PM10 Fraction Research Articles

Representativeness of the particulate matter pollution assessed by an official monitoring station of air quality in Santiago, Chile: projection to human health

Santiago, capital city of Chile, presents air pollution problems for decades mainly by particulate matter, which significantly affects population health, despite national authority efforts to improve air quality. Different properties of the particulate matter (PM10, PM2.5 and PM1 fractions, particle surface and number) were measured with an optical spectrometer. The sampling was done during spring 2019 at different sites within the official representative area of Independencia monitoring station (ORMS-IS). The results of this study evidence large variations in PM mass concentration at small-scale areas within the ORMS-IS representative zone, which reports the same value for the total area. Results from PM properties such as PM1, particle number and particle surface distribution show that these properties should be incorporated in regular monitoring in order to improve the understanding of the effects of these factors on human health. The use of urban-climate canopy-layer models in a portion of the sampled area around the monitoring station demonstrates the influence of street geometry, building densities and vegetation covers on wind velocity and direction. These factors, consequently, have an effect on the potential for air pollutants concentrations. The results of this study evidence the existence of hot spots of PM pollution within the area of representativeness of the ORMS-IS. This result is relevant from the point of view of human health and contributes to improve the effectiveness of emission reduction policies.

Increased contribution to PM2.5 from traffic-influenced road dust in Shanghai over recent years and predictable future

Traffic contributes to fine particulate matter (PM2.5) in the atmosphere through engine exhaust emissions and road dust generation. However, the evolution of traffic related PM2.5 emission over recent years remains unclear, especially when various efforts to reduce emission e.g., aftertreatment technologies and high emission standards from China IV to China V, have been implemented. In this study, hourly elemental carbon (EC), a marker of primary engine exhaust emissions, and trace element of calcium (Ca), a marker of road dust, were measured at a nearby highway sampling site in Shanghai from 2016 to 2019. A random forest-based machine learning algorithm was applied to decouple the influences of meteorological variables on the measured EC and Ca, revealing the deweathered trend in exhaust emissions and road dust. After meteorological normalization, we showed that non-exhaust emissions, i.e., road dust from traffic, increased their fractional contribution to PM2.5 over recent years. In particular, road dust was found to be more important, as revealed by the deweathered trend of Ca fraction in PM2.5, increasing at 6.1% year−1, more than twice that of EC (2.9% year−1). This study suggests that while various efforts have been successful in reducing vehicular exhaust emissions, road dust will not abate at a similar rate. The results of this study provide insights into the trend of traffic-related emissions over recent years based on high temporal resolution monitoring data, with important implications for policymaking.

Bushfire smoke plume composition and toxicological assessment from the 2019–2020 Australian Black Summer

Many of the population centres in southeast Australia were swathed in bushfire smoke during the 2019–2020 austral summer. Bushfires burning during what is now known as the Black Summer was historically large and severe, and the fire season historically long. The chemical composition in the gas and aerosol phase of aged plumes measured near Wollongong, NSW in early 2020 is reported in this work. Enhancement ratios to carbon monoxide are presented for thirteen species (acetaldehyde, acetone, acetonitrile, black carbon aerosol, benzene, methane, methacrolein + methyl vinyl ketone, methyl ethyl ketone, methanol, ammonium ion PM1 fraction, nitrate ion PM1 fraction, organic PM1 fraction and PM2.5). Observed plume composition is comparable to that measured in fresh smoke from Australian fires reported in the literature. Enhancements of biogenic volatile organic compounds such as isoprene (smoke-effected period mean 1 ppb, maximum 6 ppb) were observed along with elevated concentrations of particulate variables. Enhancement ratios reported here can be used in plume modelling of landscape-scale fires and assist in concentration estimates of infrequently measured atmospheric pollutants. The relative toxicological contribution of species present in the plumes was determined for plume exposure at the measurement site and for concentrated plumes at a population centre case study. Similar results were apparent at both locations. Contributions to the toxicological loading were dominated by respirable particles (~ 52–63% total contribution), formaldehyde (~ 30–39% total contribution) and acrolein. This is a reminder to consider the toxicological contributions in the gas phase when considering health impacts of population exposure to bushfire smoke.

Impacts of the COVID-19 lockdown measures on coarse and fine atmospheric aerosol particles (PM) in the city of Rome (Italy): compositional data analysis approach.

In the year 2020, Italy faced a pandemic due to the virus SARS-CoV-2 for short COVID-19. Following this pandemic, a national lockdown period was imposed and throughout the year 2020 various measures were taken by the government to limit the mobility of people and contain the mortality associated with COVID-19. In Italy, pandemic measures led to a reduction in anthropogenic activities and provided an unprecedented opportunity to evaluate the possible effects that restrictions on anthropogenic activities may have on the air quality. Two background site (i.e., Cipro and Cinecittà) and a traffic sites (i.e., Corso Francia) were studied in the city of Rome. PM10 and PM2.5 were considered for the years 2019 and 2020. Moreover, the vehicular mobility, the emission classes of the vehicles, and the people mobility were taken into consideration along with meteorological variables. A compositional data analysis was used to evaluate the effect of pandemic measures on the fine- and coarse-size fractions of PM in the three considered sites. The results showed that in the traffic site (i.e., Corso Francia site) in 2020, there was a reduction of fine-size fraction of PM of about 10% when compared to the data of 2019, whereas in the background site (i.e., Cinecittà site) in 2020 there was an increase of fine-size fraction of PM of about 14% when compared to the data of 2019. No variation in the coarse- and fine-size fractions of PM were observed at the background site Cipro. This study showed how, in an urban context, PM can be influenced by strong changes in people’s habits and in vehicular mobility such as those recorded during the investigated period and due to pandemic lockdown measures.

Channeled PM10, PM2.5 and PM1 Emission Factors Associated with the Ceramic Process and Abatement Technologies.

A sampling methodology and a mathematical data treatment were developed that enable to determine not only total suspended particulates (TSP) emitted at channeled sources but also the PM10, PM2.5, and PM1 mass fractions (w10, w2.5, and w1) and emission factors (E.F.), using a seven-stage cascade impactor. Moreover, a chemical analysis was performed to identify the elements present in these emissions. The proposed methodology was applied to different stages of the ceramic process, including ambient temperature (milling, shaping, glazing) and medium–high-temperature (spray-drying, drying, firing, and frit melting) stages. In total, more than 100 measurements were performed (pilot scale and industrial scale), which leads to a measurement time of 1500 h. Related to the mass fractions, in general, the mean values of w10 after the fabric filters operated at high performance are high and with little dispersion (75–85%), and it is also observed that they are practically independent of the stage considered, i.e., they are not significantly dependent on the initial PSD of the stream to be treated. In the case of the fine fraction w2.5, the behavior is more complex (w2.5: 30–60%), probably because the only variable is not the cleaning system, but also the nature of the processed material. Regarding abatement measures, the use of high-efficiency cleaning systems considerably reduces the emission factors obtained for fractions PM10, PM2.5, and PM1. In reference to chemical analysis, the presence of ZrO2 and Ni in the spray-drying and pressing stages, the significant concentration of ZrO2 in the glazing stage, the presence of Pb, As, and Zn in the firing stage, and the presence of Zn, Pb, Cd, and As compounds in the frits manufacturing should all be highlighted. Nevertheless, it should be pointed out that the use of some compounds, such as cadmium and lead, has been very limited in the last years and, therefore, presumably, the presence of these elements in the emissions should have been also reduced in the same way.

Impacts of Sugarcane Fires on Air Quality and Public Health in South Florida.

Background:Preharvest burning of sugarcane is a common agricultural practice in Florida, which produces fine particulate matter [particulate matter (PM) with aerodynamic diameter ()] that is associated with higher mortality.Objectives:We estimated premature mortality associated with exposure to from sugarcane burning in people age 25 y and above for 20 counties in South Florida.Methods:We combined information from an atmospheric dispersion model, satellites, and surface measurements to quantify concentrations in South Florida and the fraction of from sugarcane fires. From these concentrations, estimated mortalities attributable to from sugarcane fires were calculated by census tract using health impact functions derived from literature for six causes of death linked to . Confidence intervals (CI) are provided based on Monte Carlo simulations that propagate uncertainty in the emissions, dispersion model, health impact functions, and demographic data.Results:Sugarcane fires emitted an amount of primary similar to that of motor vehicles in Florida. from sugarcane fires is estimated to contribute to mortality rates within the Florida Sugarcane Growing Region (SGR) by 0.4 death per 100,000 people per year (95% CI: 0.3, 1.6 per 100,000). These estimates imply 2.5 deaths per year across South Florida were associated with from sugarcane fires (95% CI: 1.2, 6.1), with 0.16 in the SGR (95% CI: 0.09, 0.6) and 0.72 in Palm Beach County (95% CI: 0.17, 2.2).Discussion: from sugarcane fires was estimated to contribute to mortality risk across South Florida, particularly in the SGR. This is consistent with prior studies that documented impacts of sugarcane fire on air quality but did not quantify mortality. Additional health impacts of sugarcane fires, which were not quantified here, include exacerbating nonfatal health conditions such as asthma and cardiovascular problems. Harvesting sugarcane without field burning would likely reduce and health burdens in this region. https://doi.org/10.1289/EHP9957

Chemical characterization and health risk assessement of size segreated PM at world heritage site, Agra

Air quality at two traffic junctions representing GLA indicating pollution at highway and Iradatnagar indicating rural pollution was evaluated in Uttar Pradesh, India. The present study aimed to determine the concentration of size-segregated PM with the characterization of metals at different traffic junctions i.e. (Agra and Mathura). In the study, PM2.5–1.0 and PM1.0–0.5 were measured with the help of Cascade Sioutas Impactor during the study period December to January 2018. The size fraction of PM2.5–1.0 was found to be higher at GLA (350.92 µg/m3) followed by Iradatnagar (329.12 µg/m3), whereas the average value of size fraction of PM1.0–0.5 was found higher at Iradatnagar (341.01 µg/m3) in comparison with GLA (313.47 µg/m3) respectively. The average PM2.5 concentration in all the sampling sites was found to be 7–8 times higher when compared with the National Ambient Air Quality Standards (60 µg/m3) (NAAQS, India). Twelve metals viz. (Al, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) were subsequently determined by ICP-OES. Al, Ba, Ca, and Mg, were found in higher concentrations in comparison with other metals. Source apportionment of metals was done by PCA (Principal Component Analysis) which shows that metal loading of Al, Ca, Cr, Cu, Fe, and Ni was influenced by vehicular emission with 33.6% constitutes of the total variance. Higher bioavaiablity was observed for PM2.5–1.0 (5.12–6.46%) and least was found for PM1.0–0.5 (4.56–7.055%). For health risk estimation, the average value of HQs was found higher for PM1.0–0.5 size fraction. HQ values were recorded higher for GLA (7.95) for PM2.5–1.0 and (9.50) for PM1.0–0.5 fraction. Overall, the observed HQs values far exceeded the acceptable level. Average value (1 × 10–6) of carcinogenic risk factor was found higher for an adult and child respectively.

Impact of biomass burning and non-exhaust vehicle emissions on PM10 levels in a mid-size non-industrial western Iberian city

PM10 aerosol was measured during one semester, simultaneously, at a roadside (RS) and an urban background (UB) location in Coimbra, Portugal. On average, the mass concentrations were 36% higher at the RS, compared to UB. Application of Positive Matrix Factorisation (PMF) and Ionic Mass Balance (IMB) methodologies permitted to source apportion the aerosol mass. During the cold season, biomass burning was a prevalent particulate matter source at both urban locations, contributing with up to 30% of PM10. At the RS, vehicle non-exhaust emissions (brake, tyre and road dust) doubled exhaust emissions by combustion engines, accounting for 18–19% of PM10. Unreacted and reacted sea salt was an important fraction of PM10, principally during the warm season, when it composed approximately 25% of the aerosol. Secondary pollution by ammonium salts and carbonaceous matter was important across the seasons, especially at the UB location, where they dominated the particulate mass.

Aryl hydrocarbon receptor activation-mediated vascular toxicity of ambient fine particulate matter: contribution of polycyclic aromatic hydrocarbons and osteopontin as a biomarker

BackgroundExposure to ambient fine particulate matter (PM2.5) is associated with vascular diseases. Polycyclic aromatic hydrocarbons (PAHs) in PM2.5 are highly hazardous; however, the contribution of PM2.5-bound PAHs to PM2.5-associated vascular diseases remains unclear. The ToxCast high-throughput in vitro screening database indicates that some PM2.5-bound PAHs activate the aryl hydrocarbon receptor (AhR). The present study investigated whether the AhR pathway is involved in the mechanism of PM2.5-induced vascular toxicity, identified the PAH in PM2.5 that was the major contributor of AhR activation, and identified a biomarker for vascular toxicity of PM2.5-bound PAHs.ResultsTreatment of vascular smooth muscle cells (VMSCs) with an AhR antagonist inhibited the PM2.5-induced increase in the cell migration ability; NF-κB activity; and expression of cytochrome P450 1A1 (CYP1A1), 1B1 (CYP1B1), interleukin-6 (IL-6), and osteopontin (OPN). Most PM2.5-bound PAHs were extracted into the organic fraction, which drastically enhanced VSMC migration and increased mRNA levels of CYP1A1, CYP1B1, IL-6, and OPN. However, the inorganic fraction of PM2.5 moderately enhanced VSMC migration and only increased IL-6 mRNA levels. PM2.5 increased IL-6 secretion through NF-κB activation; however, PM2.5 and its organic extract increased OPN secretion in a CYP1B1-dependent manner. Inhibiting CYP1B1 activity and silencing OPN expression prevented the increase in VSMC migration ability caused by PM2.5 and its organic extract. The AhR activation potencies of seven PM2.5-bound PAHs, reported in the ToxCast database, were strongly correlated with their capabilities of enhancing the migration ability of VSMCs. Benzo(k)fluoranthene (BkF) contributed the most to the AhR agonistic activity of ambient PM2.5-bound PAHs. The association between PM2.5-induced vascular toxicity, AhR activity, and OPN secretion was further verified in mice; PM2.5-induced intimal hyperplasia in pulmonary small arteries and OPN secretion were alleviated in mice with low AhR affinity. Finally, urinary concentrations of 1-hydroxypyrene, a major PAH metabolite, were positively correlated with plasma OPN levels in healthy humans.ConclusionsThe present study offers in vitro, animal, and human evidences supporting the importance of AhR activation for PM2.5-induced vascular toxicities and that BkF was the major contributor of AhR activation. OPN is an AhR-dependent biomarker of PM2.5-induced vascular toxicity. The AhR activation potency may be applied in the risk assessment of vascular toxicity in PAH mixtures.

Sources of ambient PM2.5 exposure in 96 global cities

To improve air quality, knowledge of the sources and locations of air pollutant emissions is critical. However, for many global cities, no previous estimates exist of how much exposure to fine particulate matter (PM2.5), the largest environmental cause of mortality, is caused by emissions within the city vs. outside its boundaries. We use the Intervention Model for Air Pollution (InMAP) global-through-urban reduced complexity air quality model with a high-resolution, global inventory of pollutant emissions to quantify the contribution of emissions by source type and location for 96 global cities. Among these cities, we find that the fraction of PM2.5 exposure caused by within-city emissions varies widely (μ = 37%; σ = 22%) and is not well-explained by surrounding population density. The list of most-important sources also varies by city. Compared to a more mechanistically detailed model, InMAP predicts urban measured concentrations with lower bias and error but also lower correlation. Predictive accuracy in urban areas is not particularly high with either model, suggesting an opportunity for improving global urban air emission inventories. We expect the results herein can be useful as a screening tool for policy options and, in the absence of available resources for further analysis, to inform policy action to improve public health.

Machine Learning and Meteorological Normalization for Assessment of Particulate Matter Changes during the COVID-19 Lockdown in Zagreb, Croatia.

In this paper, the authors investigated changes in mass concentrations of particulate matter (PM) during the Coronavirus Disease of 2019 (COVID-19) lockdown. Daily samples of PM1, PM2.5 and PM10 fractions were measured at an urban background sampling site in Zagreb, Croatia from 2009 to late 2020. For the purpose of meteorological normalization, the mass concentrations were fed alongside meteorological and temporal data to Random Forest (RF) and LightGBM (LGB) models tuned by Bayesian optimization. The models’ predictions were subsequently de-weathered by meteorological normalization using repeated random resampling of all predictive variables except the trend variable. Three pollution periods in 2020 were examined in detail: January and February, as pre-lockdown, the month of April as the lockdown period, as well as June and July as the “new normal”. An evaluation using normalized mass concentrations of particulate matter and Analysis of variance (ANOVA) was conducted. The results showed that no significant differences were observed for PM1, PM2.5 and PM10 in April 2020—compared to the same period in 2018 and 2019. No significant changes were observed for the “new normal” as well. The results thus indicate that a reduction in mobility during COVID-19 lockdown in Zagreb, Croatia, did not significantly affect particulate matter concentration in the long-term..

Heavy metals in moss guide environmental justice investigation: A case study using community science in Seattle, WA, USA

AbstractHeavy metal concentrations often vary at small spatial scales not captured by air monitoring networks, with implications for environmental justice in industrial‐adjacent communities. Pollutants measured in moss tissues are commonly used as a screening tool to guide use of more expensive resources, like air monitors. Such studies, however, rarely address environmental justice issues or involve the residents and other decision makers expected to utilize results. Here, we piloted a community science approach, engaging over 55 people from nine institutions, to map heavy metals using moss in two industrial‐adjacent neighborhoods. This area, long known for disproportionately poor air quality, health outcomes, and racial inequities, has only one monitor for heavy metals. Thus, an initial understanding of spatial patterns is critical for gauging whether, where, and how to invest further resources toward investigating heavy metals. Local youth‐led sampling of the moss Orthotrichum lyellii from trees across a 250 × 250 m sampling grid (n = 79) and generated data comparable to expert‐collected samples (n = 19). We mapped 21 chemical elements measured in moss, including 6 toxic “priority” metals: arsenic, cadmium, chromium, cobalt, lead, and nickel. Compared to other urban O. lyellii studies, local moss had substantially higher priority metals, especially arsenic and chromium, encouraging community members to investigate further. Potential hotspots of priority metals varied somewhat but tended to peak near the central industrial core where many possible emission sources, including legacy contamination and converge. Informed by these findings, community members successfully advocated regulators for a second study phase—a community‐directed air monitoring campaign to evaluate residents' exposure to heavy metals—as is needed to connect moss results back to the partnership's core goal of understanding drivers of health disparities. This follow‐up campaign will measure metals in the PM10 fraction owing to clues in the current study that airborne soil and dust may be locally important carriers of priority metals. Future work will address how our approach combining bioindicators and community science ultimately affects success addressing longstanding environmental justice concerns. For now, we illustrate the potential to co‐create new knowledge, to help catalyze and strategize next steps, in a complex air quality investigation.

Aerosol liquid water content of PM2.5 and its influencing factors in Beijing, China

Aerosol liquid water content (ALWC) has important influences on atmospheric radiation and aerosol chemical processes. In this work, the changes in ALWC of PM2.5 were investigated over four seasons based on hourly monitoring of inorganic water-soluble ions and their gaseous precursors using the thermodynamic model ISORROPIA II. The results showed that the ALWC concentrations exhibited pronounced seasonal (autumn > summer > spring > winter) and diurnal variation characteristics. The sensitivity tests indicated that ALWC depended strongly on TSO4 (total sulfate (gas and aerosols) expressed as equivalent H2SO4), followed by TNO3 (total nitrate (gas and aerosols) expressed as equivalent HNO3). The relatively low concentration of TCl (total chloride (gas and aerosols) expressed as equivalent HCl) limit its importance in the atmosphere. ALWC showed exponential growth features as a function RH in all four seasons. RH became the most influential factor on the variation of ALWC when RH exceeded 80% in all seasons. The seasonal average data showed that the ALWC increased from 2.92 μg·m−3 to 75.83 μg·m−3 when ambient RH increased from 30% to 90%, the associated sulfate, nitrate, and ammonium (abbreviated as SNA) mass fraction in PM2.5 rose from 0.39 to 0.58 in the atmosphere. The ALWC facilitated the formation of SNA through gas-particle conversion and partitioning. The self-amplifying processes between ALWC and SNA enhanced aerosol formation. By modeling ALWC under different seasonal atmospheric scenarios, it was found that reductions in chemical species could reduce ALWC concentrations in different degrees. Based on the current emission conditions, controlling excess NH3 emission could effectively reduce ALWC to a maximum of 45.71% in summer, indicating that NH3 control was crucial for reducing ALWC and PM2.5 concentrations under high levels of SO42− and NO3−.

Compilation of a city-scale black carbon emission inventory: Challenges in developing countries based on a case study in Brazil

Black carbon (BC) inventories for cities are scarce, especially in developing countries, despite their importance to tackle climate change and local air pollution. Here, we draw on results from a case study in a Brazilian city to discuss the challenges of compiling a BC inventory for different activity sectors. We included traditionally inventoried sectors, such as industries and on-road transportation, other less reported sectors (food establishments and aviation), and open burning of household solid waste (HSW), typically found in developing countries. We present a machine-learning technique (Random Forest) as a novel approach to obtain HSW burning activity using a set of spatial predictors. The BC inventory was based on PM2.5 emissions weighted by the fraction of PM2.5 emitted as BC and developed for the year 2018. We also reported the disaggregated spatial PM2.5 emissions for the same combustion sources, and documented the databases used for activity data and emission factors (EF). The total estimated BC and PM2.5 emissions amounted to 57.88 and 234.75 tons, respectively, with on-road vehicle exhaust emissions and industrial combustion as the main BC sources (63 and 22%, respectively). For PM2.5 emissions, on-road transportation (exhaust and non-exhaust) contributed 48%, followed by industrial combustion (21%) and food establishments (20%). Population density, number of vacant lots, and property tax values were identified as the most important features to predict the HSW fire activity. A comparison with other inventories revealed that the BC emission profile of Londrina is similar to the profile reported for Greater Mexico City, another Latin American city. Thus, the methodology used in this study could be extended to other cities with similar local BC sources. Finally, we highlight that the lack of local activity data, representative EF, and even methodology may undermine the development of reliable BC inventories, and intensive research should be conducted to characterize the emission sources.

Application of computational modeling to study the parameters of dusty air flows in subway

To date, the subway is the most promising type of urban public transport, which is used daily by thousands of passengers in the world. In modern subways, the problem is the content of suspended dust in the air, which exceeds the maximum permissible concentration. Especially dangerous is the dust fraction PM2.5 or less, capable of penetrating through the biological barriers of the human body. This article discusses the results of a number of studies aimed at determining the concentration, fractional and chemical composition of such dust in subway structures. One of the ways to combat dustiness of the air in subways is its filtration. The authors propose the use of filters installed in the jetty ventilation breakdowns, the air flow through which is provided by the piston action of trains. Determination of optimal design and operational parameters of such filters is carried out using computer modeling by the finite volume method. The article provides an overview of the existing computational mathematical models of the movement of dusty air as a multiphase flow, and considers the possibility of their application to the conditions of underground subway structures.

Do Budget Cigarettes Emit More Particles? An Aerosol Spectrometric Comparison of Particulate Matter Concentrations between Private-Label Cigarettes and More Expensive Brand-Name Cigarettes.

Private-label cigarettes are cigarettes that belong to the retailer itself. Private-label cigarettes from discounters or supermarkets are cheaper than brand-name cigarettes, and their lower price has allowed them to garner an ever-increasing share of the tobacco product market, especially among lower socioeconomic groups. Particulate matter (PM), a considerable component of air pollution, is a substantial health-damaging factor. Smoking is the primary source of PM in smokers’ homes. In a 2.88 m3 measuring chamber, the PM emission fractions PM10, PM2.5, and PM1 from three private-label cigarette brands and three brand-name cigarette brands with identical nicotine, tar, and carbon monoxide content were measured and compared to those of a reference cigarette by laser aerosol spectroscopy. All cigarette brands emitted PM in health-threatening quantities. The measurement results ranged from 1394 µg/m3 to 1686 µg/m3 PM10, 1392 µg/m3 to 1682 µg/m3 PM2.5, and 1355 µg/m3 to 1634 µg/m3 PM1, respectively. Only one private-label brand differed significantly (p < 0.001) from the other cigarette brands, which were tested with slightly lower PM levels. All other brands differed only marginally (not significant, p > 0.05) from one another. Significant (p < 0.05) negative correlations between private-label and brand-name cigarettes were found for PM10, PM2.5, and PM1 when accounting for tobacco filling densities, and for PM1 when accounting for filter lengths. The especially health-hazardous fraction PM1 accounted for the largest proportion of PM emissions from the cigarettes tested. The results of this study suggest that- cheaper tobacco products are as harmful as more expensive ones, at least regarding PM emissions. This highlights the importance of anti-smoking campaigns, especially for lower socioeconomic groups, where smoking is more widespread. Governments should reduce the price gap between cheap and more expensive tobacco products by implementing specific tobacco taxes. In such a case, at increasing prices of tobacco products, a downward shift to private-label cigarettes would probably decrease.

Iron from coal combustion particles dissolves much faster than mineral dust under simulated atmospheric acidic conditions

Abstract. Mineral dust is the largest source of aerosol iron (Fe) to the offshore global ocean, but acidic processing of coal fly ash (CFA) in the atmosphere could be an important source of soluble aerosol Fe. Here, we determined the Fe speciation and dissolution kinetics of CFA from Aberthaw (United Kingdom), Krakow (Poland), and Shandong (China) in solutions which simulate atmospheric acidic processing. In CFA PM10 fractions, 8 %–21.5 % of the total Fe was found to be hematite and goethite (dithionite-extracted Fe), and 2 %–6.5 % was found to be amorphous Fe (ascorbate-extracted Fe), while magnetite (oxalate-extracted Fe) varied from 3 %–22 %. The remaining 50 %–87 % of Fe was associated with other Fe-bearing phases, possibly aluminosilicates. High concentrations of ammonium sulfate ((NH4)2SO4), often found in wet aerosols, increased Fe solubility of CFA up to 7 times at low pH (2–3). The oxalate effect on the Fe dissolution rates at pH 2 varied considerably, depending on the samples, from no impact for Shandong ash to doubled dissolution for Krakow ash. However, this enhancement was suppressed in the presence of high concentrations of (NH4)2SO4. Dissolution of highly reactive (amorphous) Fe was insufficient to explain the high Fe solubility at low pH in CFA, and the modelled dissolution kinetics suggest that other Fe-bearing phases such as magnetite may also dissolve relatively rapidly under acidic conditions. Overall, Fe in CFA dissolved up to 7 times faster than in a Saharan dust precursor sample at pH 2. Based on these laboratory data, we developed a new scheme for the proton- and oxalate-promoted Fe dissolution of CFA, which was implemented into the global atmospheric chemical transport model IMPACT (Integrated Massively Parallel Atmospheric Chemical Transport). The revised model showed a better agreement with observations of Fe solubility in aerosol particles over the Bay of Bengal, due to the initial rapid release of Fe and the suppression of the oxalate-promoted dissolution at low pH. The improved model enabled us to predict sensitivity to a more dynamic range of pH changes, particularly between anthropogenic combustion and biomass burning aerosols.

Correlating Traffic Data, Spectral Noise and Air Pollution Measurements: Retrospective Analysis of Simultaneous Measurements near a Highway in The Netherlands

Road traffic simultaneously emits noise and air pollution. This relation is primarily assessed by comparing A-weighted noise levels (LAeq) and various air pollutants. However, despite the common local traffic source, LAeq and the various sets of air pollution show a lower correlation than expected. Prior work, using simultaneous mobile noise and air pollution measurements, shows that the spectral content of the noise explains the complex and highly nonlinear relation between noise and air pollution significantly better. The spectral content distinguishes between traffic volume and traffic dynamics, two relevant modifiers explaining both the variability in noise and air pollution emissions of the local traffic flow. In May 2011, the environmental agency in the Netherlands performed noise and air pollutant measurements near a major highway and included spectral noise. In the resulting report, the analysis of the traffic, the noise and a wide set of air pollutants only showed a strong correlation between noise and NO. In this work, this dataset is re-evaluated using the noise-related covariates, engine noise and cruising noise, defined in prior work. The modeling approach proves valid for most of the measured air pollutants except for the large PM fractions. Conclusion: the prior established methodology explains the complex interaction between traffic dynamics, noise emission and air pollution emissions for a wide variety of air pollutants. The applicability of the ‘noise-as-a-traffic-proxy’ approach is extended.

Levels and Factors of the Accumulation of Metals and Metalloids in Roadside Soils, Road Dust, and Their PM10 Fraction in the Western Okrug of Moscow

Levels and Factors of the Accumulation of Metals and Metalloids in Roadside Soils, Road Dust, and Their PM10 Fraction in the Western Okrug of Moscow

Carbonaceous aerosols in five European cities: Insights into primary emissions and secondary particle formation

Carbonaceous material is an important component of atmospheric aerosol particles, which plays a significant role in air quality and climate, and also has potentially negative impacts on human health. There is a lack of data reported in the literature regarding the carbonaceous fraction of aerosol in the North-West European ‘air pollution hotspot’ and this work reports a comprehensive one-year intensive measurement campaign, where organic carbon (OC) and elemental carbon (EC) fractions of PM10 (particulate matter of diameter ≤ 10 μm) were measured. Owing to the importance of carbonaceous aerosols in understanding particulate pollution sources, ~2000 PM10 samples were simultaneously collected across North-West Europe at four urban background sites located in Amsterdam (AD), Antwerp (AP), Leicester (LE) and Lille (LL), and one industrial site at Wijk aan Zee (WZ). PM10 samples were chemically analysed by OC-EC analyser for carbonaceous species (OC, and EC) and trends were identified. OC accounted for 12.8%, 13.9%, 15.3%, 15.1% and 9.8%, and EC accounted for 2.4%, 4.9%, 4.4%, 4.0%, and 2.4% of total PM10 mass for AD, AP, LE, LL and WZ, respectively. Secondary organic carbon (SOC) contributions were higher in warmer months compared to colder months, and SOC concentration levels were similar at all five locations, with SOC contributing more than primary organic aerosol (POC) in each city. The lower effective carbon ratio (ECR) values (≤0.3) at all five sites in October, November, and February can be attributed to higher combined POC and EC concentrations and lesser contributions from SOC, meaning that SOC with a greater relative formation has a greater tendency to disperse solar radiation. Higher ECR values in April, May, and July, on the other hand, indicate that more absorbing types of carbonaceous aerosols are also present. More than 90% of the air-mass trajectories were from the north and northeast. This paper details atmospheric processes and sources influencing the seasonal variability of the carbonaceous components of PM10.