This study compares air quality in two European cities with contrasting characteristics during July–October 2024: Leon (Spain) and Gliwice (Poland). Concentrations of PM10, PM2.5, particulate matter chemical composition, and trace gases were analysed alongside meteorological data. The results show that both cities were influenced by local emissions, primarily from traffic, as well as by Saharan dust transport events. Leon, located closer to North Africa, experienced an intense dust intrusion episode with a PM10 peak of 116 µg m−3, whereas Gliwice reached 62 µg m−3. The comparison revealed differences in aerosol intensity and composition, which are determined by geographic location and atmospheric conditions. This analysis highlights the importance of integrating local and regional data to understand urban aerosol dynamics in Europe.

Abstract. Prescribed fires were conducted in two shrubland communities dominated by Genista hispanica subsp. occidentalis and Calluna vulgaris in La Cueta, León, Spain, to characterise particulate and gaseous emissions during combustion. Distinct fire dynamics were observed: Calluna exhibited a Modified Combustion Efficiency (MCE) of 90.6, indicative of flaming combustion, while Genista showed an MCE of 70.8, characteristic of smouldering conditions. Gas-phase analysis revealed notably higher concentrations of CO2, CO, CH4, C2H6, and total organic carbon (TOC) in Calluna compared to Genista, with CO2 showing the greatest difference. Conversely, Genista exhibited slightly elevated NO and NO2 levels. Most gas concentrations were higher for Calluna, except for hydrogen fluoride (HF), which was more abundant in Genista. Elemental carbon (EC) and organic carbon (OC) accounted for 28.1 % and 32.9 % of PM2.5 mass in Calluna and Genista, respectively. Water-soluble inorganic ions contributed 6.9 % and 4.5 % to PM2.5 mass, with most ions more abundant in Calluna, except chloride (Cl⁻), which was higher in Genista. In both cases, Cl-, SO42-, Na+, Mg2+, and Ca2+ dominated the ionic composition. Morphological analysis revealed a population dominated by tar balls (submicrometer spherical particles) and aggregates with thick organic coatings. Derived emission factors are expected to provide valuable input for numerical models evaluating the impacts of prescribed and unplanned forest fires in the Mediterranean region.

Indoor air quality is crucial for human health due to the significant time people spend at home, and it is mainly affected by internal sources such as solid fuel combustion for heating. This study investigated the indoor air quality and health implications associated with residential coal burning covering gaseous pollutants (CO, CO2 and total volatile organic compounds), particulate matter, and toxicity. The PM10 chemical composition was obtained by ICP-MS/OES (elements), ion chromatography (water-soluble ions) and thermal-optical analysis (organic and elemental carbon). During coal combustion, PM10 levels were higher (up to 8.8 times) than background levels and the indoor-to-outdoor ratios were, on average, greater than unity, confirming the existence of a significant indoor source. The chemical characterisation of PM10 revealed increased concentrations of organic carbon and elemental carbon during coal combustion as well as arsenic, cadmium and lead. Carcinogenic risks associated with exposure to arsenic exceeded safety thresholds. Indoor air quality fluctuated during the study, with varying toxicity levels assessed using the Aliivibrio fischeri bioluminescence inhibition assay. These findings underscore the importance of mitigating indoor air pollution associated with coal burning and highlight the potential health risks from long-term exposure. Effective interventions are needed to improve indoor air quality and reduce health risks in coal-burning households.

The impact on indoor air quality during metal casting processes using the 3D printing (3DP) binder jetting technique to manufacture moulds is analyzed in this research. This study investigates the particle size distribution and gas concentration during the manufacturing stages of 3DP moulds, with focus on particle deposition in the human respiratory system. The goal is to understand the risks associated with particle and gas emissions in binder jetting 3D printing, and thus improve worker safety. The results indicate that particle emission rates are lowest during printing (0.01 1011particles min-1) but increase during post-processing and melting-pouring phases (3.07 1011 particles min � 1). During melting and pouring, the emission of particles was mainly in the range 7.9-71 nm, with values 10 times higher than in the previous phases. The study calculates the deposition of inhaled particles in different parts of the respiratory tract and reveals a 2.39 times higher extrathoracic mass deposition during 3DP mould manufacturing stages compared to melting-pouring stages. Additionally, alveolar mass deposition is higher during melting-pouring stages due to an increase in ultrafine emission rates. The study emphasizes the importance of insulation equipment and workplace ventilation in indoor spaces, particularly during heating processes that generate ultrafine particles through nucleation, so that health risks can be mitigated.

The below cloud scavenging of aerosols by snow has been analysed in León (NW Spain). Six snow events were registered over the course of one year of study. Ultrafine and accumulation aerosol particles were measured using a scanning mobility particle sizer spectrometer, while hydrometeors were characterized using a disdrometer. Furthermore, the chemical composition of the melted snow-water samples (soluble and insoluble fractions) was analysed. The scavenging coefficient (λ) showed a great variability among events. An effective washing of particles was observed during the first 30 min of snowfall. The mean change in the scavenging efficiency (%ΔC) of particle number concentration (PNC) and λ coefficient during this time interval were: i) nucleation mode: 36.3 % and 3.02 · 10-4 s-1; ii) Aitken mode: 30.4 % and 2.37 · 10-4 s-1 and iii) accumulation mode: 22.4 % and 1.77 · 10-4 s-1. The range of particle sizes that is less efficiently scavenged by snowfall was observed between 400 and 600 nm. When analyzing the whole snow event, an increase of PNC was observed. Two possible explanations underlie this behaviour: it could be caused by changes in air masses or by the resuspension of aerosol particles scavenged by snowflakes upon reaching the ground. A clear relationship was observed between Ca2+, SO42- and NO3- concentrations of aerosol particles before the snow event and the concentrations registered in the melted snow-water. The largest and smallest changes in aerosol number concentrations were caused by snowflakes of 3 and 6 mm in diameter, respectively. The particle size distributions (PSD) were fitted to log-normal distributions and the parameters were compared before and after snowfall.

Real-time measurements of particles in the 15-736 nm range have been obtained by a Scanning Mobility Particle Sizer to characterize the evolution of particle size distribution and new particle formation (NPF) events in an urban background area. The annual, weekly and diurnal variations of the modal (nucleation (Nnuc), Aitken (NAit) and accumulation (Nacc)) particle concentrations were characterised. The NAit and Nacc registered their maximums in cold months during rush hours, in the morning (0600-0900 UTC) and in the afternoon (1700-2000 UTC), while the maximums for Nnuc were reached in warm months during midday hours. NAit, Nacc and Ntotal showed a significant negative correlation with wind speed and a different relationship with the planetary boundary layer (PBL) height by periods. In the warm period, a positive significant correlation between PBL and Nnuc was registered, indicating that the higher dispersion promoted by a high PBL causes favourable conditions for the occurrence of NPF events (a low polluted atmosphere). NPF processes are one of the main sources of ultrafine particles (<100 nm) in the warm period. After a visual-based classification, 45 NPF events of type Ia (strong and with a good confidence level) were identified and analysed, occurring primarily between 1100 and 1500 UTC, mainly in spring and summer. In addition, a two-step method was developed for identifying NPF events: cluster analysis followed by discriminant analysis. The application of discriminant analysis to one of the clusters, grouping 93 days, enabled us to identify 55 of the 56 NPF events days included in the cluster. This method is a valuable tool for identifying NPF events quickly and effectively.

The radiative forcing before and after rain events was studied between 12 February 2016 and 14 March 2017 in Leon, Spain. For this purpose, the radiative forcing fluxes were calculated using the Radiative Transfer Model Global Atmospheric ModEl (RTM GAME). After the application of a set of selection criteria (based on the availability of AERONET data, rain characteristics and lightning maps), 16 stratiform rain events were identified, concentrated in spring and winter, and 15 convective rain events were found concentrated in spring and summer. Rainfall events were grouped according to the atmospheric forcing (Delta F-ATM) before rain: "low" or "high" (lower or higher than 30 W m(-2)). The threshold has been set at this value because it is the mean Delta F-ATM of all the selected events before rain. There were significant statistical differences between stratiform and convective events in rain duration, mean raindrop diameter and parameters a and b of radar reflectivity Z and rainfall intensity R relationship (Z = a R-b). When comparing "low" and "high" groups, raindrop diameter was similar in stratiform (0.51 +/- 0.08 vs 0.48 +/- 0.12 mm) and convective events (0.96 +/- 0.98 vs 0.83 +/- 0.63 mm), registering higher values for the latter. In stratiform events, the rain scavenging effect on aerosol particles is clearly observed in the "high" group with a decrease of radiative forcing of -27.0 +/- 25.3%, and to a lesser extent, in the "low" group, probably because of a lower aerosol load in the atmosphere. In stratiform events, the mode of the raindrop size gamma distribution presented statistical differences between "low" (0.25 +/- 0.13 mm) and "high" (0.35 +/- 0.05 mm) groups. We claim that this points towards a relationship between radiative forcing before rain and the specific characteristics of rainfall measured at ground level. This study increases our knowledge on the important role of rainwater as a clean agent of the atmosphere and its impact on climate (through radiative forcing).

Black carbon (BC) aerosol characteristics have been analysed from January 2016 to March 2017 in an urban background area (Leon, Spain), located in a coal-mining region, where this fuel is commonly used. The monthly and seasonal variations of BC and source contributions were examined. The mean equivalent BC concentration (eBC) during cold and warm months were 1.0 & PLUSMN; 0.5 and 0.6 & PLUSMN; 0.2 mu gm(-3), respectively. eBC can be further divided into eBC(ff) (eBC from liquid fossil fuel) and eBC(bb+cc) (eBC from biomass burning plus coal combustion), with mean annual values of 0.6 & PLUSMN; 0.3 and 0.3 & PLUSMN; 0.3 mu gm(-3) (cold months) and 0.4 & PLUSMN; 0.2 mu gm(-3) and 0.1 & PLUSMN; 0.1 mu g m(-3) (warm months), respectively. The eBC obtained from the aethalometer and the elemental carbon (EC) quantified through a Thermal Optical Transmittance method presented a significant strong positive correlation in both warm (r = 0.82) and cold (r = 0.88) periods. A mass absorption cross-section (MAC) of 4.46 & PLUSMN; 0.16 between two techniques has been obtained. In the cold period, a multilinear regression model to decouple eBC(bb) from eBC(cc) was established (r(2) = 0.85) based on two tracers: arsenic for coal combustion and potassium for biomass burning. The model application enabled us to distinguish the contributions to eBC(bb+cc) (as a function of the variance explained by the tracers) in the cold period: 74% from biomass burning and 26% from coal combustion. The highest eBC(cc) concentration was estimated for December 2016 and January 2017 (0.18 mu g m(-3)). This result was supported by the Absorption Angstrom Exponent (AAE), which showed the maximum value in January 2017 (1.43 & PLUSMN; 0.37) due to the high biomass burning and coal combustion contributions.

Domestic chores are an important part of the household's daily routine and can contribute significantly to personal exposure. In this study, the particulate mass and number concentrations were assessed when using two irons (steam iron and steam iron with boiler) under distinct conditions (minimum ventilation and indoor doors open) and in the background air. The detailed PM10 chemical characterisation included organic and elemental carbon, elements and organic speciation. Particle number emission rates ranged from 8.1 +/- 0.09 x 10(11) to 15 +/- 3.5 x 10(11) particles min(-1). Ratios of peak to background levels indicate that ironing can elevate the ultrafine particle number concentrations by a factor ranging from 35 to 194. PM10 emission rates from steam iron, under minimum ventilation conditions (6.6 +/- 1.4 mu g s(-1)), were higher than those from steam iron with the doors open (1.9 +/- 1.6 mu g s(-1)). The highest particle number and mass emission rates were recorded when the steam iron with boiler was used. Regarding the chemical composition of particles, elemental carbon and strontium were only detected during ironing. Bromide concentrations increased noticeably over background levels (9-51 times) during ironing. PM10 samples encompassed a wide range of organic compounds, part of which can be attributed to the handling of textiles and the use of detergents, fabric softeners, cosmetics and personal care products. Substances emitted by volatilisation or shedding of textile fibres, or due to handling, can contribute to human exposure through inhalation. The cancer risks associated with inhalation of metals and PAH were found to be negligible.

Bioaerosols play a major role in the plant life of ecosystems. In addition, they have a profound impact on human health, since they may cause lung diseases or allergies. The key objective of this study is to assess the below cloud scavenging effect of rainfall on pollen concentration. The analysis is based on a sampling carried out in León, Spain, between 2015 and 2018. The rainfall variables and the pollen concentrations have been obtained with a disdrometer and a volumetric Hirst type spore-trap, respectively. In order to evaluate the scavenging, three parameters have been calculated: scavenging efficiency (through the concentration-weighted average (%ΔC)), the scavenging coefficient (λ) and the percentage of events with a decrease in pollen concentration (%ES) also called events with effective scavenging. 71% of rain events presented an effective scavenging that affected all types of pollen. The %ΔC mean value of total pollen was 24 ± 18% (positive values indicate an effective scavenging) and the types of pollen with the highest values were Castanea and Cupressaceae (71 and 40%, respectively). A linear model (R2 = 0.94) to estimate the pollen concentration after rain was built with variables such as pollen concentration before rain and other variables from a weather station and a disdrometer. Furthermore, we have shown the possibility of knowing in real time the probable Cupressaceae pollen concentration, from the initial pollen concentration and the physical parameters of rain (such as raindrop size, rain intensity or volume swept by raindrops in their falling path).

This paper studies the below-cloud scavenging caused by precipitation on ultrafine and accumulation modes, as well as the role of the different raindrop sizes in an urban environment. The equipment used to measure aerosol particles and raindrop variables includes a scanning mobility particle sizer spectrometer-SMPS and a Laser Precipitation Monitor (LPM), respectively. An analysis of the scavenging efficiency and the scavenging coefficient (A) by modes and rain intensities was carried out. The main results observed have been: i) the nucleation (between 14 and 30 nm), Aitken (between 30 and 100 nm), accumulation 1 (between 100 and 300) and accumulation 2 (between 300 and 1000 nm) modes presented a scavenging efficiency of 15, 4, 22 and 21%, respectively; ii) events with rain intensities between 1 and 3 mm h-1 caused less scavenging in all modes; iii) raindrop sizes between 1.25 and 3.5 mm scavenged mainly particle sizes between 70 and 250 nm. Lower scavenging was observed on particle sizes >300 nm, and particle sizes >600 nm were only scavenged by raindrop sizes >4.75 mm; iv) the respirable fraction before and after the rain events presented a statically significant decrease of -35%. The combination in this study of SMPS and disdrometer measurements has resulted in a more detailed characterization of the influence of this process on the submicrometer aerosol fraction, noting that below-cloud scavenging is one of the main removal pathways for submicrometer aerosol particles. This study thus contributes to improving the current state of knowledge of below-cloud scavenging.

A one-year aerosol sampling campaign, between 2016 and 2017, was conducted in a suburban area of León city, Spain. An association between the Positive Matrix Factorization (PMF) results and air masses through circulation weather types was carried out, through the construction of linear models from the PM10 concentrations and its chemical composition. The aerosol sources, identified by PMF six-factor solution, were: traffic (29%), aged sea salt (26%), secondary aerosols (16%), dust (13%), marine aerosol (7%) and biomass burning (3%). Traffic and secondary factors showed the highest PM10 contribution in the hybrid cyclonic types with wind component from the first and second quadrant. Anticyclonic types with wind component from the first quadrant exhibited high values of secondary, aged sea salt and dust factors. The highest contributions of the dust factor were also associated with northerly types. The linear models built for estimating the source apportionment of PM10, from aerosol chemical composition and geostrophic flow, showed positive coefficients for: westerly flows (WF) in marine factor, southerly flows (SF) in secondary and traffic factors, and shear southerly vorticities (ZS) in dust factor. Negative dependences were observed for ZS in aged sea salt factor and for SF in dust factor. The PM10 mass concentration calculated by the linear models and by the PMF model were strongly correlated. This can be very useful to determine the contribution of a specific source to PM10 in León, only by knowing some meteorological and chemical variables.

The daily evolution of seventeen sugar compounds (seven saccharides, seven alcohol-saccharides and three anhydrosaccharides) in atmospheric aerosol samples collected between 9 March 2016 and 14 March 2017 was studied in Le ' on (Spain). The main links between the concentration of sugar compounds and various chemical species, pollen, fungal spores and meteorological conditions were investigated. The results showed that, in spring, when high levels of metabolic activity of the plants occur and temperatures increase, glucose, sucrose, 2-methyl-erithritol, mannitol, arabitol and inositol, are significantly correlated with airborne pollen concentrations. Between spring and autumn, Alternaria air concentrations are significantly correlated with temperatures, arabitol and sorbitol + adonitol concentrations. Furthermore, during rainy days, Alternaria is also correlated with mannitol. In autumn, lower temperatures cause an increase in the concentrations of levoglucosan, mannosan and galactosan, probably due to the increased use of domestic heating devices. These anhydrosugars and arabinose, fructose and glucose, are significantly correlated with K, NO3- , EC, OC, Cu, Zn, Se, Pb, V and Ni, while mannosan also correlates with As, showing that these anhydrosaccharides can be emitted from different anthropogenic sources. Precipitation causes an increase in glucose and sucrose concentrations, due to the break of pollen particles that produce hundreds of fine size particles. Besides, precipitation causes an increase in arabitol concentrations, due to the release and growth of fungi.

Beauty salons are considered occupational environments where the staff personnel and clients are exposed to high levels of airborne pollutants. In this study, air quality monitoring was carried out in Le ' on, Spain. Temperature, relative humidity, CO2, CO and particulate matter were continuously monitored inside and outside areas of the salon. PM10 was simultaneously collected onto filters. Volatile organic compounds and carbonyls were sampled inside the salon. Indoor PM10 concentrations exceeded the recommended 24-h guideline of 50 mu g m-3. A detailed PM10 chemical characterisation included organic and elemental carbon, trace elements, watersoluble ions and organic speciation. Indoor vs outdoor ratios of PM10, as well as the majority of PM10-bound organic compounds, were >1. During work periods, organic carbon accounted for 29.5 +/- 1.8 and 16.2 +/- 4.5 % wt. of PM10 indoors and outdoors, respectively. More than 200 individual organic compounds were detected in the PM10, including aliphatic alcohols, fatty acids, phthalates, glycerol derivatives, fatty acid alkyl esters, phenolic compounds, alkanes and polycyclic aromatic hydrocarbons, among others. Many of them are part of formulations widely used in hair cosmetics, personal care and cleaning products. Inadequate ventilation, working activities and the use of specific products can greatly contribute to high indoor levels of organic air pollutants. Formaldehyde revealed a cancer risk of 4.6 x 10-6, higher than the guideline level, suggesting a "possible risk" for workers. The total excess lifetime cancer risk from exposure to multiple compounds was 9.3 x 10-6, which is lower than the acceptable risk, but not negligible.

Vacuum cleaning can be a household source of particulate matter (PM) both from the vacuum motor and from settled dust resuspension. Despite the evidence of this contribution to PM levels indoors, the effect of this source on PM composition is still unknown. In this study, four vacuum cleaners (washable filter bag less, wet, bagged and HEPA filter equipped robot) were tested for the emission rate of particulate mass and number. The detailed PM chemical characterisation included organic and elemental carbon, metals and organic speciation. PM10 emission rates from bagged vacuum operation were much higher (207 +/- 99.0 mu g min(-1)) compared with the ones obtained from wet (86.1 +/- 16.9 mu g min(-1)) and washable filter bag less vacuums (75.4 +/- 7.89 mu g min(-1)). Particle (8-322 nm) number emission rates ranged from 5.29 x 10(11) (washable filter bag less vacuum) to 21.2 x 10(11) (wet vacuum) particles min(-1). Ratios of peak to background levels indicate that vacuuming can elevate the ultrafine particle number concentrations by a factor ranging from 4 to 61. No increase in PM mass or number concentrations was observed during the HEPA filter equipped vacuum operation. The increase in copper and elemental carbon PM10 contents during vacuuming suggested motor emissions. Organic compounds in PM10 included alkanes, PAHs, saccharides, phenolics, alcohols, acids, among others. However, it was not possible to establish a relationship between these compounds and vacuuming due to the vast array of possible household sources. The cancer risks associated with metals and PAH inhalation were negligible.

A one-year campaign of joint sampling of aerosols and precipitation, carried out in León, Spain, allowed to study the impact of two special events that affected the air quality in the north of the country, on rainfall in the city: a period with wildfires and a Saharan dust intrusion. The wildfires that occurred in northern Portugal and northwestern Spain in August 2016 affected the chemistry of rainfall on 15 August 2016, causing an increase in concentrations of NH4+, Na+, Cl−, K+, Mg2+, Ca2+, SO42− and NO3− and in the concentrations of organic acids, which was reflected in the levels of soluble and insoluble organic carbon. This led to acidification of rainwater (pH = 4.8). The second precipitation event was registered between 11 and 14 February 2017, during which the rainwater was collected in four daily fractions (P1, P2, P3 and P4). The rain sample of 12 February (P2) coincided with a Saharan dust intrusion that reached northern Iberia that day. The chemical composition of P2 showed an increase in the Ca2+ (>800%), Mg2+ (71%), Cl− (62%), and SO42− (33%) concentrations, with respect to P1. The input of crustal elements to the atmosphere helped to neutralize the P2 rainwater, causing pH values higher than 6.5. Once the dust intrusion left the north of the Peninsula, the composition of rainwater P3 and P4 revealed a mixture of marine contribution with local anthropogenic emissions, as well as a decrease in ion concentrations and conductivity, and an increase in pH values.

A one-year study was carried out in Leon, Spain, in order to characterize physically and chemically the precipitation. With the aim of studying the scavenging process of atmospheric pollutants, scavenging ratio and removal coefficients were calculated through physical parameters of raindrops (obtained by disdrometer data) and through chemical properties of aerosols. Finally, linear models for the prediction of the chemical composition of rainwater and the efficiency of the removal effect were established. In general, the rainwater was dominated by NH4+ > SO42- > NO3- in all seasons. Higher ion concentrations and conductivity and lowest pH were observed in summer, due to the low volume of rain. In winter, the high values of Na+ and Cl- in the rainwater showed the contribution from marine sources, while in summer the high concentrations of Ca2+, Mg2+, SO42-, NH4+ and NO3- reflected the contribution from both crustal and anthropogenic sources. The linear models revealed that the amount of dissolved organic carbon and of the water-soluble ions in rain samples, Ca2+, SO42-, NO3-, increases with the volume swept by the falling drops. Insoluble carbon fraction has a negative dependence with the volume swept and positive with the diameter of the raindrop. Removal coefficients are affected by the concentration in the air of each species before precipitation, the duration of the event and the time elapsed between two precipitation events. (c) 2020 Elsevier Ltd. All rights reserved.

A sampling campaign was conducted in the Liberdade Avenue tunnel (Braga, Portugal) during a week (with 56,000 vehicles) to monitor black carbon (eBC-equivalent black carbon) by means of an Aethalometer AE-31, and gaseous pollutants (CO2, CO, NOx). Inside the tunnel, the mean eBC mass concentration was 21 ± 10 μg m-3, reaching a maximum hourly value of 49.0 μg m-3. An hourly and weekday-weekend study was carried out. Regarding the Absorption Ångström exponent (AAE), a mean value of 0.97 ± 0.10 was obtained, for a source of practically pure traffic. There was a positive significant correlation between eBC and the number of light vehicles (r = 0.47; p < 0.001) and between eBC and the gaseous emissions: CO (r = 0.67; p < 0.001), CO2 (r = 0.71; p < 0.001), NO (r = 0.63; p < 0.001) and NO2 (r = 0.70; p < 0.001). The mean black carbon emission factors (EFBC) inside the tunnel were 0.31 ± 0.08 g (kg fuel)-1 and 0.11 ± 0.08 mg veh-1 km-1, similar to those found in other studies for gasoline and diesel vehicles in road tunnels.

A short but exhaustive air sampling campaign was conducted in a university cafeteria, an occupational environmental not yet studied. Carbonyls and volatile organic compounds were collected by passive diffusion samplers. Temperature, relative humidity, CO2, CO and particulate matter were continuously monitored indoors and outdoors. Simultaneous PM10 sampling with high and low volume instruments, equipped with quartz and Teflon fillers, respectively, was performed during working hours and at night. The quartz filters were analysed for their carbonaceous content by a thermo-optical technique and organic constituents by GC-MS. Water-soluble ions and elements were analysed in the Teflon filters by ion chromatography and PIXE, respectively. Low air change rates (0.31-1.5 h(-1)) and infiltration factors of 0.14, for both PM2.5 and PM10, indicate poor ventilation conditions. Concentrations of both gaseous pollutants and particulate matter were much higher in the cafeteria than outdoors, showing strong variations throughout the day depending on occupancy and activities. The average concentration of indoor-generated PM10 was estimated to be 32 mu g m(-3). Organic compounds in PM10, included alkanes, PAHs, saccharides, phenolics, alcohols, acids, alkyl esters, triterpenoids, sterols, among others. The complex particle composition reveals the multiplicity of sources, formation reactions and removal processes, not yet fully known, and suggests the contribution from dust resuspension, abrasion and off-gassing of building materials, cooking emissions, tobacco smoke, and several consumer products. Many compounds are in the list of ingredients of personal care products, pesticides, plasticisers, flame retardants and psychoactive drugs. The inhalation cancer risks of metals and PAHs were found to be negligible.

The incomplete wood combustion in appliances operated in batch mode is a recognised source of both in- and outdoor airborne pollutants, especially particulate matter (PM). Data on pollutant levels and PM characteristics in households with wood burning devices in developed countries are scarce with most studies describing stove change out programmes or other intervention measures. The aim of the present study was to simultaneously evaluate indoor and outdoor concentrations of CO, CO2 and PM10 during the operation of wood burning appliances (open fireplace and woodstove) in unoccupied rural households. PM10 samples were analysed for water soluble inorganic ions, major and trace elements, organic carbon (OC), elemental carbon (EC), and detailed organic speciation. The CO 8-hour average concentrations did not exceed the protection limit despite the sharp increases observed in relation to background levels. During the open fireplace operation, PM10 levels rose up 12 times compared to background concentrations, while the airtight stove resulted in a 2-fold increase. The inhalation cancer risk of particulate bound PAHs in the room equipped with woodstove was estimated to be negligible while the long-term exposure to PAH levels measured in the fireplace room may contribute to the development of cancer. The excess lifetime cancer risk resulting from the partide-bound Cr(VI) exposure during the fireplace and woodstove operation was higher than 1.0 x 10(-6) and 1.0 x 10(-5), respectively. Levoglucosan was one of the most abundant individual species both indoors and outdoors. This study underlines air pollution hazards and risks arising from the operation of traditional wood burning appliances. (C) 2019 Elsevier B.V. All rights reserved.