Smelting Facility Research Articles

Polycyclic aromatic hydrocarbons within the vicinity of a scrap-iron smelting plant: indoor-outdoor and seasonal pattern, source, and exposure risk assessment

ABSTRACT The growing demand for ferrous metals and abundant scrap materials has fueled Nigeria’s scrap-iron smelting industry, leading to hazardous pollutant emissions. This study investigated the concentrations, seasonal and indoor-outdoor variations, origins, and health impacts of polycyclic aromatic hydrocarbons (PAHs) in dust samples around a scrap-iron smelting facility. Analyses of dust samples revealed that high molecular weight PAHs (HMWPAHs) dominated during both seasons, with 5-ring PAHs (34%) contributing most during the rainy season and 3-ring PAHs (36%) during the dry season. Carcinogenic PAHs were more prevalent in the rainy season compared to the dry season. Seven PAH sources were identified, with gasoline combustion being the dominant source during the rainy season and iron and steel production during the dry season. Incremental lifetime cancer risk (ILCR) assessments showed PAH concentrations within safe limits, with dermal contact identified as the primary exposure pathway for both children and adults in the study area.

A NOVEL HYBRID DECISION-MAKING MODEL: FUZZY AHP-TOPSIS APPROACH FOR PRIORITISING COPPER SMELTING PROCESSES

The construction of a copper smelting facility and its undisturbed and profitable business undoubtedly contribute to the development of each country’s economy. These facilities employ many workers and produce a large amount of copper, reducing imports and dependence on this important raw material, thereby improving the economic situation in a given country. More than a hundred copper smelters operate worldwide, many of which use different types of copper extraction processes. Strict legislation relating to ecology and environmental protection as well as stakeholder involvement in selecting and constructing copper smelting facilities limit the maximisation of short-term economic objectives. The prioritisation of technological processes for the extraction of copper must consider the impacts of often mutually opposing economic, technical and environmental objectives. No research from the available literature analyses the economic, technical and environmental parameters systematically. Studies have mainly dealt with exploring individual influences of factors through the use of one selection method. This paper presents the development of a novel hybrid AHP-TOPSIS model in fuzzy environments that will provide both informative decisions and optimum results of decision making.

Human Health Risk Assessment for Exposure to Heavy Metals via Dietary Intake of Rainbow Trout in the Influence Area of a Smelting Facility Located in Peru.

Abandoned mining-metallurgical sites can significantly impact the environment and human health by accumulating heavy metals in aquatic ecosystems. The water in the sub-basin near an abandoned smelting facility in the city of La Oroya, Peru, is primarily used for pisciculture. The objective of this study was to assess the risk to human health from exposure to heavy metals via dietary intake of rainbow trout (Oncorhynchus mykiss) in the influence area of a smelting facility located in the central Andean region of Peru. The bioconcentration factor, biosediment accumulation factor, and consumption risks were evaluated using the Monte Carlo method. The results showed that the concentrations of elements (Zn > Pb > Cu > As) in rainbow trout muscle did not exceed the maximum limit (ML). However, the water significantly exceeded the ML for Pb in all sectors and As in the lower and middle parts of the river. The concentration of Pb in sediments also significantly exceeded the ML in the upper and lower parts of the river. Consequently, rainbow trout consumption in the study area presents risks to human health due to the bioaccumulation of heavy metals, with a 1.27% carcinogenic risk in samples from the lower part of the river.

Investigation of flow distribution in energy intensive aluminium production reduction cells: An exploratory study

The process of making aluminium often involves electrolytic cells, also known as reduction cells. The reduction cell exhaust manifolds must achieve a steady distribution of exhaust from each cell in the network. This will prevent fugitive pollutants, which are harmful to both human and environmental health. While ducts are adjusted to achieve appropriate flow rates, they become asymmetrical over time. A few case studies available in the literature that discuss the flow distribution in an electrolytic cell, and almost none provide insight into the operational flow distribution of reduction cells in service. As part of this study, the operating flow distribution in service reduction cells is examined, determined which factors contribute to poor gas patterns produced by reduction line cells and analysed the flow conditions that result in sediment deposition within the ducting that connects the reduction cells to the superstructure, which is the novelty of this case study. Various instruments were used to record the temperature and pressure of a smelting facility. Flow information for each cell was collected using Pitot traverses. Infrared thermography of the ducts was used to locate temperature anomalies and possible areas of particle build-up. These tests indicated a number of probable contributing causes that have contributed to the inadequate airflow pattern from each reduction cell.

Disparities in job characteristics by race and sex in a Southern aluminum smelting facility.

Former workers at a Southern aluminum smelting facility raised concerns that the most hazardous jobs were assigned to Black workers, but the role of workplace segregation had not been quantified or examined in the company town. Prior studies discuss race and gender disparities in working conditions, but few have documented them in the aluminum industry. We obtained workers' company records for 1985-2007 and characterized four job metrics: prestige (sociologic rankings), worker-defined danger (worker assessments), annual wage (1985 dollars), and estimated total particulate matter (TPM) exposure (job exposure matrix). Characteristics of job at hire and trajectories were compared by race and sex using linear binomial models. Non-White males had the highest percentage of workers in low prestige and high danger jobs at hire and up to 20 years after. After 20 years tenure, 100% of White workers were in higher prestige and lower danger jobs. Most female workers, regardless of race, entered and remained in low-wage jobs, while 50% of all male workers maintained their initial higher-wage jobs. Non-White females had the highest prevalence of workers in low-wage jobs at hire and after 20 years-increasing from 63% (95% CI: 59-67) to 100% (95% CI: 78-100). All female workers were less likely to be in high TPM exposure jobs. Non-White males were most likely to be hired into high TPM exposure jobs, and this exposure prevalence increased as time accrued, while staying constant for other race-sex groups. There is evidence of job segregation by race and sex in this cohort of aluminum smelting workers. Documentation of disparities in occupational hazards is important for informing health interventions and research.

Kewenangan Pemerintah Dalam Pengadaan Tanah untuk Kepentingan Swasta berdasarkan Undang-Undang Nomor 2 Tahun 2012 tentang Pengadaan Tanah Bagi Pembangunan untuk Kepentingan Umum

This research aims to find out the authority and process and mechanism of land acquisition for private interests in terms of building the smelter facility of PT. Amman Mineral Nusa Tenggara (AMMAN) in the industrial area of Maluk Village, Maluk District, West Sumbawa Regency which is a National Strategic Project regulated in the Presidential Regulation of the Republic of Indonesia Number 18 of 2020 concerning the 2020-2024 National Medium Term Development Plan. In carrying out the development agenda (national priority) of the 2020-2024 RPJMN, Strategic Priority Projects (Major Projects) are prepared, namely 9 industrial areas outside Java and 31 smelters. In this regard, in terms of solving problems or answering problems, empirical normative types are used by using 3 approaches, namely the Conceptual Approach, the Statute Approach and the case approach by collecting data which includes data Primary and secondary data were studied and analyzed using qualitative-descriptive analysis. By using this method, the author is finally able to answer the existing problems, namely land acquisition for private interests in terms of the construction of PT. Amman Mineral Nusa Tenggara (AMMAN) based on Law Number 2 of 2012 concerning Land Acquisition for Public Interest for the construction of a smelter is carried out through 4 stages, namely the planning stage, the preparation stage, then the implementation stage and the results delivery stage. As for the process of implementing compensation for land acquisition for the public interest, the construction of the smelter PT. AMNT starts from the stages of inventory and identification of land tenure, ownership, use and utilization. After the inventory was carried out, the implementing team then carried out an assessment of compensation for community land which included the area of land required in this land acquisition.

Development of a Reverse Logistics Modeling for End-of-Life Lithium-Ion Batteries and Its Impact on Recycling Viability—A Case Study to Support End-of-Life Electric Vehicle Battery Strategy in Canada

The deployment of a sustainable recycling network for electric vehicle batteries requires the development of an infrastructure to collect and deliver batteries to several locations from which they can be transported to companies for repurposing or recycling. This infrastructure is still not yet developed in North America, and consequently, spent electric vehicle batteries in Canada are dispersed throughout the country. The purpose of this reverse logistics study is to develop a spatial modeling framework to identify the optimal locations of battery pack dismantling hubs and recycling processing facilities in Canada and quantify the environmental and economic impacts of the supporting infrastructure network for electric vehicle lithium-ion battery end-of-life management. The model integrates the geographic information system, material flow analysis for estimating the availability of spent battery stocks, and the life cycle assessment approach to assess the environmental impact. To minimize the costs and greenhouse gas emission intensity, three regional recycling clusters, including dismantling hubs, recycling processing, and scrap metal smelting facilities, were identified. These three clusters will have the capacity to satisfy the annual flow of disposed batteries. The Quebec–Maritimes cluster presents the lowest payload distance, life-cycle carbon footprint, and truck transportation costs than the Ontario and British Columbia–Prairies clusters. Access to end-of-life batteries not only makes the battery supply chain circular, but also provides incentives for establishing recycling facilities. The average costs and carbon intensity of recycled cathode raw materials are CAD 1.29/kg of the spent battery pack and 0.7 kg CO2e/kg of the spent battery pack, respectively, which were estimated based on the optimization of the transportation distances.

Mineral dust and fossil fuel combustion dominate sources of aerosol sulfate in urban Peru identified by sulfur stable isotopes and water-soluble ions

High sulfur emissions in the Central Andes have in the past been attributed to active volcanoes and numerous copper smelting facilities in the region. This study evaluates the contribution of these sources on Arequipa, Peru through an evaluation of aerosol sulfate δ34S values and water-soluble ions (WSI). The anthropogenic and natural sources of particulate pollution were determined by aerosol filter sampling from four different locations (urban, suburban, industrial, and rural) providing a view of the spatial variability of aerosols within the city. Sulfate (avg. 2.97 μm/m3) is the most abundant ion species in the aerosols sampled contributing on average 20% of the molar mass. Ion composition profiles between sampling sites are very similar indicating common sources and high contributions of mobilized local surface salt to the aerosols in this desert region. The regional atmospheric chemistry model (RACM) 0-D run for the area confirms that emissions from fuel combustion sources alone cannot account for the high concentrations of sulfate observed. A combination of the RACM results, WSI data, and a Bayesian δ34S isotope mixing model determined that the majority of aerosol sulfates in the area are from mineral dust adding to fossil fuel combustion sources. Mineral dust entrainment in the region is likely elevated by the close proximity of open-pit mining and unpaved roads near the city. Marine organic aerosols and smelting located along the Pacific contribute little to Arequipa's aerosol sulfate concentration. While the influence of volcanic sulfate (9% on average) is low, overall natural sulfate (dust, volcanic, and DMS) accounts for 43% of the aerosol sulfate. Therefore, even though the local environment creates high sulfate background levels, a reduction of sulfate aerosol pollution would be possible if fossil fuel emissions were reduced.

Review of Zambia’s potential for more value addition to the downstream copper chain

Zambia copper industry has been in existence for over a century. The country contains most known reserves in Africa and holding about 6 percent known copper reserves in the world. Copper production plays a big role in the performance of the economy. Copper exports account for more than 70 per cent of total exports and 12 per cent of the country GDP. However, with the rich history of mining and copper reserves, studies have shown that Zambia still exports more than 70 per cent of her raw copper blister or copper anodes. Only 5 percent of copper cathodes produced consumed locally to further produce finished products such as copper rods and cables. The study will, therefore, focus on the potential that Zambia has to add value in the copper chain downstream. Specifically, the research focused on the downstream copper production and processing potential in respect of copper blister or anodes, copper cathodes, copper rod and cables. In addition the study reviewed whether the current mineral development policies and taxation are adequate to encourage value addition downstream and also investigate local and regional market for the final copper product. The research utilised statistical data available from Central Statistical Office, Bank of Zambia, Chambers of Mines, ZCCM-IH and international Copper Study groups to establish production, export copper and import of copper rods or cables. In addition to the above, research included visits to the only two copper fabricators ZAMEFA based in Luanshya and Neelkanth Cables Limited in Ndola. Using the statistical data collected and field visits to the fabrication industry, it was established that Zambia has a potential to add more value to its downstream copper chain by producing more than 1 million copper blister or cathodes from the available smelter facilities and though enhancement of policies and taxation incentives.

Ground-level Particulate Sulphate and Gaseous Sulphur Dioxide Downwind of an Aluminium Smelter

ABSTRACT Particulate sulphate (pSO42–) is an atmospheric pollutant known to affect human/environmental health and global radiative-forcing. The Rio Tinto (RT) aluminium smelting facility in Kitimat, British Columbia, is the primary source of sulphur dioxide (SO2) emissions to the surrounding Kitimat Valley, a relatively isolated and unpolluted region. A network of active two-stage filter-packs and passive-diffusive samplers was established between June 2017 to October 2018 with the objective to evaluate the spatiotemporal variation and relative contribution of pSO42– to total anthropogenic atmospheric oxidized sulphur (SOx = SO2 + pSO42–). Average pSO42– across all sites (n = 9) was 0.41 µg m–3 (24–48 hour exposures) and ranged from 0.03 to 2.03 µg m–3. In contrast, average filter-pack SO2 ranged from 0.11 to 8.9 µg m–3 (during the same exposure periods). The filter-pack pSO42–/SOx concentration ratio (Fs) increased downwind of the smelter, indicating that the relative concentration of pSO42– increased with distance from the smelter. Furthermore, the increasing pSO42–/vanadium (V) ratio (used as a tracer of smelter emissions) relative to distance confirmed particulate formation was occurring within the emission plume during the sampling period. Irrespective of in-plume aerosol formation, pSO42– contributed a relatively minor fraction of total atmospheric SOx within the emission plume (field campaign averages Fs 1.0 µg S m–3).

Assessment of element mobility from copper smelting waste slag into forest soils

Research subject. In this paper, we investigate the possibility of recycling wastes from copper smelting facilities in brown mountain forest soils. The research object was “technical sand” obtained at the Sredneuralsky copper smelter as a byproduct. This finely dispersed material rich in copper, zinc and other chalcophilic elements undergo mechanical activation during crushing of the cast slag.Materials and methods. Experiments were carried out in the southern taiga district of the Trans-Ural hilly-foothill province (Middle Urals) in autumn before snow cover. Two types of forest areas identified according to the genetic forest typology were investigated: cowberry shrub pine forest and berry pine forest with linden, both under trees and in clear-cutting areas. The experiments involved scattering 1kg of waste across 1m2 of experimental soil, packing such a sand in 100 g packages made of non-woven material and burying these packages in 3 experimental plots a depth of 7–10 cm. Following 2 years, the packages were retrieved and weighed. The microelement analysis of soil samples was carried out by the method of inductively coupled plasma mass-spectrometry using an Elan-9000 ICP mass-spectrometer at the Geoanalitik center of the Institute of Geology and Geochemistry, Ural Branch of RAS.Results. It was found that, after 2 years of residing in the soil, copper smelting waste slag loses 11% of its mass. The majority of chalcophilic elements are involved in the biogeochemical cycle. The content of zinc, arsenic, cadmium and selenium varies most signfificantly. A difference in the degree of element migration from the “technical sand” to the brown mountain forest soil was observed for 2 forest types and clear-cutting areas. A single surface application of mineral waste (1 kg/m2 ) in autumn did not affect the qualitative composition of the grassy layer of all forest types and clear-cutting areas in the following spring–summer period.Conclusion. The findings can be of interest for specialists developing new methods for recycling mineral wastes from copper smelters. Future research should analyse the distribution of components migrating from the “technical sand” along the soil profile of forest soils, as well as their involvement in biogeochemical cycles.

Impacts of industrial atmospheric emissions on watershed export of dissolved ions in coastal streams: a Bayesian modeling approach.

Anthropogenic atmospheric emission and subsequent deposition of sulfur (S) has been linked to disrupted watershed biogeochemical processes through soil and surface water acidification. We investigated watershed-scale impacts of acidic deposition on tributary concentrations and watershed exports of major nutrients and ions for the Kitimat River Watershed, British Columbia. Since the 1950s,the Kitimat watershed hadan aluminum smelting facility with substantial emissions at the river estuary. Emissions loadthe airshed overlying the watershed and potentially impact western tributaries leaving eastern tributaries available as reference. We assessed concentrations and export of key compounds in three reference and six potentially impacted tributaries and watersheds in 2015 and 2016. Sulfate (SO4), fluoride (F), nitrate (NO3), and chloride (Cl) were significantly higher in impacted tributaries. F concentrations exceeded the Canadian Council of Ministers of the Environment guideline for aquatic life in 83% of samples collected from impacted streams. Watershed export and associated uncertainty were determined by bootstrapped flow-stratified Beale's unbiased estimator. Impact of emissions on watershed export was modeled in a Bayesian approach to include variance in the export estimate to inform the uncertainty of model parameters. Export of SO4 and Ca increased significantly within 16 km and 8 km, respectively, toward the smelter emissions. The corresponding impacted area for SO4 and Ca was approximately 100 km2 and 45 km2, respectively. SO4 export is likely due to direct impacts of S deposition, with excess S being flushed from the watersheds. Ca export patterns likely result from indirect impacts of S deposition on soil chemistry and flushing of Ca. These impacts may contribute to effects within tributaries on benthic stream communities and regionally important juvenile Pacific salmon.

Analysis of the variability of airborne particulate matter with prevailing meteorological conditions across a semi-urban environment using a network of low-cost air quality sensors

The concentrations of fine and coarse fractions of airborne particulate matter (PM) and meteorological variables (wind speed, wind direction, temperature and relative humidity) were measured at six selected locations in Ile Ife, a prominent university town in Nigeria using a network of low-cost air quality (AQ) sensor units. The objective of the deployment was to collate baseline air quality data and assess the impact of prevailing meteorological conditions on PM concentrations in selected residential communities downwind of an iron smelting facility. The raw data obtained from OPC-N2 of the AQ sensor units was corrected using the RH correction factor developed based k-Kohler theory. This PM (corrected) fast time resolution data (20 s) from the AQ sensor units were used to create daily averages. The overall mean mass concentrations for PM2.5 and PM10 were 213.3, 44.1, 23.8, 27.7, 20.2 and 41.5 μg/m3 and; 439.9, 107.1, 55.0, 72.4, 45.5 and 112.0 μg/m3 for Fasina (Iron-Steel Smelting Factory, ISSF), Modomo, Eleweran, Fire Service, O.A.U. staff quarters and Obafemi Awolowo University Teaching and Research Farm (OAUTRF), respectively. PM concentration and wind speed showed a negative exponential distribution curve with the lowest exponential fit coefficient of determination (R2) values of 0.08 for PM2.5 and 0.03 for PM10 during nighttime periods at Eleweran and Fire service sites, respectively. The relationship between PM concentration and temperature gave a decay curve indicating that higher PM concentrations were observed at lower temperatures. The exponential distribution curve for the relationship between PM concentration and relative humidity (RH) showed that PM concentrations do not vary for RH < 80 % while stronger relationship was noticed with higher PM concentration for RH > 80 % for both day and nighttime. The performances of the MLR model were slightly poor and as such not too reliable for predicting the concentration but useful for improving predictive model accuracy when other variables contributing to the variability of PM is considered. The study concluded that the anthropogenic and industrial activities at the smelting factory contribute significantly to the elevated PM mass concentration measured at the study locations.

Dissociation mechanism of particulate matter containing arsenic and lead in smelting flue gas by pyrite

Copper smelters are the main anthropogenic source of arsenic. In this study, the formation pathway of arsenic-lead particulate matter in a heat recovery steam generator (HRSG) of a copper smelting facility were investigated. Lead monoxide and arsenic trioxide reacted easily with each other to form particulate matter with a high arsenic content, while the relative content of lead arsenate and lead arsenite in the particulate matter varied with the fluctuation of the smelting flue gas. The dissociation mechanism by pyrite of particulate matter containing arsenic and lead were also studied for the first time. The structures and components of the resultant composites were characterized by ion chromatography plasma optical emission spectrometry, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Pyrite promoted the dissociation of lead arsenate and lead arsenite due to the formation of more lead sulfate, and then further inhibited the formation of lead arsenate and lead arsenite. This study is of great significance for the control of arsenic in flues.

The effect of heavy metal contamination on humans and animals in the vicinity of a zinc smelting facility.

A diagnosis of heavy metal poisoning in sheep living on pastures in the vicinity of a smelting facility in the Wumeng mountain area of China was based on laboratory tests and clinical symptoms. Furthermore, heavy metal contamination in the food chain was found to have a deleterious effect on the health of local residents. The levels of copper(Cu), zinc(Zn), cadmium (Cd), and lead (Pb) in irrigation water, soil, forages, and animal tissues were measured in samples taken from the vicinity of a smelting facility and control samples. Heavy metal contents in food (corn, rice, and wheat), as well as in human tissues (blood and hair) obtained from local residents were also determined. Hematological values were also determined in human and animal samples. The content of Cu, Zn, Cd, and Pb in irrigation water, soils, and forages were markedly higher in affected areas than in samples from healthy pastures. Concentrations of Cd and Pb were 177.82 and 16.61 times greater in forages than controls, respectively, and 68.71 and 15.66 times greater in soils than controls, respectively. The heavy metal content in food (corn, rice, and wheat) from affected areas was markedly higher than in the control samples. Cd and Pb content in the tissues of affected sheep were markedly higher than in control animals (P < 0.01), while concentrations of Cd and Pb in blood and hair samples from local residents were markedly higher than in control samples (P < 0.01). The occurrence of anemia in affected humans and animals followed a hypochromic and microcytic pattern. The intake of Cd and Pb was estimated according to herbage ingestion rates. It was found that the levels of Cd and Pb which accumulated in sheep through the ingestion of vegetation growing in the sites closest to the smelter were approximately 3.36 and 38.47 mg/kg body wt./day, respectively. Such levels surpassed the fatal dosages for sheep of 1.13 mg Cd/kg body wt/day and 4.42 mg Pb/kg body wt./day. The serum total antioxidant capacity in affected humans and animals was significantly lower than in the controls (P < 0.01). Serum protein parameters in affected humans and animals were significantly reduced (P < 0.01); therefore, it was concluded that heavy metal contamination caused harm to sheep, and also posed a significant risk to humans living in the vicinity of the zinc smelting facility.

The Truth Fairy Project

TPS 621: Exposure to metals, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background/ Aim: Lead (Pb) is a potent neurotoxicant with no safe level of exposure. Elevated levels of Pb and arsenic (As) are found near facilities that recycle lead-acid batteries in the United States. Assessing historical exposure to toxic chemicals, especially in situations of a specific industrial source of pollution affecting a community, is critical for informing appropriate public health and policy responses. We describe a community-driven approach to integrate retrospective environmental hazard exposure assessment with community organizing to address concerns about the extent of exposure to toxic metals in a predominantly working-class, Latinx community living near a now-closed lead-acid battery smelter facility. Methods: In this pilot study coined the “Truth Fairy” Project, 50 shed deciduous teeth from 43 children living their entire lives within 2 miles of the smelter to understand in retrospective exposure to toxic metals using community-driven research approach. Concentrations of Pb and As in teeth were assessed using laser-ablation-inductively coupled plasma-mass spectrometry. Soil Pb concentrations were determined using spatial kriging of surface soil measurements. Results: The mean prenatal calcium normalized Pb concentration in teeth samples (reported as a ratio 208Pb:43Ca), was 4.104 x 10-4 (SD 4.123 x 10-4), and the mean postnatal 208Pb:43Ca level was 4.109 x 10-4 (SD 3.369 x 10-4). Adjusted for maternal education and analytical batch, we observe positive significant relationship between prenatal teeth Pb per 100 ppm increase in soil Pb (β=3.48, 95% CI 1.11, 5.86), indicating higher Pb exposures near the site of industrial exposure. Study results were disseminated to the community using infographics. Conclusions: The Truth Fairy study provides insights into assessing retrospective exposure to toxic metals among children living near legacy sources. This project integrated community mobilization with empirical research, informing residents about toxic metal exposures and improving the community’s capacity to respond to a public health crisis.

A Collaborative Approach to Assess Legacy Pollution in Communities Near a Lead-Acid Battery Smelter: The "Truth Fairy" Project.

Advocates for civil rights, environmental justice, and movements promoting social justice require data and may lack trust in public authorities, turning instead to academic scientists to help address their questions. Assessing historical exposure to toxic chemicals, especially in situations of a specific industrial source of pollution affecting a community, is critical for informing appropriate public health and policy responses. We describe a community-driven approach to integrate retrospective environmental hazard exposure assessment with community organizing to address concerns about the extent of exposure to toxic metals in a predominantly working-class, Latinx community living near a now-closed lead-acid battery smelter facility. Named the "Truth Fairy Project" by leaders of the community organization East Yard Communities for Environmental Justice, this community-university partnership aimed to assess prenatal and early-life exposures to toxic metals through biomarkers of exposure in baby/deciduous teeth. This partnership integrated community mobilization with empirical research, informing residents about toxic metal exposures and improving the community's capacity to respond to a public health crisis.

A comparative chemical study of PM10 in three Latin American cities: Lima, Medellín, and São Paulo

The study was part of the South American Emissions, Megacities and Climate Project (SAEMC). The objective was to identify and quantify organic and elemental carbon (OC and EC), monosaccharides, polycyclic aromatic hydrocarbons (PAHs), oxy and nitro-PAHs, water-soluble ions (WSI), and elements in particulate matter collected in intensive campaigns during a period (June, 2010) in Sao Paulo (Brazil), Lima (Peru), and Medellin (Colombia). PM10 concentration was higher in Sao Paulo than in the other two sites and 75% of the samples had concentrations above the World Health Organization (WHO) guideline. High concentrations of levoglucosan, a biomass burning tracer, highlighted the importance of this source in the Brazilian megacity. Levoglucosan-to-mannosan ratios for Sao Paulo suggested sugarcane burning, which in 2010 occurred in 70% of the state municipalities during harvest. Vehicular-related elements (Fe and Cu) had higher concentrations in Sao Paulo. As and Pb in Medellin were attributed to industrial emissions. Ni in Lima was associated with emissions from metal smelting facilities and ship heavy oil combustion. Higher total PAH concentrations and benzo[a]pyrene equivalent (BaPE) index in Sao Paulo indicated a stronger influence of vehicular exhaust in this megacity. The results highlighted the importance of biomass burning and vehicular sources for Sao Paulo, vehicular exhaust, biomass burning, and industrial sources for Medellin, and marine aerosol, together with vehicular, industrial, and ship exhaust, for Lima.

Capability for metallurgical processing of Intermediate products for the processing of polymetallic ores

The copper smelting facilities of the Ural Mining and Metallurgical Company (UMMC) mostly rely on copper-zinc and polymetallic ores. Finely disseminated minerals are associated with increased cost of selective flotation and mineral losses with dissimilar concentrates. In selective flotation of copper-zinc ores from the Urals region, between 6% (high zinc ores) and 23&ndash;44% of zinc get lost with copper concentrates depending on metal concentration and intergrowth of minerals in the ore, with the concentration of zinc in it being less than 1 %. In metallurgical processing, 90&ndash;95% of zinc contained in copper concentrates go to waste with the slag. Processing of polymetallic ores from the Altay deposits is associated with high losses of copper, lead and zinc, which get lost with dissimilar concentrates. The authors of this paper propose to obtain bulk concentrates from low zinc (0.4&ndash;1% Zn) and highly complex copper-zinc ores; obtain high-quality zinc and polymetallic (copper-lead-zinc) concentrates from polymetallic ores; set up a processing facility for polymetallic concentrates at the Mednogorsk Copper-Sulphur Plant (MCSP) that would involve the following stages: matte and zinc slag smelting &ndash; matte converted to blister copper &ndash; copper extraction from and fuming of smelter and converter slags. The main smelting vessel is currently under reconstruction aimed at introducing high-pressure highly concentrated blast oxygen; a slag fuming complex will need to be built with gas scrubbers to produce lead-zinc sublimates. An existing oxygen plant is utilised, and all sulphur containing gases are treated in a sulphuric acid facility present at the site. The advantages of the proposed processing scheme include: increased end-to-end recovery (from complex ores to refined ingots): copper &mdash; by 2.7%, zinc &mdash; by 8.1%; the output of refined lead at UMMC increased by 14 th tons with no special investment made; simpler processing schemes and a significant reduction in processing and transportation costs; rational use of the MCSP production facilities and infrastructure, raw materials available on a stable and long-term basis; an increase of 3.8 bln rubles per annum in the commodity output of UMMC.

Spatial distribution of smelter emission heavy metals on farmland soil.

This work was conducted to explore heavy metal pollution in soils in an area near lead smelters in Jiyuan City, which is one of the main lead production areas in China. Altogether, 88 topsoil samples (0-20cm) were collected from farmlands near the Yuguang lead smelting facilities; the sampling sites were 1570 to 6388m to the main stack of the Yuguang. Analysis of the samples indicated that (i) the ranges of total Cd and Pb concentrations were 0.81-4.30 and 64.5-435mgkg-1, respectively, mean pollution indices (concentration in soil/background value, PI) were 32.8 and 9.11, respectively, and the concentrations of total Cu, Zn, and Ni were slightly higher than the background values. Mean concentrations of DTPA-extractable Cd and Pb were 0.752 and 58.7mgkg-1, respectively. (ii) The total concentrations of Cd, Pb and Pb/Cd ratios of samples decreased as the distance to the main stack of the Yuguang increased. Abnormal variations of these trends suggested these parameters of certain samples were affected by pollution sources other than the Yuguang. (iii) Judged by the results of this work, the area of the heavy metal-polluted land in Jiyuan was much greater than 115km2, a value reported by an earlier investigation. These results indicate that the soil in the study area was polluted by Cd and Pb emissions from more than one polluting sources, the variation of Cd, Pb concentration and Pb/Cd ratios of samples to the distance of the pollution source can be potentially used for pollution source identification.