PM10 Fraction Research Articles

Differential effects of size-specific particulate matter on lower respiratory infections in children: A time-series analysis in Lanzhou, China

This study aimed to assess the differential effects of size-specific PM (PM2.5, PM10–2.5, and PM10) on daily outpatients for Lower Respiratory Infection (LRI), Pneumonia, and Bronchitis among children in Lanzhou, China. A distributed lag nonlinear model (DLNM) was employed to evaluate the non-linear and delayed effects. The models were fitted with different lag structures, including single lag days from the current to the previous seven days (lag0 to lag7) and moving average concentrations over seven lag days (lag0–1 to lag0–7). We found that different PM fractions were significantly associated with hospital visits for LRI, pneumonia, and bronchitis, and cumulative effects increased with the increasing number of lag days investigated. Relative risk (RR) of LRI outpatient visits among children per 10 µg/m3 increase in PM2.5, PM10–2.5, and PM10 were 1.070 (95% CI: 1.059, 1.081), 1.010 (95% CI: 1.006, 1.015), and 1.013 (95% CI: 1.010, 1.016), respectively. For every 10 μg/m3 increase in PM2.5, PM10–2.5, and PM10, the RR values for pneumonia were 1.081, 1.013, and 1.019, and those for bronchitis were 1.069, 1.009, and 1.012, respectively. Boys and children aged 0–3 years were more sensitive to PM exposure. We also found significantly higher effects of PM in cold seasons than that in warm seasons. Our results suggested that short-term exposure to size-specific PM, PM2.5 in particular, might be an important trigger of outpatient visits for overall and cause-specific LRI.

Disease burden and health risk to rural communities of northeastern India from indoor cooking-related exposure to parent, oxygenated and alkylated PAHs

Exposure to a total of 51 targeted and non-targeted polycyclic aromatic hydrocarbons (PAHs) and their oxygenated and alkylated derivatives associated with size-segregated aerosol was investigated in rural kitchens using liquefied petroleum gas (LPG), mixed biomass (MB) and firewood (FW) fuels in northeastern India. The averaged PM10-associated parent-, alkylated-, and oxygenated-PAHs concentrations increased notably from LPG (257, 54, and 116 ng m−3) to MB (838, 119, and 272 ng m−3) to FW-using kitchens (2762, 225, and 554 ng m−3), respectively. PAHs were preferentially associated with the PM1 fraction with contributions increasing from 80 % in LPG to 86 % in MB and 90 % in FW-using kitchens, which in turn was dominated by <0.25 μm particles (54–75 % of the total). A clear profile of enrichment of low-molecular weight PAHs in cleaner fuels (LPG) and a contrasting enrichment of high-molecular weight PAHs in biomass-based fuels was noted. The averaged internal dose of Benzo[a]pyrene equivalent was the lowest in the case of LPG (19 ng m−3), followed by MB (161 ng m−3) and the highest in FW users (782 ng m−3). Estimation of incremental lifetime cancer risk (ILCR) from PAH exposure revealed extremely high cancer risk in biomass users (factors of 8–40) compared to LPG. The potential years of life lost (PYLL) and PYLL rate averaged across kitchen categories was higher for lung cancer (PYLL: 10.55 ± 1.04 years; PYLL rate: 204 ± 426) compared to upper respiratory tract cancer (PYLL: 10.02 ± 0.05 years; PYLL rate: 4 ± 7), and the PYLL rates for biomass users were higher by factors of 9–56 as compared to LPG users. These findings stress the need for accelerated governmental intervention to ensure a quick transition from traditional biomass-based fuels to cleaner alternatives for the rural population of northeastern India.

Variability of airborne microbiome at different urban sites across seasons: a case study in Rome

Introduction: Biogenic fraction of airborne PM10 dominated by bacteria and fungi, has been recognized as serious environmental and human health issues in cities.Methods: In the present study, we combined a high-throughput amplicon sequencing of the bacterial 16S rRNA gene and the fungal internal transcribed spacer (ITS) region, with elemental analysis of airborne particulate matter (PM10) to investigate the community compositions and structures of PM10-associated bacteria and fungi across four different seasons in three urban sites of Rome with differential pollution rate.Results: In this study, а clear seasonal shift of bacterial and fungal community structure driven by PM10 mass concentrations and environmental factors, such as temperature and precipitations, has been identified. In addition, the seasonal impact of local sources and long-range transported air masses on the community structures of the microbes has been also postulated. Our data revealed that the lack of precipitation and the subsequent resuspension of dust produced by vehicular traffic might contribute to the maximum abundance of soil-associated microbes in winter and summer. However, the increase of PM10 concentrations favoured also by climatic conditions, domestic heating and dust advection event from African desert further shaped the community structure of winter. Across three seasons, the pollutant removal-hydrogen oxidation bacteria and the opportunist-human pathogenic fungi progressively increased with pollution levels, in the sequence from green to residential and/or polluted area close to the traffic roads, with highest fraction during winter.Discussion: Hence, our results highlight a close interrelationship between pollution, climatic factors and abundance of certain bacterial and fungal predicted functional groups also with potential implications for human health.

A Three-Year Analysis of Toxic Benzene Levels and Associated Impact in Ploieşti City, Romania.

This study examines the levels of benzene and the potential health impact during three years of continuous monitoring (2019-2021), including the COVID-lockdown period from 2020 in a city that is an important Romanian center for petroleum refining and associated product manufacturing. The dataset contains benzene, toluene, NOx, PM10 concentrations, and meteorological factors monitored by six automatic stations from the national network of which four are in the city and two outside. Special attention was given to the benzene dynamics to establish patterns related to the health impact and leukemia. An assessment of the exposure was performed using EPA's ExpoFIRST v. 2.0 for computing the inhalation Average Daily Dose (ADD) and Lifetime Average Daily Dose (LADD). The health impact was estimated based on several indicators such as lifetime cancer risk (LCR), Hazard Quotient (HQ), Disability-Adjusted Life Years (DALY), and Environmental burden of disease (EBD). Overall, the annual average of all stations was almost similar between years i.e., 3.46 in 2019, 3.41 in 2020, and 3.63 µg/m3 in 2021, respectively. The average of all stations during the lockdown period was 2.67 µg/m3, which was lower than the multiannual average of the 2019-2021 period, i.e., 3.5 µg/m3. Significant correlations were present between benzene and other pollutants such as NOx (r = 0.57), PM10 fraction (r = 0.70), and toluene (r = 0.69), and benzene and temperature (r = -0.46), humidity (r = 0.28), and wind speed (r = -0.34). Regarding the ADD, in all scenarios, the most affected age categories are small children, despite a lower outdoor exposure time. From birth to <70 years, the ADD varied depending on the exposure scenario resulting in 3.27 × 10-4, 5.6 × 10-4, and 4.04 × 104 mg/kg-day, and 3.95 × 10-4, 10.6 × 10-4, and 6.76 × 10-4 mg/kg-day for the LADD, respectively. The Integrated Lifetime Cancer Risk (ILTCR) values were 14.1 × 10-5 in winter, 9.04 × 10-5 in spring, 8.74 × 10-5 in summer, and 10.6 × 10-4 in autumn. The ILTCR annual averages were 1.08 × 10-4 (2019), 1.07 × 10-4 (2020), 1.04 × 10-4 (2021), and 1.06 × 10-4 for the entire period. The resulting ILTCR values point out very risky conditions, with the annual averages reaching the definite cancer risk category. The corresponding burden based on the DALY's loss due to leukemia in Ploieşti was estimated at 0.291 (2 μg/m3 benzene), 0.509 (3.5 μg/m3 benzene), 0.582 (4 μg/m3 benzene), and 0.873 DALYs per 100,000 inhabitants (6 μg/m3 benzene), respectively. The current study provides useful insights for a better understanding of the exposure levels to benzene and associated health impact in Ploieşti despite the limitations determined by the data hiatus and incomplete or missing information regarding the health impact.

Efficacy of green infrastructure in reducing exposure to local, traffic-related sources of airborne particulate matter (PM)

One aim of roadside green infrastructure (GI) is to mitigate exposure to local, traffic-generated pollutants. Here, we determine the efficacy of roadside GI in improving local air quality through the deposition and/or dispersion of airborne particulate matter (PM). PM was collected on both pumped air filters and on the leaves of a recently installed ‘tredge’ (trees managed as a head-high hedge) at an open road environment next to a primary school in Manchester, U.K. The magnetic properties of PM deposited on leaves and filters (size fractions PM10 and PM2.5) were deduced from hysteresis loops, first-order reversal curves (FORCs), and low-temperature remanence measurements. These were complemented with electron microscopy to identify changes in magnetic PM concentration downwind of the tredge/GI. We show that the tredge is permeable to airflow using a simple CO2 tracer experiment; hence, it allows interception and subsequent deposition of PM on its leaves. Magnetic loadings per m3 of air from filters (PM10 saturation magnetisation, Ms, at 5 K) were reduced by 40 % behind the tredge and a further 63 % in the playground; a total reduction of 78 % compared to roadside air. For the PM2.5 fraction, the reduction in magnetic loading behind the tredge was remarkable (82 %), reflecting efficient diffusional capture of sub-5 nm Fe-oxide particles by the tredge. Some direct mixing of roadside and playground air occurs at the back of the playground, caused by air flow over, and/or through gaps in, the slowly-permeable tredge. The magnetic loading on tredge leaves increased over successive days, capturing ~23 % of local, traffic-derived PM10. Using a heuristic two-dimensional turbulent mixing model, we assess the limited dispersion of PM < 22.5 μm induced by eddies in the tredge wake. This study demonstrates that PM deposition on leaves reduces exposure significantly in this school playground setting; hence, providing a cost-effective mitigation strategy.

Characteristics and atmospheric processes of water-soluble ions in PM2.5 and PM10 over an industrial city in the National Capital Region (NCR) of India

This study investigates water-soluble inorganic ions (WSIIs), their potential formation mechanism, particle bound water content and acidity (pH) in ambient aerosols in Ghaziabad, an industrial city located downwind of Delhi, the Indian National Capital. 24-hour integrated PM2.5 and PM10 samples were collected using collocated samplers at two receptor locations every third day throughout the year. The samples were collected on Nylon filter substrates (preceded by a denuder upstream for capturing acidic gases) and Teflon filter substrates for WSII and mass measurements, respectively. Further, on-site meteorological parameters were recorded at both locations. The annual average PM concentrations observed were: PM2.5: 144 ± 81 μgm−3 (Site A), 163 ± 95 μgm−3 (Site B); and PM10: 245 ± 116 μgm−3 (Site A), 279 ± 152 μgm−3 (Site B). On average, SO42−, NO3−, Cl− and NH4+ contributed to ∼90% to PM2.5WSII mass and ∼82% to PM10WSII mass, which in turn made up ∼35% of PM2.5 mass and ∼23% of the PM10 mass across both sites. SO42− concentration was found to be highest followed by NO3−, NH4+ and Cl− for both PM fractions. Mann-Whitney U test revealed that both sites were similar with respect to WSII mass indicating city's airshed average concentration with respect to the major ions. The highest WSII contribution to the total PM was found in winter season (37–40% for PM2.5 and 27–31% for PM10) followed by monsoon (36–38% for PM2.5 and 18–21% for PM10), post-monsoon (28–34% for PM2.5 and 21–23% for PM10) and pre-monsoon (21–27% for PM2.5 and 15% for PM10). High contribution during winter was because of higher emissions of precursor gases in combination with moderate relative humidity (36–59%) and minimal precipitation (average ∼0.2 mm). Sulphur Oxidation Ratio and Nitrogen Oxidation Ratio indicated high photochemical oxidation with a greater extent of SO42− formation compared to NO3−. Although high concentrations of NH3 gas were observed, there was insufficient NH4+ ions for neutralizing counter ions with Ammonium Neutralization Ratio values of 0.76±0.14 for PM2.5 and 0.62±0.14 for PM10. Finally, aerosol liquid water content (ALWC) and acidity were estimated using a thermodynamic equilibrium model, ISORROPIA-II. It was found that PM2.5 pH varied from 2.9 to 6.2 (avg. 4.4±0.8) and the PM2.5 mass doubled at RH ∼90% because of the high particle bound water. Consequently, a reduction in SO2 would result in instantaneous cuts of SO42−, PM2.5, and ALWC.

Ecological and Geochemical State of Soil Cover in Gusinoozersk in the Zone of Influence of Coal Thermal Power Plant

The pollution of the topsoils of the city of Gusinoozersk (Republic of Buryatia) under the influence of emissions from State District Power Plant (SDPP) which used the Okino-Klyuchevskiy brown coal as fuel was studied. The content of 14 elements (Sr, As, Co, Mo, Sb, V, Cu, Ni, Cr, W, Zn, Bi, Cd, Pb) in bulk samples, as well as in the fraction of physical clay (particles with a diameter 10 µm, PM10) and in samples of brown coal and ash from the SDPP. Strontium, As, Co, Mo, Sb, V are the priority pollutants in the soils of Gusinoozersk with higher concentrations of most elements in the PM10 fraction. Soils and the PM10 fraction in the industrial operating subzone are the most polluted with Sr, As, Co, V, Cu, Mo, Ni, Cr, which are contained in the fly ash of the Gusinoozerskaya SDPP. Most of the territory (57% for soils in general and 47% for the PM10 fraction) is characterized by a low level of pollution (Zc = 8–16). Arsenic poses the greatest environmental hazard; in the PM10 fraction, its concentrations exceeded the MPC in 90% of the studied samples. In soils and their PM10 fraction, the leading factors for the accumulation of elements are the content of Fe2O3, organic matter, soil texture, alkaline-acid conditions, and belonging to a functional zone, which determine the formation of various classes of geochemical barriers. The polluting effect of brown coals depends on the content of heavy metals and metalloids in them. Comparison of the chemical composition of the Okino-Klyuchevskii brown coal and ash from the Gusinoozerskaya SDPP and the Kansk-Achinskii coal and ash from the Central Thermal Power Plant of Severobaikalsk showed that the brown coal and ash from Severobaikalsk were slightly enriched in metals and metalloids, which significantly reduced their accumulation in soils.

Spatial-temporal evolution patterns and drivers of PM2.5 chemical fraction concentrations in China over the past 20 years.

The quantitative assessment of the spatial and temporal variability and drivers of fine particulate matter (PM2.5) fraction concentrations are important for pollution control and public health preservation in China. In this study, we investigated the spatial temporal variation of PM2.5 chemical component based on the PM2.5 chemical component datasets from 2000 to 2019 and revealed the driving forces of the differences in the spatial distribution using geodetector model (GD), multi-scale geographically weighted regression model (MGWR), and a two-step clustering approach. The results show that: the PM2.5 chemical fraction concentrations show a trend of first increasing (2000-2007) and then decreasing (2007-2019). From 2000 to 2019, the change rates of PM2.5, organic matter (OM), black carbon (BC), sulfates (SO2- 4), ammonium (NH+ 4), and nitrates (NO- 3) were -0.59, -0.23, -0.07, -0.15, -0.02, and 0.04μg/m3/yr in the entirety of China. The secondary aerosol (i.e., SO2- 4, NO- 3, and NH+ 4; SNA) had the highest fraction in PM2.5 concentrations (55.6-68.1% in different provinces), followed by OM and BC. Spatially, North, Central, and East China are the regions with the highest PM2.5 chemical component concentrations in China; meanwhile, they are also the regions with the most significant decrease in PM2.5 chemical fraction concentrations. The GD and MGWR model shows that among all variables, the number of enterprises, disposable income, private car ownership, and the share of secondary industry non-linearly enhance the differences in the spatial distribution of PM2.5 component concentrations. Electricity consumption has the strongest influence on NH+ 4 emissions in Northwest China and BC and OM emissions in Northeast China.

Distinctive features of inorganic PM1.0 components during winter pollution events over the upwind and downwind regions in Northeast Asia

The air quality of Northeast Asia cannot be improved by the individual national efforts because of the proximity of countries. To foster understanding of this problem, the Fine Particle Research Initiative in East Asia considering National Differences (FRIEND) Project was launched in 2020. During the first FRIEND campaign conducted from December 15, 2020 to January 15, 2021, gaseous and aerosol components were monitored simultaneously with high temporal resolution at the following key sites in Northeast Asia: Ulaanbaatar, Mongolia; Beijing, China; Seosan and Seoul, Republic of Korea; and Noto, Japan. The chemical components of PM1.0 were monitored with Aerosol Chemical Speciation Monitors (ACSMs) at the Beijing, Seoul, and Noto sites. Over the upwind region of Northeast Asia (Beijing and Seoul), sulfate aerosol (SO42−) was a high as a fraction of PM1.0 and nitrate aerosol (NO3−) was high, whereas over the downwind region (Noto), SO42− was high and NO3− was low. We used regional numerical modeling to clarify the reason for these distinctive PM1.0 differences over the upwind and downwind regions. The model also reproduced higher NO3− in the upwind region and higher SO42− in the downwind region, and captured the ACSMs measurements based on the statistical analyses. The conversion ratio from SO2 to SO42− (FS) indicated lower oxidation over the Asian continent and increased oxidation toward the downwind region. The OH radical and cloud fraction suggested that the gas- and aqueous-phase SO2 oxidation processes were inactive over the Asian continent. In contrast to FS, the conversion ratio from HNO3 to NO3− (FN) indicated a higher production ratio over the Asian continent and a strong decline toward the downwind region. HNO3 concentration in northeastern China was close to zero, whereas NH3 concentration was high, suggesting NH3-rich conditions where HNO3 was fully neutralized to form NO3−, whereas the conditions were NH3-poor toward the downwind region. Therefore, these factors govern the transformation process of PM1.0 during long-range transport from the upwind to downwind region in Northeast Asia and determine the distinctive features of inorganic PM1.0.

Health risk associated with exposure to particulate matter and volatile organic compounds among two-wheeler delivery personnel in Ghaziabad, India

The growth in India's food delivery sector is tremendous, with the increasing potential to deliver food to the doorsteps. This increases the number of food delivery persons on the road. Commuters on Delhi – National Capital Region streets are highly exposed to traffic-related air pollution. This study assessed the exposure of delivery persons in Ghaziabad to Particulate matter (PM) and Volatile Organic Compounds (VOC), followed by a probabilistic health risk assessment. The mean exposure level while riding was 516, 180 and 113 μg/m3 for PM10, PM2.5 and PM1, respectively. The exposure values showed significant diurnal variation. The order of diurnal variation was night > morning > afternoon. The multiple path particle dosimetry model results showed that the total deposition fraction of PM10 in the respiratory tract was 2.5 and 3.7 times higher than PM2.5 and PM1, respectively. The total VOC concentrations detected at the traffic intersections, on the road while riding and in the front office of restaurants were 172, 50 and 16 μg/m3, respectively. Benzene was observed to be the major contributor to carcinogenic and non-carcinogenic risk. Results from sensitivity analysis indicated that the concentration of pollutants in the traffic junctions was the major parameter influencing the risk.

Physical and chemical properties of PM1 in Delhi: A comparison between clean and polluted days

Considering the significance of PM1 aerosol in assessing health impacts of air pollution, an extensive analysis of PM1 samples collected at an urban site in Delhi is presented in this study. Overall, PM1 contributed to about 50 % of PM2.5 mass which is alarming especially in Delhi where particle mass loadings are usually higher than prescribed limits. Major portion of PM1 consisted of organic matter (OM) that formed nearly 47 % of PM1 mass. Elemental carbon (EC) contributed to about 13 % of PM1 mass, whereas SO42− (16 %), NH4+ (10 %), NO3− (4 %) and Cl− (3 %) were the major inorganic ions present. Sampling was performed in two distinctive campaign periods (in terms of meteorological conditions and heating (fire) activities), during the year 2019, each spanning two-week time, i.e. (i) September 3rd-16th (clean days), and (ii) November 22nd-December 5th (polluted days). Additionally, PM2.5 and black carbon (BC) were measured simultaneously for subsequent analysis. The 24-h averaged mean concentrations of PM2.5 and BC during clean days (polluted days) were 70.6 ± 26.9 and 3.9 ± 1.0 μg m−3 (196 ± 104 and 7.6 ± 4.1 μg m−3), respectively, which were systematically lower (higher) than that of the annual mean (taken from studies conducted at same site in 2019) of 142 and 5.7 μg m−3, respectively. Changes in characteristic ratios (i.e., organic carbon (OC)/elemental carbon (EC) and K+/EC) of chemical species detected in PM1 show an increase in biomass emissions during polluted days. Increase in biomass emission can be attributed to increase in heating practices (burning of biofuels such as wood logs, straw, and cow-dung cake) in- and around- Delhi because of fall in temperature during second campaign. Furthermore, a significant increase in NO3− fraction of PM1 is observed during second campaign which shows fog processing of NOX due to conducive meteorological conditions in winters. Also, comparatively stronger correlation of NO3− with K+ during second campaign (r = 0.98 as compared to r = 0.5 during first campaign) suggests the increased heating practices to be a contributing factor for increased fraction of NO3− in PM1. We observed that during polluted days, meteorological parameters such as dispersion rate also played a major role in intensifying the impact of increased local emissions due to heating activities. Apart from this, change in the direction of regional emission transport to study site and the topology of Delhi are the possible reasons for the elevated pollution level, especially PM1 during winter in Delhi. This study also suggests that black carbon measurement techniques used in current study (optical absorbance with heated inlet and evolved carbon techniques) can be used as reference techniques to determine the site-specific calibration constant of optical photometers for urban aerosol.

Physicochemical Assessment of the Road Vehicle Traffic Pollution Impact on the Urban Environment

Vehicle traffic pollution requires complex physicochemical analysis besides emission level measuring. The current study is focused on two campaigns of emissions measurements held in May and September 2019 in Alba Iulia City, Romania. There was found a significant excess of PM2.5 for all measuring points and PM10 for the most circulated points during May, along with significant VOC and CO2 emissions. September measurements reveal threshold excess for all PM along with increased values for VOC and CO2 emissions. These are the consequences of the complex environmental interaction of the traffic. Street dust and air-suspended particle samples were collected and analyzed to evidence the PM2.5 and PM10 sources. Physicochemical investigation reveals highly mineralized particulate matter: PM2.5 fractions within air-suspended particle samples predominantly contain Muscovite, Kaolinite, and traces of Quartz and Calcite, while PM10 fractions within air-suspended particle samples predominantly contain Quartz and Calcite. These mineral fractions originate in street dust and are suspended in the atmosphere due to the vehicles’ circulation. A significant amount of soot was found as small micro-sized clusters in PM2.5 and fine micro-spots attached over PM10 particles, as observed by Mineralogical Optical Microscopy (MOM) and Fourier Transformed Infrared Spectroscopy (FTIR). GC-MS analysis found over 53 volatile compounds on the investigated floating particles that are related to the combustion gases, such as saturated alkanes, cycloalkanes, esters, and aromatic hydrocarbons. It proves a VOC contamination of the measured particulate matters that make them more hazardous for the health. Viable strategies for vehicle traffic-related pollutants mitigation would be reducing the street dust occurrence and usage of modern catalyst filters of the combustion gas exhausting system.

Differential effects of size-specific particulate matter on frailty transitions among middle-aged and older adults in China: findings from the China Health and Retirement Longitudinal Study (CHARLS), 2015-2018.

This study aimed to assess the long-term effects of size-specific particulate matter (PM) on frailty transitions in middle-aged and older Chinese adults. We included 13910 participants ≥45y of age from the China Health and Retirement Longitudinal Study (CHARLS) for 2015 and 2018 who were classified into three categories in 2015 according to their frailty states: robust, prefrail and frail. Air quality data were obtained from the National Urban Air Quality Real-time Publishing Platform. A two-level logistic regression model was used to examine the association between concentrations of PM and frailty transitions. At baseline, the total number of robust, prefrail and frail participants were 7516 (54.0%), 4324 (31.1%) and 2070 (14.9%), respectively. Significant associations were found between PM concentrations and frailty transitions. For each 10μg/m3 increase in the 3-y averaged 2.5-μm PM (PM2.5) concentrations, the risk of worsening in frailty increased in robust (odds ratio [OR] 1.06 [95% confidence interval {CI} 1.01 to 1.12]) and prefrail (OR 1.07 [95% CI 1.01 to 1.13]) participants, while the probability of improvement in frailty in prefrail (OR 0.91 [95% CI 0.84 to 0.98]) participants decreased. In addition, the associations of PM10 and coarse fraction of PM with frailty transitions showed similar patterns. Long-term exposure to PM was associated with higher risks of worsening and lower risks of improvement in frailty among middle-aged and older adults in China.

Exposure to ambient air pollution and elevated blood levels of gamma-glutamyl transferase in a large Austrian cohort

Gamma glutamyl transferase (GGT) is related to oxidative stress and an indicator for liver damage. We investigated the association between air pollution and GGT in a large Austrian cohort (N = 116,109) to better understand how air pollution affects human health.Data come from voluntary prevention visits that were routinely collected within the Vorarlberg Health Monitoring and Prevention Program (VHM&PP). Recruitment was ongoing from 1985 to 2005. Blood was drawn and GGT measured centralized in two laboratories. Land use regression models were applied to estimate individuals' exposure at their home address for particulate matter (PM) with a diameter of <2.5 μm (PM2.5), <10 μm (PM10), fraction between 10 μm and 2.5 μm (PMcoarse), as well as PM2.5 absorbance (PM2.5abs), NO2, NOx and eight components of PM. Linear regression models, adjusting for relevant individual and community-level confounders were calculated.The study population was 56 % female with a mean age of 42 years and mean GGT was 19.0 units. Individual PM2.5 and NO2 exposures were essentially below European limit values of 25 and 40 μg/m3, respectively, with means of 13.58 μg/m3 for PM2.5 and 19.93 μg/m3 for NO2. Positive associations were observed for PM2.5, PM10, PM2.5abs, NO2, NOx, and Cu, K, S in PM2.5 and PM10 fractions and Zn mainly in PM2.5 fraction. The strongest association per interquartile range observed was an increase of serum GGT concentration by 1.40 % (95 %-CI: 0.85 %; 1.95 %) per 45.7 ng/m3 S in PM2.5. Associations were robust to adjustments for other biomarkers, in two-pollutant models and the subset with a stable residential history.We found that long-term exposure to air pollution (PM2.5, PM10, PM2.5abs, NO2, NOx) as well as certain elements, were positively associated with baseline GGT levels. The elements associated suggest a role of traffic emissions, long range transport and wood burning.

Characterization of free L- and D-amino acids in size-segregated background aerosols over the Ross Sea, Antarctica

The study of airborne chemical markers is crucial for identifying sources of aerosols, and their atmospheric processes of transport and transformation. The investigation of free amino acids and their differentiation between the L- and D- enantiomers are even more important to understand their sources and atmospheric fate. Aerosol samples were collected with a high-volume sampler with cascade impactor at Mario Zucchelli Station (MZS) on the coast of the Ross Sea (Antarctica) for two summer campaigns (2018/19 and 2019/20). The total mean concentration of free amino acids in PM10 was 4 ± 2 pmol m-3 for both campaigns and most of free amino acids were distributed in fine particles. The coarse mode of airborne D-Alanine and dimethylsufoniopropionate in seawater showed a similar trend during both Antarctic campaigns. Thus, the study of D/L Ala ratio in fine, coarse and PM10 fractions indicated the microlayer as the local source. This paper demonstrated that free amino acids follow the trend of DMS and MSA release occurred in the Ross Sea, confirming their applicability as markers for phytoplankton bloom also in paleoclimatic studies.

Investigation of Changes in Atmospheric Pollutants due to the Cessation of Anthropogenic Activities: Spatial Heterogeneity and Complex Atmospheric Chemistry

The current study examines the air quality trends in response to Covid-19-induced lockdowns at various locations in Delhi. The primary pollutants like NO2, CO, and PM10 have shown reductions during the lockdown phase, but the magnitude varied significantly in different places. Also, during the lockdown, air quality in some areas of Delhi exceeded National Ambient Air Quality Standards. Secondary pollutants like O3 have shown mixed trends due to complex atmospheric processes and dependence on relative proportions of VOC and NOx levels. A total of six sites, including traffic, industrial, and residential sites, have been studied. The diurnal behavior of pollutants also differed significantly around different places. During the lockdown, Ashok Vihar, a traffic-influenced area, showed a decrease in O3 (~ 40%), while at DTU (Traffic site), O3 levels increased (~ 48%). The industrial sites Okhla and Wazirpur also showed different trends during the lockdown; O3 in Wazirpur decreased by 50%, whereas Okhla increased by 25%. NOx concentration was lesser in 2020 at all the stations compared to 2019, indicating the positive impact of the lockdown on air pollution due to vehicular emissions. The Approximate Envelope Method estimates the secondary fraction of PM2.5. This fraction of PM is dominated in the lockdown year in the residential site, while it remains unchanged in the traffic site and increased by 11% in the industrial area. Despite being not so far from each other, these sites show very different patterns of pollutants during lockdown episodes.

Facility-Level Emissions and Synergistic Control of Energy-Related Air Pollutants and Carbon Dioxide in China.

Boilers involve ∼60% of primary energy consumption in China and emit more air pollutants and CO2 than any other infrastructures. Here, we established a nationwide, facility-level emission data set considering over 185,000 active boilers in China by fusing multiple data sources and jointly using various technical means. The emission uncertainties and spatial allocations were significantly improved. We found that coal-fired power plant boilers were not the most emission-intensive boilers with regard to SO2, NOx, PM, and mercury but emitted the highest CO2. However, biomass- and municipal waste-fired combustion, regarded as zero-carbon technologies, emitted a large fraction of SO2, NOx, and PM. Future biomass or municipal waste mixing in coal-fired power plant boilers can make full use of the advantages of zero-carbon fuel and the pollution control devices of coal-fired power plants. We identified small-size boilers, medium-size boilers using circulating fluidized bed boilers, and large-size boilers located in China's coal mine bases as the main high emitters. Future focuses on high-emitter control can substantially mitigate the emissions of SO2 by 66%, NOx by 49%, PM by 90%, mercury by 51%, and CO2 by 46% at the most. Our study sheds light on other countries wishing to reduce their energy-related emissions and thus the related impacts on humans, ecosystems, and climates.

Pollutant concentrations and exposure variability in four urban microenvironments of London

We compared various pollutant concentrations (PM1, PM2.5, PM10, PNC, BC) at four different urban microenvironments (MEs) in London (Indoor, IN; Traffic Intersection, TI; Park, PK; and Street Canyon, SC). The physico-chemical characteristics of particles were analysed, and the respiratory deposition doses (RDD) were estimated. Field measurements were conducted over a period of 121 days. The mean PM2.5 (PNC) concentrations were found to be 9.47 ± 7.05 (16366 ± 11815), 8.09 ± 4.57 (10951 ± 6445), 5.11 ± 2.96 (7717 ± 4576), 3.88 ± 3.06 (5672 ± 2934) μg m−3 (# cm−3) at TI, SC, PK and IN, respectively. PM2.5, PM10 and PNC exhibited a trend of TI > SC > PK > IN; higher concentrations for PM1 and BC were observed at IN than PK due to the emissions from printers, producing a trend of TI > SC > IN > PK. We observed 12%–30% higher fine PM concentrations at TI and SC sites during morning peak (07:00–09:30) than the evening peak hours (16:00–19:00); while IN showed a smaller variation in fine PM concentrations compared with outdoor TI, PK and SC sites owing to their prevalence in the IN for a longer time. Fine and ultrafine PM containing potentially toxic trace transition metals including Fe, Ti, Cr, Mn, Al and Mg were detected by high resolution electron microscopy at all sites. There was a similar relative abundance of different elements at the TI, IN and PK sites, which suggests a transport of PM between MEs. RDD for PM1 was highest (2.45 ± 2.27 μg h−1) at TI for females during running; PM2.5 and PM10 were highest at SC (11.23 ± 6.34 and 37.17 ± 20.82 μg h−1, respectively). The results show that the RDD variation between MEs does not follow the PM concentration trend. RDD at PK was found to be 39%–53% lower than TI and SC during running for all the PM fractions. Overall, the study findings show the air quality variation at different MEs and reveals the exposure inequalities around the city, which enable the management of personal exposure by selecting appropriate MEs for different activities.

The effect of fine suspended particles in the atmospheric air on the formation and course of the T2 endotype of bronchial asthma: a case-control study

The aim of the study was to investigate the effect of fine suspended particles in the atmospheric air on the formation and course of allergic and non-allergic phenotypes of the T2 endotype of bronchial asthma (BA) using the case-control study. Materials and methods. BA patients were selected in the course of seeking medical help. The groups were formed on the base of matching criteria (gender, age, body mass index, level of education), supplemented by the collection of information about potential cofounders. Based on the data on monitoring the content of fine suspended particles in the atmospheric air of Kazan, the average annual and maximum concentrations of PM2.5 and PM10 fractions were determined in the residential areas. The group of “cases” included forty patients with an allergic phenotype and 42 patients with an eosinophilic non-allergic phenotype of bronchial asthma, the control group included forty eight people. Additionally, sampling of atmospheric air was carried out using an 8-stage impactor to assess the content of bacterial endotoxin, and elemental composition. Results. Higher levels of pollution with fine suspended particles were demonstrated in the areas of residence of BA patients, comparing to the control group. An increase in the average annual concentration of the PM2.5 by 10 µg/m3 increases the odds of the eosinophilic non-allergic BA phenotype in adults by 4.76 times. The odds of the allergic phenotype of bronchial asthma increases in the presence of bacterial endotoxin - 1.32 times per 0.01 EU/m3 of endotoxin in the 3.2-18 µm size fraction. A more severe course of the eosinophilic non-allergic BA phenotype was noted at higher average annual concentrations of the PM2.5. The control of allergic asthma depends on the bacterial contamination of the aerosol. Limitations of the study are related to the use of geospatial approach to assess personalized average annual and maximum annual concentrations. Conclusion. The role of fine suspended particles in the atmospheric air in the development of bronchial asthma in adults has been shown. Various mechanisms were established to be involved in the formation of the clinical picture of the eosinophilic non-allergic and allergic phenotypes of bronchial asthma.

Impact of dry deposition flux and dust intrusion phenomena on elemental concentrations of air particulate matter

Depositions of trace elements of air particulates in the atmosphere have gained much attention in recent times due to their environmental, climatic and health impacts. In the current study, trace elements of size-segregated rural and urban particulate matter (PM2.5 and PM2.5−10) were characterized using particle-induced X-ray emission method. Effects of dry deposition flux and Saharan dust intrusion on the elemental concentrations were determined. The mean elemental concentration in the rural fine PM ranged between 0.0002 ± 0.0002 μg m−3 (for Se) and 0.6658 ± 0.5816 μg m−3 (for S) whereas in the urban fine PM the concentration ranged between 0.0007 ± 0.0008 μg m−3 (for As) and 0.5869 ± 0.3429 μg m−3 (for Ca). In the coarse PM fraction, concentration ranged between 0.0001 ± 0.0001 μg m−3 (for Se) and 0.5886 ± 0.5343 μg m−3 (for Ca) at the rural site; and between 0.0002 ± 0.0002 μg m−3 (for Se) and 1.9201 ± 1.911 μg m−3 (for Ca) at the urban site. Mainly crustal elements (Al, Ca, Fe) and ‘pollution’ source element (S) recorded high and significant dry deposition fluxes across the two sites in both PM modes. Deposition flux was relatively higher in the coarse than in the fine PM mode. The average dry deposition flux estimated for fine and coarse PM at the rural and urban sites were 33.68 ± 57.19 μg m−2 day−1 and 47.71 ± 92.19 μg m−2 day−1; 36.66 ± 61.95 μg m−2 day−1 and 107.02 ± 237.71 μg m−2 day−1, respectively. Mainly crustal (Al, Ca, Fe) and “pollution” (S) element recorded high and significant dry deposition fluxes across the two sites and in the two PM modes. The impacts of dust on climate, air quality, and the environment in general have increased the need to better understand the dust flow system. In the current study, dust intruding the study area from the Sahara was analyzed using the NMMB/BSC dust model. The model’s output indicated that, the highest daily surface dust concentration was observed in the central and south-west of Turkey which corresponded with the peak period of Saharan dust transport to the Eastern Mediterranean in the month of March.