studies.

Halophytes are able to tolerate relatively high concentrations of hazardous metals in a growing substrate, what makes them suitable candidates for phytoremediation of metal-contaminated soils. In this work, we aimed to study the physiological responses of the halophyte Sesuvium portulacastrum L. to Ni, with main focus on Ni localization, compartmentation and ligand environment, to decipher Ni tolerance and toxicity mechanisms. Seedlings were grown in hydroponic nutrient solution containing 0, 25, 50 and 100μM Ni as NiCl2 for 3weeks. Ni localization in leaves was assessed by micro-proton-induced X-ray emission (micro-PIXE). Ni ligand environment was studied by Ni K-edge X-ray absorption near edge structure (XANES). In addition, Ni-soluble, weakly bound/exchangeable and insoluble leaf tissue fractions were determined by sequential extraction. Results show that S. portulacastrum is able to tolerate up to ~ 500μgg-1 dry weight (DW) of Ni in the shoots without significant growth reduction. At higher Ni concentrations (> 50μM Ni in nutrient solution), chloroses were observed due to the accumulation of Ni in photosynthetically active chlorenchyma as revealed by micro-PIXE. Water storage tissue represented the main pool for Ni storage. Incorporation of Ni into Ca-oxalate crystals was also observed in some specimens, conferring tolerance to high leaf Ni concentrations. The majority of Ni (> 70%) was found in soluble tissue fraction. Ni K XANES revealed Ni bound mainly to O- (55%) and N-ligands (45%). Ni toxicity at higher Ni levels was associated with Ni binding to amino groups of proteins in cytosol of chlorenchyma and increased level of lipid peroxidation. Proline levels also increased at high Ni exposures and were associated with Ni-induced oxidative stress and alteration of water regime.

Assessment of Hazardous Metal Concentrations in Organs of Selected Game Animals in the Natural Environment

The study was conducted to determine the levels of hazardous metals in game animals. A total of eighteen (18) animals which comprised six species of three (3) each from the same location were trapped or hunted and sacrificed. Organs analyzed for hazardous metal levels were skin, liver, kidney and heart using Atomic Absorption Spectrometry and content expressed in mgkg-1. The statistical analysis was done with Genstat (2007). Results obtained showed that all the hazardous metals under study were present in the organs at variable concentrations. Lead: skin (0.18 – 0.46) mgkg-1, liver (0.03 – 0.4) mgkg-1, heart (0.25 – 0.58) mgkg-1 and kidney (0.38 1.12) mgkg-1; Cadmium: skin (0.08 – 0.58) mgkg-1 and kidney (0.09 – 0.7) mgkg-1; Zinc : skin ( 0.46 – 0.66) mgkg-1, liver (90.04 – 0.82) mgkg-1, heart (0.42 – 1.21) mgkg-1 and kidney (0.43 – 1.58) mgkg-1; Copper: skin (6.13 – 12.57) mgkg-1, liver (5.1 – 9.56) mgkg-1, heart (6.89 - 15.15) mgkg-1 and kidney (7.63 – 24.87) mgkg-1; Iron : skin (9.53 – 26.35) mgkg-1, liver (8.07 -28.08) mgkg-1, heart (13.83 - 46.40) mgkg-1 and kidney (12.43 – 47.61) mgkg-1. Iron was highly (p &lt;0.05) deposited in all species of animals in the heart 19.88 mgkg-1, 46.40 mgkg-1, 40.83 mgkg-1, 13.83 mgkg-1 and 41.38 mgkg-1 respectively for civet (Civettictis civeta), antelope (Antilocapra americana), grasscutter (Thryonomys swiderianus), hedgehog (Atelerix albiventris) and bush dog (Speothos venaticus) except the bush rat (Rattus fuscipes) that had its highest deposition (46.71 mgkg-1) in the kidney. Copper was also highly deposited in animals after iron with higher concentrations in heart and kidney. The highest concentration was recorded for bush rat (Rattus fuscipes) (15.15 mgkg-1) in heart and 24.87 mgkg-1 in kidney. Due to bioaccumulation of hazardous metals, care should be taken in patronizing bushmeat obtained from the studied ecosystem since failure could be perilous to the health of consumers as their concentrations are beyond the safe limits for the respective metals. It is further recommended that environmental safety principles for safe disposal of hazardous metals are appropriately carried out.

Hazardous metals emissions from e-waste-processing sites in a village in northern Vietnam

Abstract Inappropriate e-waste-processing operation is a serious issue in developing countries since the early 2000's. Field research was conducted to clarify its influences and diffuse toxic substances in the environment at e-waste-processing sites in a village in northern Vietnam from 2012 to 2014. We investigated surface soil samples collected from e-waste-processing sites, open burning sites, and rice paddy sites. Sediment samples and water samples were also collected from a river that runs through the village. The hazardous metal concentration in soil and river sediment samples indicated that 7 elements (Ca, Cu, Mo, Ni, Pb, Sn, and Zn) had high concentrations as a result of e-waste-processing. Most notably, Pb and Cu had high concentrations in soil samples (Pb: 26–2200 mg/kg, Cu: 22–3000 mg/kg). The results of a multivariate analysis indicated that these 7 elements were closely correlated with e-waste-processing. Concentrations of hazardous metals showed an upward trend where e-waste-processing occurred during the 3-year study period, although it was not significant statistically at present. Open burning activity had a great influence on Cu accumulation, and maximum Cu concentrations increased from 340 mg/kg in 2012–3000 mg/kg in 2014 in soil samples from open-burning sites. There were large differences in the dominant hazardous metal depending on the type of e-waste-processing workshop because hazardous metal composition was influenced by the types of e-waste and the processing procedures. It is necessary to avoid e-waste processing in open-air environment to control emissions of hazardous substances. Especially, open burning should be prohibited.

H emibagrus sp. as a potential bioindicator of hazardous metal pollution in Selangor River.

The spatial distributions of Na, Mg, K, Ca, Cr, Fe, Ni, Cu, Zn, As, Se and Pb in Hemibagrus sp. from Selangor River and a reference site were determined with inductively coupled plasma-mass spectrometer, in comparison to the levels in their surrounding water body and sediments. The results demonstrated significant differences in elemental accumulation pattern in different fish tissues originated from both sites. The variations observed were mainly subjected to their metabolic activities, and also the influence of the surrounding medium. In general, the liver tends to accumulate higher concentration of metals followed by the gills, and muscle tissues. The data also indicate associations between the concentrations of metal contaminants measured in the fish and the levels observed at the sites. The concentrations of hazardous metals As, Se and Pb in all the studied tissues reflect the influence of anthropogenic inputs. This suggests the potential utility of widely available Hemibagrus sp. as a valuable bioindicator of metal pollution in environmental monitoring and assessment.

Recycling of cathode ray tube panel glasses as aggregates of concrete blocks and clay bricks

While the cathode ray tube (CRT) funnel containing lead could be transported to a smelting facility to recover lead, which could be an available option in domestic, a proper technology to recycle a CRT panel must be developed. Thus, it was suggested that CRT panel glass be used as aggregates of concrete blocks and clay bricks. Samples of blocks and bricks were fabricated with CRT powders and tested to measure their strength and absorption rate to determine their qualities, and environmental soundness was determined by measuring the leaching rate of hazardous metals. For concrete blocks, CRT panel glass powders incorporated as aggregates up to 40 % replacing stone powder was proposed as the proper condition for manufacturing blocks. Around 2 % of CRT panel incorporated into clay brick to substitute Kaoline was suggested to fabricate the best quality of clay brick. Results of leaching test met the criteria with much less concentration of hazardous metals, even lead compound containing in the CRT funnel. To conclude, the use of CRT panel powder after crushing it to the proper size as an aggregate of concrete blocks or clay bricks could be one of the appropriate alternatives to recycle for CRT glass waste being generated drastically in a short term.

Bioaccumulation of Heavy Metals in the Mussel Mytilus galloprovincialis in the Changseon area, Korea, and Assessment of Potential Risk to Human Health

From 2008 to 2013, the mussel Mytilus galloprovincialis were collected from a major area of mussel production (Changseon area), which is a designated shellfish-cultivating area for export, located on the southern coast of Korea. The samples were analyzed for mercury (Hg) using a direct Hg analyzer and for other metals, such as cadmium (Cd), lead (Pb), arsenic (As), chromium, copper, nickel, and zinc, using inductively coupled plasma mass spectrometry. The concentrations and bioaccumulation of the heavy metals were determined, and a potential risk assessment was conducted to evaluate their hazards towards human consumption. The concentration and bioaccumulation ratio of Cd were the highest of the three hazardous metals (Cd, Pb, and Hg). The concentrations of hazardous metals in all samples were within the limits set by Korea and other countries. The estimated dietary intake (EDI) was compared to the provisional tolerable daily intake (PTDI) adopted by the Joint FAO/WHO Expert Committee on Food Additives and the U.S. Environmental Protection Agency. The EDIs of all heavy metals tested for mussel samples ranged from 0.01 to 4.99% of the PTDI; the highest value was measured for As. The hazard index (HI) can be used to assess the risk of heavy metal consumption associated with contaminated food. The HI for all samples was far less than 1.0, which indicates that the mussels produced in the Changseon area do not represent an appreciable hazard to humans and are fit for consumption.

Hazardous Metal Pollution in the Republic of Fiji and the Need to Elicit Human Exposure

The fact that hazardous metals do not bio-degrade or bio-deteriorate translates to long-lasting environmental effects. In the context of evidently rapid global industrialization, this ought to warrant serious caution, particularly in developing countries. In the Republic of Fiji, a developing country in the South Pacific, several different environmental studies over the past 20 years have shown levels of lead, copper, zinc and iron in sediments of the Suva Harbor to be 6.2, 3.9, 3.3 and 2.1 times more than the accepted background reference levels, respectively. High levels of mercury have also been reported in lagoon shellfish. These data inevitably warrant thorough assessment of the waste practices of industries located upstream from the estuaries, but in addition, an exposure and health impact assessment has never been conducted. Relevant government departments are duty-bound, at least to the general public that reside in and consume seafood from the vicinities of the Suva Harbor, to investigate possible human effects of the elevated hazardous metal concentrations found consistently in 20 years of surface sediment analysis. Furthermore, pollution of the intermediate food web with hazardous metals should be investigated, regardless of whether human effects are eventually confirmed present or not.

Fast-Scan Deposition-Stripping Voltammetry at Carbon-Fiber Microelectrodes: Real-Time, Subsecond, Mercury Free Measurements of Copper

Elevated concentrations of hazardous metals in aquatic systems are known to threaten human health. Mobility, bioavailability, and toxicity of metals are controlled by chemical speciation, a dynamic process. Understanding metal behavior is limited by the lack of analytical methods that can provide rapid, sensitive, in situ measurements. While electrochemistry shows promise, it is limited by its temporal resolution and the necessity for Hg modified electrodes. In this letter, we apply fast-scan deposition-stripping voltammetry at carbon-fiber microelectrodes for in situ measurements of Cu(II). We present a novel, Hg-free technique that can measure Cu(II) with ppb sensitivity at 100 ms temporal resolution.

Airborne trace metals from coal combustion in Beijing

Prior studies have measured elevated ambient concentrations of hazardous metals in Beijing, attributable to coal combustion. The 2008 Olympic Games led to an intense investment in air pollution controls at the major power plants in the region, accounting for 30% of coal combustion in Beijing. Recently Chinese coal beds have been characterized in the World Coal Quality Index, facilitating the development of trace metal emission factors for Beijing coals. This study quantifies the relative value of the power plant air pollution controls in terms of public health risk from chronic exposure to trace metals. Ambient concentrations from power plants were estimated using an atmospheric dispersion model (CALPUFF), outlining spatial and temporal variations. The following toxic, refractory metals were evaluated for health risk using the USEPA Integrated Risk Information System: antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, nickel, and selenium. Stringent use of power plant air pollution controls significantly reduces population risk, averting a cancer risk of 1 in 5,000. However, other sources of coal combustion, such as industrial and household uses, are more relevant to public health than power plant emissions. Coal washing has potential to reduce the hazard from these diffuse sources and avert a greater number of potential cancer cases.

Validation of Three New Methods for Determination of Metal Emissions Using a Modified Environmental Protection Agency Method 301

Three new methods applicable to the determination of hazardous metal concentrations in stationary source emissions were developed and evaluated for use in U.S. Environmental Protection Agency (EPA) compliance applications. Two of the three independent methods, a continuous emissions monitor-based method (Xact) and an X-ray-based filter method (XFM), are used to measure metal emissions. The third method involves a quantitative aerosol generator (QAG), which produces a reference aerosol used to evaluate the measurement methods. A modification of EPA Method 301 was used to validate the three methods for As, Cd, Cr, Pb, and Hg, representing three hazardous waste combustor Maximum Achievable Control Technology (MACT) metal categories (low volatile, semivolatile, and volatile). The modified procedure tested the methods using more stringent criteria than EPA Method 301; these criteria included accuracy, precision, and linearity. The aerosol generation method was evaluated in the laboratory by comparing actual with theoretical aerosol concentrations. The measurement methods were evaluated at a hazardous waste combustor (HWC) by comparing measured with reference aerosol concentrations. The QAG, Xact, and XFM met the modified Method 301 validation criteria. All three of the methods demonstrated precisions and accuracies on the order of 5%. In addition, correlation coefficients for each method were on the order of 0.99, confirming the methods’ linear response and high precision over a wide range of concentrations. The measurement methods should be applicable to emissions from a wide range of sources, and the reference aerosol generator should be applicable to additional analytes. EPA recently approved an alternative monitoring petition for an HWC at Eli Lilly’s Tippecanoe site in Lafayette, IN, in which the Xact is used for demonstrating compliance with the HWC MACT metal emissions (low volatile, semivolatile, and volatile). The QAG reference aerosol generator was approved as a method for providing a quantitative reference aerosol, which is required for certification and continuing quality assurance of the Xact.

State of the environment in the arrangement area of the enterprises for repairing and utilization of nuclear-powered submarines

The influence of nuclear-powered utilization (disjunction) upon the state of health of the soil, vegetation and atmospheric air was studied. It was stated that the concentration of hazardous metals in the air of an industrial site did not exceed the permissible levels. In the residential area the cases of increased concentrations of manganese and chromium were noted. The major pollutants of vegetation are manganese, titanium, copper and nickel. The authors propose a complex of anthropogenic factors to be the cause of the environmental contamination by hard metals. The volume activity of radioactive aerosols in the studied site is confined to the local hum.