Toxic Metal Emissions Research Articles

Elemental biomapping of human tissues suggests toxic metals such as mercury play a role in the pathogenesis of cancer.

Toxic metals such as mercury, lead, and cadmium have multiple carcinogenic capacities, including the ability to damage DNA and incite inflammation. Environmental toxic metals have long been suspected to play a role in the pathogenesis of cancer, but convincing evidence from epidemiological studies that toxic metals are risk factors for common neoplasms has been difficult to gain. Another approach is to map the location of potentially toxic elements in normal human cells where common cancers originate, as well as in the cancers themselves. In this Perspective, studies are summarized that have used elemental biomapping to detect toxic metals such as mercury in human cells. Two elemental biomapping techniques, autometallography and laser ablation-inductively coupled-mass spectrometry imaging, have shown that multiple toxic metals exist in normal human cells that are particularly prone to developing cancer, and are also seen in neoplastic cells of breast and pancreatic tumors. Biomapping studies of animals exposed to toxic metals show that these animals take up toxic metals in the same cells as humans. The finding of toxic metals such as mercury in human cells prone to cancer could explain the increasing global incidence of many cancers since toxic metals continue to accumulate in the environment. The role of toxic metals in cancer remains to be confirmed experimentally, but to decrease cancer risk a precautionary approach would be to reduce emissions of mercury and other toxic metals into the environment from industrial and mining activities and from the burning of fossil fuels.

Hemispheric-scale heavy metal pollution from South American and Australian mining and metallurgy during the Common Era

Records from polar and alpine ice reflect past changes in background and industrial toxic heavy metal emissions. While Northern Hemisphere records have been used to evaluate environmental effects and linkages to historical events such as foreign conquests, plagues, economic downturns, and technological developments during the past three millennia, little is known about the magnitude and environmental effects of such emissions in the Southern Hemisphere or their historical linkages, especially prior to late 19th century industrialization. Here we used detailed measurements of the toxic heavy metals lead, cadmium, and thallium, as well as non-toxic bismuth, cerium, and sulfur in an array of five East Antarctic ice cores to investigate hemispheric-scale pollution during the Common Era. While thallium showed no anthropogenic increases, the other three metals increased by orders of magnitude in recent centuries after accounting for crustal and volcanic components. These first detailed records indicate that East Antarctic lead pollution started in the 13th century coincident with Late Intermediate Period metallurgy in the Andes and was pervasive during the Spanish Colonial period in parallel with large-scale exploitation of Andean silver and other ore deposits. Lead isotopic variations suggest that 19th-century increases in lead, cadmium, and bismuth resulted from Australian lead and Bolivian tin mining emissions, with 20th century pollution largely the result of the latter. As in the Northern Hemisphere, variations in heavy metal pollution coincided with plagues, cultural and technological developments, as well as global economic and political events including the Great Depression and the World Wars. Estimated atmospheric heavy metal emissions from Spanish Colonial-era mining and smelting during the late 16th and early 17th century were comparable to estimated European emissions during the 1st-century apex of the Roman Empire, with atmospheric model simulations suggesting hemispheric-scale toxic heavy metal pollution during the past five centuries as a result.

Centennial-scale source shift in potentially toxic metal(loid)s in Yangtze River

Estuarine sedimentation is an important historical record of potentially toxic metal (PTM) emissions from human activities that can be used to improve environmental management. However, the contribution of different human activities to PTM deposition has not been accurately estimated, and their coupled relationship with riverine organic matter is typically not considered. In this study, we reconstruct the century-scale PTM depositional history of sediment cores from the Yangtze Grand Delta. Eight potential metal sources (PMSs) were identified using positive matrix factorization, and the results of lagged correlation determined the PMSs associated with the riverine discharge of the Yangtze River. Riverine PTMs were predominantly composed of Cr (79.0%), Ni (77.3%), and Pb (64.1%) but were deprived in Cu (34.9%). Glomalin-related soil protein (GRSP), which is a typical terrestrial refractory carbon, has a strong affinity for Cu, and contributed to 2.82–22.6% Cu deposition. The change in the PMS is mainly related to power generation, whereas the GRSP-bound PTM is mainly related to road construction and transportation. We advocate for responsible management of human activities in river catchments, particularly on coal-based power generation and road transportation, to maintain ecological security and promote the overall achievement of the Sustainable Development Goals.

Investigation of the nanometal levels in the atmosphere of Chakan high tech industrial Park, Chakan (MH), India

Nanometals contained in airborne particles pose a public health risk since they can enter people's respiratory systems and cause lung damage. In general, air pollution is defined as any substance that has been discharged into the atmosphere and has the potential to seriously harm both the environment and living creatures. The current study was conducted in India's Chakan High Tech Industrial Area, which is affected by various industries, such as automotive, electric, power, and iron smelting, which may contribute to environmental air pollution. Sampling of PM2.5 was carried out by high-volume samplers with cascade impactors over two year (2021 and 2022) at two separate locations, one in an industrial park and the other in a residential area. The heavy metals linked to the particulate matter were identified using inductive coupled plasma optical emission spectrometry (ICP-OES). Results revealed that the industrial park had higher levels of particle pollution than the residential neighborhood of Chakan. The primary sources of toxic metal emissions into the atmosphere are industrial and commercial activity. Thankfully, none of the nanometals' concentrations exceeded the limits set by the World Health Organization (WHO) and India's Air (P&CP) Act of 1981. This study was conducted to help identify and measure the concentration of nanometals in air, with the aim of protecting both the environment and living beings from potential harm. Further research will be needed to protect people from the numerous diseases, respiratory conditions, and other health issues brought on by exposure to air pollution in this region.

Spatial trend and source apportionment of metals in wet atmospheric precipitation: a study on drying Urmia Lake implications, NW Iran

ABSTRACT During this decade, the drying of Urmia Lake resulted in devastating tragedies in the region, resulting in the emission of toxic metals into the atmosphere. Urmia city’s wet atmospheric depositions were analysed to assess the quantity and spatial trends of numerous heavy metals and sodium (Na), as well as their sources. Wet precipitation was collected as rainwater, and the concentration of metals was determined using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The mean concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), and sodium (Na) were 0.14, 0.18, 1, 3.7, 2.9, 5.6, 6.3 µg/L, and 2.6 mg/L, respectively, following the sequence Na > Zn > Ni > Cu > Pb > Cr > Cd > As. To identify the sources of these metals, enrichment factor analysis and principal component analysis (PCA) were employed. The enrichment factor analysis revealed that Na and As exhibited relatively low enrichment factors suggesting natural sources, whereas Zn, Cd, Cr, Cu, Ni, and Pb were highly enriched, indicating significant contributions from anthropogenic sources. The distribution map of Urmia City demonstrated that the northern and western parts of the city were highly polluted with As, Ni, Cr, and Zn. PCA analysis revealed that the emissions from vehicles and fuel combustion were the primary sources of Cd, Cr, Cu, Ni, and Pb, whereas the drying of the Urmia lake is the primary source of Na, As, and Zn. The process of the lake bottom drying likely releases these metals into the atmosphere, leading to their deposition in the surrounding areas.

A cross-sectional examination of the early-onset hypertensive disorders of pregnancy and industrial emissions of toxic metals using Kentucky birth records, 2008-2017.

This cross-sectional study assessed geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP) in primiparous mothers and exposure to industrial emissions using geocoded residential information from Kentucky live (N = 210,804) and still (N = 1,247) birth records (2008–2017) and census block group estimates of aerosol concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), selenium (Se), and zinc (Zi) from the Risk Screening Environmental Indicators (RSEI) model. A latent class analysis allowed for the identification of four district exposure classes—As, Cd, and Pb (12.6%); Se and Zi (21.4%); Pb and Cr (8%); and low or no exposures (57.9%). Women classified as having a high probability of exposure to both Pb and Cr had a statistically significantly greater prevalence of eHDP after adjusting for demographic factors (aPR = 1.22, 95% CI: 1.04, 1.44) relative to those with low or no exposure. Our findings contribute to the emerging literature on the association of metal exposures with pregnancy outcomes.

Ecological and health risks assessment of lead in environmental and plants in an artisanal mining area in Nigeria

Background and Aim: The emission of persistent toxic metals into the environment from artisanal mining remains a major challenge to the environment and risk to public health. Thereby causing severe diseases and eventual death amongst adults and children. The study determined the ecological and health risk assessment of lead emission from gold mining in Arufu, Northeast, Nigeria. Methods: Fifty-sixty (56) samples, comprising 30 soils, 10 stream sediments, 6 rocks, 5 mine tailings and 5 plants were collected in areas close to mining excavation. All samples were air-dried and pulverized while rock samples was crushed and pulverized. Samples were analysed for Lead (Pb) using High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry. Statistical evaluations of rate of bioaccumulation of metals in plant and health risk assessment for carcinogenic and non-carcinogenic effect were also assessed. Results: Mean concentration of Pb in soils, sediments, tailings, rocks and plants are: 1,100 mg/kg, 15,800 mg/kg, 110 mg/kg, 12,756 mg/kg, 7,105 mg/kg and 50 mg/kg, respectively. Bioaccumulation factor showed metal mobility from soil to plant. Ecological risk assessment revealed that Pb poses threat to the environment and metals in all the media pose high carcinogenic and non-carcinogenic health risk especially in children. Pollution load index (PLI) revealed all samples to be highly polluted with Pb due to mining. Conclusion: Mining and geogenic activities contributes significantly to the contamination of media in the area. Lead in the samples poses both carcinogenic and non-carcinogenic health diseases. It is recommended from this study that artisanal mining in the area should be regularly monitored to forestall future epidemic. Keywords: Artisanal, Bioaccumulation factor, Ecological risk, Diseases, Mining

Mercury removal in coal-fired power plants, possibilities how to attain very low emissions and minimization of hazardous waste stream

Emissions of toxic heavy metals (HMs), as Hg, As, Cd, Pb, etc., and some harmful compounds of F, Se, and B are related to waste streams from coal-fired power plants (CFPP). Coal/lignite combustion, due to relatively high content of ash, sulfur, and chlorine, generates in flue gas cleaning processes tremendous amount of fly ash, CaSO4 and CaCl2. Measures for minimization of Hg- and NOx-emissions (e.g. addition of bromides and NH3) change properties of fly ash, wastewater and speciation/partition of HMs. Wet flue gas desulfurization (FGD) consumes high amount of fresh water and generates harmful wastewater with water soluble salts. The planned, more stringent limits on emissions of dust, Hg, HCl, HF, SO2, etc. in CFPP will increase contents of polluting compounds in solid and liquid waste streams. We critically assess possibilities, measures and obstacles for higher efficiency of Hg and HMs removal from flue gas in CFPP, together with efficient removal of other pollutants including mutual influences and interrelations. The fates of mercury, selected harmful HMs, and some other pollutants in waste streams from wet FGD are critically analyzed and discussed. Non-toxic, stable forms of mercury (e.g. HgS) and other HMs in solid waste should be preferred. Schemes and measures for minimization of emissions and hazardous waste streams from air pollution control (APC) are compared and discussed for three selected technologies of coal combustion with different methods of gas cleaning.

Copyrolysis of food waste and rice husk to biochar to create a sustainable resource for soil amendment: A pilot-scale case study in Jinhua, China

Worldwide, massive amounts of food waste have been generated at increasingly accelerated rates, posing potentially great risks to the environment. Shifting traditional waste treatment to a sustainable bioeconomy thus challenges food chain management worldwide. In this study, food waste was copyrolyzed with rice husk to produce biochar with a pilot-scale industrialized system. The efficiency of the material conversion and the properties and functions of the produced biochars as well as the potential environmental impacts of pyrolysis were evaluated using in situ measurements, physico-chemical characterization and in vitro (pot) experiments with biochar. The results showed that the emissions of potential toxic compounds and metals from the pyrolysis system were within the guideline limits under the legislation of China or the EU commission. On average, biochar yielded approximately 20% of feedstock and contained a total organic carbon content of 433 g kg−1. In the pot experiment, Chinese cabbage yield and quality were significantly improved, and the plant uptake of heavy metals was significantly reduced in soil amended with food waste biochar compared to no biochar amendment. Furthermore, the food waste biochar was blended with mineral nutrients to create a biochar based compounded N-P-K fertilizer. Application of the biochar based compound fertilizer exerted a significant positive effect on cabbage growth and nutrient use efficiency relative to a conventional mineral compound fertilizer. For per tonne of dry mass of food waste, copyrolysis costed less than 60 USD but gained a gross profit of more than 30 USD. Therefore, the copyrolysis of food waste with crop residues could be applicable to the safe recycling of food waste into value added products to raise agricultural production.

The co-benefits of clean air and low-carbon policies on heavy metal emission reductions from coal-fired power plants in china

China has implemented a series of measures to address air pollutants and carbon emissions from coal-fired power plants, which can mitigate toxic heavy metal emissions simultaneously. By integrating plant-level information and energy activity data, we investigated the co-benefits of clean air and low-carbon policies by compiling a detailed inventory of historical heavy mental emissions (i.e., Hg, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, Zn, As, and Se) for China's coal-fired power plants during 2005–2020. Several scenarios were then designed to assess the evolution of heavy metal emissions for each coal-fired power plant with consideration given to the coal washing rate, air pollution control devices, operational hours and lifetime. The total emissions decreased from 12.9 thousand tons in 2005 to 8.8 thousand tons in 2020, which was mainly due to the widely installation of upgraded end-of-pipe devices and the decommissioning of small and emission-intensive plants, especially in Sichuan, Jiangsu and Zhejiang. Scenario analysis shows that reducing the operational lifetime to 20 years is the most effective measure to reduce national HM emissions, but the effects differ widely between regions. This study provides insights for the precise co-control of both heavy metals and carbon emissions, which is highly important for meeting the requirements of the Minamata Convention and carbon neutrality.

Modelling air quality levels of regulated metals: limitations and challenges.

Toxic metals as arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) exist in the atmosphere as particulate matter components. Their concentration levels in the European Union (EU) are regulated by European legislation, which sets target and limit values as annual means, and by the World Health Organization (WHO) that defines guidelines and reference values for those metal elements. Modelling tools are recommended to support air quality assessment regarding the toxic metals; however, few studies have been performed and those assessments rely on discrete measurements or field campaigns. This study aims to evaluate the capability of air quality modelling tools to verify the legislation compliance concerning the atmospheric levels of toxic elements and to identify the main challenges and limitations of using a modelling assessment approach for regulatory purposes, as a complement to monitoring. The CAMx air quality model was adapted and applied over Porto and Lisbon urban regions in Portugal at 5 × 5-km2 and 1 × 1-km2 horizontal resolution for the year 2015, and the results were analysed and compared with the few measurements available in three locations. The comparison between modelled and measured data revealed an overestimation of the model, although annual averages are much lower than the regulated standards. The comparison of the 5-km and 1-km resolutions' results indicates that a higher resolution does not necessarily imply a better performance, pointing out uncertainties in emissions and the need to better describe the magnitude and spatial allocation of toxic metal emissions. This work highlighted that an increase of the spatial and temporal coverage of monitoring sites would allow to improve the model design, contribute to a better knowledge on toxic metals atmospheric emission sources and to increase the capacity of models to simulate atmospheric particulate species of health concern.

Critical review on secondary zinc resources and their recycling technologies

In a race to save the earth of its rapidly depleting natural resources, the use of Secondary Raw Materials (SMRs) as alternative replacements in several processes is currently intensively pursued. The valorization of SMRs is consistent with the sustainable circular economy, where resource efficiency is maximized for the benefit of both the economy and green environment. In line with this mandate, this article focuses on investigating recent studies on secondary zinc (Zn) resources and describing state-of-art Zn recycling technologies. Globally, some of the main Zn-containing secondary raw materials are mine/concentrator/smelter tailings, wastes, slags, scraps, dust, etc.Although the pyrometallurgical process has been dominant in the secondary metal recycling processes, there has been growing interest and pressure to achieve sustainable and greener recycling methods to remediate the environmental problems caused by emissions of toxic heavy metals and sulfur oxides in the traditional smelting process. In the last decades, many sustainable and environmentally friendly novel hydrometallurgical processes for Zn extraction were developed to overcome tougher legislation and meet cost competitiveness. Secondary Zn recycling focuses on the development of selective Zn-rich but Pb, Fe, As-lean recovery processes.

Spatial-temporal characteristics and driving factors of the human health impacts of five industrial aquatic toxic metals in China.

With the rapid advancement of industrialization without effective supervision, industrial aquatic toxic metal (TM) emissions pose threats to human health in China. Due to differences in socioeconomic development, the regional disparity of industrial aquatic TM emissions is obvious nationwide. In this study, the human health impacts (HHIs) of industrial aquatic TM emissions (i.e., mercury (Hg), cadmium (Cd), hexavalent chromium (Cr(VI)), lead (Pb), and arsenic (As)) in the 31 provinces of China were evaluated based on the ReCiPe method, and the driving factors affecting HHIs from 2000 to 2015 were decomposed using the logarithmic mean Divisia index (LMDI) method. The results showed that the HHIs gradually decreased, with more than an 80% decrease from 2000 to 2015. The order of the TMs contributing to the national HHIs in 2015 was as follows: As (79.5%) > Cr(VI) (19.6%) > Hg (0.4%) > Pb (0.2%) = Cd (0.2%), and 21 (68%) provinces were dominated by industrial aquatic As emissions. Economic development is the major driving factor of the increase in HHIs, while the HHI strength and wastewater discharge intensity are the key driving factors causing reductions in the HHIs. Hunan, Inner Mongolia, Hubei, and Jiangxi accounted for approximately 55% of the total HHIs in 2015. Some suggestions for reducing HHIs based on the local realities of different provinces were put proposed considering two aspects: economic strategy and technical capability.

Concentrations, enrichment, and sources of metals in PM2.5 in Beijing during winter

Serious haze-fog problems in Beijing have aroused considerable concern. The objectives of this study are to determine elemental concentrations in PM2.5, assess their enrichment in PM2.5, and identify their sources during winter in Beijing. Daily PM2.5 samples were collected at the Beijing Normal University campus from January 28 to February 27, 2014. Twenty-three metal elements were determined following digestion by using inductively coupled-plasma mass spectrometry (ICP-MS). The daily PM2.5 concentration ranged from 21.8 to 474.3 μg m−3, with a mean of 172 μg m−3. The daily PM2.5 concentration exceeded 75 mg m−3 (China ambient air quality standards: grade II) for 23 days of the month; therefore, ambient air pollution was severe. The median of daily elemental concentrations in the air decreased in the order of K, Na, and Al (> 103 ng m−3); Ca, Fe, Mn, Mg, Zn, Pb, and Cu (> 102 ng m−3); Ba, P, Ti, and Sr (> 10 ng m−3); and Rb, Sb, Ga, V, Ce, Cd, Tl, Li, La, and Co (> 1 ng m−3). Average and median values of enrichment factors were > 100 for Cd, Sb, Pb, Cu, Zn, and Tl but < 10 for Sr, V, K, Co, Na, Li, Rb, La, Mg, Ce, Ca, Fe, and Al. Enrichment factor, correlation, and principal component analyses demonstrated that Cd, Sb, Pb, Cu, Zn, and Tl in PM2.5 mainly originated from anthropogenic sources, whereas V, Co, Na, Li, Rb, La, Ce, Fe, and Al mainly originated from lithogenic sources. However, the ignition of fireworks during Spring Festival resulted in three pronounced peaks of Ba, K, Mg, Sr, and Cu concentrations. Therefore, national and local governments should continue controlling atmospheric emissions of toxic heavy metals and prohibit firework displays in megacities during Spring Festival.

Anthropogenic atmospheric toxic metals emission inventory and its spatial characteristics in Guangdong province, China

Atmospheric toxic metals (TMs) may cause adverse effects on the environment and human health due to their bioavailability and toxicity. High-resolution TMs emission inventory is important input data for assessing human exposure risks, especially synergistic toxicity of multiple toxic metals. By using the latest city- and enterprise-level environment statistical data, an emission inventory of five TMs (Hg, As, Pb, Cd, Cr) in Guangdong province for the year of 2014 was developed using a bottom-up approach. The total emissions of Hg, As, Pb, Cd and Cr in Guangdong were estimated as 17.70, 32.59, 411.34, 13.13, and 84.16 t, respectively. Major emission sources for each TM were different. Hg emissions were dominated by coal combustion (33%), fluorescent lamp (18%) and cement (17%). 78% of Hg emissions were in the form of Hg0, 19% of Hg2+, and only 3% of Hgp due to strict particulate matter control policies. Coal combustion (48%), nonferrous metal smelting (25%) and iron and steel industry (24%) were the major sources of As. Pb emissions primarily came from battery production (42%), iron and steel industry (21%) and gasoline combustion (17%). Cd and Cr emissions were dominated by nonferrous metal smelting (71%) and iron and steel industry (82%), respectively. Most of these TMs were emitted in the non-Pearl River Delta region, where the newly-built iron and steel industry, nonferrous metal smelting and cement production factories were intense. The uncertainties in the five TM emissions were high, due much to high uncertainties in TM emission factors and limited activity data. Thus, to improve the accuracy of these estimates, we recommend more field tests of TM emissions, especially for the industrial process sector. This study provides scientific support for formulating robust TMs control policies to alleviate the high risk of TMs exposure in Guangdong.

EFFECTS OF CADMIUM, AN ENVIRONMENTAL AND OCCUPATIONAL POLLUTANT, ON LIPID PEROXIDATION IN RAT PANCREATIC TISSUE

Technological development, industrialization and economic development have improved living standards, but also increased toxic metal emissions in the living and working environment. The aim of this study is the monitoring of lipid peroxidation in case of acute intoxication by heavy metal cadmium and the protective role of α-lipoic acid. In this study, we used healthy albino Wistar female rats, two or three months old. Based on the results obtained in this study, we note that cadmium-induced intoxication increases the level of malondialdehyde (MDA) in the pancreatic tissue homogenate. MDA is a direct indication of lipid peroxidation. Alpha-lipoic acid suggests reduction and correction of the toxic effect of cadmium after its exposure.

Sources of atmospheric pollution in the rust belt, Ohio, USA

Industrial regions in the rust belt are sites of significant legacy atmospheric pollution, and despite recent regulations, continue to be sites of ongoing atmospheric emissions of toxic metals. Source attribution in such areas is complicated by the presence of multiple potential point sources, including steel production plants and coal fired power plants. This study focuses on a region in Ohio, USA, in the vicinity of a steel manufacturing plant and coke production facility. Scanning electron microscopy of atmospheric particulate matter, combined with major and trace element and Pb and Os isotopic analysis of dust, lichen and tree bark, have been employed to identify the primary contributors to the atmospheric metal load. Our results suggest that steel production, coal burning, and traffic emissions are all significant sources of metals to the local environment.

Heavy Metals and Polycyclic Aromatic Hydrocarbons in Soil from E-waste Dumpsites in Lagos and Ibadan, Nigeria.

Background.Soil contamination from heavy metals and polycyclic aromatic hydrocarbons (PAHs) released during informal e-waste processing and disposal poses human and ecological health risks in Nigeria.Objectives.This study assesses the levels of heavy metals and PAHs in soils of e-waste dumpsites in Lagos and Ibadan, Nigeria.Methods.Composite soil samples were collected at depths of 0–15 cm, 15–30 cm and 30–45 cm from major e-waste dumpsites in Lagos and Ibadan and analyzed for lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn), chromium (Cr) and PAHs to evaluate the potential contaminant contribution from e-waste activities. Control samples were collected at the Botanical Garden, University of Ibadan. Samples were analyzed for heavy metals after acid digestion using atomic absorption spectrophotometry, while PAHs were extracted using cold solvent extraction and quantified by gas chromatography-mass spectrometry. Blank determination and recovery studies were carried out for each metal. Contamination and ecological risks were assessed using soil contamination indices such as contamination factor, geo-accumulation and pollution load indices, and potential ecological risk index to categorize contaminant concentrations and associated impacts. Soil physico-chemical characteristics such as pH and total organic matter were also determined.Results.Metals concentrations in the dumpsite soils ranged from 114–2,840 mg/kg and not detectable - 6.50 mg/kg for Pb and Cd, and 42.8–5,390 mg/kg, 27.5–3,420 mg/kg, 11.0–128 mg/kg and 94.0–325 mg/kg for Cu, Zn, Ni and Cr, respectively. Serious metals accumulation was observed at every e-waste dumpsite, as shown by the pollution load index. The potential ecological risk values were between 584 and 10,402 at all of the dumpsites, signifying very high ecological risk. The total PAHs ranged from 1,756–2,224 μg/kg at the 0–15 cm level, 1,664–2,152 μg/kg at 15–30 cm and 278 μg/kg in the top- and sub-soil of the control site.Discussion.The total PAHs in the soil of e-waste dumpsites was significantly higher than in the control soil.Conclusions.The results of this study indicate that indiscriminate dumping and open burning of e-waste are potential sources of PAH and toxic metal emissions, which can pose serious human health and ecological risks.

Atmospheric emissions of typical toxic heavy metals from open burning of municipal solid waste in China

Municipal solid waste (MSW) contains considerable hazardous components and the widely-distributed open MSW burning in heavily-populated urban areas can cause direct exposure of hazardous materials to citizens. By determining the best available representation of composition-varying and time-varying emission factors with fuzzy mathematics method and S-shape curves, a comprehensive atmospheric emission inventories of 9 typical toxic heavy metals (THMs, e.g. mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), chromium (Cr), selenium (Se), copper (Cu), zinc (Zn), and nickel (Ni)) from open MSW burning activities in China is established during the period of 2000–2013 for the first time. Further, the emissions in 2013 are allocated at a high spatial resolution of 0.5° × 0.5° grid by surrogate indexes. The results show that 9 typical THMs emissions from open MSW burning are estimated at 21.25 t for Hg, 131.52 t for As, 97.12 t for Pb, 10.12 t for Cd, 50.58 t for Cr, 81.95 t for Se, 382.42 t for Cu, 1790.70 t for Zn, and 43.50 t for Ni, respectively. In terms of spatial variation, the majority of emissions are concentrated in relatively developed and densely-populated regions, especially for the eastern, central and southern regions. Moreover, future emissions are also projected for the period of 2015–2030 based on different scenarios of the independent and collaborative effects of control proposals including minimizing waste, improving MSW incineration ratio, and enhancing waste sorting and recycling, etc. The collaborative effect of the above proposals is expected to bring the most effective reduction to THMs emissions from open MSW burning in China except for Hg. The results will be supplementary to all anthropogenic emissions and useful for relevant policy-making and the improvement of urban air quality as well as human health.

Heavy Metal Pollution in Settled Dust Associated with Different Urban Functional Areas in a Heavily Air-Polluted City in North China.

Understanding variations of heavy metals in atmospheric particles between different functional areas is significant for pollution control and urban planning in cities. To reveal pollution and spatial distribution of heavy metals in atmospheric particles from different urban functional areas in Shijiazhuang in North China, 43 settled dust samples were collected over the main urban area and heavy metal concentrations were determined in their <63 μm fractions using an ICP-OES. The results suggest that Cr, Mn, Fe, Co, Ni, and V in the dust are not or slightly enriched and their concentrations vary slightly between different sites, implying their natural origins; whereas Cu, Zn, Cd, and Pb are often notably enriched and their concentrations vary significantly between different functional areas, indicating their anthropogenic sources. Integrated pollution indexes (IPIs) of the ten heavy metals are 2.7–13.6 (5.7 ± 2.2), suggesting high or very high pollution levels of most dust. Relatively lower IPIs occur mainly in the administration-education area, the commercial area, and other unclassified sites; while peaks occur mainly in the North Railway Station, the northeastern industrial area, and some sites near heavily trafficked areas, implying the significant influence of intensive industrial (including coal combustion) and traffic activities on atmospheric heavy metal accumulation. These results suggest a clear need of mitigating atmospheric heavy metal pollution via controlling emissions of toxic metals (especially Cd and Pb) from industrial and traffic sources in the city.