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.

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.

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.

Determination of low 137Cs concentration in the atmosphere due to Chernobyl contaminated forest-wood burning.

The determination procedure of low 137Cs concentrations in air using γ-spectrometry is essential wherever the net counts are smaller than the background of the spectrum. Such measurements have performed in April 2020 during the Chernobyl wildfires period. A significant event recorded in Thessaloniki's atmosphere during April 12, 2020, with 25.7 ± 0.7 µBq m-3 of 137Cs, was measured. Besides, a minor incident with a lower 137Cs concentration of 9.6 ± 0.8 µBq m-3 has occurred on April 21, 2020. The above results resemble to a previous one noticed during winter 2013, when signals up to 12.1 ± 0.8 µBq m-3 of 137Cs detected in the atmosphere, due to extensive use of 137Cs contaminated wood for residential heating. The results obtained demonstrate that no radiation hazard rose for the general public due to inhalation of the 137Cs in the air of Thessaloniki, Greece. Moreover, the residence time of the aerosol-bound 137Cs has estimated. The data presented are useful for basic simulation-inputs and comparison with global atmospheric models, which also discussed after comparison with the back trajectories predicted by the NOAA-HYSPLIT model.

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.

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.

Polybrominated diphenyl ethers (PBDEs) in background air around the Aegean: implications for phase partitioning and size distribution.

The occurrence and atmospheric behavior of tri- to deca-polybrominated diphenyl ethers (PBDEs) were investigated during a 2-week campaign concurrently conducted in July 2012 at four background sites around the Aegean Sea. The study focused on the gas/particle (G/P) partitioning at three sites (Ag. Paraskevi/central Greece/suburban, Finokalia/southern Greece/remote coastal, and Urla/Turkey/rural coastal) and on the size distribution at two sites (Neochorouda/northern Greece/rural inland and Finokalia/southern Greece/remote coastal). The lowest mean total (G + P) concentrations of ∑7PBDE (BDE-28, BDE-47, BDE-66, BDE-99, BDE-100, BDE-153, BDE-154) and BDE-209 (0.81 and 0.95 pg m-3, respectively) were found at the remote site Finokalia. Partitioning coefficients, K P, were calculated, and their linear relationships with ambient temperature and the physicochemical properties of the analyzed PBDE congeners, i.e., the subcooled liquid pressure (P L°) and the octanol-air partition coefficient (K OA), were investigated. The equilibrium adsorption (P L°-based) and absorption (K OA-based) models, as well as a steady-state absorption model including an equilibrium and a non-equilibrium term, both being functions of log K OA, were used to predict the fraction Φ of PBDEs associated with the particle phase. The steady-state model proved to be superior to predict G/P partitioning of BDE-209. The distribution of particle-bound PBDEs across size fractions < 0.95, 0.95-1.5, 1.5-3.0, 3.0-7.2, and > 7.2 µm indicated a positive correlation between the mass median aerodynamic diameter and log P L° for the less brominated congeners, whereas a negative correlation was observed for the high brominated congeners. The potential source regions of PBDEs were acknowledged as a combination of long-range transport with short-distance sources.

Toxic organic substances and marker compounds in size-segregated urban particulate matter - Implications for involvement in the in vitro bioactivity of the extractable organic matter.

Toxic organic substances and polar organic marker compounds, i.e. polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and their nitro-derivatives (N-PAHs), as well as dicarboxylic acids (DCAs) and sugars/sugar anhydrites (S/SAs) were analyzed in size-segregated PM samples (<0.49, 0.49-0.97, 0.97-3 and >3 µm) collected at two urban sites (urban traffic and urban background) during the cold and the warm season. The potential associations between the organic PM determinants and the adverse cellular effects (i.e. cytotoxicity, genotoxicity, DNA damage, oxidative DNA adduct formation, and inflammatory response) induced by the extractable organic matter (EOM) of PM, previously measured in Velali et al. (2016b), were investigated by bivariate correlations and Principal Component Analysis (PCA). Partial Least Square regression analysis (PLS) was also employed in order to identify the chemical classes mainly involved in the EOM-induced toxicological endpoints in the various particle size fractions. Results indicated that particle size range <0.49 µm was the major carrier of PM mass and organic compounds at both sites. All toxic organic compounds exhibited higher concentrations at the urban traffic site, except PCBs and OCPs that did not exhibit intra-urban variations. Conversely, wintertime levels of levoglucosan were significantly higher at the urban background site as a result of residential biomass burning. The PLS regression analysis allowed quite good prediction of the EOM-induced cytotoxicity and genotoxicity based on the determined organic chemical classes, particularly for the finest size fraction of PM. Nevertheless, it is expected that other chemical constituents, not determined here, also contribute to the measured toxicological responses.

Legacy and novel brominated flame retardants in interior car dust - Implications for human exposure.

Brominated flame retardants (BFRs) are organobromine compounds with an inhibitory effect on combustion chemistry tending to reduce the flammability of products. Concerns about health effects and environmental threats have led to phase-out or restrictions in the use of Penta-, Octa- and Deca-BDE technical formulations, increasing the demand for Novel BFRs (NBFRs) as replacements for the banned formulations. This study examined the occurrence of legacy and NBFRs in the dust from the interior of private cars in Thessaloniki, Greece, aged from 1 to 19 years with variable origin and characteristics. The determinants included 20 Polybrominated Diphenyl Ethers (PBDEs) (Di-to Deca-BDEs), four NBFRs such as Decabromodiphenylethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), three isomers of hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA). The concentrations of ∑20PBDE ranged from 132 to 54,666 ng g-1 being dominated by BDE-209. The concentrations of ∑4NBFRs ranged from 48 to 7626 ng g-1 and were dominated by DBDPE, the major substitute of BDE-209. HBCDs ranged between <5 and 1745 ng g-1, with alpha-HBCD being the most prevalent isomer Finally, the concentrations of TBBPA varied from <10 to 1064 ng g-1. The concentration levels and composition profiles of BFRs were investigated in relation to the characteristics of cars, such as year of manufacture, country of origin, and interior equipment (type of car seats, electronic and electrical components, ventilation, etc.). The average daily intakes of selected BFRs (BDE-47, BDE-99, BDE-153, BDE-209, TBB, BTBPE, TBPH, DBDPE, HBCDs and TBBPA) via ingestion and dermal absorption were estimated for adults and toddlers. The potential health risk due to BFRs was found to be several orders of magnitude lower than their corresponding reference dose (RfD) values.

New insight into the distribution pattern, levels, and risk diagnosis of FRs in indoor and outdoor air at low- and high-altitude zones of Pakistan: Implications for sources and exposure.

Data regarding flame retardants (FRs) in indoor and outdoor air and their exposure to population are scarce and especially unknown in the case of Pakistan. The current study was designed to probe FR concentrations and distribution pattern in indoor and outdoor air at different altitudinal zones (DAZs) of Pakistan with special emphasis on their risk to the exposed population. In this study, passive air samplers for the purpose of FR deposition were deployed in indoor and outdoor air at the industrial, rural, and background/colder zones/sites. All the indoor and outdoor air samples collected from DAZs were analyzed for the target FRs (9.30-472.30 pg/m3), showing a decreasing trend as follows: ∑NBFRs > ∑PBDEs > ∑DP. However, significant correlations among FRs in the indoor and outdoor air at DAZs signified a similar source of FR origin that is used in different consumer goods. Furthermore, air mass trajectories revealed that movement of air over industrial area sources influenced concentrations of FRs at rural sites. The FR concentrations, estimated daily intake (EDI) and the hazard quotient (HQ), were recorded to be higher in toddlers than those in adults. In addition, indoor air samples showed higher FR levels, EDI and HQ, than outdoor air samples. An elevated FR concentrations and their prevalent exposure risks were recorded in the industrial zones followed by rural and background zones. The HQ for BDE-47 and BDE-99 in the indoor and outdoor air samples at different industrial and rural sites were recorded to be >1 in toddlers and adults, this further warrants a health risk in the population. However, FR investigation in indoor and outdoor air samples will provide a baseline data in Pakistan to take further steps by the government and agencies for its implementations.

Cytotoxicity and genotoxicity induced in vitro by solvent-extractable organic matter of size-segregated urban particulate matter.

Three organic fractions of different polarity, including a non polar organic fraction (NPOF), a moderately polar organic fraction (MPOF), and a polar organic fraction (POF) were obtained from size-segregated (<0.49, 0.49-0.97, 0.97-3 and >3 µm) urban particulate matter (PM) samples, and tested for cytotoxicity and genotoxicity using a battery of in vitro assays. The cytotoxicity induced by the organic PM fractions was measured by the mitochondrial dehydrogenase (MTT) cell viability assay applied on MRC-5 human lung epithelial cells. DNA damages were evaluated through the comet assay, determination of the poly(ADP-Ribose) polymerase (PARP) activity, and the oxidative DNA adduct 8-hydroxy-deoxyguanosine (8-OHdG) formation, while pro-inflammatory effects were assessed by determination of the tumor necrosis factor-alpha (TNF-α) mediator release. In addition, the Sister Chromatid Exchange (SCE) inducibility of the solvent-extractable organic matter was measured on human peripheral lymphocyte. Variations of responses were assessed in relation to the polarity (hence the expected composition) of the organic PM fractions, particle size, locality, and season. Organic PM fractions were found to induce rather comparable Cytotoxicity and genotoxicity of PM appeared to be rather independent from the polarity of the extractable organic PM matter (EOM) with POF often being relatively more toxic than NPOF or MPOF. All assays indicated stronger mass-normalized bioactivity for fine than coarse particles peaking in the 0.97-3 and/or the 0.49-0.97 µm size ranges. Nevertheless, the air volume-normalized bioactivity in all assays was highest for the <0.49 µm size range highlighting the important human health risk posed by the inhalation of these quasi-ultrafine particles.

Atmospheric occurrence and gas-particle partitioning of PBDEs at industrial, urban and suburban sites of Thessaloniki, northern Greece: Implications for human health.

Air samples were collected during the cold and the warm period of the year 2012 and 2013 at three sites in the major Thessaloniki area, northern Greece (urban-industrial, urban-traffic and urban-background) in order to evaluate the occurrence, profiles, seasonal variation and gas/particle partitioning of polybrominated diphenyl ethers (PBDEs). The mean total concentrations of particle phase ∑12PBDE in the cold season were 28.7, 19.5 and 3.87 pg m(-3) at the industrial, urban-traffic and urban-background site, respectively, dropping slightly in the warm season (23.7, 17.5 and 3.14 pg m(-3)), respectively. The corresponding levels of gas-phase ∑12PBDE were 14.4, 7.15 and 4.73 pg m(-3) in the cold season and 21.2, 11.1 and 6.27 pg m(-3) in the warm season, respectively. In all samples, BDE-47 and BDE-99 were the dominant congeners. Absorption of PBDEs in the organic matter of particles appeared to drive their gas/particle partitioning, particularly in the cold season. The estimated average outdoor workday inhalation exposure to ∑12PBDE in the cold and the warm period followed the order: industrial site (288 and 299 pg day(-1)) > urban-traffic site (178 and 191 pg day(-1)) > urban-background site (58 and 63 pg day(-1)). The exposures to BDE-47, BDE-99, BDE-153 and ∑3PBDE via inhalation, for children outdoor worker and seniors were several orders of magnitude lower than their corresponding oral RfD values.