Metals In PM2 Research Articles

Emerging investigator series: aqueous-phase processing of atmospheric aerosol influences dissolution kinetics of metal ions in an urban background site in the Po Valley.

Metals are an important atmospheric aerosol component; their impacts on health and the environment depend also on their solubility, dissolution kinetics and chemical form in which they are present in the aerosol (e.g., oxidation state, inorganic salt or oxide/hydroxide, organic complex). In this study, we investigated the impact of fog processing on the solubility and dissolution of metals in PM2.5 samples collected in an urban background site in Padova (Italy). For each sample, we determined the solubility and dissolution kinetics of 17 elements in a solution simulating fog water in the winter season in the Po Valley (pH 4.7, T 5 °C, and water content ∼0.5 g m-3). We also determined water-soluble inorganic and organic compounds having ligand properties. We used the model E-AIM IV to calculate the aerosol liquid water (ALW) content and pH, and we used the model Visual MinteQ to determine the speciation picture of the most important elements under conditions of both deliquescent aerosol (ALW and pH calculated using E-AIM IV, ambient temperature) and simulated fog. We found that the dissolution of Al, Cu, and Fe metal ions, predicted to be largely coordinated with organic compounds under fog conditions, was either immediate or considerably faster in samples collected on days with observed fog events compared with those collected on days having drier conditions. For readily soluble elements, such as As, Cd, Cr, Sr, and Zn, such an effect was not observed. Our study highlights the importance of coordination chemistry in atmospheric aerosol and fog in determining the bioavailability of particle-bound metals.

Source Apportionment and Risk Estimation of Heavy Metals in PM10 at a Southern Vietnam Megacity

Airborne particulate matter (PM) pollution is a global concern, in which partitioned heavy metals (HMs) could impose great risks to residents living in metropolitan areas. In this study, PM10 samples were collected in Ho Chi Minh City (HCMC) – a megacity in southern Vietnam – and analyzed for 11 HMs to investigate their concentration profiles, perform source apportionment and estimate their risk factors. Results showed that atmospheric HMs concentration decreased following the order of Al > Fe > Sr > Mn> Pb > Cu > Cr > V > Ni > Sb > As. Traffic activities were likely the major cause of rush-hour peaks for most HMs in which Cr, As, and Cu showed > 20% increases in their relative proportions. For seasonal variation, most HMs showed a dry > rainy pattern as a result of washout by higher rainfall in the rainy season while crustal elements (Al, Sr, Mn) showed a rainy > dry pattern and might be explained by the difference in air mass transport modulating by monsoon activities. The positive-matrix factorization (PMF) model revealed 5 primary sources for HMs, including traffic emission, shipping activity and combustion activity, fugitive dust re-suspension and waste incineration. Combustion activity might enrich As, Sb, Pb levels at HCMC, and As contributed half (50.8%) to the potential ecological risk (PER) in the city. Besides, the current Cr level could impose a carcinogenic effect towards children in HCMC (total carcinogenic index > 10-4) while Mn might impose intolerable non-carcinogenic risk (hazard index > 1). This study provides information on local air quality status for scientific and regulatory perspectives as well as helps fill the information gap and update the understanding of air pollution in South and Southeast Asia.

Potential years of life lost due to PM2.5-bound toxic metal exposure: Spatial patterns across 60 cities in China

To clarify the spatial patterns of disease burden caused by toxic metals in fine particulate matter (PM2.5) across China, annual concentration levels of typical toxic metals in PM2.5 over 60 cities of China were retrieved. Then, potential years of life lost (PYLL) attributable to toxic metal (As, Cd, Cr (VI), Mn, and Ni) exposure was calculated from health risk assessments and lifetable estimates. The results show that Cr(VI) and As were the most polluted metals and greatly exceeded the recommended annual values in the National Ambient Air Quality Standard of China. PYLL for each death (mean ± standard deviation) of 19.8 ± 4.5 years was observed for lung cancer, followed closely by COPD and pneumonia. Furthermore, the PYLL rate (years per 100,000 people) attributable to exposure to these toxic metals was 457 (male: 505, female: 402) years for different cities; therein, Cr(VI) contributed the highest PYLL among these toxic metals, with a proportion of 72.7% (male: 75.3%, female: 69.5%), followed by As of 16.4% (male: 13.8%, female: 19.8%). The concentration level and PYLL both showed large spatial variability, of which the top-ranking cities were observed to be affected by well-developed metal-related industries and coal-powered industrial sectors.

Composition, sources, and health risk assessment of particulate matter at two different elevations in Delhi city

The PM10 and PM2.5 source apportionment and health risk assessment were performed for two different elevations (lower elevation (LE) ∼5–10 m and higher elevation (HE) ∼30–45 m) at four different locations of Delhi city during January 2017–March 2017. The measured 24-h average PM10 and PM2.5 concentrations at different locations were found between 134.7 and 257.7 μg/m3 and 78.7–121.1 μg/m3, respectively. The 24-h average PM10 and PM2.5 concentrations at the study sites were exceeding the national (NAAQS) and WHO limits by more than 1.3 and 3 times, respectively. The PM mass was enriched with carbonaceous matter, ions, crustal and trace elements and their concentrations (except, Sr, Ni, S, As, V, Sb, Ga- the trace elements associated with coal and heavy oil combustion & NO3− - due to high nitrate formation ability at greater heights) were found higher in LE. The source apportionment study was performed with positive matrix factorisation (PMF). PMF analysis identified vehicular emission (PM10, 9.6–24.3% & PM2.5, 12.1–25.3%), secondary inorganics (PM10, 6.4–22.5% & PM2.5, 11–23%), crustal source (PM10, 9–52% & PM2.5, 3.8–10.7%), fuel oil combustion (PM10, 3–21% & PM2.5, 9–23%), biomass burning (PM10, 7.4–28.6% & PM2.5, 6–50.5%), and coal combustion (PM10, 13–17% & PM2.5, 14–19.1%) as the main sources of PM10 and PM2.5 at the study sites. A significant difference in source contribution between the elevations was observed for coal combustion, fuel oil combustion, biomass burning, and crustal sources. The contribution of vehicular emission and secondary inorganics estimates were broadly similar at both elevations. Coal and fuel oil combustion contribution was found relatively higher at HE. Further, health risk due to exposure to toxic heavy metals in PM2.5 was assessed. Non-carcinogenic and carcinogenic risks (averaged of four sites) for both children and adults were exceeding the acceptable limit by more than 1.13 times. Results also showed that the public residing at HE is more susceptible to have greater health risks than LE at Delhi city. Sources contribution to carcinogenic risk was assessed and the results indicated that coal combustion (41%) contribution was highest followed by crustal sources (22%), fuel oil combustion (17%), vehicular emission (12%), biomass burning (4%) and secondary inorganics (4%).

Concentrations of heavy metals in PM2.5 and health risk assessment around Chinese New Year in Dalian, China

Abstract Twelve samples of heavy metals were analyzed by using a 1108A-1 mid-current particle sampler in Dalian, Liaoning Province, for 31 days before and after the spring festival 2019. The results showed that the concentrations of heavy metals were decreased by more than 25% during the spring festival, which was probably due to the shutdown of the factories and the decrease in people’s travel. During the spring festival, the concentration of Ba was increased by 343.39% as compared to the concentration of Ba before the spring festival, which indicated that the fireworks had a great influence on the concentration of Ba. At the same time, this study also evaluated the health risk of heavy metals. For the heavy metals As, Cd, Co, Cr, and Ni, the lifetime cancer risk was found to be 2.13 × 10−4, 2.08 × 10−5, 8.64 × 10−7, 4.39 × 10−4 and 7.93 × 10−7, respectively. The lifetime cancer risk of As, Cd, and Cr exceeds the threshold range of cancer risk (10−6–10−4), indicating that they are carcinogenic to humans. Also, during the spring festival, the non-carcinogenic risk value of V exceeded the limit value of environmental protection agency (EPA), and the lifetime carcinogenic risk value of As, Cd, and Cr exceeded the threshold range of carcinogenic risk; hence, they need to be carefully monitored and controlled.

Concentrations, Source Characteristics, and Health Risk Assessment of Toxic Heavy Metals in PM2.5 in a Plateau City (Kunming) in Southwest China.

To explore the mass concentration levels and health risks of heavy metals in the air in dense traffic environments, PM2.5 samples were collected at three sites in the city of Kunming in April and October 2013, and January and May 2014. Ten heavy metals––V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb––were analyzed by ICP–MS, and the results showed PM2.5 concentrations significantly higher in spring and winter than in summer and autumn, especially for Zn and Pb. The concentration of heavy metals on working days is significantly higher, indicating that vehicle emissions are significant contributors. An enrichment factor analysis showed that Cr, Mn, Ni, Cu, Zn, As, Cd and Pb come mainly from anthropogenic sources, while V and Co may be both anthropogenic and natural. The correlation and principal component analysis (PCA) showed that Ni, Cu, Zn, Cd and Pb mainly come from vehicles emissions and metallurgical industries; Cr and Mn, from vehicles emissions and road dust; and As, mainly from coal combustion. The health risk assessment shows that the non-carcinogenic risk thresholds of the heavy metals in PM2.5 to children and adult men and women are all less than 1. The carcinogenic risk of Cr for men and women in traffic-intensive areas exceeds 10−4, reaching 1.64 × 10−4 and 1.4 × 10−4, respectively.

The heavy metals in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area

To compare the pollution characteristics and sources of heavy metal in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area in winter of Qian'an City, PM2.5 samples were collected in January 2016. The methods of EF and PCA were used to discuss the sources of heavy metal in PM2.5. The results showed that the average concentration indoor and outdoor PM2.5 were 128.45 and 46.27 μg/m3) in coal-fired area, 66.64 and 29.82 μg/m3 in non-coal-fired area. The ratio of I/O was more than one for Cr, Cu, Zn, Cd and Pb, and lower one for Ni indoor and outdoor environment. Indoor sources were more contributed to Cr in coal-fired area. About 4% of Ni, 40% Cu, 64% Zn, 62% Cd, 54% Pb entered indoor from outdoor for coal-fired area. The 11% of Ni entered indoor from outdoor for non-coal-fired area. EF and PCA method indicated that coal combustion and metal smelting was main contributor for indoor PM2.5, however metal smelting was main sources for outdoor PM2.5. The present study suggested that the central heating and industry reduction would effectively improve indoor air quality in rural-urban fringe zone.

Insights into Elemental Composition and Sources of Fine and Coarse Particulate Matter in Dense Traffic Areas in Toronto and Vancouver, Canada.

Traffic is a significant pollution source in cities and has caused various health and environmental concerns worldwide. Therefore, an improved understanding of traffic impacts on particle concentrations and their components could help mitigate air pollution. In this study, the characteristics and sources of trace elements in PM2.5 (fine), and PM10-2.5 (coarse), were investigated in dense traffic areas in Toronto and Vancouver, Canada, from 2015–2017. At nearby urban background sites, 24-h integrated PM samples were also concurrently collected. The PM2.5 and PM10-2.5 masses, and a number of elements (i.e., Fe, Ba, Cu, Sb, Zn, Cr), showed clear increases at each near-road site, related to the traffic emissions resulting from resuspension and/or abrasion sources. The trace elements showed a clear partitioning trend between PM2.5 and PM10-2.5, thus reflecting the origin of some of these elements. The application of positive matrix factorization (PMF) to the combined fine and coarse metal data (86 total), with 24 observations at each site, was used to determine the contribution of different sources to the total metal concentrations in fine and coarse PM. Four major sources were identified by the PMF model, including two traffic non-exhaust (crustal/road dust, brake/tire wear) sources, along with regional and local industrial sources. Source apportionment indicated that the resuspended crustal/road dust factor was the dominant contributor to the total coarse-bound trace element (i.e., Fe, Ti, Ba, Cu, Zn, Sb, Cr) concentrations produced by vehicular exhaust and non-exhaust traffic-related processes that have been deposited onto the surface. The second non-exhaust factor related to brake/tire wear abrasion accounted for a considerable portion of the fine and coarse elemental (i.e., Ba, Fe, Cu, Zn, Sb) mass at both near-road sites. Regional and local industry contributed mostly to the fine elemental (i.e., S, As, Se, Cd, Pb) concentrations. Overall, the results show that non-exhaust traffic-related processes were major contributors to the various redox-active metal species (i.e., Fe, Cu) in both PM fractions. In addition, a substantial proportion of these metals in PM2.5 was water-soluble, which is an important contributor to the formation of reactive oxygen species and, thus, may lead to oxidative damage to cells in the human body. It appears that controlling traffic non-exhaust-related metals emissions, in the absence of significant point sources in the area, could have a pronounced effect on the redox activity of PM, with broad implications for the protection of public health.

Atrial proarrhythmic effect of lead as one of the PM10 metal components of air pollution. An in-silico study.

Particulate matter (PM) is considered the most severe environmental pollution problem due to its serious effects on human health associated with an increased risk of cardiovascular morbidity and mortality. In this work, a physicochemical characterization of PM10 from the city of Medellin was developed. The results evince that lead (Pb) is one of the most abundant elements since it is present in all analyzed samples. Therefore, Pb was chosen to perform an in-silico study to assess its effects on atrial arrhythmias generation. For this purpose, we developed a model representing the Pb2+ blocking effect on the L-type calcium channel. This formulation was incorporated in a human atrial cell mathematical model and in 2D and 3D models of human atria. The simulations showed a proarrhythmic effect at high Pb2+ concentrations, through shortening of action potential duration inducing the generation of reentrant activity and atrial flutter. The results contribute to the knowledge about the cardiac physiopathological processes, triggered by lead as one of the main PM10 metal components of air pollution, that yields the generation of arrhythmias.

Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 Under Winter Haze Conditions in Central China: A Case Study of Huanggang, Hubei Province

To explore the pollution characteristics and potential health risks of heavy metals in PM2.5 on haze days in Central China, PM2.5 samples were collected from the Huanggang monitoring station, a regional observation point in Central China, between January 13 and 24, 2018. The contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, and Pb in PM2.5 were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), and the enrichment factor method was used to determine the potential risk based on the exposure model recommended by the Environmental Protection Administration(EPA). The results showed that during the observation period, the concentrations of Zn in PM2.5 were highest, and the concentrations of the carcinogens As and Cd were higher than the secondary standard limits of China's ambient air quality standard(GB 3095-2012), with 70% of these elemental concentrations accounting for the largest proportion in the middle haze period. The enrichment factor analysis showed that Cd, Sn, Co, Pb, and Zn were the most abundant elements, especially during the middle haze period, and were mostly derived from transportation and coal combustion. The results of the human health risk assessment showed that exposure via hand-mouth feeding was the main non-carcinogenic risk, and the exposure and non-carcinogenic risks of children were significantly higher than those of adults. Pb poses a non-carcinogenic risk to children, while heavy metals in PM2.5 pose no non-carcinogenic risks to adults and carcinogenic heavy metals pose no carcinogenic risks.

Association of Sulfur, Transition Metals, and the Oxidative Potential of Outdoor with Acute Cardiovascular Events: A Case-Crossover Study of Canadian Adults.

Background:We do not currently understand how spatiotemporal variations in the composition of fine particulate air pollution [fine particulate matter with aerodynamic diameter ()] affects population health risks. However, recent evidence suggests that joint concentrations of transition metals and sulfate may influence the oxidative potential (OP) of and associated health impacts.Objectives:The purpose of the study was to evaluate how combinations of transition metals/OP and sulfur content in outdoor influence associations with acute cardiovascular events.Methods:We conducted a national case-crossover study of outdoor and acute cardiovascular events in Canada between 2016 and 2017 (93,344 adult cases). Monthly mean transition metal and sulfur (S) concentrations in were determined prospectively along with estimates of OP using acellular assays for glutathione (), ascorbate (), and dithiothreitol depletion (). Conditional logistic regression models were used to estimate odds ratios (OR) [95% confidence intervals (CI)] for across strata of transition metals/OP and sulfur.Results:Among men, the magnitudes of observed associations were strongest when both transition metal and sulfur content were elevated. For example, an OR of 1.078 (95% CI: 1.049, 1.108) (per ) was observed for cardiovascular events in men when both copper and S were above the median, whereas a weaker association was observed when both elements were below median values (, 95% CI: 1.007, 1.031). A similar pattern was observed for OP metrics. was not associated with acute cardiovascular events in women.Discussion:The combined transition metal and sulfur content of outdoor influences the strength of association with acute cardiovascular events in men. Regions with elevated concentrations of both sulfur and transition metals in should be examined as priority areas for regulatory interventions. https://doi.org/10.1289/EHP9449

Transport route-based cluster analysis of chemical fingerprints and source origins of marine fine particles (PM2.5) in South China Sea

The fingerprints and source origins of marine PM2.5 at two background islands in the South China Sea were clustered via trajectory analysis and positive matrix factorization. High PM2.5 concentrations at the Dongsha Islands occurred for the north routes, while Nansha Islands had similar PM2.5 concentrations amongst the transport routes. However, the chemical characteristics of PM2.5 varied with the transport routes. Secondary inorganic aerosols (NO3-, SO42-, and NH4+) were abundant in water-soluble ions which dominated PM2.5. Crustal metals were the abundant metals in PM2.5, while trace metals were primarily originated from man-made sources. Organic carbon was superior to elemental carbon, and high concentrations of levoglucosan and organic acids were observed for the north routes. Overall, marine PM2.5 at the Dongsha Islands was highly influenced by long-range transport of Asian continental outflows, while particulate air quality at the Nansha Islands was mainly governed by clean air parcels blown from the SCS.

Spatiotemporal variations and source apportionment of metals in atmospheric particulate matter in Beijing and its surrounding areas

To explore the pollution characteristics and sources of metals in fine particulate matter (PM2.5) in Beijing and surrounding areas, PM2.5 samples were collected at four sites in North China (Dongzhimen and Huairou in Beijing, Baoding, and Cangzhou in Hebei) for one year. Sixteen metals (K, Na, Ca, Mg, Al, Fe, Cu, Pb, Zn, Cd, As, Mn, Co, Ni, Cr, and V) were identified via inductively coupled plasma mass spectrometry (ICP-MS) assisted by microwave digestion. Concentrations of PM2.5 and the detected elements were the highest at Baoding and lowest at Huairou sites. Similar diurnal variations were observed at higher levels of PM2.5 and metals at night than during the day at four sites. Enrichment factor analysis indicated that Zn, As, Cu, Cd and Pb were the most abundant elements in the study area and originated from anthropogenic emissions. The positive matrix factorization (PMF) model was used to analyze the sources of PM2.5, namely, soil dust, vehicle emissions, fuel combustion, and coal combustion. The major source of metals in PM2.5 at the four sampling sites was soil dust and its contribution was above 35%. A health risk assessment revealed that Ni poses no cancer risk to adults and children at any site; Cd and Co pose no cancer risk to children at Dongzhimen, Huairou, and Cangzhou; and As and Cr pose cancer risk to adult men, women, and children.

Source Apportionment and Health Risk Assessment of Heavy Metals in PM2.5 in Handan: A Typical Heavily Polluted City in North China

In order to determine the pollution sources and human health risks of metal elements in PM2.5, samples were collected by a large flow particulate matter sampler in the four seasons in 2013, 2015, and 2017 (January, April, July, and October). The mass concentrations of 10 metals (Ti, V, Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The sources of heavy metals were identified by Unmix, and the potential non-carcinogenic/carcinogenic risk was evaluated. The influences of local and regional sources were also explored during the high-carcinogenic risk period (HCRP). The wind field and 72 h backward trajectories were performed to identify the potential local and regional sources in HCRP. The results showed that the average annual concentrations of PM2.5 in the urban area of Handan city were 105.14, 91.18, and 65.85 μg/m3 in 2013, 2015, and 2017, respectively. The average daily concentrations of the metals in PM2.5 in January were higher than that of April, July, and October. The average mass concentrations of the 10 heavy metal elements in PM2.5 were 698.26, 486.92, and 456.94 ng·m−3 in 2013, 2015, and 2017, respectively. The main sources of the metals in PM2.5 were soil dust sources, vehicular emissions, coal burning, and industrial activities. The carcinogenic risks of Cr and As were above 1 × 10−6 over the three years. Wind direction analysis showed that the potential local sources were heavy industry enterprises and the economic development zone. The backward trajectory analysis indicated that PM2.5 long transported from Shandong, Henan, and the surrounding cities of Handan had quite an impact on the heavy metals contained in the atmosphere of the studied area. The health risk assessment results demonstrated that the trend for non-carcinogenic risk declined, and there was no non-carcinogenic risk in 2017. However, the carcinogenic risk levels were high over the three years, particularly in January.

Metal concentration, source, and health risk assessment of PM2.5 in children's bedrooms: Rural versus urban areas

The objective of this study is to gain a better understanding of the metal characteristics, sources, and health risks of children's exposure to PM2.5 and related metals in children's bedrooms in urban and rural areas. PM2.5 personal environmental monitoring samplers were used to collect both indoor and outdoor PM2.5 in urban and rural areas in Taiwan. Al, Cd, Cr, Mn, Pb, V, and Zn were analyzed by inductively coupled plasma mass spectrometry. Source apportionment of metals in PM2.5 was carried out with factor analysis (FA). Health risk assessment of metals was performed on children via inhalation. The average indoor PM2.5 concentrations were 11.9 ± 5.2 μg/m3 and 11.9 ± 4.7 μg/m3 in urban and rural areas, respectively. The most predominant metal indoors in urban areas was Al, followed by Zn, Pb, Mn, V, Cr, and Cd, with a similar result in rural areas. The results from FA indicated that traffic emission and oil combustion in the outside environment were major pollution sources to indoor Mn, V, and Zn; corrosion of building material could be a contributor to Al, Cd, and Pb; pollution sources were different to Cr in two areas. The carcinogenic risk for indoor Cr(VI) via inhalation was higher in urban areas (boy: 6.61E-06; girl: 6.18E-06) than that in rural areas (boy: 2.80E-06; girl: 2.62E-06). These findings will help us to further understand the pollution sources, health risks, and control strategies for metals in PM2.5 in children's bedrooms for reducing adverse health effects, including in rural areas.

The Role of Fossil Fuel Combustion Metals in PM2.5 Air Pollution Health Associations

In this review, we elucidate the central role played by fossil fuel combustion in the health-related effects that have been associated with inhalation of ambient fine particulate matter (PM2.5). We especially focus on individual properties and concentrations of metals commonly found in PM air pollution, as well as their sources and their adverse health effects, based on both epidemiologic and toxicological evidence. It is known that transition metals, such as Ni, V, Fe, and Cu, are highly capable of participating in redox reactions that produce oxidative stress. Therefore, particles that are enriched, per unit mass, in these metals, such as those from fossil fuel combustion, can have greater potential to produce health effects than other ambient particulate matter. Moreover, fossil fuel combustion particles also contain varying amounts of sulfur, and the acidic nature of the resulting sulfur compounds in particulate matter (e.g., as ammonium sulfate, ammonium bisulfate, or sulfuric acid) makes transition metals in particles more bioavailable, greatly enhancing the potential of fossil fuel combustion PM2.5 to cause oxidative stress and systemic health effects in the human body. In general, there is a need to further recognize particulate matter air pollution mass as a complex source-driven mixture, in order to more effectively quantify and regulate particle air pollution exposure health risks.

Selection of metric for indoor-outdoor source apportionment of metals in PM2.5 : mg/kg versus ng/m3.

Trends in the elemental composition of fine particulate matter (PM2.5) collected from indoor, outdoor, and personal microenvironments were investigated using two metrics: ng/m3 and mg/kg. Pearson correlations that were positive using one metric commonly disappeared or flipped to become negative when the other metric was applied to the same dataset. For example, the correlation between Mo and S in the outdoor microenvironment was positive using ng/m3 (p < 0.05) but negative using mg/kg (p < 0.05). In general, elemental concentrations (mg/kg) within PM2.5 decreased significantly (p < 0.05) as PM2.5 concentrations (µg/m3) increased—a dilution effect that was observed in all microenvironments and seasons. An exception was S: in the outdoor microenvironment, the correlation between wt% S and PM2.5 flipped from negative in the winter (p < 0.01) to positive (p < 0.01) in the summer, whereas in the indoor microenvironment, this correlation was negative year‐round (p < 0.05). Correlation analyses using mg/kg indicated that elemental associations may arise from Fe‐Mn oxyhydroxide sorption processes that occur as particles age, with or without the presence of a common anthropogenic source. Application of mass‐normalized concentration metrics (mg/kg or wt%), enabled by careful gravimetric analysis, revealed new evidence of the importance of indoor sources of elements in PM2.5.

Effect of ambient air PM2.5-bound heavy metals on blood metal(loid)s and children’s asthma and allergy pro-inflammatory (IgE, IL-4 and IL-13) biomarkers

BackgroundWe investigated the concentrations of metals in fine particulate matter PM2.5 in the outdoor air around the home sites of 123 male children from Ahvaz, average age 7.56, along with their blood samples to measure pro-inflammatory responses (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13). MethodsWe measured 6 metals (As, Cd, Cr, Hg, Ni and Pb) in three Ahvaz’s regions including industrial (Padad), vehicle traffic (Golestan) and control (Kianpars). ResultsThe higher concentrations of metals in the Padad as the industrial ambient air i.e., arsenic, cadmium, chromium, mercury and nickel coincided with the higher concentrations of those metals in exposed children (P < 0.05) versus the controls. Children in Golestan, the high traffic air pollution area had the highest lead concentrations (p < 0.05). Also a significant association was shown in Padad between blood arsenic and IgE (β = 26.59, P < 0.001), IL-4 (β = 172.1, P < 0.001) and IL-13 (β = 14.84, P < 0.001), blood chromium and IgE (β = 10.38, P < 0.001), IL-4 (β = 75.27, P < 0.001) and IL-13 (β = 5.27, P < 0.001) and blood mercury and IgE (β = 13.11, P < 0.001), IL-4 (β = 108.09, P < 0.001) and IL-13 (β = 7.96, P < 0.001) and blood lead and IgE(β = 0.92, P = 0.025), IL-4(β = 7.16, P < 0.001) and IL-13(β = 0.58, P = 0.003). However, no significant relation was found for Cadmium, Nickel in blood with IgE, IL-4 and IL-13 levels. Moreover, children from industrial areas showed significantly higher concentrations of IgE (mean = 146.44 pg/200landa, P < 0.001), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 52.93 pg/200landa, P < 0.001) versus Golestan and Kianpars. ConclusionChildren residing in an industrial area with high concentrations of metals in PM2.5 had high metals in blood and high production of IgE, IL-4 and IL-13, reflecting an immune dysregulation and brisk inflammatory responses.

Chemical characterization and Health Risk Assessment of metals associated to airborne particulate matter PM2.5 in Saltillo, México

This study was carried out from September to December 2012 and January-February 2013, in the Faculty of Chemical Sciences of the Autonomous University of Coahuila, in total 13 samples were taken. On that period, dry weather predominated, with an average temperature of 17.0 °C, relative humidity of 52.0% and wind speed of 3.5 m s-1. The mean concentration for PM2.5 was 36.0 μg m-3. The most abundant metal in PM2.5 was Fe, with an average concentration of 1386.4 ng m-3 and the lowest concentration was obtained for Cd with 4.1 ng m-3. On the other hand, within the ionic species the most abundant were sulfates (3569.0 ng m-3), while ammonium was the least abundant species (490.9 ng m-3). The ion balance indicated that during the study period the suspended particles had acidic characteristics, which means that the amount of cations was not sufficient to neutralize the sulfates, nitrates and chlorides. Finally, the risk assessment indicates that of heavy metal in the PM2.5, represent a potential danger for the health of the population exposed to the inhalation of breathable suspended particles.

Influence of pollution reduction interventions on atmospheric PM2.5: A case study from the 2017 Xiamen

To investigate the influence of pollution control on particulate matter with a diameter ≤2.5 μm (PM2.5), 40 samples were collected before and during the 2017 BRICS summit (BRICS) in an urban and a suburban area of the city of Xiamen, China. The average urban and suburban area PM2.5 concentrations during the BRICS were 26.3% and 35.9% lower than those before the summit, respectively. Chemical characteristics of PM2.5, such as water-soluble ions (WSIIs), organic and elemental carbon (OC and EC), macro elements and trace elements (inorganic elements), were measured. WSIIs and organic matter accounted for the highest proportions in PM2.5. During the BRICS, concentrations of WSIIs, OC, EC and inorganic elements decreased by 17.6%, 39.0%, 42.9%, 44.1% in urban areas and decreased by 0.9%, 35.1%, 53.8%, 79.4% in suburban areas. The influence of primary sources on WSIIs and carbon aerosol decreased and secondary formation increased. High O3 concentrations played an important role in the formation of secondary aerosols. However, the contribution of inorganic element sources did not noticeably change according to Pb–Sr-Nd isotope analysis. Pollution control during the BRICS was effective but not sufficient to reduce health risk from heavy metals in PM2.5, and carcinogenic risks from Cr, Cd, and As exceeded the safety value (10−6).