Coarse PM Research Articles

Characterization of fine particulate matter generated in a large woody biomass-firing circulating fluid bed boiler

The formation and emission of ash particles in biomass combustion is one of the most intractable challenges in the biomass-firing utility boilers. In present study, field measurements of PM10 at the inlets and outlets of the baghouse equipped on a 50 MW biomass-firing CFB boiler were carried out. The results showed that PM10 generated from the combustion of the biomass fuels in the CFB boiler exhibited a uni-modal size distribution. The sole modal peak (appeared at 5 μm) in the PSD curve was located in the size range >1 μm, while there was no visible peak in the size range <1 μm. The coarse PM mainly exhibited rough and angular surfaces with elements Ca, Si and Al as the principal constituents. The mass concentrations of PM1, PM2.5 and PM10 after the bagshouse were reduced to 0.95, 5.58 and 25.70 mg/Nm3 respectively, corresponding to the capture efficiencies of 97.80%, 98.52% and 98.64%. Moreover, the PM capture efficiency was observed to decrease with decreasing particle size in PM0.2. More Cl migrated into the fine PM when passing through the baghouse. Further comparisons revealed that the mass ratios of PM1 in PM10 in the flyash generated in the CFB boilers were <10%, which was much lower than that in the grate boilers firing biomass (40–80%), which is beneficial to PM removal in the dust removers and reduce the final PM emission during biomass combustion.

How to apply O3 and PM2.5 collaborative control to practical management in China: A study based on meta-analysis and machine learning

Constant increase of atmospheric O3 concentration is a barrier for the further air quality improvement in China. Given that PM2.5 is still controlled as a key pollutant, managements for the collaborative reduction of O3 and PM2.5 are urgently required in China. In the current work, monitoring data of O3 and PM2.5 from 2015 to 2016 in 1464 monitoring sites (MS) was collected and cleaned. Additionally, 7 anthropogenic emission reductions were jointed with the corresponding monitoring data. According to the O3 and PM2.5 variation, a meta-analysis was conducted and divided regions into 4 categories via the effect size, region I: O3 and PM2.5 collaborative reduction, region II: PM2.5 decreased and O3 increased, region III: O3 decreased and PM2.5 increased, regions IV: both O3 and PM2.5 increased. Then, based on the region labels, machine learning was used to identify the pattern between region label and its precursor reductions. The findings were as follows: (1) Principal component analysis showed that NH3 was not focused on. (2) Random forest had a well performance on region classification with the accuracy of 80.40% and the importance of the 7 precursors was in the sequence of VOCs>NH3 > PM2.5 > OC > SO2 > NOX > Coarse PM. (3) Polytomous logistic regression evaluated the critical factors that influenced the region label, which showed that the reductions of VOCs, NH3 and PM2.5 could achieve the collaborative reduction in a short time in most of cities in China. Based on the statistical results above, a kinetic management system including evaluation and policy-making sections was finally established, which filled the gap of the collaborative reduction in environmental management in China.

Simultaneous Measurements of PM2.5- and PM10-bound Benzo(a)pyrene in a Coastal Urban Atmosphere in Poland: Seasonality of Dry Deposition Fluxes and Influence of Atmospheric Transport

Parallel 24-h measurements of PM2.5- and PM10-bound benzo(a)pyrene (BaP) were conducted in a coastal urban region in northern Poland in 2019. The aim was to examine distribution profiles, dry deposition fluxes and perform a trajectory analysis to investigate potential source regions of pollutants. The mean ratio of PM2.5/PM10 was 0.70 ± 0.23, suggesting significant heterogeneity in PM composition during the study period, both in fine and coarse fraction. The measurements revealed a strong seasonal variation in the concentration and dry deposition fluxes of BaP. The peak BaP concentrations of 6.14 ng m–3 and 6.65 ng m–3, respectively in fine and coarse PM fractions were observed in December. They were directly attributed to local emission from major industrial (i.e., coal-fired power plants, refinery, solid waste burning, metal recycling plants) and residential sources (domestic heating units), and to the meteorological situation that led to the reduced dissipation of air pollutants and their transport outside the study domain. During the period from October to November, high Pb/Zn ratios in PM2.5 and PM10 were also observed, suggesting significant contribution of industrial emission (coal combustion) and local non-exhaust traffic emissions, including tyre abrasion in the case of Zn and the resuspension of road dust rich in Pb. The highest daily BaP deposition fluxes of 2652 ng m–2 (PM2.5) and 5561 ng m–2 (PM10) were reported in winter, while the lowest values of daily BaP deposition (2 ng m–2) were found during spring and summer measurements. Additionally, the three-dimensional FLEXTRA transport model was used to identify the impact of different sources on air masses over the study domain. FLEXTRA results showed that the air masses transported from distant S to W regions greatly affected the chemical composition of PM2.5 and PM10 during autumn and winter.

The characteristics of carbonaceous particles down to the nanoparticle range in Rangsit city in the Bangkok Metropolitan Region, Thailand.

Atmospheric size-classified particles in sizes ranging from small to nanoparticles (PM0.1) are reported for Rangsit City in the Bangkok Metropolitan Region (BMR) of Thailand, for October 2019 (wet season) and January-February 2020 (dry season). The sampling involved the use of a PM0.1 cascade air sampler to determine the mass concentration. The PMs consisted of six stages including TSP-PM10, PM2.5-10, PM1.0-2.5, PM0.5-1.0, PM0.5-1.0 and PM0.1. Elemental carbon (EC) and organic carbon (OC) were evaluated by a carbon analyzer following the IMPROVE_TOR protocol. The average PM0.1 mass concentrations were found to be 13.47±0.79 (wet season) and 18.88±3.99 (dry season) μg/m3, respectively. The average OC/EC ratio for the rainy season was lower than that in the dry season. The char-EC/soot-EC ratios were consistently below 1 for the PM0.1 fraction in both seasons indicating that vehicular traffic appeared to be the main emission source. However, the influence of open biomass burning on fine and coarse PM particles on local air pollution was found to be an important issue during the wet season. In addition, long-range transport from other countries may also contribute to the carbon content in the Bangkok Metropolitan Region (BMR) atmosphere during the dry season. The higher secondary organic carbon to organic carbon (SOC/OC) ratio in the dry season is indicative of the contribution of secondary sources to the formation of PM, especially finer particles. A strong correlation between OC and EC in nanoparticles was found, indicating that they are derived from sources of constant emission, likely the diesel engines. Conversely, the OC and EC correlation for other size-specific PMs decreased during the dry season, indicating that these emission sources were more varied.

Comparison of five methodologies to apportion organic aerosol sources during a PM pollution event

This study presents a comparison of five methodologies to apportion primary (POA) and secondary organic aerosol (SOA) sources from measurements performed in the Paris region (France) during a highly processed PM pollution event. POA fractions, estimated from EC-tracer method and positive matrix factorization (PMF) analyses, conducted on measurements from PM10 filters, aerosol chemical speciation monitor (ACSM) and offline aerosol mass spectrometry (AMS), were all comparable (2.2–3.7 μg m−3 as primary organic carbon (POC)). Associated relative uncertainties (measurement + model) on POC estimations ranged from 8 to 50%. The best apportionment of primary traffic OA was achieved using key markers (EC and 1-nitropyrene) in the chemical speciation-based PMF showing more pronounced rush-hour peaks and greater correlation with NOx than other traffic related POC factors. All biomass burning-related factors were in good agreement, with a typical diel profile and a night-time increase linked to residential heating. If PMF applied to ACSM data showed good agreement with other PMF outputs corrected from dust-related factors (coarse PM), discrepancies were observed between individual POA factors (traffic, biomass burning) and directly comparable SOA factors and highly oxidized OA. Similar secondary organic carbon (SOC) concentrations (3.3 ± 0.1 μg m−3) were obtained from all approaches, except the SOA-tracer method (1.8 μg m−3). Associated uncertainties ranged from 14 to 52% with larger uncertainties obtained for PMF-chemical data, EC- and SOA-tracer methods. This latter significantly underestimated total SOA loadings, even including biomass burning SOA, due to missing SOA classes and precursors. None of the approaches was able to identify the formation mechanisms and/or precursors responsible for the highly oxidized SOA fraction associated with nitrate- and/or sulfate-rich aerosols (35% of OA). We recommend the use of a combination of different methodologies to apportion the POC/SOC concentrations/contributions to get the highest level of confidence in the estimates obtained.

Chemical characterization and source apportionment of fine and coarse atmospheric particulate matter in Doha, Qatar

Atmospheric particulate matter of two size fractions (i.e., PM2.5 and PM10) were sampled simultaneously at an urban site in Doha, Qatar, and characterized to measure chemical constituents (including trace elements, organic and elemental carbon (OC/EC), and water-soluble ions). The composition data were applied to mass closure analysis and Positive Matrix Factorization (PMF) model along with detailed wind direction analysis for quantifying and identifying the probable sources of both PM size fractions. The average concentrations of PM2.5 (40 μg m−3) and PM10 (146 μg m−3) were greatly exceeded the WHO air quality thresholds for 78–92% of the sampling days. Mass closure indicated the predominance of secondary inorganic aerosol (39%) and EC (7%) in fine PM, while mineral dust contributes 50% to the total mass of coarse particles. PMF identified six major sources of fine and coarse PM, including secondary inorganic aerosols, vehicular emissions, heavy oil combustion, marine aerosols, mineral and fugitive dust. The wind direction analysis indicated that both local and regional sources impact Qatar's air quality attributed to specific wind conditions. Two main sources of heavy oil combustion and secondary aerosols are closely related to regional emissions from shipping vessels and the petrochemical industry in the Gulf region. The desert dust transport mixed with local re-suspended dust and sea-salt particles also contributes considerably to the local PM concentrations. The significant contributions of regional anthropogenic and natural emissions pose a significant challenge in meeting local PM standards, signifying the importance of regional collaboration for better control policies on reducing transboundary air pollution.

Effects of urban dust emissions on fine and coarse PM levels and composition

Simulation of the concentration of urban dust and its interactions with other inorganic components of particulate matter (nitrate, ammonium, sulfate) remains a major modeling challenge. In this study the chemical transport model PMCAMx is applied over Europe during the EUCAARI 2008 summer campaign. The default emission inventory leads to significant underprediction of PM10 levels in both urban and rural areas. We test the hypothesis that this is due to a large extent to an underprediction of urban dust by increasing the corresponding emissions by a factor of ten. This leads to improved PM10 predictions in all sites in Europe and especially in urban areas. The PM10 fractional bias of the model decreased by 23% and the fractional error by 13%. Average predicted PM1 nitrate decreases on average by 20% over the modeling domain due to the increased urban dust. Fine nitrate reductions of 0.5–1 μg m−3 are predicted for areas of the Netherlands, Belgium, France and United Kingdom. Fine ammonium and sulfate also decrease by 9% and 7.5% respectively, when the higher urban dust emissions are used. At the same time predicted coarse nitrate concentrations increase on average by 10% with absolute increases of 1.2 μg m−3 in the Netherlands and Belgium and 1 μg m−3 in Paris. Coarse ammonium and sulfate increase by 16% and 6% respectively due to the higher levels of urban dust.

Fine and coarse particulate matter, trace element content, and associated health risks considering respiratory deposition for Ergene Basin, Thrace

Ergene Basin is located in Thrace, Turkey, where industries are densely populated. This study aimed to determine exposure of people living in Ergene Basin (Çorlu and Çerkezköy) to fine and coarse PM, and its potentially toxic element (PTE) content by considering variation in respiratory airway deposition rates with daily activities and PM particle size by employing deposition models of International Commission on Radiological Protection and Multiple Path Particle Dosimetry. Fine and coarse PM samples were collected daily for a year at points in Çorlu and Çerkezköy representing urban and industrial settings, respectively. A questionnaire survey was conducted in the study area to obtain time-activity budgets, and associated variation was included in the health risk assessment by considering time-activity-dependent inhalation rates. The studied PTEs were Al, As, Ba, Cd, Cr, Co, Mn, Ni, Pb, and Se. The mean fine and coarse PM concentrations were measured as 23 and 14 μg/m3 in Çorlu, and 22 and 12 μg/m3 in Çerkezköy, respectively. The only PTE that exceeded acceptable risk in terms of total carcinogenic risk was Cr. Non-carcinogenic risks of all the PTEs including Cr were below the threshold. The use of deposition fractions in the health risk assessment (HRA) calculations was found to prevent overestimation of health risks by at least 91% and 87% for fine and coarse PM, respectively, compared to the regular HRA. Minor differences in risk between Çorlu and Çerkezköy suggest that urban pollution sources could be at least as influential on human health as industrial sources.

A cohort study on long-term exposure to air pollution and incidence of liver cirrhosis.

We used an administrative cohort established from the 2001 census. We included all adults of 30 years of age or older who were free of cirrhosis, resulting in a study population of over 1.2 million subjects. Follow-up of the subjects ended on 31 December 2015. We ascertained incident cases of cirrhosis from regional mortality and hospital discharge registries using a validated algorithm. We assessed exposure of the subjects to PM10, PM coarse, PM2.5, PM2.5 absorbance, NO2, NOx, and PM metal components at their residential address using Land Use Regression models. We used Cox regression models, adjusted for relevant covariates, to estimate the association between air pollution exposure and cirrhosis incidence. We observed 10,111 incident cases of cirrhosis, with a crude incidence rate of 67 × 100,000 person-years. Long-term exposure to all pollutants tested was significantly associated with cirrhosis, e.g., PM10 (hazard ratios [HR], 1.05; 95% confidence interval [CI], 1.01-1.09, per 10 µg/m3 increments), PM coarse (HR, 1.11; 95% CI, 1.05-1.17, per 10 µg/m3 increments), PM2.5 (HR, 1.08; 95% CI, 1.03-1.13, per 5 µg/m3 increments), and NO2 (HR, 1.03; 95% CI, 1.02-1.05, per 10 µg/m3 increments). The associations were robust in secondary analyses. Our findings suggest a possible contribution of air pollution to the development of cirrhosis.

Seasonality of ship emission related atmospheric pollution over coastal and open waters of the North Sea

The seasonal changes of a large set of atmospheric pollutants (i.e., gases, water-soluble aerosols, metallic/elemental components and black carbon (BC) content) have been studied over the southern bight of the North Sea (the Belgian Continental Shelf) and the English Channel during several marine sampling campaigns, carried out in 2010–2011. A coastal research station at De Haan, Belgium was concurrently used as a background air monitoring site. Size-segregated aerosols (PM1, PM2.5-1, PM10-2.5) were analyzed for particulate mass, elemental content and water-soluble (ionic) compounds, while the equivalent BC content in PM10 was monitored with an Aethalometer. The results clearly demonstrated that the aerosols originating from ship exhaust emissions contributed mostly to fine fraction (PM1), and to a lesser extent to medium-sized fraction (PM2.5-1), whereas components of sea spray and of mineral/soil origin were dominating in the medium-size and coarse aerosol fractions. Looking at seasonal differences, more ship emission related components occurred in the fine and medium-sized PM during winter. Mineral aerosol components were more apparent in coarse PM and especially during the cold season, increased levels were noted. Similarly, higher concentrations of marine fine PM were found during winter, likely due to more extensive ship emissions and/or calm weather conditions. Gaseous pollutants (e.g., HNO2, HNO3, HCl, SO2, NH3) originating from exhaust fumes of ocean-going ships mostly reached the maximum levels in the cold season as well, thus supporting the more intense formation of secondary aerosols. The seasonal trends of total (inorganic) ionic species sampled on the open sea and at the coastal station were usually similar to those of the corresponding PM masses, peaking in the cold season. Sea salt bound fine sulfate and nitrate peaked in spring or the cold season for marine areas, whereas for the coastal site they clearly reached the maximum in the cold season. Ammonium-bound nitrates and sulfates in each PM fraction reached their peak air levels in the cold season over marine sites. Similar seasonal trends could be observed for the coastal station. The general tendency of aerosol distribution over the study areas was independent of the sampling site: the higher the aerosol mass on the open sea with ship traffic, the higher the suspended particulate mass sampled at the coast.

Fine and Coarse Carbonaceous Aerosol in Houston, TX, during DISCOVER-AQ

To investigate major sources and trends of particulate pollution in Houston, total suspended particulate (TSP) and fine particulate matter (PM2.5) samples were collected and analyzed. Characterization of organic (OC) and elemental (EC) carbon combined with realtime black carbon (BC) concentration provided insight into the temporal trends of PM2.5 and coarse PM (subtraction of PM2.5 from TSP) during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Campaign in Houston in 2013. Ambient OC, EC, and BC concentrations were highest in the morning, likely due to motor vehicle exhaust emissions associated with the morning rush hour. The morning periods also had the lowest OC to EC ratios, indicative of primary combustion sources. Houston also had significant coarse EC at the downtown site, with an average (±standard deviation) PM2.5 to TSP ratio of 0.52 ± 0.18 and an average coarse EC concentration of 0.44 ± 0.24 µg·C·m−3. The coarse EC concentrations were likely associated with less efficient industrial combustion processes from industry near downtown Houston. During the last week (20–28 September, 2013), increases in OC and EC concentrations were predominantly in the fine fraction. Both PM2.5 and TSP samples from the last week were further analyzed using radiocarbon analysis. Houston’s carbonaceous aerosol was determined to be largely from contemporary sources for both size fractions; however, PM2.5 had less impact from fossil sources. There was an increasing trend in fossil carbon during a period with the highest carbonaceous aerosol concentrations (September 24 night and 25 day) that was observed in both the PM2.5 and TSP. Overall, this study provided insight into the sources and trends of both fine and coarse PM in a large urban U.S. city impacted by a combination of urban, industrial, and biogenic emissions sources.

A systematic approach for the comparison of PM10, PM2.5, and PM1 mass concentrations of characteristic environmental sites.

This study explores the use of a systematic approach in the comparison of simultaneous measurements of PM10, PM2.5, and PM1 mass concentrations using Aitchison geometry. Three case studies in three different Asian cities where the PM coarse, fine, and ultrafine size fraction prevail were investigated and the data was displayed using a dedicated triangular diagram. Simultaneous size-segregated PM measurements, for each case study, were assessed in terms of PM ratios and PM10 levels and were compared to similar measurements reported in literature. Non-central chi-squared distribution quantiles, for each case study, were evaluated and used to investigate the degree of similarity between simultaneous size-segregated PM ratios. Likewise, a comparative number k was used to show the proportion between PM10 levels. The issues relating to the location of the simultaneous size-segregated PM ratios on the triangular diagram were examined and the effects of the non-centrality parameter λ on PM comparison were indicated. The results show that the proposed systematic approach can estimate an explorative quantile (i.e., 2.5%) within which the simultaneous size-segregated PM measurements from one site can be compared with simultaneous size-segregated PM measurements from other sites reported in literature highlighting the existence of possible similarities or correspondences in the kind of sources influencing the PM.

Review of PM Oxidative Potential Measured with Acellular Assays in Urban and Rural Sites across Italy

This work is an overview of the oxidative potential (OP) values up to date measured in Italy, with the aim to provide a picture of the spatial and seasonal variability of OP in the various geographical areas across Italy. The summarized works used the common acellular assays-based dithiothreitol (OPDTT), ascorbic acid (OPAA), glutathione (OPGSH), and 2′,7′-dichlorodfluorescein (OPDCFH) assays. The paper describes the association of OP responses with PM chemical composition, the sensitivity of various acellular OP assays to PM components and emission sources, and PM size distribution of the measured OP values. Our synthesis indicates that crustal and transition metals (e.g., Fe, Ni, Cu, Cr, Mn, Zn, and V), secondary ions and carbonaceous components (elemental carbon, EC, organic carbon, OC and water soluble carbon, WSOC) show significant correlations with OP across different urban and rural areas and size ranges. These chemical species are mainly associated with various PM sources, including residual/fuel oil combustion, traffic emissions, and secondary organic aerosol formation. Although the OP assays are sensitive to the same redox-active species, they differ in the association with PM chemical components. The DDT assay is mainly sensitive to the organic compounds that are mostly accumulated in the fine PM fraction, i.e., tracers of burning sources, and redox active organics associated with other markers of photochemical aging. In contrast, OPAA and OPGSH were mostly responsive to metals, mainly those related to non-exhaust traffic emissions (Cu, Zn, Cr, Fe, Ni, Mn, Sn, Cd, Pb), that are mainly accumulated in the coarse PM. Among the investigated sites, our synthesis shows larger OP values in Trentino region and the Po Valley, that may be explained by the high density of anthropogenic sources, and the orographic and meteorological characteristics, that favor the pollutants accumulation and aerosol photo-oxidative aging.

Characterization and health risks of criteria air pollutants in Delhi, 2017

Severe air pollution events were observed frequently in north India in recent years especially at its capital, Delhi. Criteria air pollutants data at 10 sites for 2017 in Delhi were analyzed. The results show annual fine particulate matter (PM2.5) concentrations exceeded the National Ambient Air Quality Standards (NAAQS) of 60 μg/m3 at all sites from 105.51 (site 10) to 143.23 μg/m3 (site 7). Sub-urban sites (site 8, 9 and 10) had lower PM2.5 concentrations than urban sites. Coarse PM (PM10) and ozone (O3) were also important with annual averages of 399.56 μg/m3 and 75.69 ppb, respectively. Peak PM2.5 occurred at the Diwali in early November and Christmas. Only PM10 showed a significant weekly difference with a weekdays/weekends ratio of ∼1.5. PM2.5/PM10 ratio in episode days with PM2.5 of >60 μg/m3 was higher than non-episode days. Pearson correlation coefficients show O3 was negatively related with CO, SO2, and NO2, while PM2.5 was positively related to these pollutants. Analysis of two extreme events from Nov. 6th to Nov. 14th and Dec. 18th to Dec. 26th shows that meteorological conditions with low wind speed and warm temperature kept PM2.5 concentrations at a high level during these events. Backward trajectory and cluster analysis show the wind coming from northwest of Delhi, where massive anthropogenic emissions were generated, led to high concentrations of air pollutants to Delhi. Health risk analysis reveals that PM2.5 and PM10 were the two major pollutants threatening public health among the six criteria pollutants.

Long-Term Exposure to Ultrafine Particles and Incidence of Cardiovascular and Cerebrovascular Disease in a Prospective Study of a Dutch Cohort.

Background:There is growing evidence that exposure to ultrafine particles (UFP; particles smaller than ) may play an underexplored role in the etiology of several illnesses, including cardiovascular disease (CVD).Objectives:We aimed o investigate the relationship between long-term exposure to ambient UFP and incident cardiovascular and cerebrovascular disease (CVA). As a secondary objective, we sought to compare effect estimates for UFP with those derived for other air pollutants, including estimates from two-pollutant models.Methods:Using a prospective cohort of 33,831 Dutch residents, we studied the association between long-term exposure to UFP (predicted via land use regression) and incident disease using Cox proportional hazard models. Hazard ratios (HR) for UFP were compared to HRs for more routinely monitored air pollutants, including particulate matter with aerodynamic diameter (), PM with aerodynamic diameter (), and .Results:Long-term UFP exposure was associated with an increased risk for all incident CVD [ per ; 95% confidence interval (CI): 1.03, 1.34], myocardial infarction (MI) (; 95% CI: 1.00, 1.79), and heart failure (; 95% CI: 1.17, 2.66). Positive associations were also estimated for (; 95% CI: 1.01, 1.48 per ) and coarse PM (; HR for all ; 95% CI: 1.01, 1.45 per ). CVD was not positively associated with (HR for all ; 95% CI: 0.75, 1.28 per ). HRs for UFP and CVAs were positive, but not significant. In two-pollutant models ( and ), positive associations tended to remain for UFP, while HRs for and generally attenuated towards the null.Conclusions:These findings strengthen the evidence that UFP exposure plays an important role in cardiovascular health and that risks of ambient air pollution may have been underestimated based on conventional air pollution metrics. https://doi.org/10.1289/EHP3047

The influence of local emissions and regional air pollution transport on a European air pollution hot spot.

The EU air quality standards have been frequently exceeded in one of the European air pollution hot spots: Ostrava. The aim of this study was to perform an air quality comparison between an urban site (Radvanice), which has a nearby metallurgical complex, and a suburban site (Plesná) to estimate air pollution sources and determine their local and/or regional origins. Twenty-four hour PM1 and PM10 (particular matter) concentrations, detailed mass size distributions (MSDs) to distinguish the sources of the fine and coarse PM, and their chemical compositions were investigated in parallel at both sites during the winter of 2014. Positive matrix factorization (PMF) was applied to the PM1 and PM10 chemical compositions to investigate their sources. During the measurement campaign, prevailing northeastern-southwestern (NE-SW) wind directions (WDs) were recorded. Higher average PM10 concentration was measured in Radvanice than in Plesná, whereas PM1 concentrations were similar at both sites. A source apportionment analysis revealed six and five sources for PM10 and PM1, respectively. In Radvanice, the amount of PM and the most chemical species were similar under SW and NE WD conditions. The dominant sources were industrial (43% for PM10 and 27% for PM1), which were caused by a large metallurgical complex located to the SW, and biomass burning (25% for PM10 and 36% for PM1). In Plesná, the concentrations of PM and all species significantly increased under NE WD conditions. Secondary inorganic aerosols were dominant, with the highest contributions deriving from the NE WD. Therefore, regional pollution transport from the industrial sector in Silesian Province (Poland) was evident. Biomass burning contributed 22% and 24% to PM10 and PM1, respectively. The air quality in Ostrava was influenced by local sources and regional pollution transport. The issue of poor air quality in this region is complex. Therefore, international cooperation from both states (the Czech Republic and Poland) is needed to achieve a reduction in air pollution levels.

Air quality modeling for effective environmental management in the mining region

ABSTRACTAir quality in the mining sector is a serious environmental concern and associated with many health issues. Air quality management in mining regions has been facing many challenges due to lack of understanding of atmospheric factors and physical removal mechanisms. A modeling approach called the mining air dispersion model (MADM) is developed to predict air pollutants concentration in the mining region while considering the deposition effect. The model takes into account the planet’s boundary conditions and assumes that the eddy diffusivity depends on the downwind distance. The developed MADM is applied to a mining site in Canada. The model provides values for the predicted concentrations of PM10, PM2.5, TSP, NO2, and six heavy metals (As, Pb, Hg, Cd, Zn, Cr) at various receptor locations. The model shows that neutral stability conditions are dominant for the study site. The maximum mixing height is achieved (1280 m) during the evening in summer, and the minimum mixing height (380 m) is attained during the evening in winter. The dust fall (PM coarse) deposition flux is maximum during February and March with a deposition velocity of 4.67 cm/sec. The results are evaluated with the monitoring field values, revealing a good agreement for the target air pollutants with R-squared ranging from 0.72 to 0.96 for PM2.5, from 0.71 to 0.82 for PM10, and from 0.71 to 0.89 for NO2. The analyses illustrate that the presented algorithm in this model can be used to assess air quality for the mining site in a systematic way. Comparisons of MADM and CALPUFF modeling values are made for four different pollutants (PM2.5, PM10, TSP, and NO2) under three different atmospheric stability classes (stable, neutral, and unstable). Further, MADM results are statistically tested against CALPUFF for the air pollutants and model performance is found satisfactory.Implications: The mathematical model (MADM) is developed by extending the Gaussian equation particularly when examining the settling process of important pollutants for the industrial region. Physical removal effects of air pollutants with field data have been considerred for the MADM development and for an extensive field case study. The model is well validated in the field of an open pit mine to assess the regional air quality. The MADA model helps to facilitate the management of the mining industry in doing estimation of emission rate around mining activities and predicting the resulted concentration of air pollutants together in one integrated approach.

Long-term Exposure to Ultrafine Particles and Incidence of Cardiovascular and Cerebrovascular Disease

Background/Aim: Multiple lines of research have indicated that exposure to ambient air pollution (mostly measured as particulate matter less than 2.5 µm in size [PM2.5]) plays a significant role in morbidity and mortality. However, there is growing evidence that exposure to ultrafine particles (UFP – particles smaller than 100nm) may play an under-explored role in the aetiology of several illnesses, including cardiovascular disease. Methods: We studied the association between long-term exposure to UFP (predicted via land use regression) and incident cardiovascular disease using Cox proportional hazard models in a longitudinal study of 40,011 Dutch residents. Hazard ratios (HR) for UFP were compared to HRs for more routinely monitored air pollutants including PM10, PM2.5 and NO2. Results: Long-term UFP exposure was associated with an increased risk for all incident cardiovascular disease (HR: 1.18 per 10,000 particles/cm3, 95% CI: 1.03:1.34), myocardial infarction (HR: 1.34, 95% CI: 1.00:1.79), and heart failure (HR: 1.76, 95% CI 1.17:2.66). Similar findings were observed for NO2 and coarse PM (PM between 10 and 2.5 µm) but not for PM2.5. Elevated (albeit non-statistically significant) HRs for UFP exposure were also observed for cerebrovascular diseases. Two-pollutant models (UFP + NO2 and UFP + PMcoarse) identified that the elevated risk estimate remained for UFP, while results for PMcoarse and NO2 typically attenuated towards the null. Conclusions: These findings strengthen the evidence that UFP exposure plays an important role in cardiovascular health and that risks of ambient air pollution may have been underestimated based on conventional air pollution metrics such as PM2.5.

Temporal variations of fine and coarse particulate matter sources in Jeddah, Saudi Arabia

ABSTRACTThis study provides the first comprehensive analysis of the seasonal variations and weekday/weekend differences in fine (aerodynamic diameter <2.5 μm; PM2.5) and coarse (aerodynamic diameter 2.5–10 μm; PM2.5–10) particulate matter mass concentrations, elemental constituents, and potential source origins in Jeddah, Saudi Arabia. Air quality samples were collected over 1 yr, from June 2011 to May 2012 at a frequency of three times per week, and analyzed. The average mass concentrations of PM2.5 (21.9 μg/m3) and PM10 (107.8 μg/m3) during the sampling period exceeded the recommended annual average levels by the World Health Organization (WHO) for PM2.5 (10 μg/m3) and PM10 (20 μg/m3), respectively. Similar to other Middle Eastern locales, PM2.5–10 is the prevailing mass component of atmospheric particulate matter at Jeddah, accounting for approximately 80% of the PM10 mass. Considerations of enrichment factors, absolute principal component analysis (APCA), concentration roses, and backward trajectories identified the following source categories for both PM2.5 and PM2.5–10: (1) soil/road dust, (2) incineration, and (3) traffic; and for PM2.5 only, (4) residual oil burning. Soil/road dust accounted for a major portion of both the PM2.5 (27%) and PM2.5–10 (77%) mass, and the largest source contributor for PM2.5 was from residual oil burning (63%). Temporal variations of PM2.5–10 and PM2.5 were observed, with the elevated concentration levels observed for mass during the spring (due to increased dust storm frequency) and on weekdays (due to increased traffic). The predominant role of windblown soil and road dust in both the PM2.5 and PM2.5–10 masses in this city may have implications regarding the toxicity of these particles versus those in the Western world where most PM health assessments have been made in the past. These results support the need for region-specific epidemiological investigations to be conducted and considered in future PM standard setting.Implications: Temporal variations of fine and coarse PM mass, elemental constituents, and sources were examined in Jeddah, Saudi Arabia, for the first time. The main source of PM2.5–10 is natural windblown soil and road dust, whereas the predominant source of PM2.5 is residual oil burning, generated from the port and oil refinery located west of the air sampler, suggesting that targeted emission controls could significantly improve the air quality in the city. The compositional differences point to a need for health effect studies to be conducted in this region, so as to directly assess the applicability of the existing guidelines to the Middle East air pollution.

Effect of long-term exposure to air pollution on anxiety and depression in adults: A cross-sectional study.

The association between exposure to air pollutants and mental disorders among adults has been suggested, although results are not consistent. To analyze the association between long-term exposure to air pollution and history of anxiety and depression disorders and of medication use (benzodiazepines and antidepressants) in adults living in Barcelona. A total of 958 adults (45-74 years old) residents in Barcelona, most of them having at least one of their parents diagnosed with dementia (86%), and participating in the ALFA (Alzheimer and Families) study, were included. We used Land Use Regression (LUR) models to estimate long-term residential exposure (period 2009-2014) to PM2.5, PM2.5 absorbance (PM2.5 abs), PM10, PM coarse, NO2 and NOx. Between 2013 and 2014 participants self-reported their history of anxiety and depression disorders and related medication use. The analysis was focused on those participants reporting outcome occurrence from 2009 onwards (until 2014). We observed an increased odds of history of depression disorders with increasing concentrations of all air pollutants [e.g. an increased odds of depression of 2.00 (95% CI; 1.37, 2.93) for each 10μg/m3 NO2 increase]. Such associations were consistent with an increased odds of medication use in relation to higher concentrations of air pollutants [e.g. an increased odds of antidepressants use of 1.23 (1.04, 1.44) for each 20μg/m3 NOx increase]. Associations regarding anxiety disorders did not reach statistical significance. Our study shows that increasing long-term exposure to air pollution may increase the odds of depression and the use of antidepressants and benzodiazepines. Further studies are needed to replicate our results and confirm this association.