Size-fractionated Particulate Matter Research Articles

Evaluation of the inhaled dose across different microenvironments

The principal aim of the INSIDE project (INdividual air pollution exposure, extracellular vescicles SIgnaling and hypertensive disorder DEvelopment in pregnancy) is to assess the molecular effects of environmental exposure to airborne particulate matter (PM) of susceptible subject. Different approaches are considered to evaluate these effects, including an exposure-effect study performed on a selected population. The short-term exposure to different pollutants (PM and NO2) was evaluated considering 51 subjects recruited from October 2017 to April 2018. Each subject was asked to carry personal instruments for few hours before a clinical evaluation (blood and cardiological examination) from home to hospital. Instruments used in the study were: (I) CairClip – CairPol (NO2) and (II) Aerocet 831 - Aerosol Mass Monitor, Met One Instruments (size-fractionated PM). Moreover, a (III) smartphone with a GPS application and a (IV) Time Activity Diary (TAD) were used in this study to acquire information about the microenvironments (MEs) visited by subjects during the monitoring sessions.The experimental design of the project allowed to further investigate issues related to the mode of exposure: through the analysis of TADs and GPS data, it was possible to document the time spent by each subject in the different MEs and characterize the average exposure and inhaled dose associated to different MEs.The microenvironmental inhaled dose of pollutants was estimated considering the average exposure to PM and NO2, the time spent across these MEs and the specific ventilation rate of each subject. Moreover, to understand which of these parameters has the major impact of the dose model, a sensitivity analysis was performed, on the total and on the MEs dataset.

Urine metabolites associated with cardiovascular effects from exposure of size-fractioned particulate matter in a subway environment: A randomized crossover study

BackgroundAmbient particulate matter (PM) is closely associated with morbidity and mortality from cardiovascular disease. Urine metabolites can be used as a non-invasive means to explore biological mechanisms for such associations, yet has not been performed in relation to different sizes of PM. In this randomized crossover study, we used metabolomics approach to explore the urine biomarkers linked with cardiovascular effects after PM exposure in a subway environment. Methods and resultsThirty-nine subjects were exposed to PM for 4 h in subway system, with either a respirator intervention phase (RIP) with facemask and no intervention phase (NIP) in random order with a 2-week washout period. Electrocardiogram (ECG) parameters and ambulatory blood pressure (BP) were monitored during the whole riding period and urine samples were collected for metabolomics analysis. After exposure to PM for 4 h in subway system, 4 urine metabolites in male and 7 urine metabolites in female were screened out by UPLC/Q-TOF MS/MS-based metabolomics approach. Cardiovascular parameters (HRV and HR) predominantly decreased in response to all size-fractions of PM and were more sensitive in response to different size-fractioned PM in males than females. Besides LF/HF, most of the HRV indices decrease induced by the increase of all size-fractioned PM while PM1.0 was found as the most influential one on indicators of cardiovascular effects and urine metabolites both genders. Prolyl-arginine and 8-OHdG were found to have opposing role regards to HRV and HR in male. ConclusionOur data indicated that short-term exposure to PM in a subway environment may increase the risk of cardiovascular disease as well as affect urine metabolites in a size dependent manner (besides PM0.5), and male were more prone to trigger the cardiovascular events than female after exposure to PM; whereas wearing facemask could effectively reduce the adverse effects caused by PM.

Particle removal in polluted cities: Insights from the wash-off process dynamics for different wetland plants

Particulate matter (PM) in the atmosphere is a threat to human health. Wetland plants were confirmed to accumulate particles on the leaf surface; at the same time, rainfall could wash-off particles and accelerate the whole removal process, however, the dynamic processes occurring during rainfall events on wetland plants remain unclear. In order to provide sustainable strategies for authorities to take measures, we need to figure out how to reduce PM on leave surface by artificial rainfall efficiently. Four wetland species (Scirpus validus, Typha orientalis, Phragmites australis, and Iris wilsonii) were selected to examine for leave surface accumulation and simulate the experiment. We estimated the wash-off ability of rainfalls with three different intensities (15, 30, and 60 mm h−1) and determined the proportions of different PM size-fractions washed by the rains. The results showed that particles accumulated on the surface could be washed off efficiently (78% ∼ 89%) by the simulated rainfalls. The removal rates were high in the first 30 min and large particles comprised a large proportion of the removed particles. The rainfall with the intensity of 30 mm h−1 removed the most particles among three different rainfall intensities. When the rainfall intensity increased, fine particles (PM2.5) could be washed off more easily. Moreover, with a thinner wax layer, fine particles on wetland plants’ leaf surfaces might be more easily removed by the rains. While wash off the plants, spraying rains with the intensity of 30 mm h−1 for about 30 min every time (high intensity with shorter time) may be particle removal efficiency.

Occupational survey of airborne metal exposures to welders, metalworkers, and bystanders in small fabrication shops

The objective of this study was to characterize worker exposure to airborne metal and particulate matter in shops where multiple types of metalworking tasks were performed. The sampling strategy included full-shift and task-based personal samples on workers who performed flux-cored arc welding, personal samples on workers performing non-welding metalworking tasks, and area samples near welders, representing bystanders to welding. Size-fractionated particulate matter adjacent to welding activities was measured using real-time monitoring devices. Samples were analyzed for 21 individual metals, of which 8 were frequently detected. Exceedance fractions were calculated based on the distribution of results for each frequently detected metal. Exceedance fractions were <5% for all metals, except manganese (6% of the REL, 55% of the inhalable TLV-TWA and 91% of the respirable TLV-TWA) and iron oxide (10% of the REL and TLV-TWA) for Shop 1 bystander samples, manganese (68% for the inhalable TLV-TWA and 98% of the respirable TLV-TWA) for welder samples, and manganese (35% for the inhalable TLV-TWA and 80% of the respirable TLV-TWA) and iron oxide (12% for the PEL and 23% for the REL and TLV-TWA) for metalworker samples. Particulate matter concentrations measured at distances of 0.9–1.5 m and 2.1–2.7 m from the welder were within the same order of magnitude. The results of this study allow for comparison to health-based exposure limits for select individual components of welding fume with a low to medium degree of censorship.

Particulate matter bound polycyclic aromatic hydrocarbons: Toxicity and health risk assessment of exposed inhabitants

In the present study, the toxicological profile of 13 polycyclic aromatic hydrocarbons (PAHs) associated with airborne particulate matter (PM) was assessed. The average concentration of both PM10 and PM2.5 exceeded the Indian National Ambient Air Quality Standards. Amongst 13 analyzed PAHs, Naphthalene (Nap) was found to be the most dominant in both size fraction of PM whereas Indeno (1, 2, 3-cd) pyrene (IP) exhibited the least concentration. The relative % distribution of Low molecular weight (LMW) three ring PAHs were found to be predominant in both sized PM. The combined results derived from diagnostic ratios and factor analysis suggested that the vehicular emission (Diesel + gasoline) and coal combustion in the vicinity of study province are probable sources of PM bound PAHs. Maximum contribution towards the carcinogenicity has been found for Benzo (a) pyrene [B(a)p] for both size PM. The cytotoxic profile of PAHs determined by MTT assay demonstrated significant decrease in cell viability and PAHs associated with PM10 samples exhibited higher cytotoxic response. The redox activity measured by DTT assay exhibited the oxidative nature of PAHs associated with both sized PM. The interaction study between the PAHs and BSA resulted in substantial decrease in fluorescence intensity of BSA, indicating that PM bound PAHs could quench intrinsic fluorescence of the protein through successive molecular interaction and further conformational changes of protein was confirmed by circular dichroism spectra. Results obtained in the present study provide a valuable approach to evaluate the toxicological profile of PAHs encountered in the atmosphere of Pune.

Oxidative stress, DNA damage, and mutagenicity induced by the extractable organic matter of airborne particulates on bacterial models

The biological activity induced by the extractable organic matter (EOM) of size-segregated airborne Particulate Matter (PM) from two urban sites, urban traffic (UT) and urban background (UB), was assessed by using bacterial assays. The Gram-negative Escherichia coli (E. coli) coliform bacterium was used to measure the intracellular formation of Reactive Oxygen Species (ROS) by employing the Nitroblue tetrazolium (NBT) reduction assay and the lipid peroxidation by malondialdehyde (MDA) measurement. To the best of our knowledge, this is the first study using E. coli for assessing the bioactivity of ambient air in term of oxidative mechanism studies. E. coli BL21 cells were further used for DNA damage assessment by employing the reporter (β-galactosidase) gene expression assay. The bacterial strain S. typhimurium TA100 was used to assess the mutagenic potential of PM by employing the well-known mutation assay (Ames test).Four PM size fractions were assessed for bioactivity, specifically the quasi-ultrafine mode (<0.49 μm), the upper accumulation mode (0.49–0.97 μm), the upper fine mode (0.97–3 μm), and the coarse mode (>3.0 μm). The EOM of each PM sample included three organic fractions of successively increased polarity: the non-polar organic fraction (NPOF), the moderately polar organic fraction (MPOF), and the polar organic fraction (POF). The toxicological endpoints induced by each organic fraction were correlated with the concentrations of various organic chemical components determined in previous studies in an attempt to identify the chemical classes involved.

Cytotoxicity and genotoxicity of size-fractionated particulate matter collected in underground workplaces

Road tunnel construction involves the use of explosives and diesel-powered machines in a very limited indoor space. Tunnel construction workers are thus exposed to a variety of toxic substances, including dust, asbestos, silica, concrete, diesel fumes, and oil mist. In this study, the low noise miniaturized Sioutas Cascade Impactor (SKC) has been used to collect PM samples as a function of particle size (i.e., aerodynamic diameter). Airborne particulates were sampled into a road tunnel (final length 2391 m) under construction near the village of Pale, Municipality of Foligno, Umbrian Apennines (State Highway 77 “Val di Chienti”). Three sampling sessions were performed: (i) in the West yard, during dislodging of rocks; (ii) in the East yard during drilling of rocks, and (iii) during scaling and grouting with quick-drying shotcrete. The aim of this study was to characterize size-fractionated PM samples for their cytotoxic/genotoxic potentials. Toxicological evaluation was carried out in vitro on A549 lung carcinoma cells: cytotoxicity was assessed by Trypan blue dye exclusion assay, whereas genotoxicity was assessed by comet assay (primary DNA damage) and cytokinesis-block micronucleus (CBMN) Cytome assay (cytogenetic effects). Primary DNA damage (i.e., strand breakage) was mainly caused by coarse fractions A (O > 2.5 μm) sampled in the West yard (sample i) and in the East yard (sample iii). Cytogenetic effects were mainly caused by the fine fractions AF (aerodynamic O < 0.25 μm) sampled in the East yard (sample ii). Results reported in this article show that particulate matter (PM) samples collected underground (i.e., during road tunnel construction) may trigger various cytotoxic/genotoxic effects. The recent classification of air pollution and PM itself as carcinogenic to humans (group 1) by the IARC makes indoor/outdoor air pollution a growing matter of concern. Our results highlight the need in this occupational setting for a reduction, if applicable, of PM emission (prevention), or an implementation of work practices by stressing the importance of proper use of protective equipment (protection).

Assessing Ecotoxicity of Size-fractionated Airborne Particulate Matter

Particulate matter (PM) is grouped as coarse, fine, and ultrafine particles (UFPs) with aerodynamic diameters of 2.5 to 10 μm (PM10), &lt;2.5 μm (PM2.5), and &lt;0.1 μm (PM0.1), respectively. The course and fine fractions have been well characterised from numerous aspects, including potential environmental hazard. However, more and more studies are targeted to the UFP fraction, as they bind relatively higher concentrations of potentially toxic materials and they might penetrate through cell biological barriers, posing higher risk to the biota. In our study, ecotoxic potential of size-fractionated urban aerosol was evaluated, using the kinetic version of the Vibrio fischeri bioluminescence inhibition bioassay. The kinetic protocol makes it possible to avoid false ecotoxicity readings which might appear in case of coloured and/or turbid samples. Our results showed that all PM fractions elucidated significant toxic response, highest toxicity was experienced in the range of 0.25/0.5μm and 0.5/1 μm (with the EC50s of 7.07 and 7.8%). Ecotoxicity in general followed the typical pattern of number size distributions of submicron particles experienced in Europe.

Spatial-Temporal Analysis of PM2.5 and NO₂ Concentrations Collected Using Low-Cost Sensors in Peñuelas, Puerto Rico.

The U.S. Environmental Protection Agency (EPA) is involved in the discovery, evaluation, and application of low-cost air quality (AQ) sensors to support citizen scientists by directly engaging with them in the pursuit of community-based interests. The emergence of low-cost (<$2500) sensors have allowed a wide range of stakeholders to better understand local AQ conditions. Here we present results from the deployment of the EPA developed Citizen Science Air Monitor (CSAM) used to conduct approximately five months (October 2016–February 2017) of intensive AQ monitoring in an area of Puerto Rico (Tallaboa-Encarnación, Peñuelas) with little historical data on pollutant spatial variability. The CSAMs were constructed by combining low-cost particulate matter size fraction 2.5 micron (PM2.5) and nitrogen dioxide (NO2) sensors and distributed across eight locations with four collocated weather stations to measure local meteorological parameters. During this deployment 1 h average concentrations of PM2.5 and NO2 ranged between 0.3 to 33.6 µg/m3 and 1.3 to 50.6 ppb, respectively. Peak concentrations were observed for both PM2.5 and NO2 when conditions were dominated by coastal-originated winds. These results advanced the community’s understanding of pollutant concentrations and trends while improving our understanding of the limitations and necessary procedures to properly interpret measurements produced by low-cost sensors.

Interannual variation of air quality across an international airshed in Detroit (USA) and Windsor (Canada): A comparison of two sampling campaigns in both cities

This study investigates air pollutant concentrations across the international airshed spanning Detroit, Michigan, USA and Windsor, Ontario, Canada. The Geospatial Determinants of Health Outcomes Consortium (GeoDHOC) measured air quality concurrently in Detroit and Windsor using consistent sampling methods and locations during separate, two-week periods in September 2008 and May/June 2009. This paper presents 2009 results and compares them to previously reported 2008 campaign results to assess spatial and temporal variability. A high-density array of 100 passive and 50 active samplers was used to measure nitrogen dioxide (NO2), 26 volatile organic compounds (VOCs), 23 polycyclic aromatic hydrocarbons (PAHs), and three size fractions of particulate matter (PM) in both campaigns. Geospatial and non-spatial tools were used to investigate changes in concentration distributions and site classification into low/medium/high tertiles between the campaigns. During the two-week 2009 campaign, general pollution patterns remained consistent with those observed during 2008. Higher concentrations in Detroit, strong correlations amongst the BTEX group, and consistency of sites falling into the low and high tertiles were observed. Similar spatial patterns for NO2, VOCs, BTEX, and PAHs were also found during both campaigns. Conversely, PM1-2.5 and PM2.5-10 distributions showed greater variability, as did toluene/benzene ratios. Observed differences are attributable to changes in point source emissions associated with changes in localized activities, possibly related to decreased economic and industrial activity in response to the downturn that began in late 2008. Repeated sampling at multiple locations is important to determine spatial and temporal variability in absolute concentrations. However, if the definition of relatively high and low concentrations regions within a well-established urban area is adequate to estimate future air pollutant exposures, a single multi-location campaign may suffice.

Removal of particulate matter and trace elements from ambient air by urban greenery in the winter season

Particulate matter (PM) is one of the most harmful inhaled pollutants. When PM is emitted into the atmosphere, the only possible method for cleaning ambient air is through vegetation acting as biological filters for pollutants. However, in winter periods when the concentration of PM is usually the highest, the efficiency of plants is very low. The aim of this work was therefore to examine the accumulation of PM and selected trace elements (TE) by three species, evergreen coniferous Taxus baccata L. and Pinus nigra Arn., and deciduous Carpinus betulus L. during the winter season. The highest amounts of PM accumulated on the foliage of P. nigra, while TE on the leaves of C. betulus. Most of the PM accumulated on plant foliage belonged to the large fraction size (10–100 μm) and was deposited on the surface of foliage (SPM). The concentration of four TE (Ni, Pb, Cd, and Sb) was higher in PM accumulated on foliage, while in the case of three other TE (Zn, Cr and Mg), their concentration was higher in plant tissue. The TE were recorded in all PM size fractions and were rather equally distributed between surface PM (SPM) and in-wax PM (WPM). These findings have implications for urban plantings in countries with short vegetative season, where tolerant conifer species and deciduous species which keep foliage through winter should be included in urban forest plantings due to their efficiency in the removal of pollutants from the air.

Effects of Wet Flue Gas Desulfurization and Wet Electrostatic Precipitators on Emission Characteristics of Particulate Matter and Its Ionic Compositions from Four 300 MW Level Ultralow Coal-Fired Power Plants.

To achieve ultralow-emission (ULE) standards, wet electrostatic precipitators (WESP) installed downstream from wet flue gas desulfurization (WFGD) have been widely used in Chinese coal-fired power plants (CFPPs). We conducted a comprehensive field test study at four 300 MW level ULE CFPPs, to explore the impact of wet clean processing (WFGD and WESP) on emission characteristics of three size fractions of particulate matter (PM: PM2.5, PM10-2.5, and PM>10) and their ionic compositions. All these CFPPs are installed with limestone-based/magnesium-based WFGD and followed by WESP as the end control device. Our results indicate that particle size distribution, mass concentration of PM, and ionic compositions in flue gas change significantly after passing WFGD and WESP. PM mass concentrations through WFGD are significantly affected by the relative strength between desulfur slurry scouring and flue gas carrying effects. Concentrations of ions in PM increase greatly after passing WFGD; especially, SO42- in PM2.5, PM10-2.5, and PM>10 increase on average by about 1.4, 3.9, and 8.3 times, respectively. However, WESP before the stack can effectively reduce final PM emissions and their major ionic compositions. Furthermore, emission factors (kg/(t of coal)) of PM for different combinations of air pollution control devices are presented and discussed.

Assessment of indoor air pollution exposure in urban hospital microenvironments

Hospitals are microenvironments containing populations with potentially enhanced sensitivity to air pollution. The objectives of this study were to characterize the concentration of indoor and outdoor size-fractionated particulate matter (PM) at two urban hospital sites in Kashan, Iran, and to evaluate the relationship between indoor and outdoor PM levels. PM1.0, PM2.5, and PM10 concentrations were measured over a 3-month period outside each hospital with parallel sampling at four indoor locations in patient wards. The results indicated that mean indoor concentrations at the sampling sites (PM1.0 = 17.8 μg/m3, PM2.5 = 45.5 μg/m3, and PM10 = 162.7 μg/m3) were found to be lower than outdoors levels (PM1.0 = 20.6 μg/m3, PM2.5 = 62.1 μg/m3, and PM10 = 300.6 μg/m3). Outdoor and indoor PM mass concentrations were associated with PM1.0, PM2.5, and PM10.0. Ambient wind speed also influenced the indoor/outdoor relationship for PM1.0 and PM2.5 but not for PM10. The average I/O ratios for PM2.5 in the intensive care unit (ICU) and children’s ward at Shahid Beheshti Hospital were close to or above 1.00. Indoor PM1.0 and PM2.5 concentrations were found to be positively associated with outdoor PM1.0 and PM2.5 concentrations, but no relationship was observed with PM10. The present findings may inform policymakers in implementing evidence-based efforts for the aim of improving the indoor air quality in closed and confined spaces.

New comprehensive approach for airborne asbestos characterisation and monitoring.

High concentrations of airborne asbestos in the ambient air are still a serious problem of air quality in numerous localities around the world. Since 2002, elevated concentrations of asbestos minerals of unknown origin have been detected in the ambient air of Pilsen, Czech Republic. To determine the asbestos fibre sources in this urban air, a systematic study was conducted. First, 14 bulk dust samples were collected in Pilsen at nine localities, and 6 bulk samples of construction aggregates for gravel production were collected in a quarry in the Pilsen-Litice district. The quarry is the largest quarry in the Pilsen region and the closest quarry to the built-up urban area. X-ray diffraction of the asbestos minerals revealed that monoclinic amphibole (MA, namely actinolite based on subsequent SEM-EDX analysis) in the bulk samples accounted for < 1-33% of the mass and that the highest values were found in the bulk dust samples from the railway platform of the Pilsen main railway station. Simultaneously, 24-h samples of airborne particulate matter (PM) at three localities in Pilsen were collected. Actinolite was identified in 40% of the PM samples. The relationship between the meteorology and presence of actinolite in the 24 PM10 samples was not proven, probably due to the long sampling integration time. Therefore, highly time-and-size-resolved PM sampling was performed. Second, sampling of size-segregated aerosols and measurements of the wind speed (WS), wind direction (WD), precipitation (P) and hourly PM10, PM2.5 and PM1 were conducted in a suburban locality near the quarry in two monthly highly time-resolved periods (30, 60, 120min). Three/eight PM size fractions were sampled by a Davis Rotating-drum Uniform-size-cut Monitor (3/8DRUM) and analysed for the presences of asbestos fibres by scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDX). Asbestos fibre detection in highly time-resolved PM samples and current WD and WS determination allows the apportionment directionality of asbestos fibre sources. The number of critical actinolite asbestos fibres (length ≥ 5μm and width < 3μm, 3:1) increased with the PM1-10/PM10 and PM2.5-10/PM10 ratios, WS > 2ms-1 and precipitation < 1mm. Additionally, the number of critical actinolite asbestos fibres was not related to a specific WD. Therefore, we conclude that the sources of airborne critical actinolite asbestos fibres in Pilsen's urban area are omnipresent. Frequent use of construction aggregates and gravel from the metamorphic spilite quarries in the Pilsen region and in many localities around the urban area is a plausible explanation for the omnipresence of the critical actinolite asbestos fibres concentration in Pilsen's ambient air. Mitigation strategies to reduce the concentrations of critical actinolite asbestos fibres must be developed. Continuous monitoring and performing SEM-EDX analysis of highly time-and-size-resolved PM samples, correlated with fast changing WS and WD, seems to be a strong tool for efficiently controlling the mitigation strategies of critical actinolite asbestos fibres.

Short-term effects of particulate matter in metro cabin on heart rate variability in young healthy adults: Impacts of particle size and source

BackgroundMetro system has become popular in urban areas. However, short-term effects of size-fractionated particulate matter (PM) on cardiac autonomic function in metro system remain unexplored. ObjectivesTo explore the contribution of ambient PM to in-cabin PM and investigate the short-term effects of exposure to size-fractionated PM and black carbon (BC) in metro system on cardiac autonomic function in young healthy adults. MethodsThirty nine young healthy adults were asked to travel in metro system during 9:00–13:00 on a weekends between March and May 2017. We performed continuous ambulatory electrocardiogram monitoring for each of them, and measured real-time size-fractionated PM, BC, nitrogen dioxide, nitric oxide, carbon dioxide, ozone, noise, temperature and relative humidity in metro cabin. We also collected the data of ambient PM2.5 (aerodynamic diameter < 2.5 µm) concentrations in Beijing. Linear regression model was used to estimate the infiltration factor of ambient PM2.5 to assess the relationship between metro cabin PM and ambient PM. Mixed-effects model was used to estimate the associations between changes in HRV parameters and PM0.5 (aerodynamic diameter < 0.5 µm), PM0.5–2.5 (aerodynamic diameter between 0.5 µm and 2.5 µm), PM2.5–10 (aerodynamic diameter between 2.5 µm and 10 µm), and BC, respectively. ResultsWe found that size-fractionated PM in metro systems were significantly associated with HRV parameters. Per IQR (interquartile range) increase in PM0.5 (1.6*107/m3) in 1-h moving average concentration was associated with a 13.96% (95% CI: − 18.99%, − 8.61%) decrease in SDNN (standard deviation of normal-to-normal intervals). Similar inverse associations were found between size-fractionated PM exposure and LF (low frequency power), HF (high frequency power), respectively, and smaller particles had greater effects on HRV parameters at shorter lag time. Sex of participants modified the adverse associations between size-fractionated PM and HRV. An IQR of 1-h PM0.5 increasing was associated with a decrease of 6.05% (95% CI: − 22.87%, − 14.44%) in males and a 34.87% (95% CI: − 49.59%, − 15.85%) in females in LF (P for interaction = 0.026). The infiltration factor of ambient PM2.5 was 0.39 (95% CI: 0.33, 0.45). It is estimated that PM2.5 originated from ambient air may account for 20.2% of the PM measured in metro cabin. Per IQR increase in BC (5.5 μg/m3) in 5-min, 1-h, and 2-h moving averages, a primary tracer for ambient PM from combustion source, was associated with decreases of 0.84% (95% CI: − 1.20%, − 0.47%), 2.22% (95% CI: − 3.20%, − 1.22%), and 4.44% (95% CI: − 6.28%, − 2.56%) in SDNN, respectively. ConclusionsShort-term exposure to PM may disturb metro commuter's cardiac autonomic function, and the potential effects depend on the size of PM and the sex of commuters. Ambient PM from combustion source may have adverse effects on the cardiac autonomic function of passengers in cabin.

Badania wpływu źródeł motoryzacyjnych na imisję frakcji wymiarowych cząstek stałych w kanionie ulicznym

W artykule przedstawiono wyniki badań empirycznych imisji frakcji wymiarowych pyłów oraz tlenku węgla i tlenków azotu w okolicach kanionu ulicznego w Warszawie w miesiącu letnim. Badano również wyniki charakteryzujące warunki atmosferyczne oraz natężenie ruchu samochodów. Do analizy wykorzystano wyniki badań, wykonywanych na stacji nadzorowania jakości powietrza Warszawa-Komunikacyjna przy Al. Niepodległości 227/233, oraz przeprowadzanych przy użyciu pyłomierza firmy TSI. Badano imisję frakcji wymiarowych cząstek stałych: PM10, PM2.5 i PM1. Stwierdzono wyraźny wpływ źródeł motoryzacyjnych na imisję frakcji wymiarowych pyłów, szczególnie pyłów drobnych. Badano również zależność korelacyjną imisji zanieczyszczeń cząstek stałych PM10 oraz dwutlenku azotu i tlenku węgla – na podstawie wyników badań na stacji nadzorowania jakości powietrza. Stwierdzono słabą korelację, co wynikało prawdopodobnie z zastosowanej metodyki pomiarów. Badania korelacyjne imisji frakcji wymiarowych cząstek stałych, wykonane na podstawie wyników badań wykonanych przy użyciu pyłomierza, wykazały bardzo silną korelację. Ogólnie stwierdzono istotny wpływ emisji zanieczyszczeń z pojazdów samochodowych na imisję cząstek stałych w kanionie ulicznym, szczególnie na imisje drobnych frakcji wymiarowych pyłów.

Oxidative potential of size-segregated PM in an urban and an industrial area of Italy

This work is focused on the relationship between the size distribution of some source tracers of atmospheric particulate matter (PM) and the oxidative potential (OP) of each PM size fraction. Size-segregated PM samples were collected by a multistage impactor (cut-sizes: 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10 and 18 μm) in two geographical areas of Italy (Rome and Ferrara), characterized by different strength of the main PM sources. The samples were analysed by three different acellular OP methods: dithiothreitol (DTT), dichlorofluorescein diacetate (DCFH) and ascorbate (AA) assay.Elemental (Li, Be, B, Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Nb, Mo, Cd, Sn, Sb, Te, Cs, Ba, La, Ce, W, Tl, Pb, Bi and U) and ionic (Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+) composition of the same samples was also determined, in order to trace the contribution of the main PM sources. The size distribution of the OP values was compared to the size distribution of some PM source tracers, with the aim of identifying the PM sources that mostly influence the oxidative properties of atmospheric dust.AA assay resulted to be more sensitive towards coarse particles and OPAA showed a size distribution very similar to that of brake dust tracers. DTT and DCFH assays resulted instead more sensitive towards fine particles. OPDTT and OPDCFH values were comparable at the two sites; sources whose strength was very different in the two monitored areas (secondary contribution and, to a less extent, industrial sources) did not then contribute significantly to the measured OP values. The dimensional behaviour of OPDTT and OPDCFH was consistent with the contribution of biomass burning.

Long-term exposure to airborne particulate matter and NO2 and prevalent and incident metabolic syndrome – Results from the Heinz Nixdorf Recall Study

IntroductionRecently, epidemiological studies have found a link between air pollution (AP) and individual components of the metabolic syndrome (MetS), a condition predisposing to cardiometabolic diseases. However, very few studies have explored a possible association between air pollution and MetS. ObjectiveWe analyzed the effects of long-term exposure to airborne particulate matter and NO2 on prevalence and incidence of MetS. MethodsWe used data of the population-based prospective Heinz Nixdorf Recall study (baseline 2000–2003) to investigate the association(s) between AP exposure and MetS prevalence at baseline (n = 4457) and MetS incidence at first follow-up visit (n = 3074; average follow-up: 5.1 years). Mean annual exposure to size-fractioned particulate matter (PM10, PM2.5, PMcoarse, and PM2.5abs) and nitrogen dioxide (NO2) was assessed using a land use regression model. MetS was defined as central obesity plus two out of four additional risk factors (i.e., elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure or elevated plasma glucose). We estimated odds ratios (ORs) of MetS prevalence and incidence per interquartile range (IQR) of exposure, adjusting for demographic and lifestyle variables. ResultsWe observed a MetS prevalence of 20.7% (n = 922) and an incidence of 9.7% (n = 299). NO2 was positively associated with MetS prevalence, with an OR increase per IQR of 1.12 (95%-CI 1.02–1.24, IQR = 6.1 μg/m3). PM10 and PM2.5 were both borderline positively associated with MetS incidence, with ORs of 1.14 (95%-CI 0.99–1.32, IQR = 2.1 μg/m3) and 1.19 (95%-CI 0.98–1.44, IQR = 1.5 μg/m3) per IQR, respectively. ConclusionIn summary, we found a weak positive association between air pollution and MetS. The strongest and most consistent effects were observed between NO2 and prevalent MetS.

Particulate matter on two Prunus spp. decreases survival and performance of the folivorous beetle Gonioctena quinquepunctata

Woody plants growing along streets and construction sites play an important role in removing harmful particulate matter (PM). Researchers rarely consider the impact of different types and size fractions of PM deposited on the leaves on insect folivores. We determined differences in the accumulation of cement and roadside PM on the leaves of two Prunus species (P. padus and P. serotina) with different leaf surface structures. We also determined the effect of PM on the beetle Gonioctena quinquepunctata, the main pest of these plants. Saplings were artificially dusted in greenhouses and leaves were utilised for larval and adult insect stages feeding in laboratory conditions. Road PM accumulated in greater amounts than did cement PM, regardless of plant species. For both PM sources, P. padus accumulated twofold more than did P. serotina. Insect survival was negatively affected by PM pollution; however, neither Prunus species nor PM source variant significantly affected masses of larvae and pupae, duration of larval and pupal development or relative growth rates. The experiment showed strong negative influences of PM were noted only for adult insects, due to the grazing period being longer than that in larvae. The mass of adult insects and the efficiency of conversion of ingested food (ECI) were lower for insects exposed to PM than those for control insects. Insects compensated for lower ECI by eating a greater total amount of food (TFE). Adult insects gained significantly higher mass when fed with P. serotina than with P. padus. The effect of PM on analysed plant metabolites was insignificant. Only Prunus sp. and date of collection affected the level of condensed tannins and total phenols. Our results indicate that, when investigating the effect of the host plant on folivore performance, the accumulation of PM, as well as its type and quantity, should be taken into account.

Early-life exposure to three size-fractionated ultrafine and fine atmospheric particulates in Beijing exacerbates asthma development in mature mice

BackgroundEpidemiological studies have suggested that elevated levels of air pollution contribute to an increased incidence or severity of asthma. Although late-onset adult asthma seems to be more attributable to environmental risk factors, limited data is available on the impact of early-life exposure to size-fractionated ambient particulate matter (PM) on asthma in adults. We aimed to determine the effect on the development and exacerbation of asthma in the adult after the mice were exposed as juveniles to three size-fractionated ambient particulates collected from Beijing.MethodsThe three size-fractionated ambient particulates were collected from urban Beijing in winter, heavily affected by traffic and coal-fired emissions. The typical morphological and major chemical components of the PM were characterized first. Oxidative stress and expression of DNA methyltransferases (DNMTs) were then examined in vitro and in the lungs of mouse pups 48 h after exposure to PM by oropharyngeal aspiration. When the exposed and control juvenile mice matured to adulthood, an antigen-induced asthma model was established and relevant bio-indices were assessed.ResultsPM with different granularities can induce oxidative stress; in particular, F1, with the smallest size (< 0.49 μm), decreased the mRNA expression of DNMTs in vitro and in vivo the most significantly. In an asthma model of adult mice, previous exposure as juveniles to size-fractionated PM caused increased peribronchiolar inflammation, increased airway mucus secretion, and increased production of Th2 cytokines and chemokines. In general, F1 and F2 (aerodynamic diameter < 0.95 μm) particulates affected murine adult asthma development more seriously than F3 (0.95–1.5 μm). Moreover, F1 led to airway inflammation in the form of both increased neutrophils and eosinophils in BALF. The activation of the TGF-β1/Smad2 and Smad3/Stat3 signaling pathways leading to airway fibrosis was more profoundly induced by F1.ConclusionThis study demonstrated that exposure to ambient PM in juvenile mice enhanced adult asthma development, as shown by increased Th2 responses, which might be associated with the persistent effects resulting from the oxidative stress and decreased gene expression of DNMTs induced by PM exposure. The observed differences between the effects of three size-fractionated particulates were attributed to particle sizes and chemical constituents, including heavy metals and also PAHs, since the amounts of PAH associated with more severe toxicity were enriched equivalently in the F1 and F2 fractions. Relative to the often mentioned PM2.5, PM with an aerodynamic diameter smaller than 0.95 μm had a more aggravating effect on asthma development.