Main components of PM10 in an area influenced by a cement plant in Catalonia, Spain: Seasonal and daily variations

Annual variation of source contributions to PM10 and oxidative potential in a mountainous area with traffic, biomass burning, cement-plant and biogenic influences

Toxicity of particulate matter (PM) depends on its sources, size and composition. We identified PM10 sources and determined their contribution to oxidative potential (OP) as a health proxy for PM exposure in an Alpine valley influenced by cement industry. PM10 filter sample chemical analysis and equivalent black carbon (eBC) were measured at an urban background site from November 2020 to November 2021. Using an optimized Positive Matrix Factorization (PMF) model, the source chemical fingerprints and contributions to PM10 were determined. The OP assessed through two assays, ascorbic acid (AA) and dithiothreitol (DTT), was attributed to the PM sources from the PMF model with a multiple linear regression (MLR) model. Ten factors were found at the site, including biomass burning (34, 40 and 38% contribution to annual PM10, OPAA and OPDDT, respectively), traffic (14, 19 and 7%), nitrate- and sulphate-rich (together: 16, 5 and 8%), aged sea salt (2, 2 and 0%) and mineral dust (10, 12 and 17%). The introduction of innovative organic tracers allowed the quantification of the PM primary and secondary biogenic fractions (together: 13, 8 and 21%). In addition, two unusual factors due to local features, a chloride-rich factor and a second mineral dust-rich factor (named the cement dust factor) were found, contributing together 10, 14 and 8%. We associate these two factors to different processes in the cement plant. Despite their rather low contribution to PM10 mass, these sources have one of the highest OPs per µg of source. The results of the study provide vital information about the influence of particular sources on PM10 and OP in complex environments and are thus useful for PM control strategies and actions.

Multimedia distribution, partitioning, sources, comprehensive toxicity risk and co-occurrence network characteristics of trace elements in a typical Chinese shallow lake with high antibiotic risk

Although the combined pollution of trace elements and antibiotics has received extensive attention, the fate and toxicity risk of trace elements with high antibiotic risk are still unclear. The multimedia distributions, partitioning, sources, toxicity risks and co-occurrence network characteristics of trace elements in surface water (SW), overlying water (OW), pore water (PW) and sediment (Sedi) samples of 61 sites from Baiyangdian (BYD) Lake were investigated. The trace elements in the SW and OW are derived mainly from traffic and agricultural sources, and those in PW and Sedi samples are primarily from lithogenic and industrial sources. The total toxicity risk index (TRI) of nine trace elements (ΣTRI) in Sedi samples showed a very high toxicity risk (18.35 ± 8.84), and a high combined pollution toxicity risk (ΣΣTRI) was observed in PW (149.17 ± 97.52) and Sedi samples (46.37 ± 24.00). The co-occurrence network from SW to PW became more vulnerable. Generally, total antibiotics and TP may be keystones of trace elements in water and sediment. The high antibiotic risk significantly influenced ΣΣTRI in water samples but not in Sedi samples. The findings provide new implications for the monitoring and control of combined antibiotic-trace element pollution in shallow lakes.

Insight into the oxidation of glutathione mediated by black carbon from three typical emission sources

Black carbon (BC) is released into the atmosphere in large quantities from different emission sources each year and poses a serious threat to human health. These BC possessed a variety of characteristics and different mediation abilities for the reactive oxygen species (ROS) generation. In this study, we collected BC (i.e., diesel BC, coal BC and wood BC) from three typica emission sources, and examined their mediation abilities to the oxidation of glutathione (GSH). Results showed that all three BC significantly promoted the GSH oxidation, and the mediation efficiencies were as follows: diesel BC > coal BC > wood BC. In comparison with the water-soluble fraction, the mediation abilities of three BC mainly came from their solid phase fractions. In the coal BC and wood BC systems, the oxidation of GSH was attributed to the catalysis of transition metals in BC. By contrast, the transition metals, phenolic -OH and persistent free radicals in diesel BC were identified as the active sites responsible for the GSH oxidation. In addition, the graphitic surface of diesel BC could synergize with these active sites to accelerate the oxidation of GSH. Under the catalysis of BC, dissolved oxygen was first reduced to ROS (O₂^•- and H₂O₂) and then caused the GSH oxidation. These findings not only help to better assess the adverse health effects of different BC, but also deepen the understanding of the reaction mechanisms.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Release and Gas-Particle Partitioning Behavior of Liquid Crystal Monomers during the Dismantling of Waste Liquid Crystal Display Panels in E-Waste Recycling Facilities

Liquid crystal monomers (LCMs) are a class of emerging chemical pollutants; however, their release and gas-particle partitioning remain unknown. This study performed the first comprehensive analysis of a wide range of 93 LCMs in the ambient air of liquid crystal display (LCD) dismantling facilities. A total of 53 of the 93 target LCMs were detected in the air samples. The total atmospheric concentrations (gas and particles) of LCMs (∑LCMs) ranged from 68,800 to 385,000 (median of 204,000) pg/m³. Most LCMs were predominant in the gas phase, implying that their atmospheric transport would be mainly governed by gas rather than particle diffusions. Differential distribution patterns of the LCMs were observed due to their different atmospheric partitioning behaviors. Significant linear correlations were found between the gas-particle partitioning coefficients (K_P) and the predicted subcooled vapor pressures (P_L) and octanol-air partitioning coefficients (K_oa) (p < 0.01). Compared with two equilibrium-state models, the experimentally observed particulate fractions (ϕ) fit better with the predicted values based on the Li-Ma-Yang (L-M-Y) steady-state model, and K_oa was identified as a key factor determining the atmospheric fate pathways of LCMs. Our study highlights another new class of chemicals significantly contributing to the chemical mixture in the ambient air at e-waste recycling areas.

Efficacy and mechanism of essential oil from Abies holophylla leaf on airway inflammation in asthma: Network pharmacology and in vivo study

BACKGROUND

Asthma is one of the most common chronic inflammatory diseases of the airways. Essential oil from Abies holophylla leaf (EOA) has been reported to have anti-inflammatory property. This study aimed to predict the inhibitory effect of EOA against asthma by network analysis and to confirm the underlying mechanism of EOA on airway inflammation.

PURPOSE AND STUDY DESIGN

The effects and underlying mechanisms of EOA on asthma were investigated by in silico network pharmacology and an experimental in vivo study.

METHODS

To define the effectiveness of EOA on asthma, the network pharmacology was constructed using major components of EOA. EOA (0.0003 and, 0.03 v/v%) was aerosolized by nebulizer 3 times a week for 5 min for 7 weeks. After 3 weeks of treating the mice with EOA, asthma was induced by sensitizing them with ovalbumin (OVA) and PM10. The effects of EOA on the IL-17 related signaling pathway was confirmed using an asthmatic model.

RESULTS

The network analysis showed that EOA is highly associated with the IL-17-related signaling pathway. EOA inhibited respiratory epithelium hyperplasia, collagen deposition and goblet cell activation in the lung and trachea tissues. In addition, EOA reduced the number of eosinophils, lymphocytes and macrophages in BALF. Furthermore, in the asthmatic model of mice, we showed that EOA inhibited IL-17-related cytokines, increased Treg-related cytokines and decreased the TRAF6 and MAPK and, suppressed the nuclear transcriptional activities of NF-kB.

CONCLUSIONS

The network pharmacology and in vivo study indicated that EOA may have an inhibitory effect on airway inflammation in asthma exposure through the IL-17-related signaling pathway.

Dust Emission Monitoring in Cement Plant Mills: A Case Study in Romania

This paper presents aspects of monitoring material dust emissions from stationary emission sources (monthly dust measurements performed on cement mill stacks-mill outlet and separator outlet). Additionally, the Portland cement mill technological process (its component parts), as well as the solutions regarding the reduction of the air emissions level, following the emission limit values (VLE), established in the integrated environmental authorization (AIM) from a cement factory in Romania, were analyzed. The paper focused on analyzing the data obtained in three different years for PM10 and dust concentrations (2018-2020). For each year, the measurements have been done in 3 months, each in a different season. The average values for each year for working conditions were: 30.22 mg/m³ (2018), 27.38 mg/m³ (2019), and 27.51 mg/m³ (2020) for working conditions and for normal conditions: 34.22 mg/m³ (2018), 30.49 mg/m³ (2019), and 30.16 mg/m³ (2020). For all 3 years, the values measured in spring were higher than the other two, both for work and normal conditions.

Historical trends of metals concentration in PM10 collected in the Mexico City metropolitan area between 2004 and 2014

In this work, we report metals concentrations in 80 PM₁₀ samples collected at four sites in the Mexico City Metropolitan Area (MCMA): Tlalnepantla (NE), Xalostoc (NE), Merced (C), and Pedregal (S), during the dry/cold season (October to January) for the 2004-2014 period. Mean PM₁₀ mass concentration (66.1 µg m^-3) significantly exceeds the annual mean air quality guidelines recommended by the World Health Organization. The statistical analysis of concentration data and meteorological parameters allows us to recognize the importance of wind intensity speed (Wsp) and wind direction conditions in the enrichment of PM concentrations. The proximity and magnitude of the emitting source is also relevant for PM concentration. Such conditions favored that higher metal concentration was recognized at the north of the studied area. By means principal component analysis (PCA) was difficult to identify the groups of metals associated with specific sources (anthropogenic and geogenic) given the high complexity of the study area and the long period of time evaluated. Metal concentration trend shows an important positive trend for Pt, V and Cr, while PM₁₀, Ni, Cu, Ag and Sb show a trend of moderate increase. In contrast, Pb and Co registered a strong percentage reduction, while Hg, Mn, As and Cd show a slight reduction, probably resulting from the implementation of regulatory measures and influenced by urban changes associated at the north of the studied area. The results of this research provide information that should be considered for evaluating the impact of anthropogenic sources and applying regulatory measures to control emissions.

Characterization of airborne particles and cytotoxicity to a human lung cancer cell line in Guangzhou, China

Air pollution by airborne particles is a serious health problem worldwide. The present study was aimed at investigating the concentrations and composition of total suspended particles (TSPs) and PM_2.5 at various industrial/commercial sites of Guangzhou, a megacity of Southern China. Major and trace elements, ions and carbonaceous fraction were determined and main components were calculated. In addition, in order to assess the potential toxic on the respiratory system of these PM, cytotoxicity of size-fractionated particles (PM_10-5.6, PM_5.6-3.3, PM_3.3-1.1, PM_1.1-0.43) for a human lung cancer cell line (A549) was also investigated. Correlations between PM constituents and toxicity were assessed. Median levels of TSPs and PM_2.5 in industrial/commercial sites were 206 and 57.7 μg/m³, respectively. Nickel, Cu, Mo, Mn, Pb, and Ti were the most abundant metals in TSPs and PM_2.5. Industrial activities and coal combustion were the most important sources of carbonaceous particles in the zone. MTT assays showed that PM_10-5.6 and PM_1.1-0.43 had the highest and the lowest cytotoxicity to A549 cell lines, respectively. Inhalable particles around the manufacturing of metal facilities and formal waste treatment plants showed a high cytotoxicity to A549 cell lines. In general terms, no significant correlations were found between main components of PM and toxicity. However, W showed a significant correlation with cell viability.

Measurements of Local Sources of Particulates with a Portable Monitor along the Coast of an Insular City

The air quality of modern cities is considered an important factor for the quality of life of humans and therefore is being safeguarded by various international organizations, concentrating on the mass concentration of particulate matter (PM) with an aerodynamic diameter less than 10, 2.5 and 1 μm. However, the different physical and anthropogenic processes and activities within the city contribute to the rise of fine (<1 μm) and coarse (>1 μm) particles, directly impacting human health and the environment. In order to monitor certain natural and anthropogenic events, suspecting their significant contribution to PM concentrations, seven different events taking place on the coastal front of the city of Limassol (Cyprus) were on-site monitored using a portable PM instrument; these included both natural (e.g., dust event) and anthropogenic (e.g., cement factory, meat festival, tall building construction, tire factory, traffic jam, dust road) emissions taking place in spring and summer periods. The violations of the limits that were noticed were attributed mainly to the various anthropogenic activities taking place on-site, revealing once more the need for further research and continuous monitoring of air quality.

Contamination identification, source apportionment and health risk assessment of trace elements at different fractions of atmospheric particles at iron and steelmaking areas in China

China has the largest share of global iron and steel production, which is considered to play a significant contribution to air pollution. This study aims to investigate trace element contamination at different fractions of particulate matter (PM) at industrial areas in China. Three PM fractions, PM2.1-9.0, PM1.1-2.1 and PM1.1, were collected from areas surrounding iron and steelmaking plants at Kunming, Wuhan, Nanjing and Ningbo in China. Multiple trace elements and their bioavailability, as well as Pb isotopic compositions, were analysed for identification of contaminants, health risk assessment and source apportionment. Results showed that PM particles in the sites near industrial areas were associated with a range of toxic trace elements, specifically As, Cr(VI), Cd and Mn, and posed significant health risks to humans. The isotopic Pb compositions identified that coal and high temperature metallurgical processes in the steelmaking process were the dominant contributors to local air pollution in these sites. In addition to iron and steelmaking activities, traffic emissions and remote pollution also played a contributing role in PM contamination, confirmed by the differences of Pb isotopic compositions at each PM fraction and statistical results from Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) and Geometrical Analysis for Interactive Aid (GAIA). The results presented in this study provide a comprehensive understanding of PM emissions at iron and steelmaking areas, which helps to guide subsequent updates of air pollution control guidelines to efficiently minimise environmental footprint and ensure long term sustainability of the industries.

Identification of cement in atmospheric particulate matter using the hybrid method of laser diffraction analysis and Raman spectroscopy

The production of cement is associated with the emissions of dust and particulate matter, nitrogen oxides (NO_x), sulfur dioxide (SO₂), carbon monoxide (CO), heavy metals, and volatile organic compounds into the environment. People living near cement production facilities are potentially exposed to these pollutants, including carcinogens, although at lower doses than the factory workers. In this study we focused on the distribution of fine particulate matter, the composition, size patterns, and spatial distribution of the emissions from Spassk cement plant in Primorsky Krai, Russian Federation. The particulate matter was studied in wash-out from vegetation (conifer needles) using a hybrid method of laser diffraction analysis and Raman spectroscopy. The results showed that fine particulate matter (PM₁₀ fraction) extended to the entire town and its neighbourhood. The percentage of PM₁₀ in different areas of the town and over the course of two seasons ranged from 34.8% to 65% relative to other size fractions of particulate matter. It was further shown that up to 80% of the atmospheric PM content at some sampling points was composed of cement-containing particles. This links the cement production in Spassk-Dalny with overall morbidity of the town population and pollution of the environment.

Characterization and risk assessment of total suspended particles (TSP) and fine particles (PM2.5) in a rural transformational e-waste recycling region of Southern China

In 2016, total suspended particles (TSP) and fine particles (PM_2.5) were collected near four e-waste recycling parks in a region of Southern China. TSP and PM_2.5 levels and composition around these industrial activities were determined and the potential risks for human health due to the exposure to toxic elements contained on fine particles (PM_2.5) were evaluated. Levels of TSP and PM_2.5 were lower with advanced recycling methods than with small recycling e-waste workshops operating in the sampling region. The main trace elements in particles were Cu, Pb, and Ti, the same as those detected before the transition to advanced dismantling methods in e-waste recycling. Significantly higher levels of Cu, Pb, Sn, Te, Tl and NH₄⁺ in TSP and Cu and Te in PM_2.5 were found in e-waste recycling areas than in BG site. Taking Cu as the indicative element emitted from e-waste recycling activities, significant high positive correlations between Cu and W, and Cu and Te were found. These elements are present and can be released from electrical and electronical components during e-waste recycling processes. Exposure to elements for the population living near these e-waste recycling parks means carcinogenic risks above the acceptable threshold (>10^-5).

Seasonal characterization and dosimetry-assisted risk assessment of indoor particulate matter (PM10-2.5, PM2.5-0.25, and PM0.25) collected in different schools

Inhalation of particulate matter (PM) has been linked to serious adverse health effects, such as asthma, cardiovascular diseases and lung cancer. In the present study, coarse (PM_10-2.5), accumulation mode (PM_2.5-0.25), and quasi-ultrafine (PM_0.25) particulates were collected inside twelve educative centers of Tarragona County (Catalonia, Spain) during two seasons (cold and warm). Chemical characterization of PM, as well as risk assessment were subsequently conducted in order to evaluate respiratory and digestive risks during school time for children. Levels and chemical composition of PM were very different among the 12 centers. Average PM levels were higher during the cold season, as well as the concentrations of most toxic metals. In most schools, PM levels were below the daily PM₁₀ threshold established in the regulation (50 μg/m³), with the exception of school number 1 during the cold season. On average, and regardless of season, coarse PM was highly influenced by mineral matter, while organic matter and elemental carbon were prevalent in quasi-ultrafine PM. The concentrations of the toxic elements considered by the legislation (As, Cd, Pb, and Ni) were below their correspondent regulatory annual limits. Calculated risks were below the safety thresholds, being fine fractions (PM_2.5-0.25 and PM_0.25) the main contributors to both digestive and respiratory risks.

Differences in oxidative potential of black carbon from three combustion emission sources in China

Black carbon (BC) is mainly derived from the incomplete combustion of fossil fuels and biomass, and poses a serious threat to human health. Actual BC from extensive emission sources presents a variety of characteristics that are likely associated with different oxidative potentials (OP) and health endpoints. In the present study, BC derived from three main emission sources (residential coal combustion, biomass burning, and diesel engine exhaust) in China was subjected to physiochemical characterization and its OP was tested using dithiothreitol (DTT) assay. In order to obtain actual BC, the water-soluble part (WS) and organic extract (OE) were eluted successively from PM and the residue particle (RP) were reserved. PM from diesel vehicles had the most effective DTT consumption capacity, followed by PM from biomass and coal burning. And the OP of PM was mostly attributed to its RP part which mainly consisted of metals and BC. SEM/TEM, OC/EC, IC, and ICP-MS measurements confirmed that soluble ions and organic compounds were washed off effectively, while some metals were still retained in the RP part. Thus, the OP of BC was evaluated after adding DTPA to inhibit DTT activity caused by metals in the RP. Significant differences in OP and physiochemical characteristics of BC from the three emission sources were observed. BC from diesel exhaust exhibited the highest DTT activity (15.5 ± 12.6 pmol min^-1 μg^-1) compared to that of BC from biomass (2.5 ± 1.0 pmol min^-1 μg^-1) and coal (1.3 ± 0.5 pmol min^-1 μg^-1) burning. Diesel exhaust BC, which was emitted under the highest combustion temperature, had the smallest size. Coal consumption in China contributes to the highest amount of BC mass emission, but our result indicates that diesel exhaust BC has the greatest OP. An emission inventory based on health impacts is urgently needed to control air pollution sources in the future.