Metals In PM2 Research Articles

Monitoring and evaluating the control effect of dust suppressant on heavy metals based on ecological and health risks: a case study of Beijing.

Dust suppressant is widely applied to control the road dust pollution, while the unified statement on its control effect has not been obtained. To fill this gap, an experiment was conducted at four typical sites in Beijing, where dust suppressant and water were sprayed at test and control sites, respectively. Samples were collected to analyze the concentrations of PM2.5, PM10, and heavy metals. With the application of potential ecological risk index and probabilistic health risk assessment, the ecological and health risks of heavy metals were obtained. Results showed that compared with control sites, the total concentrations of heavy metals in PM10 and PM2.5 at test sites decreased by 1555.40 and 784.95ng/m3 in 14days, with the suppression rate of 11.95% and 12.06%. Especially, the total ecological risks of heavy metals in PM10 reduced from 165.77 to 143.64, with their ecological hazard level changed from medium to slight. The carcinogenic risks of PM2.5 and PM10 reduced by 0.60E-05 and 1.52E-06, respectively. As for the non-carcinogenic risks, there were a reduction of 5.78% and 12.28% for PM2.5 and PM10, respectively. Notably, the ecological risk of Pb was the highest; Cr and Zn contributed the most to carcinogenic and non-carcinogenic risk. Finally, to mitigate road dust pollution from an integration perspective, some preventive measures were proposed.

In vitro assessments of bioaccessibility and bioavailability of PM2.5 trace metals in respiratory and digestive systems and their oxidative potential

Air pollution is a serious environmental issue. As a key aerosol component, PM2.5 associated toxic trace metals pose significant health risks by inhalation and ingestion, but the evidences and mechanisms were insufficient and not well understood just by their total environmental concentrations. To accurately assess the potential risks of airborne metals, a series of in vitro physiologically based tests with synthetic human lung and gastrointestinal fluids were conducted to assess both the bioaccessibility and bioavailability of various PM2.5 bound metals in the respiratory and digestive systems from both urban and industrial areas of Nanjing city. Moreover, the chemical acellular toxicity test [dithiothreitol (DTT) assay] and source analysis were performed. Generally, the bioaccessibility and bioavailability of investigated metals were element and body fluid dependent. Source oriented metals in PM2.5 showed diverse bioaccessibility in different human organs. The PM2.5 induced oxidative potential was mainly contributed by the bioaccessible/bioavailable transition metals such as Fe, Ni and Co from metallurgic dust and traffic emission. Future researches on the toxicological mechanisms of airborne metals incorporating the bioaccessibility, bioavailability and toxicity tests are directions.

Bioaccessibility, source impact and probabilistic health risk of the toxic metals in PM2.5 based on lung fluids test and Monte Carlo simulations

The soluble toxic metals (TMs) in PM2.5 have attracted increasing attention due to their high bioaccessibility and toxic potential. Here, the bioaccessibility of the TMs was determined by simulated lung fluids (SLFs), including acidic artificial lysosomal fluid (ALF) and neutral Gamble’s solution (GS). An extraction time of 48 h was determined by dissolution kinetics. The bioaccessibility for most TMs in ALF was significantly higher than that in GS, especially for Cd and Pb. Five TM sources were identified by positive matrix factorization (PMF), and their correlation with the bioaccessibility of the PM2.5-bound TMs was examined. This showed a significant negative correlation (p < 0.01) of the mass contribution of resuspended dust and a positive correlation (p < 0.01) of that of coal combustion with the bioaccessibility of some TMs, which implicated a limit vs. high potential risk of these two sources. By introducing the variability of the bioaccessibility, the probabilistic noncancer (HQ) and cancer risks (ILCR) of the soluble TMs were estimated by Monte Carlo simulations under both ALF and GS scenarios. This showed that the noncancer risk of As and the cancer risk of most TMs cannot be neglected due to their relatively high probability of exceeding the safety threshold (HQ > 1 and ILCR>1 × 10−6).

Personal exposure to PM2.5-bound heavy metals associated with cardiopulmonary function in general population.

To better understand the cardiopulmonary alterations associated with personal exposed PM2.5-bound heavy meals, we conducted a cross-sectional study in 2018 on 54 general residents. For each subject, PM2.5 exposure filter was collected by a low-volume sampler for 24h; blood and urine samples were collected subsequently. Heavy metals in PM2.5, blood, and urine samples were determined by inductively coupled plasma mass spectrometry method. PM2.5-bound Mn, Cd, Sb, Pb, and Ni levels were 20.5, 9.27, 9.59, 28.3, and 16.9ng/m3, respectively. The distribution of these metals followed the order: Pb (33.47%) > Mn (24.24%) > Ni (19.99%) > Sb (11.34%) > Cd (10.96%). The distribution of heavy meals in PM2.5, blood, and urine differed from each other. PM2.5-bound Cd, Pb levels were positively correlated with blood Cd, Pb levels (r= 0.323, r= 0.334, p< 0.05), respectively. PM2.5-bound Cd level was significantly higher in smoking group than non-smoking group (28.8 vs. 7.27ng/m3, p< 0.01), same as Sb level (12.0 vs. 9.34ng/m3, p< 0.01). Cd and Pb exposure might interact with cardiovascular function through autonomic regulation. No significant correlation was observed between metal exposure and pulmonary function. In conclusion, our data suggested that personal exposure to specific PM2.5-bound heavy metals might interact with profound cardiovascular alterations.

Health Risk Assessment of Heavy Metals Accumulated on PM2.5 Fractioned Road Dust from Two Cities of Pakistan.

The aim of this study is to identify and investigate levels of toxic heavy metals in PM2.5 fractioned road dust to better understand the associated inhalation risk and potential health impacts. To achieve this aim, concentrations of seven traffic generated heavy metals (Cu, Pb, Zn, Cd, Ni, Sb, and Cr) were determined in the PM2.5 fraction of road dust samples from four different locations (offices, residential, hospital, and school) in two cities (Karachi and Shikarpur) of Pakistan using ICP-MS. The average concentration values of heavy metals in Karachi were as follows: 332.9 mg/kg Cu, 426.6 mg/kg Pb, 4254.4 mg/kg Zn, 62.3 mg/kg Cd, 389.7 mg/kg Ni, 70.4 mg/kg Sb, 148.1 mg/kg Cr, whereas the average concentration values of heavy metals in Shikarpur were 245.8 mg/kg Cu, 538.4 mg/kg Pb, 8351.0 mg/kg Zn, 57.6 mg/kg Cd, 131.7 mg/kg Ni, 314.5 mg/kg Sb, 346.6 mg/kg Cr. The pollution level was assessed through two pollution indices enrichment factor (EF) and geoaccumulation index (Igeo). These indices showed moderate to extreme level pollution in studied areas of both cities. The health risk assessment through inhalation contact was conducted according to the United States Environmental Protection Agency’s (USEPA) model for children and adults. Both non-cancerous and cancerous risks were characterised in the road dust samples for each location. As yet, there is not a single study on the concentrations of heavy metals in PM2.5 fractions of road dust in Karachi and Shikarpur, findings of this research will facilitate researchers for further investigations in current field.

Seasonal variations, source apportionment, and health risk assessment of trace metals in PM2.5 in the typical industrial city of changzhi, China

Studying the source-specific health risks of trace metals in PM2.5 is important for controlling its emission sources that are hazardous to human health. In this study, PM2.5-bound trace metals were analyzed during winter, spring, summer, and autumn in 2018 in Changzhi, a typical industrial city in China. The results revealed that the annual concentration of total trace metals in PM2.5 was 7531.9 ng m−3 in the study area, and the concentration was maximum in spring (14,781.7 ng m−3), followed by autumn (7163.8 ng m−3), winter (5237.0 ng m−3), and summer (3226.1 ng m−3). Dry and continual windy days in spring often led to high concentrations of trace metals in Changzhi. Trace metals with high enrichment factor (>100), such as Cd, Sn, Pb, and Zn, were predominantly released from coal combustion. Four sources, such as coal combustion, traffic emissions, resuspended dust, and industry, were established by positive matrix factorization, with contributions to PM2.5-bound trace metals of 29.5%, 26.6%, 26.3%, and 17.6%, respectively. In terms of their contribution to cancer risk, the top contributor both for children and adults was industry, with 1.50×10−6 and 5.99×10−6, respectively, both of which were higher than the safe level (1 × 10−6); coal combustion ranked second (0.49 × 10−6 and 1.94 × 10−6 for children and adults, respectively). In addition to the advancement of control measures for pollutants and control of industrial production, more attention should also be given in limiting coal consumption through the use of clean energy (e.g., natural gas).

Modeling Transition Metals in East Asia and Japan and Its Emission Sources.

Emission inventories of anthropogenic transition metals, which contribute to aerosol oxidative potential (OP), in Asia (Δx = 0.25°, monthly, 2000–2008) and Japan (Δx = 2 km, hourly, mainly 2012) were developed, based on bottom‐up inventories of particulate matters and metal profiles in a speciation database for particulate matters. The new inventories are named Transition Metal Inventory (TMI)‐Asia v1.0 and TMI‐Japan v1.0, respectively. It includes 10 transition metals in PM2.5 and PM10, which contributed to OP based on reagent experiments, namely, Cu, Mn, Co, V, Ni, Pb, Fe, Zn, Cd, and Cr. The contributions of sectors in the transition metals emission in Japan were also investigated. Road brakes and iron‐steel industry are primary sources, followed by other metal industry, navigation, incineration, power plants, and railway. In order to validate the emission inventory, eight elements such as Cu, Mn, V, Ni, Pb, Fe, Zn, and Cr in anthropogenic dust and those in mineral dust were simulated over East Asia and Japan with Δx = 30 km and Δx = 5 km domains, respectively, and compared against the nation‐wide seasonal observations of PM2.5 elements in Japan and the long‐term continuous observations of total suspended particles (TSPs) at Yonago, Japan in 2013. Most of the simulated elements generally agreed with the observations, while Cu and Pb were significantly overestimated. This is the first comprehensive study on the development and evaluation of emission inventory of OP active elements, but further improvement is needed.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in Road Dust from Non-ferrous Smelting Parks

In order to explore the pollution characteristics and health risks of heavy metals in dust from roads around non-ferrous smelting activities in different regions, dust samples from urban roads, non-ferrous smelting industry park roads, and tunnel roads were collected from the Mengzi area of Yunnan Province. The dust samples were suspended on Teflon filters by re-suspension equipment to obtain PM2.5 and PM10 samples. Eight heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) were analyzed by ICP-MS. The results showed that the average content of the total heavy metals in PM2.5 was higher than that in PM10. The average contents of Pb, Cd, As, and Zn were highest in all three types of road dust, and the difference in the total average content in different types of road dust was ranked as:tunnel roads > non-ferrous smelting industrial park roads > urban roads. The average contents of Pb and As in PM2.5 from the tunnel road dust were higher than other heavy metals, and reached up to 92338.3 mg·kg-1 and 12457.7 mg·kg-1, respectively. The average contents of Pb and Zn in PM2.5 from the industrial park road dust were the highest of all heavy metals (4381.7 mg·kg-1 and 4685.0 mg·kg-1, respectively). The average content of Zn and Pb in PM2.5 were the highest of all the heavy metals in the urban road dust (1952.6 mg·kg-1 and 1944.8 mg·kg-1, respectively). The average contents of Cu, Zn, As, Cd, and Pb in the different types of road dust were all higher than their background values in Yunnan Province. The results of the enrichment factor analysis and principal component analysis indicated that Cu, Zn, As, Cd, and Pb were obviously enriched in all three types of road dust, which were significantly affected by the non-ferrous smelting industry and traffic sources. In contrast, Cr, Mn, and Ni were not obviously enriched in the three types of road dust and were less affected by anthropogenic sources. The results of the health risk assessment testified that ingestion was the main exposure route, and that the children's non-carcinogenic risk was higher than that of adults. In PM2.5, As, Cd, and Pb in all types of road dust were associated with non-carcinogenic risks for adults and children. In PM10, As, Cd, and Pb in dust from the non-ferrous smelting industry park roads and tunnel roads had non-carcinogenic risks for humans. As in PM10 from the urban road dust was associated with a non-carcinogenic risk for children, whereas As in dust from the tunnel roads had carcinogenic risks.

Human health risk assessment for toxic elements in the extreme ambient dust conditions observed in Sistan, Iran

This study evaluates the bioaccessibility and health risks related to heavy metals (Cd, Cr, Co, Cu, Mn, Ni, Pb, Zn and metalloid As) in airborne dust samples (TSP and PM2.5) in Zabol, Iran during the summer dust period, when peak concentration levels of PM are typically observed. High bioaccessibilities of carcinogenic metals in PM2.5 (i.e. 53.3%, 48.6% and 47.6% for Ni, Cr and As, respectively) were calculated. The carcinogenic and non-carcinogenic health risks were assessed for three exposure pathways (inhalation, ingestion and dermal contact), separately for children and adults. Non-carcinogenic inhalation risks were very high (Hazard Index: HI > 1) both for children and adults, while the carcinogenic risks were above the upper acceptable threshold of 10−4 for adults and marginally close (5.0–8.4 × 10−5) for children. High carcinogenic risks (>10−4) were found for the ingestion pathway both for children and adults, while HI values > 1 (8.2) were estimated for children. Carcinogenic and non-carcinogenic risk estimates for dermal contact were also above the limits considered acceptable, except for the carcinogenic risk for children (7.6 × 10−5). Higher non-carcinogenic and carcinogenic risks (integrated for all elements) were associated with the inhalation pathway in adults and children with the exception of carcinogenic risk for children, where the ingestion route remains the most important, while As was linked with the highest risks for nearly all exposure pathways. A comparative evaluation shows that health risks related with toxic elements in airborne particles in Sistan are among the highest reported in the world.

Wintertime carbonaceous species and trace metals in PM10 in Darjeeling: A high altitude town in the eastern Himalayas

Carbonaceous components [organic carbon (OC), elemental carbon (EC), water soluble organic carbon (WSOC), primary organic carbon (POC), secondary organic carbon (SOC) and carbonaceous aerosols (CAs)] and major and trace elements (Na, Mg, Ca, Al, Fe, Ti, Cl, P, S, K, Cr, Ni, Cu, Zn, Mo and B) of PM10 were studied over the eastern Himalayan high altitude station [Darjeeling: 27.01°N and 88.15°E, 2200 m average mean sea level (amsl)] during winter 2018–19 (December 2018–February 2019). The carbonaceous aerosols/species (CAs) contributed to ~23% of PM10 mass concentration, whereas major and trace elements accounted for 10% of PM10. During the entire study period, the average concentrations of PM10, OC, EC, WSOC, POC, SOC and CAs were recorded as 48 ± 16 μg m−3, 5.39 ± 1.84 μg m−3, 2.60 ± 0.94 μg m−3, 3.87 ± 1.18 μg m−3, 3.40 ± 1.23 μg m−3, 1.99 ± 1.03 μg m−3 and 11.21 ± 3.78 μg m−3, respectively. Significant positive correlation between OC & EC and OC & WSOC have been observed which are indicating their common sources. WSOC/OC ratio was estimated to be 0.71 suggesting that the biomass burning is one of the major sources of carbonaceous aerosols at Darjeeling during winter. The significant positive correlation of PM10 with crustal elements (Al, Fe, Ca, Mg and Ti) as well as the correlation of Al with other crustal elements (Fe, Ca, Mg and Ti) indicates the abundance of mineral dust at the sampling site. Principal component analysis (PCA) identified the contribution of crustal/soil dust, biomass + coal burning, vehicular emissions and solid waste to the PM10 over the eastern Himalayan region of India.

Multi-Year Concentrations, Health Risk, and Source Identification, of Air Toxics in the Venice Lagoon

This work presents and discusses the results of measurements of PM10 concentrations and of its content in metals, obtained in three different sites of the Venice lagoon area where the construction of the MOSE (Modulo Sperimentale Elettromeccanico-Electromechanical Experimental Module) mobile dams was going on. Measurements were taken between 2010 and 2015 and the spatial and seasonal variability of metals and PM10 concentration were discussed. The aim of the work is to get information on the air quality in the lagoon area related to the presence of toxic metals in particulate matter produced by construction activities. Additional measurements of PAHs concentration in gas and particle phases, and the related health risk assessment, were carried out in two out of the three sites, in order to enhance the knowledge about the air quality near the construction yards. Diagnostic ratios have been calculated for the purpose of investigating the PAH sources of the area. PM10 was collected using low volume sequential aerosol samplers, with quartz filters carefully decontaminated in an atmosphere-controlled laboratory. Inorganic elements (V, Cr, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) in PM10 samples were measured by ICP-MS. Samples for PAH analyses were collected using a high-volume air sampler that allows to sample both gaseous and particulate PAH simultaneously. Gaseous PAHs were collected on pre-cleaned polyurethane foams and particulate PAHs on pre-combusted quartz fiber filters. Samples for PAHs determinations were analyzed by GC-HRMS. Results showed limited differences in metals' and PAHs' concentrations between the sites, indicating a relatively homogeneous spatial distribution of metals in PM10 and PAHs in the Venice lagoon area. Temporal trends furthermore give indication of a slight decrease in PAHs and PM10 concentration in Punta Sabbioni and in its content of Pb, Zn, and Sb. The health risk assessment showed that congeners that most contributed to the carcinogenicity of the mixture were benzo(a)pyrene e dibenzo(A,H)anthracene, mainly in the particulate phase. The study provides an important multi-years trend of chemical characterization of the Venice lagoon aerosol and about air quality in terms of toxic chemicals concentration in the atmosphere.

Characteristics, Emission Sources, and Risk Factors of Heavy Metals in PM2.5 from Southern Malaysia

Exposure to fine particulate-bound toxic metals in ambient air poses adverse effects to human. This study aims to determine the spatial variability in heavy metals in PM2.5 samples, for identifying...

Characteristics and health risk assessments of heavy metals in PM2.5 in Taiyuan and Yuci college town, China

To clarify the pollution sources of heavy metals in PM2.5 and the health risks posed by them in heating and non-heating seasons, 42 samples were collected in 2017 and 2018 in Taiyuan and Yuci college town, China. Elemental analysis of the PM2.5 samples through acid-dissolved plasma mass spectrometry was performed to determine the concentrations of 10 elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn). We determined the types of pollution sources by enrichment factor (EF) and principal component analysis (PCA). We performed a health risk assessment based on the US Environmental Protection Agency (EPA) guidelines and the database of the International Agency for Research on Cancer (IARC) to assess both carcinogenic and non-carcinogenic risks of the heavy metals to adults and children. The results indicate that the EF values of all 10 elements were greater than 1, suggesting anthropogenic sources in both heating and non-heating seasons. PCA revealed that the three main components were soot dust, metal smelting emission, and industrial dust. Regarding the health risks caused by the heavy metals, children were more susceptible to non-carcinogenic risks than adults, and people faced higher non-carcinogenic risks during the heating season. For carcinogenic risk, Cr has the highest risk coefficient (1.68 × 10−4), higher than the US EPA’s threshold (1.00 × 10−6). People were exposed to carcinogenic risk. The study explored specific pollution sources and explained their effect on health to assist with the development of prevention and control measures.

Analysis of PM10, Pb, Cd, and Ni atmospheric concentrations during domestic heating season in Sarajevo, Bosnia and Herzegovina, from 2010 to 2019

This paper examines atmospheric concentrations of particulate matter with an aerodynamic diameter smaller than 10 μm (PM10) and related particle-phase toxic heavy metals Cd, Ni, and Pb during domestic heating seasons from 2010 to 2019 in Sarajevo, Bosnia and Herzegovina. In total, 242 daily PM10 samples were collected using medium and high volume air samplers. The mean daily PM10 mass concentration for all measurements is 75.16 μg/m3 (with the range of 28.77–149.00 μg/m3). Variation of ambient PM10 was observed throughout the study in different years. Hourly values for PM10 measurements during two heating seasons are also presented. Metal concentrations in PM10 were analyzed by electrothermal atomic absorption spectrometry (ETAAS). Quantities of atmospheric mass concentrations of studied trace metals were observed in the following order: Pb > Ni > Cd. The mean concentrations of metals varied with Pb showing the highest concentration (ranging from 1.38 to 234.00 ng/m3), Ni ranging from 0.87 to 42.43 ng/m3, and Cd showing the lowest concentration ranging from 0.26 to 10.09 ng/m3. The concentration of Pb and Cd in PM10 was strongly correlated, suggesting a common source or dependence of these metals in PM10 in Sarajevo. Bioaccessibility of metals in the synthetic gastric juice was also estimated. The quantities of average bioaccessible metal fractions in PM10 samples showed the following trend: Cd > Pb > Ni. The health risk assessment shows that the population of Sarajevo is at increased lifetime risk of experiencing cancer because of exposure to these Cd concentrations in PM10. In addition, parallel PM10 sampling on two samplers showed that obtained results are highly comparable.

Indoor generated PM2.5 compositions and volatile organic compounds: Potential sources and health risk implications

The aim of the present study was to investigate the potential sources of heavy metals in fine air particles (PM2.5) and benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) in gas phase indoor air. PM2.5 samples were collected using a low volume sampler. BTEX samples were collected using passive sampling onto sorbent tubes and analyzed using gas chromatography-mass spectrometry (GC-MS). For the lower and upper floors of the evaluated building, the concentrations of PM2.5 were 96.4 ± 2.70 μg/m3 and 80.2 ± 3.11 μg/m3, respectively. The compositions of heavy metals in PM2.5 were predominated by iron (Fe), zinc (Zn), and aluminum (Al) with concentration of 500 ± 50.07 ng/m3, 466 ± 77.38 ng/m3, and 422 ± 147.38 ng/m3. A principal component analysis (PCA) showed that the main sources of BTEX were originated from vehicle emissions and exacerbate because of temperature variations. Hazard quotient results for BTEX showed that the compounds were below acceptable limits and thus did not possess potential carcinogenic risks. However, a measured output of lifetime cancer probability revealed that benzene and ethylbenzene posed definite carcinogenic risks. Pollutants that originated from heavy traffic next to the sampling site contributed to the indoor pollution.

A Study on Characteristics of Heavy Metal Elements in Atmospheric PM2.5 During Winter in Chengdu

This paper conducted an in-depth analysis on the characteristics of components of heavy metals in PM2.5 by studying the atmospheric heavy metal elements during winter in Chengdu. On the basis of the limiting value of heavy metal element concentration in PM2.5 in major cities at home and abroad and the national standard limiting value on heavy metal element concentration, this paper compared and evaluated the pollution level of heavy metal elements in PM2.5 during winter in Chengdu and analyzed the typical characteristics of heavy metal elements in haze days and non-haze days as well as the potential sources. The following conclusions were drawn: 1) in PM2.5 during winter in Chengdu, the major component was K, minor components were Fe, Ca, Zn, Cu, Pb, Ba, Mn, As, Cr and Cd, trace components were Se, Ag, Hg, Ni, V, Au and Ga and ultra-trace components were Co, Sb, Ti and Sn, and the proportion of the aforementioned components was 2.10706%, 2.14783%, 0.01933% and 0.00009% respectively; 2) the major component, minor component, trace component and ultra-trace component of heavy metal elements respectively accounted for 1.621%, 1.641%, 0.016% and 0.00004% of PM2.5; 3) the proportion of all the heavy metal components in PM2.5 in haze days was lower than that in non-haze days, which indicates that the relatively high concentration of PM2.5 might be caused by non-metallic salts; 4) in PM2.5, the proportion of Pb, Cd, Mn and Cu was lower than both the domestic average level and the international average level; the proportion of Zn and Ni was at the domestic average level but slightly higher than the international average level; and the proportion of As was at both the domestic average level and the international average level; 5) the mean value of Pb concentration during winter was 0.08717µg/m3, which was lower than the limiting value of the national standard GB 3095-2012; and 6) there was a rather high level of consistency between such elements as were K, Ca, Fe, Zn and Ag as well as PM2.5 on the typical haze day, which shows that obvious colinearity existed in the emission source of the aforesaid elements and such elements might come from road dust sources; on the typical non-haze day, random-peak daily variation occurred in heavy metal components, which might result from unorganized emission from peripheral pollution sources; however, the proportion of ultra-trace components of heavy metals on the typical non-haze day was slightly higher than that on the typical haze day, which might be closely related to the local background transmission.

Specific sources of health risks caused by size-resolved PM-bound metals in a typical coal-burning city of northern China during the winter haze event

High particulate matter (PM) pollution frequently occurs in winter over northern China , resulting in threats to human health. To date, there are limited studies to link source apportionments and health risk assessments in the different size-resolved PM samples during high PM events. In this study, size-segregated PM samples were collected in Linfen, a typical coal-burning city, in northern China during a wintertime haze pollution. In addition to water-soluble ions and carbon contents, metallic elements in the different size-segregated PM samples were also determined for health risk assessments by inhalation of PM. During the sampling period, the average concentration of PM10 was 274 ± 57 μg m−3 with a major fraction (73%) of organic material and secondary-related aerosols, and an insignificant portion of trace elements (TEs, ~ 3%). The size distribution showed that As and Se, markers of coal combustion, exhibited a mono-modal distribution with a major peak at 0.4–0.7 μm and the others mostly possessed mono−/bi-modal patterns with a major peak at 3.3–5.8 μm. The cancer risk (CR) resulted from PM10 metals by inhalation was estimated to be 2.91 × 10−5 for children and 7.75 × 10−5 for adults while non-cancer risk (NCR) was 2.10 for children and 0.70 for adults. Chromium (Cr) was the dominant species (~89%) of cancer risk in PM10. Road dust was a major fraction (~65%) to total metals in coarse PM (dp > 3.3 μm) whereas coal combustion was a dominant source (~55%) in submicron (dp < 1.1 μm) PM metals. However, traffic emissions (40%) and coal combustion (36%) were the dominant sources of CR since both emissions contributed major fractions (74%) to Cr, especially in submicron PM which exhibited high deposition efficiency of TEs into respiratory tracts, resulting in high CR in Linfen City.

Effects of heating activities in winter on characteristics of PM2.5-bound Pb, Cd and lead isotopes in cities of China

Fossil fuel combustion was often mentioned as the most important source of air pollution, but coal-fired heating was rarely isolated to discuss its impact on air quality. In winter, the northern part of China will carry out a large area of continuous coal-fired heating activities, which contributes to a high degree of heavy metals in PM2.5. And combined with the liquidity of atmospheric particles, tends to create regional and even international problems. But many air control policies ignore this control measure. Twenty-five representative cities in heating and non-heating area in China were selected for spatial difference analysis of PM2.5-bound Pb and Cd. In addition, using the HYSPLIT model and Pb isotope ratios to verify whether coal-fired heating in heating areas (Tianjin) contribute to heavy metals in atmospheric particulate matter in non-heating areas (Shanghai). Results showed that the average Pb and Cd concentrations in the heating cities were 3.5 and 2.9 times of those in the non-heating cities, respectively. Long-distance transportation would affect the concentrations of PM2.5 in Shanghai and Tianjin, while coal-fired emissions from heating cities had a greater impact on PM2.5-bound heavy metal concentrations in non-heating cities. Therefore, cross-border environmental impact assessments need to be standardized, and monitoring of regional activities need to be strengthened.

PM2.5 monitoring during a 10-year period: relation between elemental concentration and meteorological conditions.

Four monitoring campaigns between the years 2009 and 2018 were conducted in Córdoba City, Argentina, to detect toxic metals in PM2.5 samples. The concentrations of As, Cd, Pb, Cu, Cr, Mn, Hg, Ni, and Zn, together with several other elements, were measured. The average metal concentrations followed the order: Zn > Cr > Cu > Mn > Pb > V > Ni > As ~ Sb > Cd > Tl > Pd > Hg > Pt. From the analysis of the temporal variation in the elemental concentration of PM2.5, results show seasonal variations that reach, in general, a maximum in the coldest seasons and a minimum in the warmer seasons. These differences could be explained by the different weather conditions during each season, the influence of the El Niño/La Niña regimen, and the presence of fires on certain sampling dates. The source apportionment analysis performed for the period 2017-2018 showed the contribution to PM2.5 of combustion of heavy fuel oil and diesel-powered vehicles, pet coke, metallurgical and nonferrous industries, paint plant factory, traffic, and natural sources like the soil and road dust. This last analysis completed the assignment of sources for the 10-year period of study. Thus, the results of this work contribute to the implementation of emission reduction strategies in order to decrease the impact of PM2.5 on the environment and the human health.

Chemical characteristics and health risks of trace metals in PM2.5 from firework/firecracker burning during the Spring Festival in North China

Firework/firecracker (FF) burning can significantly deteriorate air quality, whereas little is known about its influences on the elemental composition and associated health risks. Fine particles (PM2.5) and trace elements were characterized based on a multi-site campaign at Chifeng, China around 2016 Chinese Spring Festival (SF). Severe pollution levels average of 57.70 μg m−3 were observed during the SF with maximum to 471.00 μg m−3 shortly after the intensive FF activities. Largely enhanced PM2.5-bound metals were found in both urban and rural sites especially for K (8.27±5.36 μg m−3) and Al (2.36±1.41 μg m−3). Ba and Sr as the tracer of fireworks also increased more than 20-fold compared to non-SF period. Accordingly, FF burning factor identified via PMF model contributed significantly to the total elemental mass (71.34±24.94%) during the SF. Its major impacts on both crustal elements as Al, Ca, K and heavy metals as Cr, Cu and Pb were both identified. Elevated non-cancer risks (0.76 to children, 0.11 to adults) and cancer risks (3.96 × 10−6) were assessed during the SF, with As, Cd, Pb exerted the most adverse threats. The FF burning contributed the second largest share of the health threats after coal combustion, accounted for 28.35% and 12.64% of non-cancer risks for children and adults, respectively, and 10.03% of cancer risks, respectively. This study provided scientific evidences for stricter firework/firecracker regulations to protect public health.