Geochemical and statistical analysis of trace metals in atmospheric particulates in Wuhan, central China

Associations between atmospheric PM2.5 exposure and carcinogenic health risks: Surveillance data from the year of lowest recorded levels in Beijing, China

Scant research has pinpointed the year of minimum PM2.5 concentration through extensive, uninterrupted monitoring, nor has it thoroughly assessed carcinogenic risks associated with analyzing numerous components during this nadir in Beijing. This study endeavored to delineate the atmospheric PM2.5 pollution in Beijing from 2015 to 2022 and to undertake comprehensive evaluation of carcinogenic risks associated with the composition of atmospheric PM2.5 during the year exhibiting the lowest concentration. PM2.5 concentrations were monitored gradually in 9 districts of Beijing for 7 consecutive days per month from 2015 to 2022, and 32 kinds of PM2.5 components collected in the lowest PM2.5 concentration year were analyzed. This comprehensive dataset served as the basis for carcinogenic risk assessment using Monte Carlo simulation. And we applied the Positive Matrix Factorization (PMF) method to identity the sources of atmospheric PM2.5. Furthermore, we integrated this source appointment model with risk assessment model to discern the origins of these risks. The findings revealed that the annual average PM2.5 concentration in 2022 stood at 43.1 μg/m3, marking the lowest level recorded. The mean carcinogenic risks of atmospheric PM2.5 exposure calculated at 6.30E-6 (empirical 95% CI 1.09E-6 to 2.25E-5) in 2022. The PMF model suggested that secondary sources (35.4%), coal combustion (25.6%), resuspended dust (15.1%), biomass combustion (14.1%), vehicle emissions (7.1%), industrial emissions (2.0%) and others (0.7%) were the main sources of atmospheric PM2.5 in Beijing. The mixed model revealed that coal combustion (2.41E-6), vehicle emissions (1.90E-6) and industrial emissions (1.32E-6) were the main sources of carcinogenic risks with caution. Despite a continual decrease in atmospheric PM2.5 concentration in recent years, the lowest concentration levels still pose non-negligible carcinogenic risks. Notably, the carcinogenic risks associated with metals and metalloids exceeded that of PAHs. And the distribution of risk sources did not align proportionally with the distribution of PM2.5 mass concentration.

Comprehensive Assessment of Pollution Sources and Health Impacts in Suburban Area of Shanghai

Shanghai, one of China's largest metropolises, faces significant environmental pollution challenges due to rapid economic development. Suburban areas of Shanghai are affected by both long-distance transport and local sources of pollutants. This study conducted an integrated analysis that links health-risk assessment of heavy metals and source apportionment of atmospheric constituents to distinguish the contributions of emission sources and the major sources of health risks. Source-apportionment analysis revealed that secondary sources had the greatest contribution to the local pollutants, indicating the significant influence of peripheral and long-distance transport. Health-risk assessment of Cr, Ni, As, and Cd revealed that local residents were exposed to respiratory health risks, in which Cr is the major contributor. This health risk was primarily associated with emissions from nearby industry-related sources. Our study highlights the significant effects of both long-distance transport and local source emissions on atmospheric composition and human health in large urban agglomerations. The findings can inform future efforts to develop more precise emission-reduction strategies and policy improvements to mitigate environmental pollution and protect public health.

Source apportionment of PM2.5 in Seoul, South Korea and Beijing, China using dispersion normalized PMF

East Asian countries experience severe air pollution owing to their rapid development and urbanization induced by substantial economic activities. South Korea and China are among the most polluted East Asian countries with high mass concentrations of PM_2.5. Although the occurrence of transboundary air pollution among neighboring countries has been recognized for a long time, studies involving simultaneous ground-based PM_2.5 monitoring and source apportionment in South Korea and China have not been conducted to date. This study performed simultaneous daily ground-based monitoring of PM_2.5 in Seoul and Beijing from January to December 2019. The mass concentrations of PM_2.5 and its major chemical components were analyzed simultaneously during 2019. Positive matrix factorization (PMF) as well as dispersion normalized PMF (DN-PMF) were utilized for the source apportionment of ambient PM_2.5 at the two sites. 23 h average ventilation coefficients were applied for daily PM_2.5 chemical constituents' data. Nine sources were identified at both sites. While secondary nitrate, secondary sulfate, mobile, oil combustion, biomass burning, soil, and aged sea salt were commonly found at both sites, industry/coal combustion and incinerator were identified only at Seoul and incinerator/industry and coal combustion were identified only at Beijing. Reduction of the meteorological influences were found in DN-PMF compare to C-PMF but the effects of DN on mobile source were reduced by averaging over the 23 h sampling period. The DN-PMF results showed that Secondary nitrate (Seoul: 25.5%; Beijing: 31.7%) and secondary sulfate (Seoul: 20.5%; Beijing: 17.6%) were most dominant contributors to PM_2.5 at both sites. Decreasing secondary sulfate contributions and increasing secondary nitrate contributions were observed at both sites.

Pine needles as urban atmospheric pollution indicators: Heavy metal concentrations and Pb isotopic source identification

Pine needles are reliable passive bio-samplers that can be used to monitor atmospheric pollution levels. This study applied Pb isotope and multivariate statistical analyses to pine needles to examine the characteristics, sources, and ecological risks of atmospheric heavy metal pollution in the cities of the middle reaches of the Yangtze River, China. The heavy metal concentrations were higher than those measured in pine needles elsewhere in the world. They were higher in the metropolitan city (Wuhan) than in the medium-sized city (Yichang) and lowest in the natural setting (Shennongjia Forestry District), which is consistent with trends in urbanization and industrialization. Principal component analysis grouped the metals into three main sets associated with industrial activities and traffic sources. The Pb composition determined the main anthropogenic Pb sources were vehicle exhaust and industrial activities related to the lead-zinc ore, only a few of which were coal combustion. Three risk assessment indexes (pollution load index, ecological risk index, and bioconcentration factor) suggest that atmospheric heavy metals in the study area pose moderate environmental and health risks.

Spatial distribution of PM2.5-bound elements in eighteen cities over China: policy implication and health risk assessment

In this study, 30 elements in fine particulate matter (PM_2.5) were measured in 18 Chinese cities in 2013. Elemental pollution in northern, southwest, and central China were severe, attributing to excessive coal and biomass combustion in these regions. The concentrations of S, Cl, and K in these areas were 8.21 ± 3.90, 4.03 ± 1.96, and 1.59 ± 0.613 μg/m³, respectively, which were 1.6-2.7 times higher than those in other regions of China. In addition, the industrial emissions in northeast and north China were large, leading to the elevated heavy metal concentration of 1.32 ± 1.17 μg/m³, especially Zn, Pb, Cr, Cd, and Br. Soil dust was the highest in northwest China among the five regions with the concentration of crustal elements of 6.37 ± 4.51 μg/m³. Moreover, although the levels of elemental concentration in east and southeast China were relatively acceptable, regulators must pay attention to elevated level of V (0.009 ± 0.006 μg/m³) in these areas. Compared with 2003, several elements have deteriorated in some cities. For example, As increased by 70%, 18%, and 155% in Changchun, Beijing, and Jinchang, respectively. However, ~ 77% measured elements, e.g., Ti, Fe, and Pb markedly reduced in 2013, with reduction rates of 13-81%. These indicate that the government's policies related to particle-bound elements have shown certain positive environmental effects. For the health risks from the heavy metals in 2013, the non-cancer risks of As and Cd must not be neglected. The cancer risks of As and Pb were much higher than the international safety limit (10^-4). More prominent health risks were found in southwest, central, and northwest China. Therefore, the government should accelerate the shift to cleaner energy in underdeveloped areas of China to obtain more environmental and health benefits.

Analyzing Characteristics of Particulate Matter Pollution in Open-Pit Coal Mines: Implications for Green Mining

The particulate pollution in the open-pit coal mines of China is particularly severe in winter. The aim of this study is to understand the pollution characteristics of particulate matter (PM) in winter and provide a basis for the prevention and control of particulate pollution. We took the problem of PM concentration at the bottom of the Haerwusu Open-pit Coal Mine (HOCM) as the research object. Dust monitoring equipment at two measurement points at different heights were positioned for continuous monitoring of the PM concentration. The data for three months were gathered. Statistical analyses were performed to analyze the variation characteristics of the PM and its relationship with meteorological factors. The results show that the average PM concentration in the study area is below the average daily limit of the China National Ambient Air Quality Standard (GB 3095-2012). However, the average concentration of PM10 exceeded the national limit in December. The order of PM concentration is observed as December > January > February. The correlation of PM is found to be positive with humidity and negative with wind speed. Temperature is found to be positively correlated with PM in December, while it is negative in January. At the same time, the temperature difference in December is negatively correlated with PM concentration. Under the combined action of multiple meteorological factors, the magnitude of the impact on the PM concentration at the bottom of the pit in winter is humidity > temperature > wind speed > temperature difference (inverse temperature intensity). In conclusion, PM2.5 is found to be more sensitive to environmental factors. The results of this study are particularly useful to progress in green mining.

Risks related to heavy metal pollution in urban construction dust fall of fast-developing Chinese cities

Urban construction is a major contributor to air pollution, but few studies have examined heavy metal pollution in urban areas caused by construction dust fall. We measured the concentrations of Cr, Ni, Cu, Zn, Pb, Cd, and Hg and particle size distribution in dust fall from various construction activities in seven fast-developing cities in China and conducted a health risk assessment. Mean metal concentrations in construction dust fall were on the order of Zn (246.3 mg/kg) > Cr (94.2 mg/kg) > Pb (56.5 mg/kg) > Cu (53.6 mg/kg) > Ni (22.8 mg/kg) > Cd (0.68 mg/kg) > Hg (0.08 mg/kg). Cu and Zn were positively correlated in areas of subway and building construction, and Pb and Cd were positively correlated in areas of road construction, likely because of the materials specific to these activities. Enrichment factors for heavy metals at all sampling sites were on the order of Cd (10.4) > Zn (6.37) > Cu (4.25) > Pb (3.84) > Hg (2.41) > Cr (2.02) > Ni (1.32). The enrichment factors for all metals except Zn indicated that heavy metal pollution was highest in road construction, followed by building and subway construction. Non-carcinogenic risks to children (hazard index >1) were 1.01-1.08 in four of the seven sampling sites, indicating possible risk from deposition of construction dust fall. In contrast, the hazard index for adults was <1 at the seven cities and total carcinogenic risks (<1 × 10^-6) were at acceptable levels. An integrated ecological risk assessment demonstrated that heavy metal particles in construction dust fall in two of the cities (Shijiazhuang and Qingdao) were likely to be suspended in the atmosphere. Our study of heavy metal pollution in construction dust fall provides data on ecological and human health impacts and suggests that extensive measures are required to control construction dust fall in China.

Temporal trend of arsenic in outdoor air PM2.5 in Wuhan, China, in 2015-2017 and the personal inhalation of PM-bound arsenic: implications for human exposure

Arsenic in fine air particulate matter (PM_2.5) has been identified as an important factor responsible for the morbidity of lung cancer, which has increased sharply in many regions of China. Some reports in China have shown that arsenic in the air exceeds the ambient air quality standard value, while long-term airborne arsenic concentrations in central China and human exposure via inhalation of PM-bound arsenic (inhalable airborne PM) have not been well characterized. In this study, 579 outdoor air PM_2.5 samples from Wuhan, a typical city in central China, were collected from 2015 to 2017, and arsenic was measured by inductively coupled plasma-mass spectrometry. Personal exposure to PM-bound arsenic via inhalation and urinary arsenic concentration were also measured. The concentrations of arsenic in PM_2.5 were in the range of 0.42-61.6 ng/m³ (mean 8.48 ng/m³). The average concentration of arsenic in 2015 (10.7 ng/m³) was higher than that in 2016 (6.81 ng/m³) and 2017 (8.18 ng/m³), exceeded the standard value. The arsenic concentrations in spring and winter were higher than those in summer and autumn. No significant differences (p > 0.05) were found among different sites. The daily intake of arsenic inhalation based on PM₁₀ samples collected by personal samplers (median, 10.8 ng/m³) was estimated. Urban residents inhaled higher levels of PM-bound arsenic than rural residents. Daily intake of arsenic via inhalation accounted for a negligible part (< 1%) of the total daily intake of arsenic (calculated based on excreted urinary arsenic); however, potential associations between the adverse effects (e.g., lung adenocarcinoma) and inhaled PM-bound arsenic require more attention, particularly for those who experience in long-term exposure. This study is the first report of a 3-year temporal trend of airborne PM_2.5-bound arsenic in central China.

Characteristics, sources and health risks of toxic species (PCDD/Fs, PAHs and heavy metals) in PM2.5 during fall and winter in an industrial area

Particulate toxic species, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals may have significant health risks. This study investigated characteristics, sources and health risks of all three classes of toxic species in PM_2.5 (particles with aerodynamic diameter ≤2.5 μm) samples collected at an industrial area in Changzhou, a big city in the Yangtze Delta region of China. Fourteen heavy metals altogether constituted 2.87% of PM_2.5 mass, with Fe, Al and Zn as the major elements. Principal component analysis (PCA) suggested that heavy metals came from four sources: vehicles, industry, crustal dust, mixed coal combustion and industrial process. The daily average concentration of 18 PAHs was 235.29 ng/m³, accounting for 0.21% of PM_2.5 mass. The dominant PAHs were high molecular weight ones, contributing 73.5% to the total PAHs. Diagnostic analyses indicated that sources of PAHs included vehicle/coal combustion and petroleum emissions, wherein diesel emission played a more important role than gasoline emission. PCA showed that the largest contributor of PAHs was vehicle exhaust mixed with coal combustion, followed by three industry-related sources. Total concentration of 17 PCDD/Fs varied between 3.14 and 37.07 pg/m³, with an average of 14.58 pg/m³. The 10 PCDFs accounted for 70.5% of total concentration of 17 PCDD/Fs. Health risk assessments showed that the carcinogenic risk of heavy metals was acceptable, while risks from PAHs and PCDD/Fs cannot be ignored. Back trajectory analysis indicated that local/regional transported air masses from northern China was the major source areas of the toxic species.

Profiles, source identification and health risks of potentially toxic metals in pyrotechnic-related road dust during Chinese New Year

Potentially toxic metal (PTM) pollution in road dust is of great concern, however, our understanding of PTMs released by pyrotechnic displays and their adverse impacts on human health in road dust is limited. Here, we studied PTM pollution levels and Pb isotope signatures in pyrotechnic ash and road dust (aged dust and pyrotechnic-influenced dust) samples from eight cities in China during Chinese New Year and carried out a human health risk assessment. Pyrotechnic ash had higher values of Cr, Co, Ni, Cu, Zn, As, Sr and Pb but lower values of Mn and Cd than Chinese background soil. Pyrotechnic-influenced dust had significantly higher Cu and Cr values than aged dust, with enrichment of Sr, Cu, Pb, Cr and Ni in road dust after pyrotechnic displays. Both ²⁰⁸Pb/²⁰⁶Pb and Sr values were used to confirm the presence of pyrotechnic ash in road dust. A positive matrix factorization demonstrated that pyrotechnic events contributed 70.1%, 50.4%, 36.6% and 35.5% of the Sr, Cu, Cr and Pb values to these road dust, respectively. We found that non-carcinogenic and carcinogenic risks related to PTMs in road dust were at safe levels during the Chinese New Year, although both risks were elevated following pyrotechnic events. Typically, PTM pollutants related to pyrotechnic events contributed 33.99% to non-carcinogenic and 21.83% to carcinogenic risks, suggesting that more attention needs to be paid to this source of PTM pollution in China. Current results improve our understanding of PTM pollution in pyrotechnic-influenced road dust and health risks related to pyrotechnic displays in China.

Chemical Composition and Deposition Fluxes of Water-Soluble Inorganic Ions on Dry and Wet Deposition Samples in Wuhan, China

Measurement of PM_2.5 concentration, dry and wet deposition of water-soluble inorganic ions (WSII) and their deposition flux was carried out. During sampling, a total number of 31 samples of PM_2.5, five wet deposition samples and seven dry deposition samples were collected. The analyses results showed that the average concentration of PM_2.5 was 122.95 µg/m³ whilst that of WSII was 51.63 µg/m³, equivalent to 42% of the total mass of PM_2.5. The correlation coefficients between WSII in samples of PM_2.5 was significant (r = 0.50 and p-value of 0.0019). Ions of &nbsp; SO 4 2 - , NO 3 - , Cl - , and &nbsp; NH 4 + were dominant in the entire samples (PM_2.5, dry and wet depositions), nevertheless, the average concentration of both SO 4 2 - and Cl - were below the China environmental quality standard for surface water. The ratio of dominant anions in wet deposition ( SO 4 2 - / NO 3 - ) was 1.59, whilst that for dry deposition ( SO 4 2 - / Cl - ) was 1.4, indicating that acidity was mainly derived from sulphate. In the case of dominant cations, the dry and wet deposition ratios ( Ca 2 + / NH 4 + ) were 1.36 and 1.37, respectively, suggesting the alkaline substances were mainly dominated by calcium salts. Days with higher recorded concentrations of PM_2.5 were accompanied by dry and warm boundary layer structure, weak low-level wind and strong inversion layer.

A multiregional survey of nickel in outdoor air particulate matter in China: Implication for human exposure

Nickel is a widespread environmental contaminant, and it is toxic to humans in certain forms at high doses. Despite this, nationwide data on nickel in outdoor air particulate matter and human exposure to nickel through inhalation in China are limited. In the present study, 662 outdoor air samples from seven representative provinces such as Shanghai, Hubei, Hunan, Hebei, Guangdong, Yunnan, and Shanxi were collected between March 2013 and February 2014 and analyzed by inductively coupled plasma mass spectrometry. The concentrations of nickel in the air were in the range of 2.1-80.9 ng/m³ (geometric mean: 14.4 ng/m³). In most areas, the concentrations of nickel were higher in winter and spring than those measured in summer and autumn. The daily intake (median) of nickel through inhalation of air particulate matter was estimated. Although the nickel concentrations in some air samples were high, inhalation of the air particulate matter accounted for a minor part of the total nickel intake; however, the adverse effects of human exposure to nickel through inhalation and its potential sources require more attention, particularly in Shanghai. This is a multiregional survey of nickel in outdoor air particulate matter in China.

Particulate pollution in urban Chongqing of southwest China: Historical trends of variation, chemical characteristics and source apportionment

Chongqing, the largest megacity in southwest China, faces serious aerosol pollution but lacks information on particle characteristics and its sources. Official data released by Chongqing Environmental Protection Bureau demonstrated that urban PM₁₀ concentrations decreased remarkably from 150μgm^-3 in 2000 to 90μgm^-3 in 2012. However, only several peer-reviewed studies paid attention to local fine particle (PM_2.5) pollution. In the study, PM_2.5 samples were obtained and subjected to chemical analysis in an urban site of the city during 2012 to 2013. The annual mean PM₁₀ and PM_2.5 concentrations in urban Chongqing were 103.9±52.5 and 75.4±42.2μgm^-3, respectively. PM_2.5 showed a distinct seasonality of high concentration in winter and similar levels in other seasons. The average OC/EC (organic carbon/element carbon) ratio was 3.7 with more high-OC/EC ratio sources contribution in autumn and winter. The varying sources and formation mechanisms resulted in SO₄^2- and NH₄⁺ peaks in both summer and winter, whereas high nitrate concentration was only observed in winter. In the average mass closure, PM_2.5 was composed of 23.0% SO₄^2-, 11.7% NO₃^-, 10.9% NH₄⁺, 30.8% OM (organic matter), 5.2% EC, 8.2% mineral dust, 0.6% TEO (trace elements), 1.0% Cl^- and 1.1% K⁺, while exhibiting large seasonal variability. Using positive matrix factorization (PMF), six sources were apportioned in PM_2.5: secondary inorganic aerosols, coal combustion, other industrial pollution, soil dust, vehicular emission, and metallurgical industry. The annual mean contribution of above sources to PM_2.5 was 37.5, 22.0, 17.5, 11.0, 9.8 and 2.2%, respectively. Coal combustion was identified by As tracer and dominated the primary sources of PM_2.5, while the two different industrial sources were characterized by Cr and Mo, Co, Ni, and Se, respectively. The study is of great importance in characterizing the historical trends, current chemical characteristics and sources of fine particles in urban Chongqing.

Respiratory illness and air pollution from the steel industry: the case of Piquiá de Baixo, Brazil (Preliminary report)

BACKGROUND

This report is based on an independent study carried out by medical professionals of the Fondazione IRCCS Istituto Nazionale dei Tumori (National Cancer Institute) in Milan, Italy, and  aimed to assess the incidence of respiratory diseases in a Brazilian community (Piquiá de Baixo, in the city of Açailandia) exposed to extreme air pollution in connection to a local steel manufacturing plant. The study has the objective to contribute to the existing literature on the health risks associated with fine particle pollution (PM2.5) due to steel production with data from Brazil.

METHODS

The study is based on a cross-sectional sample of the resident population of Piquiá de Baixo age 16 or over consisting of 220 people. We collected data about the health conditions of participant subjects in two ways: a) medical history questionnaires and b) clinical assessment of respiratory function through spirometry testing. The results were evaluated based on comparative studies.

RESULTS

According to the spirometric tests performed, 28 % of the sample population suffers from respiratory pathologies (for the most part of restrictive rather than obstructive nature). This incidence rate is between six and two times higher than those reported in similar studies carried out in other countries (which range between 4.6 and 14.5 %). In addition, the incidence rate is also significantly high in light of the fact that our sample population did not include the category of subjects most at risk for pulmonary disorders in connection to air pollution caused by the Piquiá steel processing complex: in other words, men and women employed in the steel mills or in connection with their industrial cycle (as many as 434 Piquiá residents age 16 and over were unable to participate to our study due to "work-related reasons").

CONCLUSIONS

In light of the above considerations, we believe that our findings contribute to the existing literature on the correlation between pulmonary disease and air pollution in industrialized areas, while warranting further scientific research on the public health consequences of industrial production in Piquiá de Baixo. In turn, on the ethical plane, we believe that research of this nature strengthens the need to advocate for more severe environmental and health policies aimed at limiting the hazards associated with the steel industry in Piquiá and in similar contexts around the world.

Seasonal and spatial differences in source contributions to PM2.5 in Wuhan, China

Fine particle (PM2.5) samples were collected in 2011 and 2012 simultaneously at three sites in Wuhan in an industrial area (ID), downtown Wuhan (DT), and the Wuhan botanical gardens (BG). The annual average concentration of PM2.5 was highest in the industrial area at 180μgm-3 and lowest in the botanical gardens, with an average of 93μgm-3. The average downtown PM2.5 concentration was 113μgm-3. All sites had concentrations well above the World Health Organization (WHO) guidelines and the Chinese air quality standard. The concentration of major constituents of PM2.5 varied seasonally across all sites; specifically, sulfate, nitrate, and organic carbon varied most strongly during spring, followed by summer and fall. Organic carbon varied the most across sites for all seasons, which is attributable to large differences in local source emissions. The major primary sources contributing to OC were vehicle emissions (38.1±8.3%), coal combustion (7.0±6.2%), meat cooking (3.0±1.6%), and biomass burning (3.0±1.0%). All these sources had large seasonal variations across the three sites. Biomass burning had the largest impact at BG, mobile sources had the largest impact at DT, and coal combustion had the largest impact at ID. Mineral dust was a major contributor to PM2.5 (average 16.8±9.6μgm-3) and had very homogenous concentrations across the sites during springtime due to regional dust storms, but had much higher concentration at ID during the summer and fall. The results demonstrate the need for both regional and local air pollution control strategies to reduce air pollution in Wuhan. This research contributes to the field of particulate matter studies by providing information about seasonal and regional fluctuations in PM2.5 in large urban areas, which helps advance understanding of the sources responsible for urban haze.

The fractionation and geochemical characteristics of rare earth elements measured in ambient size-resolved PM in an integrated iron and steelmaking industry zone

Improved understanding of the fractionation and geochemical characteristic of rare earth elements (REEs) from steel plant emissions is important due to the unclear atmospheric signature of these elements and their adverse impact on human health and the environment. In this study, ambient particulate matter of different sizes was collected from one site in an integrated iron and steelmaking industrial zone (HG) and one urban background site with no direct industrial emissions (ZWY) during a 1-year sampling campaign in China. The total concentrations of REEs for TSP, PM10, and PM2.5 were 27.248, 14.989, 3.542 ng/m(3) in HG and 6.326, 5.274, 1.731 ng/m(3), respectively, in ZWY, which revealed the local influence of the steelmaking activities to the air quality. With respect to ZWY, the REEs in HG site are obviously fractionated in the coarser fraction, and LREEs account for more than 80 % of the total REE burden in all of the samples. Additionally, the REEs in HG and ZWY show a homogeneous trend with successively increased LREE/HREE ratios from the coarse particles to the fine particles. In our samples, La, Ce, Nd, and Sm are the most enriched rare earth elements, especially in the HG site. Moreover, ternary diagrams of LaCeSm indicate that the REEs in HG are potentially contributed by steelworks, carrier vehicles, coal combustion, and road dust re-suspension.

Characterization of As and trace metals embedded in PM10 particles in Puebla City, México

Forty-eight air-filter samples (PM10) were analysed to identify the concentration level of partially leached metals (PLMs; As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and V) from Puebla City, México. Samples were collected during 2008 from four monitoring sites: (1) Tecnológico (TEC), (2) Ninfas (NIN), (3) Hermanos Serdán (HS) and (4) Agua Santa (AS). The results indicate that in TEC, As (avg. 424 ng m(-3)), V (avg. 19.2 ng m(-3)), Fe (avg. 1,202 ng m(-3)), Cu (avg. 86.6 ng m(-3)), Cr (41.9 ng m(-3)) and Ni (18.6 ng m(-3)) are on the higher side than other populated regions around the world. The enrichment of PLMs is due to the industrial complexes generating huge dust particles involving various operations. The results are supported by the correlation of metals (Mn, Cd and Co) with Fe indicating its anthropogenic origin and likewise, As with Cd, Co, Fe, Mn, Pb and V. The separate cluster of As, Fe and Mn clearly signifies that it is due to continuous eruption of fumaroles from the active volcano Popocatépetl in the region.

A review on the importance of metals and metalloids in atmospheric dust and aerosol from mining operations

Contaminants can be transported rapidly and over relatively long distances by atmospheric dust and aerosol relative to other media such as water, soil and biota; yet few studies have explicitly evaluated the environmental implications of this pathway, making it a fundamental but understudied transport mechanism. Although there are numerous natural and anthropogenic activities that can increase dust and aerosol emissions and contaminant levels in the environment, mining operations are notable with respect to the quantity of particulates generated, the global extent of area impacted, and the toxicity of contaminants associated with the emissions. Here we review (i) the environmental fate and transport of metals and metalloids in dust and aerosol from mining operations, (ii) current methodologies used to assess contaminant concentrations and particulate emissions, and (iii) the potential health and environmental risks associated with airborne contaminants from mining operations. The review evaluates future research priorities based on the available literature and suggest that there is a particular need to measure and understand the generation, fate and transport of airborne particulates from mining operations, specifically the finer particle fraction. More generally, our findings suggest that mining operations play an important but underappreciated role in the generation of contaminated atmospheric dust and aerosol and the transport of metal and metalloid contaminants, and highlight the need for further research in this area. The role of mining activities in the fate and transport of environmental contaminants may become increasingly important in the coming decades, as climate change and land use are projected to intensify, both of which can substantially increase the potential for dust emissions and transport.

Geochemical evidence for the origin of vanadium in an urban environment

The city of Salamanca in central Mexico is surrounded by heavy industry, i.e., a refinery, a thermoelectric plant and chemical industries. Variable concentrations of vanadium (V) have been reported in the groundwater, and their presence has been related to particulates so this hypothesis was tested by sampling soil in the urban area and the surrounding uncontaminated country site. The 0-10-cm soil layer in the industrial and rural area was analyzed for V and other metal trace elements found in hydrocarbons, i.e., chromium (Cr), lead (Pb), zinc (Zn), and nickel (Ni). The concentrations of V were higher in the urban rather than in the rural soil, reaching values of >600 mg kg(-1) in the urban soils. In the rural area, V in the soil was related to regional geology, i.e., volcanic rocks such as basalts and rhyolites but not in the urban area where it was related to particulate distribution mostly emitted from the industries burning fuel oil number 6.

Toxic metals in the atmosphere in Lahore, Pakistan

Aerosol mass (PM(10) and PM(2.5)) and detailed elemental composition were measured in monthly composites during the calendar year of 2007 at a site in Lahore, Pakistan. Elemental analysis revealed extremely high concentrations of Pb (4.4microg m(-3)), Zn (12microg m(-3)), Cd (0.077microg m(-3)), and several other toxic metals. A significant fraction of the concentration of Pb (84%), Zn (98%), and Cd (90%) was contained in the fine particulate fraction (PM(2.5) and smaller); in addition, Zn and Cd were largely (>or=60%) water soluble. The 2007 annual average PM(10) mass concentration was 340microg m(-3), which is well above the WHO guideline of 20microg m(-3). Dust sources were found to contribute on average (maximum) 41% (70%) of PM(10) mass and 14% (29%) of PM(2.5) mass on a monthly basis. Seasonally, concentrations were found to be lowest during the monsoon season (July-September). Principle component analysis identified seven factors, which combined explained 91% of the variance of the measured components of PM(10). These factors included three industrial sources, re-suspended soil, mobile sources, and two regional secondary aerosol sources likely from coal and/or biomass burning. The majority of the Pb was found to be associated with one industrial source, along with a number of other toxic metals including As and Cr. Cadmium, another toxic metal, was found at concentrations 16 times higher than the maximum exposure level recommended by the World Health Organization, and was concentrated in one industrial source that was also associated with Zn. These results highlight the importance of focusing control strategies not only on reducing PM mass concentration, but also on the reduction of toxic components of the PM as well, to most effectively protect human health and the environment.

Heavy metal induced ecological risk in the city of Urumqi, NW China

A total of 169 samples of road dust collected in the city of Urumqi, capital of the Xinjiang Uygur Autonomous Region in northwest China, were analyzed by method of inductively coupled plasma-mass spectrometry for 10 elements (i.e., Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn, and U). The possible sources of metals are identified with multivariate analysis such as correlation analysis, principal component analysis, and cluster analysis. Besides, enrichment factors are used to quantitatively evaluate the influences of human activities on heavy metal concentrations. Moreover, the potential ecological risk index is applied to evaluating the ecological risk of heavy metal pollutants. The results indicate that: (1) the concentrations of the heavy metals involved were much higher in urban areas than the background values, except those of Co and U. Mn, U, and Co are mainly of natural origin; Cu, Pb, Zn, and Cr are mainly of traffic sources and are partly of industrial sources; Ni and Be are mainly the results of industrial activities, such as machine shops, firepower plants, tire and rubber factories, cement factories, and textile mills and are partly of the traffic sources; (2) with high "toxic-response" factor and high concentration, Cd has more serious influences on the environment than other heavy metals. Therefore, commercial and industrial areas are usually characterized by higher potential ecological risk when compared with residential areas and new developing urban areas. The results of this study could be helpful for the management of environment in industrial areas.