Concentrations of volatile organic compounds in vehicular cabin air - Implications to commuter exposure.

In this study, 117 volatile organic compounds (VOCs) were identified and quantified inside passenger cars and buses operating city and intercity routes. The paper presents data for 90 compounds with frequency of detection equal or greater than 50% that belong to various chemical classes. Total VOC concentration (TVOCs) was dominated by alkanes followed by organic acids, alkenes, aromatic hydrocarbons, ketones, aldehydes, sulfides, amines, and phenols, mercaptans, thiophenes. VOCs concentrations were compared between different vehicle types (passenger cars - city buses - intercity buses), fuel type (gasoline - diesel - liquefied petroleum gas (LPG)), and ventilation type (air condition - air recirculation). TVOCs, alkanes, organic acids and sulfides followed the order: diesel cars > LPG cars > gasoline cars. On the contrary, for mercaptans, aromatics, aldehydes, ketones, and phenols the order was: LPG cars > diesel cars > gasoline cars. Excepting ketones that were found to be higher in LPG cars with air recirculation mode, most compounds were higher with exterior air ventilation in both, gasoline cars and diesel buses. Odor pollution, expressed by the odor activity value (OAV) of VOCs, was highest in LPG cars and minimum in gasoline cars. In all vehicle types, mercaptans and aldehydes were the major contributors to odor pollution of the cabin air with lower contributions from organic acids. The total Hazard Quotient (THQ) was less than 1 for bus and car drivers and passengers indicating that adverse health effects are not likely to occur. Cancer risk from the three VOCs following the order naphthalene > benzene > ethylbenzene. For the three VOCs the total carcinogenic risk was within the safe range. The results of this study expand our knowledge of in-vehicle air quality under real commuting conditions and give an insight into the commuters' exposure levels during their normal travel journey.

Size-Resolved Redox Activity and Cytotoxicity of Water-Soluble Urban Atmospheric Particulate Matter: Assessing Contributions from Chemical Components.

Throughout the cold and the warm periods of 2020, chemical and toxicological characterization of the water-soluble fraction of size segregated particulate matter (PM) (<0.49, 0.49−0.95, 0.95−1.5, 1.5−3.0, 3.0−7.2 and >7.2 µm) was conducted in the urban agglomeration of Thessaloniki, northern Greece. Chemical analysis of the water-soluble PM fraction included water-soluble organic carbon (WSOC), humic-like substances (HULIS), and trace elements (V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd and Pb). The bulk (sum of all size fractions) concentrations of HULIS were 2.5 ± 0.5 and 1.2 ± 0.3 µg m−3, for the cold and warm sampling periods, respectively with highest values in the <0.49 µm particle size fraction. The total HULIS-C/WSOC ratio ranged from 17 to 26% for all sampling periods, confirming that HULIS are a significant part of WSOC. The most abundant water-soluble metals were Fe, Zn, Cu, and Mn. The oxidative PM activity was measured abiotically using the dithiothreitol (DTT) assay. In vitro cytotoxic responses were investigated using mitochondrial dehydrogenase (MTT). A significant positive correlation was found between OPmDTT, WSOC, HULIS and the MTT cytotoxicity of PM. Multiple Linear Regression (MLR) showed a good relationship between OPMDTT, HULIS and Cu.

Hazardous organic pollutants in indoor dust from elementary schools and kindergartens in Greece: Implications for children's health.

Children spend a significant portion of their day in school, where they may be exposed to hazardous organic compounds accumulated in indoor dust. The aim of this study was to evaluate the concentrations of major hazardous organic contaminants in dust collected from kindergartens and elementary schools in Northern Greece (n = 20). The sum concentrations of 20 targeted polybrominated diphenyl ether congeners (∑20PBDEs) in dust varied from 58 ng g-1 to 1480 ng g-1, while the sum of 4 novel brominated fire retardants (∑4NBFRs) ranged from 28 ng g-1 to 555 ng g-1. Correspondingly, the sum concentrations of phthalate esters (∑9PAEs) ranged between 265 µg g-1 and 2120 µg g-1, while the sum of organophosphate esters (∑11OPEs) was found between 2890 ng g-1 and 16,100 ng g-1. Finally, the sum concentrations of polycyclic aromatic hydrocarbons (∑16PAHs) were found within in the range 212 ng g-1 and 6960 ng g-1. Exposure to indoor dust contaminant via inhalation, ingestion and dermal absorption was investigated for children and adults (teachers). Carcinogenic and non-carcinogenic risks were also estimated. Children's estimated intakes of individual hazardous chemicals via the three exposure routes, were lower than the available health-based reference values.

Size-dependent in vitro inhalation bioaccessibility of PAHs and O/N PAHs - Implications to inhalation risk assessment.

Size segregated samples (<0.49, 0.49-0.95, 0.95-1.5, 1.5-3.0, 3.0-7.2 and > 7.2 µm) of atmospheric particulate matter (APM) were collected at a traffic site in the urban agglomeration of Thessaloniki, northern Greece, during the cold and the warm period of 2020. The solvent-extractable organic matter was analyzed for selected organic contaminants including polycyclic aromatic hydrocarbons (PAHs), and their nitro- and oxy-derivarives (NPAHs and OPAHs, respectively). Mean concentrations of ∑16PAHs, ∑6NPAHs and ∑10OPAHs associated to total suspended particles (TSP) were 18 ng m-3, 0.2 ng m-3 and 0.9 ng m-3, respectively, in the cold period exhibiting significant decrease (6.4, 0.2 and 0.09 ng m-3, respectively) in the warm period. The major amount of all compounds was found to be associated with the alveolar particle size fraction <0.49 µm. The inhalation bioaccessibility of PAHs and O/N PAHs was measured in vitro using two simulated lung fluids (SLFs), the Gamble's solution (GS) and the artificial lysosomal fluid (ALF). With both SLFs, the derived bioaccessible fractions (BAFs) followed the order PAHs > OPAHs > NPAHs. Although no clear dependence of bioaccessibility on particle size was obtained, increased bioaccessibility of PAHs and PAH derivatives in coarse particles (>7.2 µm) was evident. Bioaccessibility was found to be strongly related to the logKOW and the water solubility of individual compounds hindering limited mobilization of the most hydrophobic and less water-soluble compounds from APM to SLFs. The lifetime cancer risk due to inhalation exposure to bioaccessible PAHs, NPAHs and OPAHs was estimated and compared to those calculated from the particulate concentrations of organic contaminants.

Odor-active volatile organic compounds along the seafront of Thessaloniki, Greece. Implications for sources of nuisance odor.

Volatile organic compounds (VOCs) have long been associated with odor nuisance at urban sites close to emission sources. Sulfur containing volatile organic compounds (VOSCs) in particular, constitute a major category of malodorous compounds since some of them are characterized by intense odor and low odor thresholds. VOSCs have both, anthropogenic and biogenic sources. The purpose of this study was to assess the concentration levels of a variety of VOCs (mercaptans, sulfides, thiophenes, aromatics and aldehydes) along the seafront of the city of Thessaloniki, northern Greece, a city with frequent citizen complaints for nuisance odor. 1-Hour sampling on adsorption tubes was carried out concurrently at 3 sites along the seafront of the city (EAST, CENTER and WEST) three times during the day in winter and summer 2020. VOCs analysis, performed on a Thermal Desorption - Gas Chromatography/Mass Spectroscopy (TD-GC/MS) system. Diurnal and seasonal variations, and correlations with prevailing meteorological conditions were investigated. Concentrations found along the seafront were compared to previous data from inner-city sites affected by urban and/or industrial activities. Most VOCs were found at lower concentrations at the seafront in comparison to inner-city sites demonstrating better air quality. Typical biogenically-deriving VOSCs such as carbonyl sulfide and dimethyl sulfide were found at the seafront either at higher or at similar levels with inner city thus suggesting negligible contribution from biogenic sources. Odor activity values were further calculated and assessed. Odor nuisance at all seafront sites was significantly higher in winter, being in both seasons maximum at the WEST seafront that is closer to port activities, polluted creek estuaries and industrial facilities. Mercaptans were identified as the major contributors to odor pollution followed by aldehydes. The new findings described in this study might contribute to the better understanding of the odor pollution from VOCs at coastal urban sites.

Toxic organic pollutants in Greek house dust: Implications for human exposure and health risk.

Organic contaminants often documented in house dust include mainly chemicals released from construction materials and consumer products and compounds emitted from indoor combustion activities. The occurrence of major chemical classes of toxic organic pollutants, included polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (NPAHs), was for the first time investigated in house dust in Greece. The mean concentrations of ∑16PAHs, ∑20PBDEs, ∑7NPAHs and∑15PCBs in house dust were 4650 ng g-1, 564 ng g-1, 7.52 ng g-1, and 6.29 ng g-1, respectively. Exposure to dust organic contaminants via ingestion, inhalation and dermal absorption was estimated for two age classes (adults and children) and carcinogenic and non-carcinogenic risks were assessed. The hazard index (HI) for adults and children for PBDEs, PCBs, PAHs and NPAHs in all samples was less than 1 suggesting a very low level of concern for all human age group due to exposure to those chemicals. Total carcinogenic risk via the three exposure pathways (ingestion, inhalation and dermal contact) was within the safe range of 10-6 to 10-4.

Inter-laboratory comparison of ED-XRF/PIXE analytical techniques in the elemental analysis of filter-deposited multi-elemental certified reference materials representative of ambient particulate matter.

The quantification of the elemental concentration of ambient particulate matter is a challenging task because the observed elemental loadings are not well above the detection limit for most analytical techniques. Although non-destructive nuclear techniques are widely used for the chemical characterization of ambient aerosol, only one multi-element standard reference filter material that mimics ambient aerosol composition has become recently available in the market. To ensure accuracy, reliability and comparability of instruments performance, multiple reference materials with different elemental mass loadings are necessary. In this study, an intercomparison exercise was performed to evaluate the measurement uncertainty and instruments performance using multi-element dust standard reference samples deposited on PTFE filters. The filter samples, produced by means of dust dispersion, were tested in terms of homogeneity, reproducibility and long-term stability (≈40 months). Eight laboratories participated in the exercise. The evaluation of the results reported by the participants was performed by using two sets of reference values: a) the concentrations reported by the Expert Laboratory, b) the robust average concentrations reported by all participants. Most of the reported on the certificate of analysis elements were efficiently detected in the sample loadings prepared as representative for atmospheric samples by the Expert Laboratory. The average absolute relative difference between the reported and the reference values ranged between 0.1% (Ti) and 33.7% (Cr) (CRM-2584). The participants efficiently detected most of the elements except from the elements with atomic number lower than 16 (i.e. P, Al, Mg). The average absolute percentage difference between the participants results and the assigned value as derived by the expert laboratory was 17.5 ± 18.1% (CRM-2583; Cr, Pb excluded) and 16.7 ± 16.7% (CRM-2584; Cr, P excluded). The average "relative robust standard deviation" of the results reported by all participants was 25.1% (CRM-2583) and 22.8% (CRM-2584).

Mass dose rates of particle-bound organic pollutants in the human respiratory tract: Implications for inhalation exposure and risk estimations.

To date, little is known about the effective doses of airborne particulate matter (PM) and PM-bound hazardous organic components to the human respiratory tract (HRT). In the light of this, here we provide particle mass dose rates (dose per hour of exposure) of PM and a suite of PM-bound hazardous organic compounds in the HRT for two population age groups (adults & children). More specifically, the mass dose rates of PM and PM-bound polycyclic aromatic hydrocarbons (PAHs), nitrated-PAH (NPAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) were estimated at two urban sites using a multiple path particle dosimetry model. We find that, in most cases, the total mass doses are following similar variations across sites and seasons as their ambient total concentrations, however their distribution in the HRT is a function of the particle size distributions and the physiological parameters of each age group. More specifically, the majority of the deposited mass of PM and all the chemical components investigated was accumulated in the upper airways instead of the lungs. We further show that children, due to their different physiology, are more susceptible and receive larger fraction of the total mass doses in the deepest parts of the lungs compared to the adults' group. Comparing the traditional method for estimating the inhalation risk, which is based on the ambient concentration of pollutants, and a modified version using the mass dose in the HRT, we find that the former may overestimate the reported risks. The results presented here provide a novel dataset composed by previously undetermined doses of hazardous airborne particulate organic components in the HRT and demonstrate that alternative health risk estimation approaches may capture some variabilities that are traditionally overlooked.

Commuter exposure to particle-bound polycyclic aromatic hydrocarbons in Thessaloniki, Greece.

Commuters are exposed to high air pollution levels daily, especially in areas with dense traffic. This study examines the commuter's exposure to polycyclic aromatic hydrocarbons (PAHs) in the city of Thessaloniki, Greece, under three different commuting modes: biking, travelling by private car, and riding public transportation means (buses). The study was carried out from 2015 to 2018 including 43 volunteers (15 cyclists, 17 car drivers/passengers, and 11 bus passengers). The personal exposure concentrations to particles smaller than 4-µm aerodynamic diameter (PM4), constituting the respirable fraction of total airborne particles, and the associated PAHs were assessed for each commuting mode during the cold and the warm period of the year. Whereas the exposure of bus and car passengers to in-cabin PM4 were higher in the cold season, the exposure of cyclists exhibited the opposite seasonality. In all commuting modes, exposure to PAHs was higher in the cold season. In both seasons, exposure concentration followed the order: cyclists > bus passengers > car passengers. The carcinogenic and mutagenic potencies of the exposure PAH concentrations were calculated using Benzo[a]pyrene (BaP) carcinogenic and mutagenic equivalency factors. The inhalation cancer risk (ICR) associated to PAHs was further estimated and compared between the different commuting modes. Our data can provide relevant information for transport decision-making and increase environmental awareness for a more rational approach to urban travelling.

Indoor concentrations of PM2.5 and associated water-soluble and labile heavy metal fractions in workplaces: implications for inhalation health risk assessment.

PM2.5 (i.e., particles with aerodynamic diameters less than 2.5 µm) and the associated water-soluble, dissolved, and labile fractions of heavy metals (Cu, Pb, Mn, Ni, Co, Zn, Cr, and Cd) were determined in indoor air of twenty workplaces in Alexandroupolis (Northeastern Greece). PM2.5 concentrations exhibited significant variance across the workplaces ranging from 11.5 µg m-3 up to 276 µg m-3. The water-soluble metal concentrations varied between 0.67 ± 2.52 ng m-3 for Co and 27.8 ± 19.1 ng m-3 for Ni exhibiting large variations among the different workplaces. The water-soluble metal fractions were further treated to obtain the labile metal fraction (by binding with Chelex 100-chelating resin) that might represent a higher potential for bioaccessibility than the total water-soluble fraction. The largest labile (chelexed) fractions (48-67% of the corresponding water-soluble concentrations) were found for Cd, Mn, Cu, and Ni, while the labile fractions of Pb, Cr, Co, and Zn were relatively lower (34-42% of the corresponding water-soluble concentrations). Water-soluble and labile concentrations of heavy metals were further used to calculate cancer and non-cancer risks via inhalation of the PM2.5-bound metals. To our knowledge, this is the first study estimating the health risks due to the inhalation of water-soluble and labile metal fractions bound to indoor PM.

Spatiotemporal variation of odor-active VOCs in Thessaloniki, Greece: implications for impacts from industrial activities.

A yearlong study of odor-active VOCs was carried out in the northwestern district of the city of Thessaloniki, Greece, which is in close vicinity to a large-scale petroleum refining and petrochemical process complex, as well as other activities such as power generation from natural gas burning and liquefied petroleum gas (LPG) shipping. Odor nuisance has been a major concern in the district often rising complaints from local residents. A total of 312 samples of VOCs were collected at three sites during a 12-month period (May 2018-May 2019) on thermal desorption cartridges and analyzed by thermal desorption gas chromatography interfaced with mass selective detector (TD-CG/MS). Fifty-five odorous compounds including 8 mercaptans, 5 thiophenes, 7 sulfides, 22 aromatics, and 13 aldehydes were measured, and their spatial and temporal variations were assessed. Concentrations found were compared with those measured at other sites within the urban agglomeration Thessaloniki. Correlations with meteorological conditions (ambient temperature, relative humidity, wind direction/speed, and frequency/depth of temperature inversions) were investigated. Bivariate polar plots of the concentrations of Σ8Mercaptans, Σ5Thiophenes, Σ7Sulfides, Σ22Aromatics, and Σ13Aldehydes as a function of wind speed and wind direction were constructed for source localization.

Morphological and geochemical characterization of the particulate deposits and the black crust from the Triumphal Arch of Galerius in Thessaloniki, Greece: Implications for deterioration assessment.

In the present study, 12 particulate deposits and one black crust sample were collected from the Triumphal Arch of Galerius in Thessaloniki, Greece and characterized by employing a multi-analytical approach including chemical analysis of trace elements and ionic species, as well as scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS) to gain information about the micromorphology and the chemical composition in terms of major elements. In addition, one unaltered marble sample, e.g. the marble directly beneath the black crust, was examined by microscopic and isotopic methods to characterize its texture and origin. The particulate deposits consist mainly of calcite, quartz, aluminosilicate mineral phases, several metal oxides of Fe, Ti and FeCr with Mn and Cu. They also include bird droppings enriched in P and S, and plant residuals. The black crust has a similar mineral composition and is dominated by calcite with traces of quartz and halite, whereas P- and S-enriched particles are common. In both cases a coating on calcite crystals with a thin crust rich in Ca, Ba and S is commonly observed and is attributed to the previous conservation works. Concentrations of As, Zn, Pb, Cu, nitrate, sulfate, chloride and acetate were significantly higher in particle deposits than in the black crust as opposed to Fe, Co, Ni and formates that were at the same level. The traffic-related trace elements Pb, Zn and Cu and most ions were significantly higher in low-altitude deposition samples. The current marble deterioration is induced by a combination of factors, including mechanical, physico-chemical and biological processes.

Perfluoroalkyl substances (PFASs) in air-conditioner filter dust of indoor microenvironments in Greece: Implications for exposure.

The occurrence of perfluoroalkyl substances (PFASs) was for the first time investigated in various working microenvironments (internet cafes, electronics shops, coffee shops, restaurants, etc.) in Thessaloniki, Greece, using the dust trapped by central air conditioner (A/C) filters. Perfluorooctane sulfonic acid (PFOS) was found in the range from 16 to 227 ng g-1, however it was detectable in only 30% of samples. On the contrary, perfluorohexanoic acid (PFHxA) was found in 85% of samples in the range from 3.6 to 72.5 ng g-1, while 90-95% of samples exhibited perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDcA) and perfluorododecanoic acid (PFDoDA) in the range from 10-653 ng g-1, 3.2-7.4 ng g-1 and 3.8-13.1 ng g-1, respectively. The PFAS profile varied largely among the different microenvironment categories suggesting different sources. Estimated daily intakes through dust ingestion were calculated.

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

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

Submicron particle number doses in the human respiratory tract: implications for urban traffic and background environments.

The deposition of ambient submicron particles in the different parts of the human respiratory tract (HRT) was, for the first time, estimated for males and females from different age classes (children-adults-seniors) of urban population in the city of Thessaloniki, northern Greece, during the cold and the warm period of the year. Outdoor daily and hourly particle number doses in the different regions of the HRT, i.e., the extra-thoracic (ET), tracheobronchial (TB), and the acinar (AC) regions, were calculated by employing the Multiple-Path Particle Dosimetry (MPPD) model. Because of the absence of information being available for the hygroscopic properties of particles, three different particle hygroscopicity scenarios were considered: (i) non-hygroscopic (i.e., raw model estimations), (ii) nearly hydrophobic, and (iii) hygroscopic particles. When hygroscopic properties were considered, we found a remarkable reduction (up to ~ 55%) in the estimated total particle number doses in comparison to the non-hygroscopic particle scenario. Furthermore, we found that the size distribution pattern of the particle doses within the different parts of the HRT was strongly affected by particles' hygroscopic properties with the non-hygroscopic particle scenario significantly overestimating the particle doses in the sub-100-nm range, while underestimating the doses of larger particles. On the contrary, the deposition density appeared to be negligibly affected by the particles' hygroscopic properties, implying the existence of a possible threshold in the number of particles deposited per airway surface area. Similarly, the lobar particle number deposition fraction was unaffected by the hygroscopic properties of particles, as well as the ambient particle size distribution and the individuals' physiological parameters. The total particle number deposition doses estimated here are within the range of the corresponding values reported for other urban environments. It is hoped that our findings could contribute to better understanding of submicron particle exposure and add to the development of more sufficient methods to evaluate the related health impacts.

In vitro cellular toxicity induced by extractable organic fractions of particles exhausted from urban combustion sources - Role of PAHs.

The bioactivity of the extractable organic matter (EOM) of particulate matter (PM) exhausted from major urban combustion sources, including residential heating installations (wood-burning fireplace and oil-fired boiler) and vehicular exhaust from gasoline and diesel cars), was investigated in vitro by employing multiple complementary cellular and bacterial assays. Cytotoxic responses were investigated by applying the MTT ((3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide)) bioassay and the lactate dehydrogenase (LDH) release bioassay on human lung cells (MRC-5). Sister Chromatids Exchange (SCE) genotoxicity was measured on human peripheral lymphocytes. Lipid peroxidation potential via reactive oxygen species (ROS) was evaluated on E. coli bacterial cells by measuring the malondialdehyde (MDA) end product. Furthermore, the DNA damage induced by the organic PM fractions was evaluated by the reporter (ß-galactosidase) gene expression assay in the bacterial cells, and, by examining the fragmentation of chromosomal DNA on agarose gel electrophoresis. The correlations between the source PM-induced biological endpoints and the PM content in polycyclic aromatic hydrocarbons (PAHs), as typical molecular markers of combustion, were investigated. Fireplace wood smoke particles exhibited by far the highest content in total and carcinogenic PAHs followed by oil boilers, diesel and gasoline emissions. However, in all bioassays, the total EOM-induced toxicity, normalized to PM mass, was highest for diesel cars equipped with Diesel Particle Filter (DPF). No correlation between the toxicological endpoints and the PAHs content was observed suggesting that cytotoxicity and genotoxicity are probably driven by other extractable organic compounds than the commonly measured unsubstituted PAHs. Clearly, further research is needed to elucidate the role of PAHs in the biological effects induced by both, combustion emissions, and ambient air particles.

Legacy and emerging organophosphοrus flame retardants in car dust from Greece: Implications for human exposure.

Organophosphorus flame retardants (PFRs) and emerging PFRs (ePFRs) are two groups of compounds used as replacements for brominated flame retardants (BFRs). They have already been detected in indoor dust (mainly in homes and offices). To date, few studies investigated the occurrence of FRs in car dust and the information of possible health risks is still limited. The present study reports on the investigation of the levels and profiles of eight target PFRs: tris(2-ethylhexyl) phosphate (TEHP), tris(2-chloroethyl) phosphate (TCEP), tris(2-butoxyethyl) phosphate (TBEP), triphenyl phosphate (TPHP), 2-ethylhexyl diphenyl phosphate (EHDPHP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri cresyl phosphate (TCP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and four target ePFRs; 2,2-bis(chloromethyl)propane-1,3-diyltetrakis(2-chloroethyl)bisphosphate (V6), isodecyl diphenyl phosphate (iDDPHP), resorcinol bis(diphenylphosphate) (RDP) and bisphenol A-bis(diphenyl phosphate) (BDP) in car dust from Greece. The samples were collected from the interior of 25 private cars in Thessaloniki, Greece, with different years of manufacture (1997-2015) and continents of origin. After ultrasonic extraction and Florisil fractionation, the PFR analysis was carried out by GC-EI/MS, whereas the ePFRs were analyzed by LC-MS/MS. Levels of Σ8PFRs varied from 2000 to 190,000 ng g-1, with mean and median concentrations of 20,000 and 11,500 ng g-1, respectively. The concentrations of Σ4ePFRs ranged from 44 to 8700 ng g-1, with mean and median values at 1100 and 190 ng g-1, respectively. Estimations of human exposure showed that toddlers are more exposed than adults to both PFRs and ePFRs. Yet, the intake via dust ingestion and dermal absorption was several orders of magnitude lower than the corresponding reference doses.

Study of polar organic compounds in airborne particulate matter of a coastal urban city.

Two classes of polar organic compounds, dicarboxylic acids (DCAs) and sugars/sugar anhydrides (S/SAs), were measured in airborne particulate matter in the area of Thessaloniki, northern Greece. The target compounds were measured simultaneously in two particle fractions PM10 and PM2.5 during cold and warm periods by employing extraction in an ultrasonic bath with a mixture of MeOH/DCM (1:2 v/v), derivatization with BSTFA-TMCS and GC-MS for analysis. At both fractions, phthalic was the predominant carboxylic acid during cold season and a-ketoglutaric acid in warm season, followed by maleic and malic. Levoglucosan was the dominant sugar anhydride during the cold and arabitol during the warm season. In total, the distribution of DCAs seemed to favor the PM2.5 particle fraction, probably due to anthropogenic emissions and photochemical formation. The relative contribution of DCAs to PM2.5 fraction was 0.9-3.2% in cold and 0.9-7.0% in warm period. Regarding S/SAs, levoglucosan was also predominantly distributed in fine particles, with relative contribution to this fraction 0.1-6.3% in cold and <0.65% in warm season, suggesting impact of biomass burning emissions. In contrast, arabitol, fructose, and glucose were mainly found in coarse fraction, possibly due to their biogenic origin. Negative correlation of target compounds with temperature and total solar radiation suggested the contribution of seasonal dependant local sources. Positive relationship with NO and NO2 oxidants and relative humidity showed secondary formation of polar compounds or enhanced gas-to-particle conversion.

Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece.

The Western Macedonian Lignite Center (WMLC) in northwestern Greece is the major lignite center in the Balkans feeding four major power plants of total power exceeding 4 GW. Concentrations of PM10 (i.e., particulate matters with diameters ≤10 µm) are the main concern in the region, and the high levels observed are often attributed to the activities related to power generation. In this study, the contribution of fugitive dust emissions from the opencast lignite mines to the ambient levels of PM10 in the surroundings was estimated by performing chemical mass balance (CMB) receptor modeling. For this purpose, PM10 samples were concurrently collected at four receptor sites located in the periphery of the mine area during the cold and the warm periods of the year (November-December 2011 and August-September 2012), and analyzed for a total of 26 macro- and trace elements and ionic species (sulfate, nitrate, chloride). The robotic chemical mass balance (RCMB) model was employed for source identification/apportionment of PM10 at each receptor site using as inputs the ambient concentrations and the chemical profiles of various sources including the major mine operations, the fly ash escaping the electrostatic filters of the power plants, and other primary and secondary sources. Mean measured PM10 concentrations at the different sites ranged from 38 to 72 µg m-3. The estimated total contribution of mines ranged between 9 and 22% in the cold period increasing to 36-42% in the dry warm period. Other significant sources were vehicular traffic, biomass burning, and secondary sulfate and nitrate aerosol. These results imply that more efficient measures to prevent and suppress fugitive dust emissions from the mines are needed.