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Wood pellets are increasingly used for space heating in the United States and globally. Prior work has shown that stored bulk wood pellets produce sufficient carbon monoxide (CO) to represent a health concern and exceed regulatory standards for occupational exposures. However, most of the pellets used for residential heating are sold in 40-pound (18.1 kg) plastic bags. This study measured CO emission factors from fresh, bagged-wood pellets as a function of temperature and relative humidity. CO concentrations increased with increasing temperature and moisture in the container. CO measurements in a pellet mill warehouse with stored pallets of bagged pellets had 8-h average CO concentrations up to 100 ppm exceeding occupational standards for worker exposure. Thus, manufacturers, distributors, and home owners should be aware of the potential for CO in storage areas and design facilities with appropriate ventilation and CO sensors.

Residential coal consumption has decreased significantly since 1990 in most developed and developing countries, due to fuel switching. However, there are still countries with a high proportion of households using coal for heating purposes, in some cases with increasing coal consumption trends. This review discusses the patterns of the coal use, associated emissions, the negative impacts on health, and the policies and interventions used to limit the negative effects of high residential coal use. The patterns of residential coal use in those selected countries that account for 86% of global residential coal consumption are reviewed. Interventions in these selected countries have been accessed. It appears that the World Health Organization (WHO) may substantially underestimate the health impacts in these countries, particularly with respect to the burden of disease from household air pollution from using solid fuel for cooking as the indicator of exposure. The alternative to the WHO approach uses International Energy Agency (IEA) data because it provides the energy consumption for each country by fuel type and all household end-uses in a consistent framework. National survey data on energy and emissions also provides better metrics of exposure. Most of the assessed studies in developed countries focused on ambient air pollution, while in developing countries indoor air pollution was given primary attention (except for Mongolia). The PM concentrations within households using coal in Ireland, Mongolia, and China were compared and substantial differences were found as a result of differences in ventilation, stove design, fuel quality and stove maintenance and operation. Policy measures such as the large stove switching programs in China and Mongolia were mostly successful, but did not fully reach desired targets because of several factors. One of these key factors was the variability of human behavior and its response to the policy stimuli. Important barriers to the transition to cleaner energy alternatives are relatively low coal prices coupled with its level of supply security. Health benefits, however, are generally higher than the abatement costs in the most polluted areas, and support from governments for cleaner energy, that includes a focus on health, can be feasible and effective if carefully designed and targeted.

The incidence of hospitalizations due to cardiovascular (HACVD) and respiratory diseases (HARD) associated with PM10 was assessed with AirQ2.2.3. Daily PM10 data were used to this purpose. The results showed that 8.2% (95% CI: 5.6–11.4%), 7.2% (95% CI: 4.9–10.1%), and 4.4% (95% CI: 3.0–6.3%) of HACVD and 7.3% (95% CI: 4.5–10%), 6.4 (95% CI: 4.0–8.8%), and 3.9% (95% CI: 2.4–5.4%) of HACVD in the cities of Ahvaz, Khorramabad and Ilam were attributed to PM10, respectively. Governmental authorities need to act to control the dust hazard by spreading mulch and developing green space using vegetation amenable to the local climate.

Prior work on the mechanism of carbon monoxide (CO) formation from stored wood pellets has provided the basis for a continuous process that results in the production of pellets that do not off-gas CO. It had been shown that exposure to ozone eliminated the unsaturated hydrocarbons that autoxidize to produce hydroxyl radicals, which, in turn, react with the hemicellulose to produce CO. To develop a practical process to eliminate the CO formation, a kinetic study of the continuous ozonolysis of wood fiber was conducted using a small materials auger. The reaction was found to follow a pseudo-first-order reaction such that the reduction in CO emissions was linearly proportional to the ozone exposure (concentration × time). The exposure needed to reduce or eliminate the formation of CO from the exposed fiber was around 42 000 ppm min at a flow rate of 0.57 kg/min of fiber or approximately 0.032 g of O3/kg of fiber to be passivated. The volatile organic compounds produced during the ozonolysis of fiber were ana...

The characteristics of fugitive dust emitted from vehicles traveling on unpaved dirt roads were measured using a suite of instruments including a real-time fugitive dust sampler. The fugitive dust sampler is formed from a combination of a large particle inlet and an optical particle spectrometer that reports particle sizes from 6 to 75 µm. The large particle inlet permits the sampling of particles up to 75 µm with only a moderate dependence of sampling efficiency on wind-speed. Measurements made with the sampler showed that particles as large as ∼50 µm were suspended from vehicular movement on the dirt roads, with the mode of the fugitive dust particle number size distribution ∼2 µm, while the mass distribution mode was ∼7 µm. A comparison of the fugitive dust sampler measurements with those made using standard PM instruments showed that the conventional instruments have a wind-direction bias that can result in under-sampling of large particles. The current measurements suggest that particles susp...

Several source apportionment studies considering multiple sites showed spatial variability of source contributions. However, setting up multiple fixed sites to collect comprehensive chemical speciation data is resource demanding. In this study, field campaigns were conducted at multiple receptor sites in the Mailiao and Taishi townships in Yunlin County using a mobile platform to demonstrate the feasibility of receptor modeling with particle size distribution and PM 2.5 speciation data. Sources of air pollutants to all of the monitoring sites were identified and quantified using a modified positive matrix factorization (PMF) model. Modeling results indicated that a mixed source dominated by secondary aerosol was the largest contributor to PM 2.5 at most sites. Adding VOC measurements with high time resolution helped to improve the source separation. Different patterns of source contributions among sites and seasons were observed showing both spatial heterogeneity and seasonal variation.

Objective This study assessed the effects of particulate matter (PM), equal or less than 10 μm in aerodynamic diameter (PM10), from the Middle-Eastern Dust events on public health in the megacity of Kermanshah (Iran). Study design This study used epidemiological modeling and monitored ambient air quality data to estimate the potential PM10 impacts on public health. Methods The AirQ2.2.3 model was used to calculate mortality and morbidity attributed to PM10 as representative of dust events. Using Visual Basic for Applications, the programming language of Excel software, hourly PM10 concentrations obtained from the local agency were processed to prepare input files for the AirQ2.2.3 model. Results Using baseline incidence, defined by the World Health Organization, the number of estimated excess cases for respiratory mortality, hospital admissions for chronic obstructive pulmonary disease, for respiratory diseases, and for cardiovascular diseases were 37, 39, 476, and 184 persons, respectively, from 21st March, 2014 to 20th March, 2015. Furthermore, 92% of mortality and morbidity cases occurred in days with PM10 concentrations lower than 150 μg/m3. The highest percentage of person-days occurred for daily concentrations range of 100–109 μg/m3, causing the maximum health end-points among the citizens of Kermanshah. Conclusions Calculating the number of cumulative excess cases for mortality or morbidity attributed to PM10 provides a good tool for decision and policy-makers in the field of health care to compensate their shortcomings particularly at hospital and healthcare centers for combating dust storms. To diminish these effects, several immediate actions should be managed in the governmental scale to control dust such as spreading mulch and planting new species that are compatible to arid area. © 2017 The Royal Society for Public Health

An exposure assessment was conducted to investigate the potential for harmful concentrations of airborne short chain aldehydes emitted from recently stored wood pellets. Wood pellets can emit a number of airborne aldehydes include acetaldehyde, formaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and hexanal. Exposure limits have been set for these compounds since they can result in significant irritation of the upper respiratory system at elevated concentrations. Formaldehyde is a recognized human carcinogen and acetaldehyde is an animal carcinogen. Thus, air sampling was performed in a wood pellet warehouse at a pellet mill, two residential homes with bulk wood pellet storage bins, and in controlled laboratory experiments to evaluate the risk to occupants. Using NIOSH method 2539, sampling was conducted in five locations in the warehouse from April-June 2016 when it contained varying quantities of bagged pellets as well as two homes with ten ton bulk storage bins. The aldehyde concentrations were found to increase with the amount of stored pellets. Airborne concentrations of formaldehyde were as high as 0.45 ppm in the warehouse exceeding the NIOSH REL-C, and ACGIH TLV-C occupational exposure limits (OELs). The concentrations of aldehydes measured in the residential bins were also elevated indicating emissions may raise indoor air quality concerns for occupants. While individual exposures are of concern the combined irritant effect of all the aldehydes is a further raise the concerns for building occupants. To minimize exposure and the risk of adverse health effects to a building's occupants in storage areas with large quantities of pellets, adequate ventilation must be designed into storage areas.

Severe air pollution in the northern India coupled with the formation of secondary pollutants results in severe fog conditions during the winter. Black carbon (BC) and particulate matter (PM 2.5 ) play a vital role within the planetary boundary layer (PBL) to degrade atmospheric visibility. These species were continuously monitored during the winter of 2014 in the National Capital Region (NCR) of Delhi. The average BC concentration was 8.0 ± 3.1 μg/m 3 with the January mean (11.1 ± 5.4 μg/m 3 ) approximately two times higher than February (5.9 ± 2.1 μg/m 3 ). The average PM 2.5 concentration was 137 ± 67 μg/m 3 with monthly area-average maximum and minima in December and February, respectively. Higher concentrations of BC at 10:00 local standard time LST (8.5 μg/m 3 ) and 22:00 LST (9.7 μg/m 3 ) were consistently observed and assigned to morning and evening rush-hour traffic across Delhi. Daily average solar fluxes, varied between 17.9 and 220.7 W/m 2 and had a negative correlation (r = − 0.5) with BC during fog episodes. Ventilation coefficient (VC) reduced from ‘no fog’ to fog phase over Palam Airport (PLM) (0.49) times and Hindon Airport (HND) (0.28) times and from fog to prolonged fog (> 14 h) phase over PLM (0.35) times and HND (0.41) times, respectively, indicating high pollution over the NCR of Delhi. Ground measurements showed that daily mean aerosol optical depth at 500 nm (AOD 500 ) varied between 0.32 and 1.18 with mean AOD 500 nm being highest during the prolonged fog (> 14 h) episodes (0.98 ± 0.08) consistent with variations in PM 2.5 and BC. Angstrom exponent ( α ) and Angstrom turbidity coefficient ( β ) were found to be > 1 and 0.2, respectively, during fog showing the dominance of fine mode particles in the atmosphere.

The composition of processed wood fuels, such as pellets, is important, since large quantities of pellets are used to heat buildings and generate electricity. Prior work identified heavy metal contaminants in pellets as a result of waste wood being part of the input materials. Preparation methods for the analysis of the elemental composition of wood fuels with ICP-MS were evaluated using standard reference materials (SRM) and real wood pellet samples. The effect of different degrees of grinding (10–20 μm and 60–100 μm) on the homogeneity of the resulting samples was investigated. The finer-ground samples (particle size 10–20 μm) demonstrated good homogeneity. The amount of mass required for digestion was evaluated based on the relative mean error (%) for the elemental analyses for both direct HNO3-H2O2 and Ash-HNO3-H2O2 digestion methods. Well ground, larger pellet samples (10–20 μm and ∼1.0 g) demonstrated good agreement between two digestion methods. The precision of the analysis with ICP-MS was evaluat...

Characterization of the airborne particulate matter (PM) emitted from cooking components including cooking oil, and additives like salt has not been carefully investigated. This study provides new data on the concentration, composition, and emission rates/fluxes of PM (less than 3.3µm) generated during heating corn oil and corn oil with added table salt. The concept of emission flux was employed to estimate the emission rates in this study. A statistically significant reduction of 47.6% (P0.05) in the total PM emission rate and emission flux were observed when salt was added to the heated corn oil (5.15×10

Urban air quality represents a major public health burden and is a long-standing concern to European citizens. Combustion processes and traffic-related emissions represent the main primary particulate matter (PM) sources in urban areas. Other sources can also affect air quality (e.g., secondary aerosol, industrial) depending on the characteristics of the study area. Thus, the identification and the apportionment of all sources is of crucial importance to make effective corrective decisions within environmental policies. The aim of this study is to evaluate the impacts of different emissions sources on PM 2.5 concentrations and compositions in a mid-size city in the Po Valley (Treviso, Italy). Data have been analyzed to highlight compositional differences (elements and major inorganic ions), to determine PM 2.5 sources and their contributions, and to evaluate the influence of air mass movements. Non-parametric tests, positive matrix factorization (PMF), conditional bivariate probability function (CBPF), and concentration weighted trajectory (CWT) have been used in a multi-chemometrics approach to understand the areal-scale (proximate, local, long-range) where different sources act on PM 2.5 levels and composition. Results identified three levels of scale from which the pollution arose: (i) a proximate local scale (close to the sampling site) for traffic non-exhaust and resuspended dust sources; (ii) a local urban scale (including both sampling site and areas close to them) for combustion and industrial; and (iii) a regional scale characterized by ammonium nitrate and ammonium sulfate. This approach and results can help to develop and adopt better air quality policy action.

Sixty-six, new, low-cost Speck monitors were collocated with a Grimm 1.109 particle spectrometer and CO loggers during one indoor and two outdoor monitoring campaigns to assess the ability of the monitors to measure the PM concentrations under real use conditions. The limit of detection of the monitors was calculated, and the monitors’ bias and precision, as well as the results’ reproducibility, were determined. Correlation coefficients of 0.3 and 0.2 observed between the Speck units and the Grimm instrument during indoor and outdoor measurements were increased by separating the data into sets affected by different sources. When the ambient data were divided into combustion and non-combustion aerosol, the mean r2 increased to 0.5 and 0.4 for indoor and outdoor combustion periods data, respectively. Also, averaging the data to improve the signal to noise ratio increases the correlation for low PM concentrations. For outdoor data, the correlation increased to 0.5 when the data were averaged to hourly averages. Between the Specks, the correlation was >0.9 indoors, showing a high degree of reproducibility among the results. The limit of detection was calculated using the method of Wallace et al. (2011) and was found to be 10 µg m−3 at a 99% confidence level for 1-minute data. The mean bias values showed a PM overestimation of 200% for indoor data, and 500% for outdoor data relative to the Grimm values. However, these values are influenced by the low measured PM concentrations. The RMSE of Specks was about 10 µg m−3 and the concentrations were often about this value. The overall precision was 8.8±1.7% indoors and 12.2±6.2% outdoors, suggesting its independence from changing ambient conditions. The Speck monitors may be suitable for use in indoor and outdoor PM monitoring programs, depending on the required performance to meet the goals of the study. The instrument has a large bias at low concentrations, making it unsuitable for background measurements or for measurements in clean environments. Even at concentrations over the LOD, it is necessary to assess the bias for expected particle sources before any instrument deployment.

A major problem that limit the use of the model-free analysis methods, like positive matrix factorization (PMF), for the resolution of multivariate data is that usually, there is rotational ambiguity in the results. Implementing adequate constraints may reduce such ambiguities. In some special cases, non-negativity constraints may serve as a sufficient condition to uniquely resolve profiles. In this study, effect of adding new variables on the extent of rotational ambiguity is investigated, and profiles with lower rotation have been obtained on the basis of data set structure. The displacement (DISP) method of error estimation (EE) for the factor elements incorporated into the US Environmental Protection Agency's version of positive matrix factorization (PMF) has been applied to capture the uncertainty of PMF analyses due to rotational ambiguity. To explore these considerations, results are presented for synthetic including submicron particle size distributions (12–470 nm) measured between January 2008 and December 2010 at the New York State Department of Environmental Conservation (NYS DEC) site in Rochester, NY. Generally, added informative variables can reduce the ambiguity in the profiles. The results of the PMF analysis showed the effect of adding new variables to feasible solutions led to significantly decreased (up to 44%) DISP intervals. More robust results with lower rotational uncertainty became possible and the results were more easily interpreted. This approach can be applied to any other field that utilize quantitative factor analysis methods.

Exposure to particulate matter, carbon dioxide, and carbon monoxide inside a car during commuting were determined during the period October–November 2017 in Nur-Sultan, Kazakhstan. We choose to follow five bus routes (#10, 18, 19, 37 and 53) that cover the majority of the city's area. CO (ppm), CO2 (ppm) and PM1, PM2.5, PM4, and PM10 mass concentration (μg/m3) were measured in this study. PM11 was found to be the largest fraction of all sizes of PM. The mean PM1 concentrations along the forward (backward) paths for each of the five bus routes were measured as 11 ± 14 (11 ± 7), 14 ± 8 (16 ± 6), 25 ± 11 (21 ± 14), 23 ± 8 (15 ± 6) and 76 ± 26 (99 ± 55) μg/m3, respectively. Average CO concentrations among five bus routes (#10, 18, 19, 37 and 53) along the forward (backward) paths were 0.67 ± 0.16 (0.78 ± 0.17), 0.7 ± 0.16 (0.53 ± 0.32), 1.04 ± 0.01 (2.3 ± 0.95), 2.67 ± 1.3 (2.03 ± 0.41), 3.54 ± 3.57 (2.17 ± 0.37) ppm. The mean PM1/PM2.5 and PM2.5/PM10 ratios were 0.96 and 0.91, respectively. Nur-Sultan could be an example for those cities that are under major developments and candidates to be green cities by showing the exposures to atmospheric pollutants across the city. Those cities that are developing themselves as tourist attractions should create maps of PM exposures along major urban routes, and route traffic to exclude tourist areas from being hotspots.

During August and September 2012, a study was conducted to determine the sources of PM2.5 adjacent to the I-710 Long Beach Freeway. The site is directly affected by the emissions from heavy diesel traffic flowing from major container ports about 10 km south of the sampling site. Hourly average data were obtained for particulate species including PM2.5, black carbon and UV absorbing carbon, EC, fine particulate nonvolatile and semi-volatile organic material (NVOM and SVOM), sulfate, nitrate, chloride, ammonium ion, and Na ion, and for related factors including O3, CO, NOX, SO2, and total traffic flow on the I-710. A total of 520 hourly averaged data sets with 15 measured variables were analyzed by EPA-PMF v5.0. The data were best described by a 10-factor solution. Based on the composition and diurnal patterns of the factors, they were assigned to three diesel-related factors (two of which appeared to represent traffic from the ports and one general freeway diesel factor), a light-duty, spark-ignition vehicle-related factor, three secondary factors (one of which was associated with O3 formation processes), and three factors dominated by sulfate, SO2, and chloride, respectively. The diurnal patterns for these last three factors are strongly correlated. Meteorological and refinery upset data indicate that they are associated with emissions from a nearby refinery. The results of the PMF analysis were combined with nephelometer light scattering, corrected for coarse particle scattering and estimated aerosol water content in a multilinear regression analysis to identify visibility degradation sources. Major contributors were the aerosol water content, and the secondary PMF factors associated with either Nitrate and NVOM or NVOM and SVOM. The use of hourly average data made possible the identification of factors associated with gasoline vehicle emissions and both port and non-port diesel emissions.

Prior work found increased rates for emergency department (ED) visits for asthma and hospitalizations for chronic obstructive pulmonary disease per unit mass of PM2.5 across New York State (NYS) during 2014–2016 after significant reductions in ambient PM2.5 concentrations had occurred following implementation of various policy actions and major economic disruptions. The associations of source-specific PM2.5 concentrations with these respiratory diseases were assessed with a time-stratified case-cossover design and logistic regression models to identify the changes in the PM2.5 that have led to the apparently increased toxicity per unit mass. The rates of ED visits and hospitalizations for asthma and COPD associated with increases in source-specific PM2.5 concentrations in the prior 1, 4, and 7 days were estimated for 6 urban sites in New York State. Overall, there were similar numbers of significantly increased (n = 9) and decreased rates (n = 8) of respiratory events (asthma and COPD hospitalizations and ED visits) associated with increased source-specific PM2.5 concentrations in the previous 1, 4, and 7 days. Associations of source-specific PM2.5 concentrations with excess rates of hospitalizations for COPD for spark- and compression ignition vehicles increased in the 2014–2016 period, but the values were not statistically significant. Other source types showed inconsistent patterns of excess rates. For asthma ED visits, only biomass burning and road dust showed consistent positive associations with road dust having significant values for most lag times. Secondary nitrate also showed significant positive associations with asthma ED visits in the AFTER period compared to no associations in the prior periods. These results suggest that the relationships of asthma and COPD exacerbation with source-specific PM2.5 are not well defined and further work will be needed to determine the causes of the apparent increases in the per unit mass toxicity of PM2.5 in New York State in the 2014-16 period.

This study investigated the association of short-term exposure to PM10, PM2.5, NO2, O3, and CO with daily all-cause, cardiovascular, ischemic heart disease (IHD), cerebrovascular, and respiratory deaths in Mashhad, a tourist megacity in Iran (2014–2018). A distributed-lag-day, nonlinear model (DLNM) and generalized additive model (GAM) based on the quasi-Poisson distribution were used to explore the exposure-lag-day-response associations. The average (± standard deviation) concentrations of PM10, PM2.5, NO2, O3, and CO were 67.1 (± 35.5), 29.6 (± 14.2), 57.3 (± 24.1), 55.9 (± 16.9), and 1907.6 (± 1362.7) μg/m3, respectively. NO2 was associated with IHD mortality in lag-days 0 to 0–7, and lag-day 1. The relative risks (RRs) for a 10 μg/m3 increase in NO2 ranged from 1.01 (95% CI 0.93, 1.11) at lag-day 0 to 1.04 (95% CI 0.94, 1.16) and 1.03 (95% CI 0.93, 1.14) for lag-day 0–1 (cumulative) and lag-day 1 (non-cumulative), respectively. For all-cause mortality, cumulative exposure to PM2.5 for lag-day 0–7 (1.07, 95% CI 1.00, 1.15) and non-cumulative exposure to NO2 at lag-day 6 (1.02, 95% CI 1.00, 1.03) were significant. Exposure to PM10 (per 10 μg/m3) was significantly associated with respiratory mortality at several lag-days. Adjusting for Ramadan did not significantly affect the results. PM10 had significant associations with respiratory mortality of people > 65 years old, and men for several lag-days. For IHD, NO2 affected older people, and men and women over different lag-days. Results of multi-pollutant models were similar to the single-pollutant model outcomes. In conclusion, NO2 and PM10 had more significant relationships with adverse health outcomes than the other pollutants.

Here we report results of a detailed analysis of the urban and non-urban contributions to particulate matter (PM) concentrations and source contributions in five European cities, namely Schiedam (the Netherlands, NL), Lens (France, FR), Leipzig (Germany, DE), Zurich (Switzerland, CH) and Barcelona (Spain, ES). PM chemically speciated data from 12 European paired monitoring sites (one traffic, five urban, five regional and one continental background) were analysed by positive matrix factorisation (PMF) and Lenschow's approach to assign measured PM and source contributions to the different spatial levels. Five common sources were obtained at the 12 sites: sulfate-rich (SSA) and nitrate-rich (NSA) aerosols, road traffic (RT), mineral matter (MM), and aged sea salt (SS). These sources explained from 55 % to 88 % of PM mass at urban low-traffic-impact sites (UB) depending on the country. Three additional common sources were identified at a subset of sites/countries, namely biomass burning (BB) (FR, CH and DE), explaining an additional 9 %-13 % of PM mass, and residual oil combustion (V-Ni) and primary industrial (IND) (NL and ES), together explaining an additional 11 %-15 % of PM mass. In all countries, the majority of PM measured at UB sites was of a regional+continental (R+C) nature (64 %-74 %). The R+C PM increments due to anthropogenic emissions in DE, NL, CH, ES and FR represented around 66 %, 62 %, 52 %, 32 % and 23 %, respectively, of UB PM mass. Overall, the R+C PM increments due to natural and anthropogenic sources showed opposite seasonal profiles with the former increasing in summer and the latter increasing in winter, even if exceptions were observed. In ES, the anthropogenic R+C PM increment was higher in summer due to high contributions from regional SSA and V-Ni sources, both being mostly related to maritime shipping emissions at the Spanish sites. Conversely, in the other countries, higher anthropogenic R+C PM increments in winter were mostly due to high contributions from NSA and BB regional sources during the cold season. On annual average, the sources showing higher R+C increments were SSA (77 %-91 % of SSA source contribution at the urban level), NSA (51 %-94 %), MM (58 %-80 %), BB (42 %-78 %) and IND (91 % in NL). Other sources showing high R+C increments were photochemistry and coal combustion (97 %-99 %; identified only in DE). The highest regional SSA increment was observed in ES, especially in summer, and was related to ship emissions, enhanced photochemistry and peculiar meteorological patterns of the Western Mediterranean. The highest R+C and urban NSA increments were observed in NL and associated with high availability of precursors such as NOx and NH3. Conversely, on average, the sources showing higher local increments were RT (62 %-90 % at all sites) and V-Ni (65 %-80 % in ES and NL). The relationship between SSA and V-Ni indicated that the contribution of ship emissions to the local sulfate concentrations in NL has strongly decreased since 2007 thanks to the shift from high-sulfur-to low-sulfur-content fuel used by ships. An improvement of air quality in the five cities included here could be achieved by further reducing local (urban) emissions of PM, NOx and NH3 (from both traffic and non-traffic sources) but also SO2 and PM (from maritime ships and ports) and giving high relevance to non-urban contributions by further reducing emissions of SO2 (maritime shipping) and NH3 (agriculture) and those from industry, regional BB sources and coal combustion., Measurements were funded by the Spanish Ministry of Economy, Industry and Competitiveness and FEDER funds under the project HOUSE (CGL2016-78594-R) and by the Generalitat de Catalunya (AGAUR 2014 SGR33, AGAUR 2017 SGR41 and the DGQA), by the French Ministry of Environment (Bureau de l'Air du Ministère de l'Ecologie, du Développement durable, et de l’Energie), by the French National Research Agency (ANR) and by the Regional Council “Hauts-de-France” and the European Regional Development Fund (ERDF), and by the Saxon State Office for Environment, Agriculture and Geology (LfULG).

This study investigates the major chemical components, particle-bound water content, acidity (pH), and major potential sources of PM2.5in major cities (Belluno, Conegliano, Vicenza, Mestre, Padua, and Rovigo) in the eastern end of the Po Valley. The measured PM2.5mass was reconstructed using a multiple-site hybrid chemical mass closure approach that also accounts for aerosol inorganic water content (AWC) estimated by the ISORROPIA-II model. Annually, organic matter accounted for 31–45% of the PM2.5at all sites, followed by nitrate (10–19%), crustal material (10–14%), sulfate (8–10%), ammonium (5–9%), elemental carbon (4–7%), other inorganic ions (3–4%), and trace elements (0.2–0.3%). Water represented 7–10% of measured PM2.5. The ambient aerosol pH varied from 1.5 to 4.5 with lower values in summer (average in all sites 2.2±0.3) and higher in winter (3.9±0.3). Six major PM2.5sources were quantitatively identified with multiple-site positive matrix factorization: secondary sulfate (34% of PM2.5), secondary nitrate (30%), biomass burning (17%), traffic (11%), re-suspended dust (5%), and fossil fuel combustion (3%). Biomass burning accounted for ~90% of total PAHs. Inorganic aerosol acidity was driven primarily by secondary sulfate, fossil fuel combustion (decreasing pH), secondary nitrate, and biomass burning (increasing pH). Secondary nitrate was the primary driver of the inorganic AWC variability. A concentration-weighted trajectory (multiple-site) analysis was used to identify potential source areas for the various factors and modeled aerosol acidity. Eastern and Central Europe were the main source areas of secondary species. Less acidic aerosol was associated with air masses originating from Northern Europe owing to the elevated presence of the nitrate factor. More acidic particles were observed for air masses traversing the Po Valley and the Mediterranean, possibly due to the higher contributions of fossil fuel combustion factor and the loss of nitric acid due to its interaction with coarse sea-salt particles.

Objective Review advances in exposure assessment offered by the exposome concept and new -omics and sensor technologies. Methods Narrative review of advances, including current efforts and potential future applications by the US military. Results Exposure assessment methods from both bottom-up and top-down exposomics approaches are advancing at a rapid pace, and the US military is engaged in developing both approaches. Top-down approaches employ various -omics technologies to identify biomarkers of internal exposure and biological effect. Bottom-up approaches use new sensor technology to better measure external dose. Key challenges of both approaches are largely centered around how to integrate, analyze, and interpret large datasets that are multidimensional and disparate. Conclusions Advances in -omics and sensor technologies may dramatically enhance exposure assessment and improve our ability to characterize health risks related to occupational and environmental exposures, including for the US military.

Objective Benzo(ghi)perylene (BghiP) and 1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin (HpCDD) were elevated in serum from personnel deployed to sites with open burn pits. Here, we investigated the ability of BghiP and HpCDD to regulate microRNA (miRNA) expression through the aryl hydrocarbon receptor (AHR). Methods Human lung fibroblasts (HLFs) were exposed to BghiP and HpCDD. AHR activity was measured by reporter assay and gene expression. Deployment related miRNA were measured by quantitative polymerase chain reaction. AHR expression was depleted using siRNA. Results BghiP displayed weak AHR agonist activity. HpCDD induced AHR activity in a dose-dependent manner. Let-7d-5p, miR-103-3p, miR-107, and miR-144-3p levels were significantly altered by HpCDD. AHR knockdown attenuated these effects. Conclusions These studies reveal that miRNAs previously identified in sera from personnel deployed to sites with open burn pits are altered by HpCDD exposure in HLFs.

OBJECTIVE: To develop an approach for a retrospective analysis of post-exposure serum samples using diverse molecular profiles. METHODS: The 236 molecular profiles from 800 de-identified human serum samples from the Department of Defense Serum Repository were classified as smokers or non-smokers based on direct measurement of serum cotinine levels. A machine-learning pipeline was used to classify smokers and non-smokers from their molecular profiles. RESULTS: The refined supervised support vector machines with recursive feature elimination predicted smokers and non-smokers with 78% on the independent held-out set. Several of the identified classifiers of smoking status have previously been reported and four additional miRNAs were validated with experimental tobacco smoke exposure in mice, supporting the computational approach. CONCLUSIONS: We developed and validated a pipeline that shows retrospective analysis of post-exposure serum samples can identify exposures to environmental exposures.

The response of respiratory infections to source-specific particulate matter (PM) is an area of active research. Using source-specific PM2.5 concentrations at six urban sites in New York State, a case-crossover design, and conditional logistic regression, we examined the association between source-specific PM and the rate of hospitalizations and emergency department (ED) visits for influenza or culture-negative pneumonia from 2005 to 2016. There were at most N = 14 764 influenza hospitalizations, N = 57 522 influenza ED visits, N = 274 226 culture-negative pneumonia hospitalizations, and N = 113 997 culture-negative pneumonia ED visits included in our analyses. We separately estimated the rate of respiratory infection associated with increased concentrations of source-specific PM2.5, including secondary sulfate (SS), secondary nitrate (SN), biomass burning (BB), pyrolyzed organic carbon (OP), road dust (RD), residual oil (RO), diesel (DIE), and spark ignition vehicle emissions (GAS). Increased rates of ED visits for influenza were associated with interquartile range increases in concentrations of GAS (excess rate [ER] = 9.2%; 95% CI: 4.3%, 14.3%) and DIE (ER = 3.9%; 95% CI: 1.1%, 6.8%) for lag days 0–3. There were similar associations between BB, SS, OP, and RO, and ED visits or hospitalizations for influenza, but not culture-negative pneumonia hospitalizations or ED visits. Short-term increases in PM2.5 from traffic and other combustion sources appear to be a potential risk factor for increased rates of influenza hospitalizations and ED visits.

Increased ambient air pollutant concentrations during pregnancy have been associated with reduced birth weight, but the etiologically relevant pregnancy time window(s) is/are unclear. In 76,500 singleton births in Monroe County, NY (2005-2016), who were 37-42 gestational weeks at delivery, we used generalized linear models to regress term birth weight against mean gestational month pollutant concentrations, adjusting for mean temperature, and maternal, infant, and medical service use characteristics. Overall, there were no clear patterns of term birth weight change associated with increased concentrations of any pollutant across gestational months. However, among Hispanic women only, increases in all pollutants, except O

This study investigates the major chemical components, particle-bound water content, acidity (pH), and major potential sources of PM

Prior work found increased rates for emergency department (ED) visits for asthma and hospitalizations for chronic obstructive pulmonary disease per unit mass of PM(2.5) across New York State (NYS) during 2014 to 2016 after major reductions in ambient PM2.5 concentrations had occurred following implementation of various policy actions and major economic disruptions. The associations of source-specific PM(2.5) concentrations with these respiratory diseases were assessed with a time-stratified case-control design and logistic regression models to identify the changes in the PM(2.5) that have led to the apparently increased toxicity per unit mass. The rates of ED visits and hospitalizations for asthma and COPD associated with increases in source-specific PM2.5 concentrations in the prior 1, 4, and 7 days were estimated for 6 urban sites in New York State. Overall, there were similar numbers of significantly increased (n=9) and decreased rates (n=8) of respiratory events (asthma and COPD hospitalizations and ED visits) associated with increased source-specific PM(2.5) concentrations in the previous 1, 4, and 7 days. Associations of source-specific PM(2.5) concentrations with excess rates of hospitalizations for COPD for spark- and compression ignition vehicles increased in the 2014–2016 period, but the values were not statistically significant. Other source types showed inconsistent patterns of excess rates. For asthma ED visits, only biomass burning and road dust showed consistent positive associations with road dust having significant values for most lag times. Secondary nitrate also showed significant positive associations with asthma ED visits in the AFTER period compared to no associations in the prior periods. These results suggest that the relationships of asthma and COPD exacerbation with source-specific PM(2.5) are not well defined and further work will be needed to determine the causes of the apparent increases in the per unit mass toxicity of PM(2.5) in New York State in the 2014–16 period.

This study characterized and quantified the bacterial and fungal bioaerosols in nine wards of the Razavi Hospital (Mashhad, Iran) that is equipped with an advanced heating, ventilating, and air conditioning (HVAC) system including HEPA filters for air cleaning. In this study, 432 samples were taken from the indoor air of multiple hospital wards during the morning and afternoon shifts during summer and autumn. The particle number concentrations with sizes of > 0.3, > 0.5, > 1, > 2, > 5, and > 10 μm were measured using a 6-channel handheld particle counter. A greater diversity of bioaerosol types were observed during the morning shifts and during summer. The microbial load was not affected significantly by the temperature, relative humidity, working shift, season, and number of visitors, indicating the effectiveness of a well-designed ventilation system to eliminate site-specific variations. For microbial number concentrations, a significant correlation was only observed between the number of particles with a diameter of > 10 μm and the airborne microbial loading. Thus, passive sampling may not properly reflect the actual concentrations of smaller bioaerosols. In conclusion, HEPA filters in the HVAC system successfully decreased the bioaerosol concentrations in the hospital environment. Additionally, we recommend that active sampling be used in cases where a well-functioning HVAC system exists.

Polybrominated diphenyl ethers (PBDEs) were widely used as fire retardants and have been detected throughout the Great Lakes (GL) ecosystem. The concentration trends (after fish age normalization) of PBDEs in top predator fish (lake trout and walleye) of the GLs were determined from 1979 to 2016, which includes most of the period when PBDEs were manufactured and used in this region. The fish samples were collected by two national (U.S. and Canada) long-term monitoring and surveillance programs. Trends in total concentrations (age-normalized) of the five major PBDE congeners (BDE-47, 99, 100, 153, and 154) found in fish across all five lakes have varied over time. Significant increases were observed from 1990 to 2000 (16.3% per year). Rapidly decreasing concentrations (-19.5% per year) were found from 2000 to 2007. Since 2007, the decreasing trend has become smaller (less than -5.5% per year) and relatively unchanged from 2011 to 2015. BDE-47, the congener with the highest concentrations in lake trout, has decreased continuously (ranging from -6.7% to -16.2% per year) in all lakes except Lake Erie. This decrease can be associated with the voluntary and regulatory phase out of production and/or usage of PBDEs since 2000. However, it has been offset by recent (since 2007) increasing trends of the other four higher brominated BDE congeners, especially BDE-100 and 154. Production and usage of commercial penta- and octa- BDE mixtures containing primarily the five major PBDE congeners was discontinued in 2004 in the U.S.A. and 2008 in Canada. These results indicate increasing fish uptake and bioaccumulation of higher brominated BDE congeners may be related to the transformation of BDE-209 to lower brominated BDE compounds in the GL environment or food web. Considering the abundance of BDE-209 in existing products and sediment in GL region, the duration of the unchanging total PBDE concentration trend in GL fish could be longer than expected.

Benzene, toluene, ethylbenzene, and xylene (BTEX) concentrations were measured in beauty salons (BS) and in the urine of the beauty practitioners and a control group. Indoor and outdoor concentrations of BTEX were measured in 36 randomly selected salons. Before- and after-shift urinary BTEX were measured from one female non-smoker employee in each salon, and repeated three times. Clinical symptoms in that beautician were assessed by a physician. Thirty-six unexposed women were included as the control group. Cancer and non-cancer risks of exposure were assessed using deterministic and stochastic methods. Average indoor concentrations of BTEX were higher than those in the ambient air. Urinary BTEX concentrations in the beauty practitioners were significantly higher than in the control group. Linear regression showed that 77% of urinary benzene and toluene variations can be explained by their airborne concentrations. A positive significant relationship was found between age and urinary BTEX concentrations. Although the BTEX cancer and non-cancer risks were not significant, BTEX led to irritation of the eyes, throat, lung, and nose. In addition, toluene caused menstrual disorders among beauty practitioners. These results suggest that it is essential to decrease the exposure of beauty practitioners to BTEX compounds.

International audience; he present study proposes an advanced methodology to refine the source apportionment of organic aerosol (OA). This methodology is based on the combination of offline and online datasets in a single Positive Matrix Factorization (PMF) analysis using the multilinear engine (ME-2) algorithm and a customized time synchronization procedure. It has been applied to data from measurements conducted in the Paris region (France) during a PM pollution event in March 2015. Measurements included OA ACSM (Aerosol Chemical Speciation Monitor) mass spectra and specific primary and secondary organic molecular markers from PM10 filters on their original time resolution (30 min for ACSM and 4 h for PM10 filters). Comparison with the conventional PMF analysis of the ACSM OA dataset (PMF-ACSM) showed very good agreement for the discrimination between primary and secondary OA fractions with about 75% of the OA mass of secondary origin. Furthermore, the use of the combined datasets allowed the deconvolution of 3 primary OA (POA) factors and 7 secondary OA (SOA) factors. A clear identification of the source/origin of 54% of the total SOA mass could be achieved thanks to specific molecular markers. Specifically, 28% of that fraction was linked to combustion sources (biomass burning and traffic emissions). A clear identification of primary traffic OA was also obtained using the PMF-combined analysis while PMF-ACSM only gave a proxy for this OA source in the form of total hydrocarbon-like OA (HOA) mass concentrations. In addition, the primary biomass burning-related OA source was explained by two OA factors, BBOA and OPOA-like BBOA. This new approach has showed undeniable advantages over the conventional approaches by providing valuable insights into the processes involved in SOA formation and their sources. However, the origins of highly oxidized SOA could not be fully identified due to the lack of specific molecular markers for such aged SOA.

Positive Matrix Factorization receptor model developed by the United States Environmental Protection Agency known as EPA PMF receptor model and reconstructed mass model were applied to air pollution data collected over Ibadan south west Nigeria. The essence was to determine the source profiles responsible for the high pollution level of Ibadan and to compare the sources resolved by these two methods. Particulate matter load was sampled over Ibadan, southwest Nigeria with the aid of low volume Gent air sampler, equipped with the Norwegian Institute for Air Research (NILU) Stacked Filter Unit (SFU). Two separate 47-mm nuclepore filters were mounted on the SFU to collect both fine and coarse particulates separately. Trace elements were determined using instrumental neutron activation analysis (INAA) and energy dispersive x-ray fluorescence (EDXRF) spectrometry. Five factors were resolved each for both fine and coarse fractions using EPA PMF. For the fine fraction, soil dust, vehicular emission, oil combustion, open burning and copper-rich source were the major sources of fine particulates over Ibadan city contributing 42, 16, 10, 22 and 10% respectively to the total aerosol loading over Ibadan. Vehicular emission, continental soil, sea salt, locally generated dust and copper-rich source were the sources identified for the coarse particulates. These contributed 7, 49, 13, 23 and 8% respectively. It was observed that emission from open burning was very high (22%), being the second largest contributor to the fine particulates. Reconstructed mass model showed good agreement with PMF in implicating soil dust as the major contributor of airborne pollutants over Ibadan. There was good correlation between the reconstructed mass and the measured mass with r 2 values of 0.87 and 0.98 for fine and coarse particulates respectively. The result of this work showed that re-suspended soil particulates were the major constituents of airborne particulate matter over Ibadan, with over 70 % contribution to the coarse mass and over 40 % contribution to the fine mass. Keywords: Particulate Matter, Reconstructed mass, Refuse burning, PMF, Receptor model, Composite Variables

Lockdown measures to curtail the COVID-19 pandemic in China halted most non-essential activities on January 23, 2020. Despite significant reductions in anthropogenic emissions, the Beijing-Tianjin-Hebei (BTH) region still experienced high air pollution concentrations. Employing two emissions reduction scenarios, the Community Multiscale Air Quality (CMAQ) model was used to investigate the PM2.5 concentrations change in this region. The model using the scenario (C3) with greater traffic reductions performed better compared to the observed PM2.5. Compared with the no reductions base-case (scenario C1), PM2.5 reductions with scenario C3 were 2.70, 2.53, 2.90, 2.98, 3.30, 2.81, 2.82, 2.98, 2.68, and 2.83 μg/m3 in Beijing, Tianjin, Shijiazhuang, Baoding, Cangzhou, Chengde, Handan, Hengshui, Tangshan, and Xingtai, respectively. During high-pollution days in scenario C3, the percentage reductions in PM2.5 concentrations in Beijing, Tianjin, Shijiazhuang, Baoding, Cangzhou, Chengde, Handan, Hengshui, Tangshan, and Xingtai were 3.76, 3.54, 3.28, 3.22, 3.57, 3.56, 3.47, 6.10, 3.61, and 3.67%, respectively. However, significant increases caused by unfavorable meteorological conditions counteracted the emissions reduction effects resulting in high air pollution in BTH region during the lockdown period. This study shows that effective air pollution control strategies incorporating these results are urgently required in BTH to avoid severe pollution.

This work presents the first assessment of temporal trends (2005-2016) for perfluoroalkyl acids (PFAAs) in top predator fish of the Laurentian Great Lakes except Lake Ontario, for which we provide a post-2008 update. Lake trout (Salvelinus namaycush) or walleye (Sander vitreus; Lake Erie only) collected annually from 2005 to 2016 were analyzed for 12 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkyl sulfonic acids (PFSAs) with carbon chain lengths between 4 and 16 (C4-C16). Individual analyte concentrations generally decreased in fish basin-wide between 2005 and 2016, including Lake Ontario lake trout previously found to lack declining PFAA concentrations up until 2008. Declining fish PFAA burden reflects a positive response to the industrial phase-outs of these chemicals. Notable exceptions to this general decline included most analytes in lake trout collected from Lake Superior near Keweenaw Point and C6 and C8 PFSAs and C9 PFCAs in Lake Erie lake trout and walleye, which exhibited constant or increasing concentrations in recent years. Recent increases in Lake Superior shoreline development and mobilization from increased sediment resuspension and contamination from biosolids-amended agricultural soils in the Lake Erie watershed are plausible explanations for these cases. However, data scarcity prohibits confirmation of these suspected causes. The lingering lack of declining concentrations noted in this study together with the ongoing evolution of the fluorinated chemical industry emphasize the vigilance needed to better understand how past and future emissions will affect the Great Lakes and global ecosystems.

Although the basic approach to quantitative resolution of air pollutant concentrations has been available for more than 2 decades, there have been a number of useful advances that have helped to improve the resolution of source profiles and the likely accuracy of resulting source contributions. These advances include source apportionment software the implements the use of data from multiple monitoring sites, imposes constraints, and provides improved solution diagnostics. New R-packages are available to make auxiliary analyses that combine meteorological data with the resolved source contributions to indicate the likely local sources or most likely distant source locations. There are new ways to preprocess the data to reduce the influence of local scale meteorology. These developments have aided in providing additional and better information to inform the development of air quality management strategies that can then be used to improve air quality and associated public health.

Rotational ambiguity is a major problem in the application of factor analysis methods to the mixture resolution problem. However, self-modeling curve resolution of spectrochemical data is often able to achieve good separations given fixed spectral characteristics including true zero absorbance values and typically smaller measurement uncertainties. For air pollution mixture problems such as the identification and quantification of sources of ambient particulate matter (PM), there are problems of the lack of true zero values in either the source profiles or their contributions to the ambient concentrations, variability in the source profiles, and typically much larger measurement uncertainties. Recent work has provided several approaches to reducing rotational ambiguity and providing improved resolution including preprocessing the data to remove the meteorologically induced covariance, applying constraints based on a priori knowledge, and analysis of multiple site data. Examples of these applications to airborne PM have shown improved results.

Ambient fine particulate matter (PM2.5) data of similar continuously monitored species at two air monitoring sites with different characteristics within the City of Toronto were used to gauge the intra-city variations in the PM composition over a largely concurrent period spanning two years. One location was

Particulate matter (PM) measurements were conducted during heating corn oil, heating corn oil mixed with the table salt and heating low fat ground beef meat using a PTFE-coated aluminum pan on an electric stove with low ventilation. The main objectives of this study were to measure the size segregated mass concentrations, emission rates, and fluxes of 24 trace elements emitted during heating cooking oil or oil with salt and cooking meat. Health risk assessments were performed based on the resulting exposure to trace elements from such cooking activities. The most abundant elements (significantly different from zero) were Ba (24.4 ug m−3) during grilling meat and Ti during heating oil with salt (24.4 ug m−3). The health assessment indicates that the cooking with an electric stove with poor ventilation leading to chronic exposures may pose the risk of significant adverse health effects. Carcinogenic risk exceeded the acceptable level (target cancer risk 1 × 10−6, US EPA 2015) by four orders of magnitude, while non-carcinogenic risk exceeded the safe level (target HQ = 1, US EPA 2015) by a factor of 5–20. Cr and Co were the primary contributors to the highest carcinogenic and non-carcinogenic risks, respectively.

Long-term atmospheric mercury measurements at Underhill, VT (VT99), and Huntington Forest, NY (NY20), from 1992 to 2014 and 2005 to 2014, respectively, were used to determine concentration trends using Mann–Kendall’s tau test with Sen’s slope estimator. These data, measured generally downwind of large Hg sources in the Midwestern United States, provide the longest record of ambient Hg concentrations available in the United States. At VT99, concentrations of gaseous element mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (PBM) declined at rates of −1.8, −3.2, and −6.7%/year, respectively. At NY20, GEM and GOM concentrations declined at rates of −1.6 and −7.8%/year, respectively; however, PBM concentrations increased at a rate of 2.0%/year, which is likely related to winter wood burning. A trajectory ensemble analysis using the potential source contribution function indicates the source locations associated with high mercury concentrations changed from Toronto–Buffalo and Pennsylva...

Kandy is the second largest city in Sri Lanka and a major tourist destination. It is a fast growing city with continuous construction of buildings, roads and historical places. More than 100 samples of fine particulate matter (PM) were collected using a GENT stacked filter sampler from a fixed site at the regional sampling station of Department of Meteorology situated in Katugastota, Kandy over the period of 2012 to 2014. Black carbon (BC) in these filters were determined by reflectance measurements while their elemental compositions were determined using the X-ray fluorescence spectrometry. Analysis of the elemental data suggests that the PM in Kandy originates largely from re-suspended soil and anthropogenic sources. The fine particulate matter data including BC and major elements (Na, Mg, Al, Si, Cl, Fe, Zn, Ni, Cu, V, S, Br, Pb, Cr, K, Ca and Ti) was analyzed using EPA-PMF version 5.0 (Positive Matrix Factorization) to explore the possible sources of the PM at the study site. Five factors were found and identified as soil, aged sea salt, vehicular emissions, biomass burning, and industrial sources.

Experiments were conducted in a dynamic chamber system to measure the formation of secondary organic aerosol (SOA) and particle-bound reactive oxygen species (ROS) produced from limonene ozonolysis in the presence of NO by varying the ratio of O_3 to NO. A diffusion cell system was used to produce the constant input of limonene in to the chamber, and six sets of experiments were conducted. The concentration of SOA mass and ROS produced were measured at steady-state. ROS, including peroxides, peroxy radicals and ions, was determined using dichlorofluorescin (DCFH) and converted to equivalent H_2O_2 concentration. The particle mass was measured using a tapered element oscillating microbalance (TEOM) and a scanning mobility particle sizer (SMPS) was used to obtain particle volume distributions. The results showed that the SOA mass concentration ranged from 30.3 to 157.3 μg m^(-3), and the ROS concentration ranged from 6.1 to 29.4 nmol m^(-3) of H_2O_2. For the different combinations of NO_x and O_3, the concentration ratio of [O_3]/[NO] around 1 was found to produce highest SOA mass and ROS, which is 157.3 μg m^(-3) and 29.4 nmol m^(-3). The SOA density was estimated by comparing the mass concentrations with the volume concentrations ranged from 1.21 to 1.48 g cm^(-3). The highest SOA density (1.48 g cm^(-3)) occurred with the lowest concentration ratio of [O_3]/[NO]. Compared with other monoterpene and linalool where each has one unsaturated carbon bond in other studies, limonene which has two unsaturated carbon bonds. Thus, it is the most efficient in generating the SOA and ROS concentrations in prior experiments without NO present.

Experiments were conducted in an on-campus house at Middle East Technical University Northern Cyprus Campus during January 2015. Low fat ground beef meat was grilled using an electric stove with no mechanical or natural ventilation. Five PM size fractions ranging from 3.3 µm to less than 0.43 µm were investigated in this study. The total particle emission rate and flux values were found to be 4.49×10 1 mg min -1 and 1.45×10 3 mg min -1 m -2 , respectively. Total OC emission rate and flux values were 2.3×10 1 mg min -1 and 7.33×10 2 mg min -1 m -2 , respectively, and total EC emission rate and flux values were determined to be 1.19 mg min -1 and 3.85×10 1 mg min -1 m -2 , respectively. Analyses of trace metal concentrations showed that Fe (0.429 mg m -3 ), Ti (0.270 mg.m -3 ), Sr (0.27 mg m -3 ), Ba (0.24 mg m -3 ) and Li (0.23 mg m -3 ) were the five most abundant trace elements in the PM produced during grilling ground beef. Pb, Mn, and V concentrations were found to be greater than the World Health Organization (WHO) exposure limit.

Biomass burning is a major global source of fine primary carbonaceous particles including strongly light absorbing compounds and marker compounds. In a prior study, particulate matter (PM) sampling was conducted during 2010–2012 period at sites in Rajshahi, Dhaka, Khulna, and Chittagong. PM samples were collected using dichotomous samplers in the PM2.5 and PM2.5–10 size fractions. The samples were analyzed for mass, black carbon at 370 nm (UVBC) and 880 nm (BC), Delta-C (UVBC-BC), and elemental compositions with X-ray fluorescence. Source apportionment using PMF was performed to identify and quantify the PM sources. Results showed that biomass burning contributions during winters in Rajshahi were substantially higher than in Dhaka, Khulna, or Chittagong. Agricultural burning areas of the Indo-Gangetic Plain were hypnotized as the primary source region. The present study explores the relationships between the source regions using trajectory ensemble models and determines if transported biomass PM has disproportionately affected air quality in Rajshahi. The probable source locations that were identified included Pakistan, northern India, Nepal, Bangladesh, Northeastern India, and Myanmar. To assess the model results, satellite measurements of fire radiative power (FRP) were calculated based on fire data acquired by the MODerate-resolution Imaging Spectro-radiometer (MODIS) sensor in six defined areas. High fire occurrences from MODIS coincident with the source regions identified in Nepal, Northeastern India and Myanmar in winter. The instantaneous FRP values ranged between 4.4 MW and 2449 MW. The mean winter FRP values for Nepal and Northeastern India were higher than for the other regions with Nepal having the overall highest value. Fire locations with their mean power, NASA Satellite pictures and particles speed along trajectories have been analyzed. In summary, the integrated outcome of the different techniques has identified Northern India and Nepal as the main source area responsible for the increased biomass burning concentration difference at Rajshahi.

To better understand the chemical characteristics and the potential source regions of PM2.5 measured from 18 January until 22 January 2016 in Shijiazhuang, China, PM2.5 was measured continuously and integrated daily sampling using mid-volume samplers was conducted at the three sites. The mean concentration of PM2.5 at the three sites reached 113, 131 and 119 µg m–3 during the sampling period, the higher concentrations occurred at early morning and noon, similar variation trends were found in the three sites. The concentrations of OC were higher than EC at three sampling sites and the OC/EC ratios ranged from 9.09 to 12.4 with a daily mean value of 10.8 during a haze pollution episode (HPE), which suggested that carbonaceous compositions might be from same source. The total concentration of water soluble inorganic ions (WSII) at the sites ranged from 72.2 to 100.0 µg m–3 with a mean of 84.3 µg m–3. The dominant species were NO3–, SO42–, NH4+, Cl–, accounting for 88.4% of the mean PM2.5 WSII mass. The most abundant measured element was Na with average mass concentrations of 41.5, 37.0, and 38.1 µg m–3 during the HPE. Relative humidity during HPE was higher than during clean days with average values of 70.1% and 60.2%, suggesting that high relative humidity and low wind speed favored formation of secondary inorganic ions and accelerated hygroscopic growth. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) and a potential source contribution function (PSCF) analysis were used to assess the data. Back-trajectories for the three sites identified similar transport pathways. PSCF analysis showed a significant regional impact on PM2.5 at Shijiazhuang during the polluted period. The potential source areas for PM2.5 in Shijiazhuang were the Beijing-Tianjin region and Shandong Province. The results of the present study show the need for the development of PM2.5 control measurements on a regional scale.

Instruments such as Beta Attenuation Monitors (BAMs) provide real-time PM2.5 mass concentration data and are now widely used in compliance monitoring networks. These devices collect the PM on a filter tape in 1-hour samples. In this work, the use of BAM filter spots for chemical speciation was investigated. Filter tapes from several sites in California were analyzed for a series of chemical species including elements, ions, organic and elemental carbon, and molecular markers. A major issue was the blank values in the filter tape. Based on blank spot analyses, it was determined that measurement of organic and elemental carbon (OC/EC) and elements were infeasible. A total of 22 BAM samples (each comprising 24 1-hour spots) from 12 sites were analyzed for ions and black carbon (BC). Additionally, 336 1-hour spots were composited to analyze for molecular markers (MM). Measurements of ions and BC at each site appear to have been underestimated likely due to volatilization losses. MM measurements in these 336 BAM filter spots suggest that organic speciation of BAM filters could be a viable method for measuring useful marker species. Statistical analysis was conducted by grouping samples into classes with mass concentrations greater and less than 80 µg m–3. Measurement of Delta-C concentrations (i.e., Delta C = BC370 nm – BC880 nm) in these two groups of samples revealed that most of the high PM2.5 concentration days PM2.5 greater than 80 µg m–3) were likely not substantially impacted by biomass combustion particles. A major portion of the samples analyzed in this work with high concentrations of PM2.5 were inorganic species such as ammonium sulfate, ammonium nitrate and other ions. Results suggested that some useful information may be derived from BAM tape analyses. However, different filter substrates and sample handling and storage practice might make a wider range of analyses possible.

Health impact assessments are useful for governmental authorities and decision-makers to determine the need for action and address potential public health problems arising from exposure to air pollution. The present study was conducted to assess the short-term health impacts of ambient air pollution in Tehran using the AirQ 2.2.3 model for March 2013–March 2016. Hourly concentrations of PM10, PM2.5, O3, NO2 and SO2 were acquired from the Department of Environment (DOE) and Tehran Air Quality Control Company (TAQCC). Air pollution data was validated according to the USEPA criteria, and only valid monitoring stations for each of the three years were entered to the AirQ 2.2.3 model. The pollutant concentrations were lower in the March 2015 March 2016 period compared to the previous years. The three-year average (± standard deviation) of PM10 and PM2.5 concentrations were 80.21 (± 34.21) and 39.17 (± 17.26) µg m–3, respectively. The three-year averages (± standard deviation) for ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2) were 54.88 (± 24.15), 103.97 (± 25.88) and 39.84 (± 11.17) µg m–3, respectively. The total estimated number of deaths attributed to PM10, PM2.5, O3, NO2 and SO2 over these three years were 4192, 4336, 1363, 2830, and 1216, respectively. The health impacts attributed to all pollutants except for PM10 were estimated to decrease in 2016, compared to the prior years. However, the air quality in Tehran still poses significant risks to public health. In conclusion, urgent efforts are needed such as mandating the replacing of old and poorly functioning vehicles from the roadways in order to reduce the health burden that air pollution is currently imposing on this city.

Recently, a number of optical particulate matter (PM) monitors employing low-cost PM sensors have become available on the consumer market. These portable low-cost monitors can be used to characterize PM concentrations with high spatial and temporal resolution. This study evaluates the performance of four low-cost PM monitors (Speck, Dylos, TSI AirAssure, and UB AirSense) against well-characterized reference instruments, and studies their suitability for PM field exposure studies. The low-cost monitors were characterized in a room-sized laboratory chamber with standard relative humidity and temperature conditions, with two PM sources: cigarette smoke and Arizona Test Dust. This study found that any of the monitors tested perform with adequate precision for monitoring air quality in an indoor microenvironment, although the field calibration of the monitor with a standard instrument for specific types of particles would be required. Other factors such as flexibility in data download methods, connectivity, compatibility with environmental conditions, and quality of technical support should also be considered when selecting low-cost PM monitors for human inhalation exposure assessment studies.

Samples of rainwater (RW) were collected to characterize the chemistry and sources in two representative megacities at Pune (Southwest) and Delhi (Northern) India from 2011 to 2014 across two seasons: monsoon (MN) and non-monsoon (NMN). Collected RW samples were analyzed for major chemical constituents (F−, Cl−, SO42−, NO3−, NH4+, Na+, K+, Ca2+, and Mg2+), pH and conductivity. In addition, bicarbonate (HCO3−) was also estimated. The mean pH values of the RW were >6 at Pune and