Mean Concentrations Of PM2 Research Articles

Assessment of particulate matter concentrations and air quality index during road construction-related activities in Ghana

Road construction involves activities that emit pollutants, including particulate matter, which harms humans. This study determined and compared particulate matter (PM1.0, PM2.5 and PM10) levels and air quality index (AQI) at unpaved roads, asphalt overlay, chip-sealed and asphalt-producing sites in Ghana and the health risks posed by their exposure. It was conducted in the Ashanti and Ahafo Regions, Ghana and was cross-sectional using the low-cost sensor, PCE-RCM16. Data collection took place, January-May, 2020. The asphalt-producing, asphalt overlay, chip-sealed and unpaved road sites had mean PM10 concentrations of 12.7-fold, 7.4-fold, 6.1-fold and 2.6-fold respectively of the 2021 World Health Organisation (WHO) air quality guideline (AQG) daily limit, 45 μg m−3. The mean PM2.5 concentrations were 30.4-fold, 17.2-fold, 14.1-fold and 6.1-fold greater than the daily AQG limit, 15 μg m−3 respectively. The mean PM1.0 values were of grave concern. Using the AQI, the asphalt-producing and asphalt overlay sites were considered “hazardous”, chip-sealed site was “very unhealthy” and the unpaved sites were “unhealthy for sensitive groups”. Type of activity influenced pollution levels (p < 0.01). All the sites were polluted above the WHO limits. Authorities should ensure the wearing of personal protective equipment, strict adherence to the WHO AQG and apply appropriate sanctions to offending firms/workers.

Spatio-temporal variability and trends of air pollutants in the Metropolitan Area of Curitiba

Monitoring air pollutants over time is essential for identifying and addressing trends, which may help improve air quality management and safeguard public health. This study investigates the spatio-temporal variability of air quality in the Metropolitan Area of Curitiba (MAC), Brazil, focusing on six pollutants (SO2, NO2, NOx, O3, CO, and PM10) measured at eight monitoring stations from 2003 to 2017. We conducted statistical analyses, including diurnal cycles, seasonal variability, spatio-temporal correlations, conditional bivariate probability functions, Theil-Sen trend analysis, and comparison with national quality standards (NAQS) and World Health Organization (WHO) guidelines. The analyses revealed large variations in pollutant concentrations across the study area. For instance, stations strongly impacted by industrial emissions presented the highest mean annual SO2 (20–28 μg/m3) and PM10 (32–34 μg/m3) concentrations, while those mostly impacted by traffic showed elevated NO2 (31–39 μg/m3), NOx (63–86 μg/m3) and CO (0.6–0.8 mg/m3) concentrations. The two residential stations recorded the highest O3 concentrations (annual mean of 30–32 μg/m3). Seasonal and diurnal patterns varied by pollutant, with winter experiencing higher concentrations and O3 peaking in spring. SO2 concentrations presented no clear seasonal or diurnal cycle patterns, and showed the highest spatial variability. Significant decreasing annual trends were observed for SO2 (−5.9%), NO2 (−2.6%), NOx (−2.6%), CO (−5.4%), and PM10 (−3.7%), which suggests the success of emission reduction programs implemented in the road transportation and industrial sectors. However, O3 concentrations increased at most stations (+3.3%/yr), likely due to reduced NOx emissions, increased emissions of volatile organic compounds from on-road transport biofuels, and regional O3 transport. Although exceedances of NAQS decreased over time, concentrations of most pollutants remained above WHO guidelines, except for CO. These results highlight the importance of targeted emission control strategies for both industrial and vehicular sources to improve local air quality and inform future policy decisions.

Complex assessment of ambient particulate matter in a small settlement with coal-handling port

Relevance. Russian coal exports have been steadily increasing in recent years, and Far Eastern ports, originally not adapted to dusty cargoes, have switched to coal operations. Unoptimized coal handling leads to increased content of coal-containing particles in the air and to various environmental problems. Aim. To analyze the concentration of particulate matter in the air and the chemical composition of particles on the surface of conifer needles in the Posyet settlement (Primorsky Krai, Russia), where a large coal terminal operates. Materials and methods. The chemical composition was studied on the surface of conifer needles by X-ray fluorescence and in washout of conifer needle samples using Raman spectroscopy and energy dispersive analysis. Concentrations of particles with the diameter of 2.5 and 10 μm (PM2.5 and PM10, respectively) were measured using automatic monitoring stations. Results and conclusions. Chemical composition was dominated by mineral particles (calcite, silicates, etc.). However, the presence of coal particles (up to 8.3%) and metal particles was also observed. Mean concentrations of PM2.5 and PM10 were within the Russian and international health standards, but close to their upper limits. Concentrations of both measured particle fractions were highest during the winter months (as well as in March, which is traditionally a cold month in the Far East), followed by a gradual decrease. The study obtained new data on the annual variations of concentrations of PM2.5 and PM10, as well as on the basic composition of particles from the surface of woody vegetation (needles) as an indicator of the state of air pollution in this settlement.

Real-ambient PM2.5 induced corneal epithelial barrier disruption through Wnt/β-catenin signaling

Continued daily exposure to fine particulate matter (PM2.5) is linked to increasing risks of ocular surface diseases. However, further study is needed to understand how real-ambient PM2.5 disrupts the barrier function of the corneal epithelial layers and its underlying mechanism. In our study, we utilized a real-ambient PM2.5 exposure system to investigate its effects on the corneal epithelial barrier in C57BL/6Jmice over 4 and 8 weeks. The mean concentration of PM2.5 in the exposure chambers over 8 weeks was 140.18 μg/m3. Following 4 and 8 weeks of continuous PM2.5 exposure, we observed disorganized cellular arrangements in the corneal epithelium of mice. Moreover, PM2.5 exposure led to a significant loss of microvilli on the surface of corneal epithelial cells and noticeable disconnections among epithelial cell layers. Subsequent in vitro analysis revealed that 100 μg/mL PM2.5 activated the Wnt/β-catenin signaling pathway in corneal epithelium, resulting in decreased expression 1.81 fold and 2.25 fold of E-cadherin and ZO-1, respectively, ultimately impairing the corneal epithelial barrier function. Our findings provide the knowledge base for promoting eye health in the context of atmospheric pollution.

Impacts of PM2.5 exposure near cement facilities on human health and years of life lost: A case study in Brazil

Cement factories significantly contribute to atmospheric pollution by generating fine particulate matter (PM2.5), which can potentially increase the mortality risk. The lack of information on the health impacts of PM2.5 pollution from cement operations in Brazil prompted this investigation. We used corrected PM2.5 measurements from low-cost sensors from March 2021 to October 2022 in Rio Branco do Sul, city in the southern region of the country and home to Latin America's largest cement plant, to assess exposure data. Disability-adjusted life years (DALY) method was applied to estimate the years of life lost (YLL) and cost estimate due to deaths from non-accidental causes, cardiovascular and respiratory diseases. The total YLL attributable to PM2.5 concentration was estimated by calculating the attributable fraction (AF) through relative risk. We also collected PM2.5 using a Harvard impactor to evaluate health risks from toxic metals components. During the study period, the analysis of chemical characterization of PM2.5 showed enrichment factors for most elements and the possible influence of the calcination process facilities on the PM2.5 levels. The mean concentration of PM2.5 exceeded the annual WHO air quality guideline (AQG) level, accounted for 3.5%, 4.7%, and 4.3% of total YLL from all causes, cardiovascular, and respiratory diseases, which corresponded to 0.23 (95% CI: 0.17–0.26), 0.06 (95% CI: 0.05–0.07) and 0.03 (95% CI: 0.01–0.06) years loss in life expectancy, respectively. An indirect health cost attributable to PM2.5 resulted in US$ 1.4 million, equivalent to about 3.5% of the total local annual health costs in Rio Branco do Sul, underscoring the significant financial burden of PM2.5 exposures. The greatest economic loss was found in the male age group of 40–69 years and among those with cardiovascular disease, rather than those with respiratory disease. Despite this, the carcinogenic and non-carcinogenic risks from inhalation of hazardous elements were within safe ranges. This work demonstrated PurpleAir's potential for air quality and public health applications. Our findings indicate health and economic benefits from reducing PM2.5 levels by adopting WHO air pollution standards. The results can guide policies toward delivering more effective health care.

Microbiological assessment of bioaerosols in the residential areas of Dhaka City, Bangladesh

This study looked at particulate matter (PM10) in terms of its microbiological features and how bacterial populations are related to PM10. It also tested the antibiotic resistance of different types of microbes that live in PM10. We conducted the study in six different locations (Badda, Chittagong Road, Basabo, Jurain, Mirpur, and Gulshan) of Dhaka city, taking into account residential and commercially important areas, traffic congestion, and infrastructure development. The microbiological study revealed that Bacillus spp. and Staphylococcus spp. were primarily present in PM10. The study also revealed that the total bacterial count (46585±1226.8 CFU/m3) of the Badda zone is higher than in another area. Similar findings were also observed in the case of Bacillus spp. (15625±5729 CFU/m3), Staphylococcus spp. (18518±5730 CFU/m3), and total fungal count (726852± 98209 CFU/m3). Moreover, a positive correlation was observed among Bacillus spp. and Staphylococcus spp. vs. mean PM10 concentration, which implies that airborne microbes in Dhaka city are likely to propagate with the increase of dust concentration. The antibiotic sensitivity assay of Bacillus spp. and Staphylococcus spp. revealed that all the Bacillus spp. (n=16) and Staphylococcus spp. (n=3) were resistant to Ceftazidime (30 µg), Oxacillin (1 µg) and Cefixime (5 µg). So, the research findings highlighted the increased levels of Bacillus spp. and Staphylococcus spp. than the international standard in PM10 of Dhaka city, suggesting potential health risks and indicating antibiotic resistance among these bacterial strains.

The Impact of the New Year Celebration on the Air-Pollution in Slovakia

Fireworks and pyrotechnics are an integral part of the New Year celebration that take place both in cities and rural areas as well. Depending on the meteorological conditions, these activities can raise air pollutant concentrations in ambient atmosphere. In order to estimate the size of this increase, air pollutant concentrations from up to 61 air quality stations situated in the Slovak Republic in period from 2010 to 2023 are analysed. Pollutant concentrations of PM10, PM2.5, CO, NO2, SO2, O3 and benzene from New Year's Eve evening to New Year's morning are compared with data from 25 December to 7 January. In case of PM10 557 cases were analysed. Among them in 64 % the significant exceedance in concentrations which can be attributed to the New Year celebration with high probability was observed. The statistical difference between mean PM10 concentrations during the New Year celebration hours and during the surrounding days was strong (p ≤ 0,001). For PM2.5 the situation was similar. The New Year celebration affects other pollutant concentrations studied in this work in less extend. For them it is difficult to attribute the exceedance to the fireworks. This analysis provides clear evidence of the negative impact of fireworks and pyrotechnics on the air quality, which can lead to public health risks. This work can support policy makers to implement more stringent strategies to reduce air pollution and its effects on health.

Effect of Air Pollutants Particulate Matter PM2.5, PM10, Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), and Ozone (O3) on Fractional Exhaled Nitric Oxide (FeNO).

This study aimed to investigate the effect of Environmental Pollutants Particulate Matter PM2.5, PM10, Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), and Ozone (O3) on lung airway inflammation by assessing the Fractional Exhaled Nitric Oxide (FeNO) in students studying in schools located in or away from air-polluted areas. This matched case-control cross-sectional study was conducted in the Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia from August 2022 to July 2023. In this study, two schools were selected, one was located near a traffic-polluted area (School #1), and the second was located away from the traffic-polluted area (School #2). A total of 300 students were recruited, 150 (75 male and 75 female) students from the school located in a traffic-polluted area, and 150 students (75 male and 75 female) from the school located away from a traffic-polluted area. Environmental pollutants PM2.5, PM10, CO, NO2, O3, and SO2, were recorded. The Fractional Exhaled Nitric Oxide (FeNO) was measured using a Niox Mino. The mean concentration of PM2.5, PM10, CO, NO2, O3, and SO2 were 35.00±0.65 significantly higher in a school located in motor vehicle polluted area compared to a school located away from a motor vehicle-polluted area (29.95±0.32) (p=0.001). The mean values for FeNO were significantly higher (18.75±0.90) among students studying in a school located in the motor vehicle-polluted area compared to students studying in a school located away from the motor vehicle-polluted area (11.26±0.56) (p=0.001). Environmental pollution can cause lung inflammation among students in schools located in traffic-polluted areas.

Effects of indoor environments and outdoor air pollutants in residential areas on acute exacerbation in patients with severe asthma

ABSTRACT This study aimed to determine the effects of indoor environment (IE) and outdoor air pollutants (OAPs) in residential areas on acute exacerbation (AE) in patients with severe asthma. A total of 115 participants were recruited. To characterize IE, we used structured questionnaires and estimated OAP concentrations using a land-use regression model. Participants who were exposed to passive smoking and lived in houses where the kitchen and living room were not separated showed a significantly higher rate of AE (p = 0.014 and 0.0016, respectively). The mean concentration of PM2.5 in residential areas during the last 3 years was significantly higher in participants with AE than that in those without AE (19.8 ± 3.1 vs. 21.0 ± 2.5 µg/m3, p = 0.033). Moreover, the serum level of 8-hydroxy-2′-deoxyguanosine significantly increased in participants with AE compared to those without AE (56.9 ± 30.0 vs. 94.7 ± 44.5 ng/mL, p = 0.0047) suggesting enhanced oxidative stress in those with AE.

Phenomenology of the Composition of PM2.5 at an Urban Site in Northern France

In this work, PM2.5 was sampled at Dunkerque, a medium-sized city located in northern France. The mean concentration of PM2.5 during the sampling period was 12.6 ± 9.5 μg·m−3. Samples were analyzed for elemental and organic carbon (EC/OC), water-soluble organic carbon (WSOC), humic-like substances (HULIS-C), water-soluble inorganic ions, and major and trace elements. The origin and the variations of species concentrations were examined using elemental enrichment factors, bivariate polar plot representations, and diagnostic concentration ratios. Secondary inorganic ions were the most abundant species (36% of PM2.5), followed by OC (12.5% of PM2.5). Secondary organic carbon (SOC) concentrations were estimated to account for 52% of OC. A good correlation between SOC and WSOC indicated that secondary formation processes significantly contribute to the WSOC concentrations. HULIS-C also represents almost 50% of WSOC. The determination of diagnostic ratios revealed the influence of anthropogenic emission sources such as integrated steelworks and fuel oil combustion. The clustering of 72 h air masses backward trajectories data evidenced that higher concentrations of PM2.5, OC, and secondary inorganic aerosols were recorded when air masses came from north-eastern Europe and the French continental sector, showing the considerable impact of long-range transport on the air quality in northern France.

Characteristic and mechanism of pollution by laser cleaning high-value vehicle parts with a complex structure in remanufacturing industry

Remanufacturing high-value vehicle parts is of substantial significance for the circular economy because it provides a second service life and reduces solid waste generation. Laser cleaning is a promising method in the remanufacturing industry owing to its high energy, precision, and efficiency. However, the pollution caused by laser cleaning remains unknown and has rarely been reported, limiting the application of this method. In this study, pollution removal and conversion using a high-energy laser were explored, and environmental life cycle and health risk assessments were conducted. The results showed that high-energy lasers might induce new organic pollutants, such as olefins, alkynes, and aldehydes. During laser cleaning, thermal elastic expansion and shock wave generation were the main mechanisms of rust removal, and evaporation and small-scope boiling were used for waste oil removal. The mean concentration of PM10 was above 7000 µg/m3 in laser rust removal, and the total concentration of volatile organic compounds (VOCs) was the highest in laser oil removal (∼ 2568 µg/m3). Particulate matter contained high amounts of Fe, Al, and Mn. An environmental life cycle assessment indicated that laser cleaning for stain removal significantly reduced the total environmental impact compared with that of traditional solvent-ultrasonic cleaning (∼ 40.0%) and sandblasting (∼ 83.3%). This study provides an environmental protection basis for increasing the use of laser cleaning in the remanufacturing industry.

Desert dust episodes during pregnancy are associated with increased preterm delivery in French Guiana.

Preterm deliveries are a major multifactorial public health problem in French Guiana. Desert dust episodes have been associated with preterm delivery in Guadeloupe, a territory with similarities to French Guiana. We thus tried to replicate this finding in the context of French Guiana. A retrospective ecological cohort study combined daily PM10 concentration measurements during pregnancy and term at delivery extracted from French Guiana's computerized pregnancy delivery registry. Daily PM10 concentrations during the course of pregnancy were analyzed as mean concentrations and as the proportion of intense dust episodes (≥55 μg PM10/m3). These exposure variables were studied in relation to the outcome of preterm delivery. Overall, 3,321 pregnant women with complete daily PM10 measurements were included, of whom 374 (11.26%) delivered prematurely. Among preterm deliveries, 168 (44.9%) were spontaneous deliveries and 206 (55.1%) were induced. Rank-sum tests showed that, for spontaneous and induced spontaneous deliveries, both mean PM10 concentrations and proportions of intense desert dust episodes were significantly greater among preterm births than among term births. Although the proportion of intense desert dust episodes during pregnancy was significantly associated with spontaneous preterm deliveries, the relation was U-shaped, with an adjusted odds ratio (AOR) = 2 (95%CI = 1.2-3.1) for lowest values relative to median values and AOR = 5.4 (95%CI = 3.2-8.9) for the highest values relative to median values. Similarly, the proportion of intense desert dust episodes during pregnancy was also significantly associated with induced preterm deliveries in a U-shaped manner (AOR = 2.7 (95%CI = 1.6-4.5) for the lowest relative to median values and AOR = 6.8 (95%CI = 3.9-11.9) for the highest relative to median values). Although in our study the relation between PM10 concentrations appeared non-linear, the highest mean concentrations and intense desert dust episodes were indeed associated with both spontaneous and induced preterm delivery.

Dynamic characteristics of wind and PM10 over desert-oasis transition zone during dust events

Dust storm events generate aeolian dust as one of the main aerosols in the atmosphere, with significant impacts on air quality and human health. Further study is needed on the dust emission processes in source regions and the impacts of underlying surfaces with forested windbreaks on the transport of wind flow and PM10 to develop more accurate dust concentration forecasts. Synchronized monitoring of wind velocity and the PM10 concentration was performed along the dust transport pathway crossing the desert and oasis in Minqin County, Gansu Province, China. Results indicated that the PM10 concentration and flux responded quickly to wind velocity in the desert with both having obvious power function relationships. The addition of supra-regional transport of PM10 particles led to an abnormal increase in PM10 concentration and flux. Between desert and oasis, a positive linear function relationship of PM10 concentrations and quadratic function relationship of PM10 flux exist. The dynamic transfer process of PM10 in the oasis roughly depends on the condition of PM10 in the desert area. Forested windbreaks significantly reduced the mean wind velocity and PM10 flux by 65.02% and 67.63%, respectively. However, forests had a weak influence on the mean PM10 concentration. The effects of forested windbreaks on the PM10 concentration are related to the windward wind velocity. With increasing velocity, difference of PM10 concentration from desert to oasis turned from negative to positive, while the positive effects of the forested windbreak system can be enhanced by an increase in the windward wind velocity.

Health impact assessment of port-sourced air pollution in Barcelona.

Air pollution is a major health risk factor. Ports might be an understudied source of air pollution. We conducted a spatial health impact assessment (HIA) of port-sourced air pollution for Barcelona for 2017 at the neighbourhood level. Total NO2 and PM10 and port-sourced NO2, PM10 and PM2.5 concentrations were available through the ADMS-Urban model. Population data, mortality and morbidity data, and risk estimates were obtained. We followed standard HIA methodologies and calculated relative risks and impact fractions for 1.35 million adults living in 73 neighbourhoods. The city-wide mean total NO2 and PM10 concentrations were 37.88 μg/m3 (range: 19.61-52.17 μg/m3) and 21.68 μg/m3 (range: 17.33-26.69 μg/m3), respectively, of which 7% (range: 2-36%) and 1% (range: 0-7%) were port-sourced, respectively. The mean port-sourced PM2.5 concentration was 0.19 μg/m3 (range: 0.06-1.38 μg/m3). We estimated that 1,123 (PI: 0-3,060) and 1,230 (95% CI: 0-2,566) premature deaths were attributable to total NO2 and PM10, respectively, of which 8.1% (91; PI: 0-264) and 1.1% (13; 95% CI 0-29) were attributable to port-sourced NO2 and PM10, respectively. 20 (95% CI: 15-26) premature deaths were attributable to port-sourced PM2.5. Additionally, a considerable morbidity burden and losses in life expectancy were attributable to port-sourced air pollution. Neighbourhoods closest to the port in the south-east were most adversely affected, gradually decreasing towards the north-west. The port is an understudied air pollution source in Barcelona with strong health impacts. Cities need local insight into health risk factors, their sources, attributable burdens and distributions for defining targeted policies.

Characterising temporal variability of PM2.5/PM10 ratio and its correlation with meteorological variables at a sub-urban site in the Taj City

The problem of air pollution poses a major challenge in the city of Taj, Agra because of rapid urbanization and tourism. Research on PM2.5/PM10 ratio contributes to a deeper understanding of the air pollution scenario and promoting sustainable development. This study was carried out at a suburban site in Agra (Jan 2021-Dec, 2022). We analyzed PM2.5/PM10 ratios, and their correlation with Air Quality Index and meteorological factors using various statistical approaches in the OpenAir package in RStudio. The mean concentrations of PM2.5 and PM10 were 46 and 67 μg/m3, respectively. The PM2.5/PM10 ratio was 0.65, indicating fine particulate dominance. Diurnal, intra-annual, and weekly cycles of PM2.5, PM10, and PM2.5/PM10 ratios were examined. PM2.5/PM10 ratio increased with increasing AQI. Correlation analysis revealed, a strong positive correlation (r = 0.94) between PM10 and PM2.5 while the PM2.5/PM10 ratios showed negative association with wind speed (WS), and temperature, and positive association with relative humidity (RH). Higher RH led to higher PM2.5/PM10 ratios indicating worsening of PM2.5 pollution during winter and post-monsoon. Bivariate polar plots exhibited the lowest PM2.5/PM10 ratios in summer at high WS (>10 m/s) from the west, and the highest PM2.5/PM10 ratios in winter and post-monsoon at low WS (<10 m/s).

Relative contributions of ambient air and internal sources to multiple air pollutants in public transportation modes

Commuters are often exposed to relatively high air pollutant concentrations in public transport microenvironments (TMEs) because of their proximity to emission sources. Previous studies have mainly focused on assessing the concentrations of air pollutants in TMEs, but few studies have distinguished between the contributions of ambient air and internal sources to the exposure of commuters to air pollutants. The main objective of this study was to quantify the contributions of ambient air and internal sources to the measured particulate matter and gaseous pollutant concentrations in selected TMEs in Hong Kong, a high-rise, high-density city in Asia. A sampling campaign was conducted to measure air pollutant concentrations in TMEs in Hong Kong in July and November 2018 using portable air quality monitors. We measured the concentrations of each pollutant in different TMEs and quantified the infiltration of particulate matter into these TMEs. The double-decker bus had the lowest particulate matter concentrations (mean PM1, PM2.5, and PM10 concentrations of 5.1, 9.5, and 13 μg/m3, respectively), but higher concentrations of CO (0.9 ppm), NO (422 ppb), and NO2 (100 ppb). For all the TMEs, about half of the PM2.5 were PM1 particles. The Mass Transit Railway (MTR) subway system had a PM2.5/PM10 ratio of about 0.90, whereas the PM2.5/PM10 ratio was about 0.60–0.70 for the other TMEs. The MTR had infiltration factor estimates <0.4 for particulate matter, lower than those of the double-decker bus and minibus. The MTR had the highest contribution from internal sources (mean PM1, PM2.5, and PM10 concentrations of 4.6, 13.4, and 15.8 μg/m3, respectively). This study will help citizens to plan commuting routes to reduce their exposure to air pollution and help policy-makers to prioritize effective exposure reduction strategies.

Key factors for abating particulate matter in a highly industrialized area in N Spain: Fugitive emissions and secondary aerosol precursors

In highly industrialized areas, abating particulate matter (PM) is complex owing to the variety of emission sources with different chemical profiles that may mix in the atmosphere. Gijón—an industrial city in northern Spain—was selected as a case study to better understand the key emission sources and improve air quality in highly industrialized areas. Accordingly, the trends of various air quality indicators (PM10, PM2.5, SO2, NO2, and O3) during the past decade (2010–2019) were analyzed. Additionally, the inorganic and organic PM10 compositions were analyzed for source apportionment studies and to assess the impact of COVID-19 restrictions on PM10 levels.The results revealed that over the past decade, PM10 concentrations decreased, whereas PM2.5 concentrations dominated by secondary inorganic aerosols (SIA) remained relatively constant. Notably, during the COVID-19 lockdown, the PM10 concentration increased by 9.1%, primarily owing to an increase in regional SIA (>65%) due to specific meteorological conditions that favor the formation of secondary PM from gaseous precursors. Overall, eight key PM10 sources were identified: “industrial fugitive PM resuspension” (FPM, 28% of mean PM10 concentration), “aged sea spray” (SSp, 16%), “secondary nitrate” (SN, 15%), “local diffuse source” (LPM, 12%), “solid fuel combustion” (SFC, 7.8%), “biomass burning” (BB, 7.4%), “secondary sulphate” (SSu, 6.0%), and “sinter” (SIN, 4.5%). The PM10 concentration in Gijón is significantly influenced by the integrated steel industry (FPM, SFC, and SIN; 41% of PM10) and fugitive primary PM emissions were the main source (FPM and LPM; 40%). To reduce PM10 and PM2.5 concentrations, industrial fugitive emissions, which are currently poorly regulated, and SIA precursors must be abated.This study provides a methodological approach that combines trend analysis, chemical speciation, and source apportionment for assessing pollution abatement strategies in industrialized areas with a complex mix of emission sources.

Winter-time pollution in Central European cities shifts the 208Pb/207Pb isotope ratio of atmospheric PM2.5 to higher values: Implications for lead source apportionment

Atmospheric lead pollution has adverse health effects on humans. Identification of anthropogenic Pb sources is thus crucial for understanding of pollution-related risks and for formulation of efficient abatement strategies. We analyzed concentrations and isotope ratios of Pb in fine air-borne particulate matter (PM2.5) in three Central European cities. Aerosol sampling in 12-h intervals was performed during summer and winter in Hradec Králové, Olomouc and Brno, regional centers of highly industrialized Czech Republic, each with a population of more than 90 thousand. Lead analysis was complemented with concentration measurements of Zn, Cu, Cd, As, Sb, and S. Trace element and PM2.5 concentrations were higher in winter than in summer in all studied cities, on average by 47%. The overall mean concentration of PM2.5 in urban air was 21 μg m−3, similar to that in Bern (Switzerland) and Vienna (Austria). Across the sites, 206Pb/207Pb ratios ranged from 1.142 to 1.178 in summer and from 1.143 to 1.173 in winter. The mean 206Pb/207Pb ratios were statistically indistinguishable in all three studied cities (1.165 in Hradec Králové, 1.163 in Olomouc, and 1.160 in Brno). In the 206Pb/207Pb vs.208Pb/207Pb graph, Pb isotope composition of summer samples formed a straight line, whereas Pb isotope composition of winter samples was shifted toward higher 208Pb/207Pb ratios. A Pb isotope inventory of regional pollution sources indicated that winter-time Pb pollution was not caused solely by household heating and increased electricity production in coal-burning power plants. Recycling of industrial Pb originating from Variscan ores and waste incineration could have shifted the 208Pb/207Pb ratio of PM2.5 to higher values, however, such sources do not emit more Pb in winter than in summer. Remobilization of legacy alkyl-Pb from gasoline additives and Pb emissions from current unleaded gasoline and diesel could have shifted both Pb isotope ratios to lower values.

In vitro toxicity and lung cancer risk: Atmospheric particulate matter from a city in southeastern Brazil impacted by biomass burning

The effects of PM10 on human health were investigated using samples collected in São Carlos city (São Paulo state), by the determination of the concentrations of PAHs and derivatives, together with evaluations of cytotoxicity and the formation of ROS in in vitro tests. In 2016, the mean concentrations of PM10, ΣPAHs, Σoxy-PAHs, Σnitro-PAHs, Σsaccharides, and Σions were 21.12 ± 9.90 μg m−3, 1.47 ± 1.70 ng m−3, 0.37 ± 0.31 ng m−3, 0.84 ng m−3, 119.91 ± 62.14 ng m−3, and 5.66 ± 4.52 μg m−3, respectively. The PM10 concentrations did not exceed the limit thresholds set by national legislation, however, the annual lung cancer risk calculated was 2.59 ± 1.22 cases per 100,000 people, in the dry season, which accounts for the annual risk (April to September). Moreover, the carcinogenic activities of the PAHs mixture were more than 1000-fold higher in the dry season (dry season: BaPeq = 0.30 ng m−3; wet season BaPeq = 0.02 ng m−3). The concentrations of most analytes were also higher during the dry season, as had already been demonstrated in the same city. This was due to reductions in precipitation, relative humidity and air temperature, and increased biomass burning, which was the main source of PM10 in the city in 2016 (contribution rate of more than 50%). Toxicological results also showed the negative impacts of PM10, exposure to PM10 extracts for 72 h reduced the viability of A549 and MRC5 cells, and the formation of ROS was observed. The cellular responses obtained using combined and individual extracts of PM10 differed and were sometimes associated with specific compounds. These demonstrate the importance of monitoring PM toxicity using different approaches and the main anthropogenic sources’ contribution. Therefore, to improve air quality and human health, existing legislation needs to be modified to incorporate these tests.

PM2.5/PM10-bound PAHs in Hotan city: Concentrations, sources, and contribution to ·OH

The air pollution in Hotan, Xinjiang is serious and the high concentration of polycyclic aromatic hydrocarbons (PAHs) cannot be ignored. Studies on the characteristics of PAHs in the region are still limited. In this paper, PM10 and PM2.5 samples were collected from the urban area of Hotan in summer and winter, and the concentrations, sources and contributions to hydroxyl radicals (·OH) of 12 PAHs were analyzed. The mean concentrations of PM2.5/PM10-bound PAHs were much higher in winter (150 ± 38.8 ng/m3 and 156 ± 38.1 ng/m3) than in summer (6.34 ± 6.28 ng/m3 and 7.64 ± 6.75 ng/m3), with greater contributions from medium and high molecular weight PAHs. PAHs are mainly derived from vehicle emissions, coal and biomass combustion, with coal combustion making the largest contribution to ·OH concentrations. The combination of air mass trajectory clustering and potential source contribution factor analysis (PSCF) revealed that long-range transport contributed less to the PAHs content, and local domestic source emissions dominated. Studies have shown a significant positive correlation between PAHs and ·OH concentrations, indicating that PAHs are oxidatively toxic to humans. Controlling PAHs emission in winter in Hotan and reducing the concentration of PAHs in respirable particulate matter will help to reduce the damage to human health.