Concentrations of selected chemicals in indoor air from Norwegian homes and schools

Effects of environmentally relevant concentration of short-chain chlorinated paraffins on BV2 microglia activation and lipid metabolism, implicating altered neurogenesis

Short-chain chlorinated paraffins (SCCPs), a class of persistent organic pollutants, have been found to cause diverse organ and systemic toxicity. However, little is known about their neurotoxic effects. In this study, we exposed BV2, a mouse microglia cell line, to environmentally relevant concentration of SCCPs (1 μg/L, 10 μg/L, 100 μg/L) for 24 h to investigate their impacts on the nervous system. Our observations revealed that SCCPs induced the activation of BV2 microglia, as indicated by altered morphology, stimulated cell proliferation, enhanced phagocytic and migratory capabilities. Analysis at the mRNA level confirmed the activation status, with the downregulation of TMEM119 and Tgfbr1, and upregulation of Iba1 and CD11b. The upregulated expression of genes such as cenpe, mki67, Axl, APOE and LPL also validated alterations in cell functions. Moreover, BV2 microglia presented an M2 alternative phenotype upon SCCPs exposure, substantiated by the reduction of NF-κB, TNF-α, IL-1β, and the elevation of TGF-β. Additionally, SCCPs caused lipid metabolic changes in BV2 microglia, characterized by the upregulations of long-chain fatty acids and acylcarnitines, reflecting an enhancement of β-oxidation. This aligns with our findings of increased ATP production upon SCCPs exposure. Intriguingly, cell activation coincided with elevated levels of omega-3 polyunsaturated fatty acids. Furthermore, activated microglial medium remarkably altered the proliferation and differentiation of mouse neural stem cells. Collectively, exposure to environmentally relevant concentrations of SCCPs resulted in activation and lipid metabolic alterations in BV2 microglia, potentially impacting neurogenesis. These findings provide valuable insights for further research on the neurotoxic effect of SCCPs.

Face mask as an indicator and shield of human exposure to traditional and novel organophosphate esters

Herein, the trapping effectiveness of N95, filter KN95, medical surgical masks (MSMs), and disposable medical masks (DMMs) against 19 airborne traditional and novel organophosphate esters (OPEs) was evaluated. Laboratory simulations (n = 24 for each type of mask) showed that time-dependent accumulation of ∑19OPEs on the four types of masks ranged between 30.1 and 86.6 ng in 24 h, with the highest and lowest median amounts trapped by the N95 masks (53.3 ng) and DMMs (43.2 ng), respectively. The trapping efficiency of the four types of masks for ∑19OPEs decreased over time from 84 % to 39 % in 24 h, with N95 masks showing the highest median efficiency (70 %). Further, field investigations were conducted in five types of microenvironments (train, hospital, bus, supermarket, and canteen), and an analysis of 200 samples showed that ∑19OPEs were accumulated in the masks with a variable amount from 3.7 to 117 ng/mask. Consistent with the laboratory simulations, the N95 masks (29.0 ng/mask) exhibited the highest hourly median amount of trapped OPEs, followed by the KN95 masks (24.5 ng/mask), MSMSs (17.4 ng/mask), and DMMs (15.8 ng/mask). Triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), and cresyl diphenyl phosphate (CDP) as well as 4-isopropylphenyl diphenyl phosphate (4IPPDPP) and 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP) were the most commonly detected traditional and novel OPEs. Based on the amount of OPEs trapped on the masks, we estimated the concentration of ∑19OPEs in the train microenvironment to be the highest (222 ng/m3), which is approximately 2-5 times higher than that in the other microenvironments. The results of this study prove that masks can effectively protect humans from exposure to OPEs and act as low-cost indicators of indoor contamination.

Physical exercise and persistent organic pollutants

Exposure to the legacy and emerging persistent organic pollutants (POPs) incessantly has become an important threat to individual health, which is closely related to neurodevelopment, endocrine and cardiovascular homeostasis. Exercise, on the other hand, has been consistently shown to improve physical fitness. Whereas associations between traditional air pollutants, exercise and lung function have been thoroughly reviewed, reviews on associations between persistent organic pollutants and exercise are scarce. Hence, a literature review focused on exercise, exposure to POPs, and health risk assessment was performed for studies published from 2004 to 2022. The purpose of this review is to provide an overview of exposure pathways and levels of POPs during exercise, as well as the impact of exercise on health concerns attributable to the redistribution, metabolism, and excretion of POPs in vivo. Therein lies a broader array of exercise benefits, including insulin sensitizing, mitochondrial DNA repair, lipid metabolism and intestinal microecological balance. Physical exercise is conducive to reduce POPs body burden and resistant to health hazards of POPs generally. Besides, individual lipid metabolism condition is a critical factor in evaluating potential link in exercise, POPs and health effects.

Human exposure to short-chain chlorinated paraffins and organophosphate flame retardants in relation to paired multiple sources

In this study, the levels and distributions of short chain chlorinated paraffins (SCCPs) and organophosphate flame retardants (OPFRs) were determined in 10-88 aged human serum/hair and their paired multiple exposure sources, including one-day composite food, drinking water, and house dust. The average concentration of SCCPs and OPFRs were respectively 6313 and 176 ng/g lipid weight (lw) in serum, 1008 and 108 ng/g dry weight (dw) in hair, 1131 and 27.2 ng/g dw in food, not detected and 45.1 ng/L in drinking water, and 2405 and 864 ng/g in house dust. The levels of SCCPs in serum of adults were significantly higher than those of juvenile (Mann-Whitney U test, p < 0.05), whereas gender showed no statistically significant difference in SCCPs and OPFRs levels. In addition, there were significant relationships of OPFR concentrations between serum and drinking water as well as hair and food using the multiple linear regression analysis, whereas no correlation was observed for SCCPs. Based on the estimated daily intake, the major exposure pathway for SCCPs was food, while for OPFRs, it was food and drinking water with three order magnitude safety margin.

Release Mechanism of Short- and Medium-Chain Chlorinated Paraffins from PVC Materials under Thermal Treatment

Chlorinated paraffins (CPs) as plasticizers are massively added to polyvinyl chloride (PVC) products, during whose life cycle CPs can be continuously released especially under thermal stress. In this study, a PVC cable sheath was adopted as a representative kind of PVC material to investigate the release behaviors of short- and medium-chain CPs (SCCPs and MCCPs) under thermal treatment. Release percentages of CPs with increasing temperature followed a Gaussian-like curve. At the unmolten stage of 80 °C, heating for 10 min caused 0.051% of added SCCPs and 0.029% of added MCCPs to be released. At the molten stage of 270 °C, accumulative release rates of SCCPs and MCCPs within 10 min were up to 30 and 14%, respectively. The developed emission model indicated that material-gas partitioning and internal diffusion simultaneously governed the release of CPs. During thermal treatment, the release of CPs could be remarkably affected by the thermal expansion of the PVC material and the formation of breakage and micropores. Congener group profiles of released CPs indicated a slight fractionation effect for SCCPs during the release process. Furthermore, the release risk of CPs from the whole life cycle of PVC products was preliminarily evaluated.

Prenatal exposure to phthalates and polybrominated diphenyl ethers on neonatal health: A birth cohort study in Guangxi, China

Few epidemiological studies have focused on prenatal phthalates (PAEs) and polybrominated diphenyl ethers (PBDEs) exposure to neonatal health in China. This study aimed to assess the associations between prenatal PAEs and PBDEs exposure and neonatal health in Guangxi, a Zhuang autonomous region of China. Concentrations of 4 PAEs metabolites (mPAEs) and 5 PBDEs congeners were measured in the serum of 267 healthy pregnant women. Birth outcomes and clinical data of neonates were collected after delivery. Mono-(2-Ethylhexyl) phthalate (MEHP) (81.52%) and BDE47 (35.21%) were the mPAEs and PBDEs congeners with the highest detection rate in serum. Prenatal exposures to mono-n-butyl phthalate (MBP), MEHP, and ΣmPAEs were negatively associated with birth weight (BW), birth length (BL), and gestational age (GA). Higher exposures to MBP, MEHP, and ΣmPAEs were associated with an increased odds ratio (OR) for low birth weight (LBW), but exposure to BDE28 exhibited the opposite effect. Moreover, higher exposures to MBP, MEHP, ΣmPAEs, BDE99, and ΣPBDEswere associated with an increased OR for premature birth (PTB) (P < 0.05). In contrast to MBP exposure, BDE28 exposure was associated with a higher OR for neonatal jaundice (NNJ) (P < 0.05). The interaction analysis showed a positive interaction between monoethyl phthalate (MEP) and BDE28 on the risk of NNJ and positive interaction between ΣmPAEs and BDE47 on the risk of NNJ. In addition, there are ethnicity-specific associations of prenatal PBDEs exposure with neonatal health in individuals of Zhuang and Han nationalities, and boy neonates were more sensitive to prenatal PBDEs exposure than girl neonates. The results revealed that prenatal exposure to mPAEs and PBDEs might have adverse effects on neonatal development, and the effects might be ethnicity- and sex-specific.

A review of critical residential buildings parameters and activities when investigating indoor air quality and pollutants

Indoor air in residential dwellings can contain a variety of chemicals, sometimes present at concentrations or in combinations which can have a negative impact on human health. Indoor Air Quality (IAQ) surveys are often required to characterize human exposure or to investigate IAQ concerns and complaints. Such surveys should include sufficient contextual information to elucidate sources, pathways, and the magnitude of exposures. The aim of this review was to investigate and describe the parameters that affect IAQ in residential dwellings: building location, layout, and ventilation, finishing materials, occupant activities, and occupant demography. About 180 peer-reviewed articles, published from 01/2013 to 09/2021 (plus some important earlier publications), were reviewed. The importance of the building parameters largely depends on the study objectives and whether the focus is on a specific pollutant or to assess health risk. When considering classical pollutants such as particulate matter (PM) or volatile organic compounds (VOCs), the building parameters can have a significant impact on IAQ, and detailed information of these parameters needs to be reported in each study. Research gaps and suggestions for the future studies together with recommendation of where measurements should be done are also provided.

Simultaneous determination of poly- and perfluoroalkyl substances and organophosphorus flame retardants in serum by ultra-performance liquid chromatography/tandem mass spectrometry

RATIONALE

Poly- and perfluoroalkyl substances (PFASs) and organophosphorus flame retardants (OPFRs) are two types of emerging organic pollutants with potential human health hazards. Here, a rapid and sensitive method was developed for the determination of sixteen PFASs and seven OPFRs in human serum by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS).

METHODS

After optimizing the chromatographic and mass spectrometric conditions, respectively, 100 μL of serum sample was liquid-liquid extracted using 8 mL of methyl tert-butyl ether. The 23 targets were quantified within 8 min. All targets were quantified by the isotope-internal standard method in both negative- and positive-ion mode by UPLC/MS/MS.

RESULTS

The method was validated in terms of sensitivity, linearity, precision, and accuracy. The limit of detection ranged between 0.004 and 0.650 ng/mL. Recoveries ranged from70.0% to 118.9% with a relative standard deviation lower than 20%. The developed method was successfully applied to analyze targeted analytes in human serum samples. A total of 13 of 23 analytes were detected in over 50% of samples.

CONCLUSIONS

A sensitive and rapid method was developed to quantify sixteen PFASs and seven OPFRs in serum. Sensitivity, linearity, recovery, and precision were validated and found to be satisfactory. This method can be a valuable tool for evaluation of exposure to both PFASs and OPFRs with high separation efficiency and sensitivity.

Phthalates in the environment: characteristics, fate and transport, and advanced wastewater treatment technologies

Phthalates are well-known emerging contaminants that harm human health and the environment. Therefore, this review aims to discuss about the occurrence, fate, and phthalates concentration in the various environmental matrices (e.g., aquatic, sediment, soil, and sewage sludge). Hence, it is necessary to treat sources containing phthalates before discharging them to aqueous environment. Various advanced wastewater treatments including adsorption process (e.g., biochar, activated carbon), advanced oxidation processes (e.g., photo-fenton, ozonation, photocatalysis), and biological treatment (membrane bioreactor) have been successfully to address this issue with high removal efficiencies (70-95%). Also, the degradation mechanism was discussed to provide a comprehensive understanding of the phthalate removal for the reader. Additionally, key factors that influenced the phthalates removal efficiency of these technologies were identified and summarized with a view towards pilot-scale and industrial applications.

Associations between phthalic acid esters in house dust and home characteristics/living habits in a rural region of Taiwan

Phthalic acid esters (PAEs) commonly used as plasticizers are distributed ubiquitously in the living environment. We conducted a field study to examine the associations between PAE residue in dust and home characteristics/living habits in 47 rural homes in Taiwan. A questionnaire regarding home characteristics/living habits and composite sampling of house dust were conducted in each participating home. Five PAEs were selected for analysis on gas chromatography-mass spectrometry with the limits of quantification being 0.5 ng/g or lower. Uni- and multivariate linear regression analyses were performed for examining the associations. The five PAEs were prevalently detected from the samples, and the concentrations were below 1000 ng/g; di(2-ethylhexyl) phthalate (DEHP) was the most frequently detected PAE (85%), whereas di-isobutyl phthalate (DiBP) appeared to the most abundant congener with the maximum concentration of 807.65 ng/g. Floor cleaning frequency and use of detergents for floor cleaning were significantly associated with DEHP in dust (P < 0.05), suggesting additives of plasticizers in detergent products. The factors of plastic wraps in storage and use of disposable cups were both significantly related to DiBP (P < 0.01), which could be extensively used in food packaging products. We confirmed that several home characteristics/living habits were related to certain PAE residue in dust.

Exploring personal chemical exposures in China with wearable air pollutant monitors: A repeated-measure study in healthy older adults in Jinan, China

The health impact of airborne contaminants has been challenging to assess due to current limitations in measurement technologies. The emergence of wearable passive samplers coupled with high resolution mass spectrometry (HR-MS) chemical analysis has enabled comprehensive characterization of personal exposures. We conducted a repeated-measure study among 84 older adults in Jinan, China, as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Study objectives were: 1) to characterize the occurrence, magnitude, and distribution of personal exposure to airborne contaminants; 2) to evaluate the temporal variation of chemical exposures across the study population; and 3) to identify behavioral and environmental factors that influence the observed variance in chemical exposures. The FreshAir wristband was worn by participants for three consecutive days each month from September 2018 to January 2019 and collected with paired time-activity logs. Passive air samplers were also deployed in parallel at a local outdoor air monitoring station. Spearman's Rho trend test and trajectory cluster analysis were used to identify exposure trends and variation patterns, respectively. Out of the 70 airborne compounds of potential concern screened, 26 compounds from 10 chemical classes were found to be above detection thresholds across >70% of the study population. Personal exposures were predominantly characterized by nine polycyclic aromatic hydrocarbons (PAHs), four phthalates, three nitroaromatics, and two volatile organic compounds (VOCs). Phthalate personal exposures were positively correlated with outdoor temperatures while the inverse relationship was observed for certain PAHs (p < 0.05). Specifically, dimethyl phthalate (r_s = 0.31) decreased as temperatures declined, while nitrobenzene (r_s = -0.35) and naphthalene (r_s = -0.40) increased as temperatures decreased. Compared to levels measured at the outdoor air monitoring site, personal exposure of phthalates was elevated (p < 0.05) and hexachlorobutadiene was lower across participants (p < 0.01). Personal exposure of these chemicals was further found to be weakly associated with daily duration participants spent outdoors. Individuals formed distinct clusters based on trajectories of chemical exposures across the sampling period (September to January), potentially suggestive of distinct emission sources. In conclusion, we demonstrate the feasibility of characterizing the occurrence and magnitude of personal exposure to airborne chemical contaminants using passive wristband samplers. The temporal variability of these personal exposure profiles was highlighted and with distinct trends identified across different groups of individuals. Future studies will integrate this data with other omics datasets collected from this population of Chinese older adults to investigate associations between exposure profiles and health relevant biomarkers, to provide evidence in feasibility of disease prevention through environmental improvements.

Elemental and microbiota content in indoor and outdoor air using recuperation unit filters

This paper presents the results of a twelve-month measurement campaign conducted at a rural single-family house in Poland. The external and internal filters of a recuperator used to mechanically ventilate the building were used to separate the total suspended particles (TSPs), and the concentrations of fifteen elements and abundance of fungi and bacteria were determined. Lower annual mean concentrations were observed indoors, and the concentrations of most elements did not significantly change between seasons. There were some differences between winter and summer, which may have resulted from changes in the ventilation regimes in the house. The number of bacteria was similar outdoors and indoors, while the amounts of fungi were higher indoors (p < 0.05). The order of metal concentrations outdoors agreed well with observations in other countries, while indoors the metal concentrations order indicated the individual characteristics of the building. The species diversity of fungi was higher than that of bacteria, and different species were found indoors and outdoors, while bacteria were typically present both indoors and outdoors. Different TSP sources were identified indoors and outdoors, suggesting limited penetration between the two environments. However, both environments were affected by traffic. Mechanical ventilation systems with built-in filters (such as recuperators) were useful in assessing the air quality within the building, and the changeable recuperation filters offer an approach to assess the air quality in several houses without any additional cost or discomfort to the residents.

Occurrences, congener group profiles, and risk assessment of short- and medium-chain chlorinated paraffins in cup instant noodles from China

Dietary intake is an important route of human exposure to chlorinated paraffins (CPs). Cup instant noodles are widely popular food and millions packet of instant noodles are consumed every year. To investigate the levels, congener groups, and health risk of SCCPs and MCCPs in each component of cup instant noodles, samples of nine common brands were collected and analyzed by comprehensive two dimensional gas chromatography coupled with mass spectrometry. The mean concentrations in the noodles were 1.2 × 10³ ng/g wet weight (ww) (SCCPs) and 1.2 × 10² ng/g ww (MCCPs), the mean concentrations in the seasoning were 1.4 × 10³ ng/g ww (SCCPs) and 1.3 × 10² ng/g ww (MCCPs), and the mean concentrations in the soup were 5.6 × 10² ng/L (SCCPs) and 5.4 × 10² ng/L (MCCPs). The SCCP to MCCP ratio were similar in the soup and soup container, which means CPs in the soup might be migrated from the soup container. Seasoning and noodles from the same brands have similar congener profiles of SCCPs and MCCPs, which may be raised from the manufacturing process or food packaging materials. The dominant SCCP congener groups were C_10-11Cl_6-7 in noodles and seasoning, and C_10,13Cl_6-7 in soup. The dominant MCCP congener groups were C_14-15Cl_6-7 in noodles and seasoning, and C_14-15Cl_6-7 in soup. A preliminary health risk assessment indicated that the current intakes of SCCPs and MCCPs through cup instant noodles in China did not pose a significant risk to human health.

Indoor phthalate exposure and contributions to total intake among pregnant women in the SELMA study

Phthalates are widely used in consumer products. Exposure to phthalates can lead to adverse health effects in humans, with early-life exposure being of particular concern. Phthalate exposure occurs mainly through ingestion, inhalation, and dermal absorption. However, our understanding of the relative importance of different exposure routes is incomplete. This study estimated the intake of five phthalates from the residential indoor environment for 455 Swedish pregnant women in the SELMA study using phthalate mass fraction in indoor dust and compares these to total daily phthalate intakes back-calculated from phthalate metabolite concentrations in the women's urine. Steady-state models were used to estimate indoor air phthalate concentrations from dust measurements. Intakes from residential dust and air made meaningful contributions to total daily intakes of more volatile di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) (11% of total DEP intake and 28% of total DnBP and DiBP intake combined). Dermal absorption from air was the dominant pathway contributing to the indoor environmental exposure. Residential exposure to less volatile phthalates made minor contributions to total intake. These results suggest that reducing the presence of low molecular weight phthalates in the residential indoor environment can meaningfully reduce phthalate intake among pregnant women.

COVID-19 face masks: A new source of human and environmental exposure to organophosphate esters

For the first time, organophosphate ester (OPE) content was studied in different types of surgical, self-filtering (KN95, FFP2, and FFP3) and reusable face masks used for COVID-19 prevention. OPEs were detected in all mask samples, although in highly variable amounts which ranged from 0.02 to a maximum of 27.7 µg/mask, with the highest mean concentrations obtained for KN95 masks (11.6 µg/mask) and the lowest for surgical masks (0.24 µg/mask). Twelve out of 16 tested analytes were detected, with TEP, TPHP, TNBP, TEHP and TClPP being the most common OPEs as well as present at the highest concentrations. The non-carcinogenic and carcinogenic risks of OPE inhalation were calculated as being always several orders of magnitude lower than threshold levels, indicating that the use of face masks is safe with regard to OPE contamination. However, given the wide range of OPEs observed in different masks, it can be concluded that some masks (e.g. reusable) are less OPE-contaminated than others (e.g. KN95). With regard to environmental pollution, the disposal of billions of face masks is adding to the already substantial levels of microplastics and associated toxic additives worldwide, an impact that is lessened by use of reusable masks, which also have the lowest economic cost per user. However, in situations of relatively high risk of viral inhalation, such as poorly ventilated indoor public spaces, we recommend the use of FFP2 masks.

Evaluation of the immunomodulatory effects of C9-13-CPs in macrophages

Short-chain chlorinated paraffins (SCCPs) have been listed as a new class of persistent organic pollutants by the Stockholm Convention. SCCPs exhibit carcinogenic-, endocrine-, and metabolism-disrupting effects. However, the knowledge of the immunomodulatory effects of SCCPs and their underlying mechanisms, especially in specific immune cells, remains limited. In addition to SCCPs, C9-13-CPs have also been detected in humans. In this study, murine RAW264.7 macrophages were exposed to C9-13-CPs at environmentally relevant concentrations to investigate whether or how C9-13-CPs exhibit immunomodulatory effects. The results showed that the exposure of RAW264.7 cells to C9-13-CPs increased cell viability, as assayed by MTT analysis at 490 nm, and also promoted cell proliferation, as indicated by EdU uptake assay, which was measured at excitation and emission wavelengths of 488 and 512 nm, respectively. In addition, exposure to C9-13-CPs not only led to elevated ATP level and intracellular Ca2+ level but also caused AMPK signaling activation and NF-κB signaling inhibition. Moreover, molecular docking showed that the β2-AR receptor could bind to C9-13-CPs. Taken together, these results suggest that the immune dysfunction of RAW264.7 cells caused by C9-13-CPs is closely related to the β2-AR/AMPK/NF-κB signaling axis.

Optimization of a low flow sampler for improved assessment of gas and particle bound exposure to chlorinated paraffins

An optimized low volume sampler was developed to determine both gas- and particle bound concentrations of short and medium-chain chlorinated paraffins (S/MCCPs). Background contamination was limited by the sampler design, providing method quantification limits (MQLs) at least two orders of magnitude lower than other studies within the gas (MQL: 500 pg (ΣSCCPs), 1.86 ng (ΣMCCPs)) and particle (MQL: 500 pg (ΣSCCPs), 1.72 ng (ΣMCCPs) phases. Good repeatability was observed between parallel indoor measurements (RSD ≤ 9.3% (gas), RSD ≤ 14% (particle)) with no breakthrough/saturation observed after a week of continuous sampling. For indoor air sampling, SCCPs were dominant within the gas phase (17 ± 4.9 ng/m³) compared to MCCPs (2.7 ± 0.8 ng/m³) while the opposite was observed in the particle bound fraction (0.28 ± 0.11 ng/m³ (ΣSCCPs) vs. 2.7 ± 1.0 ng/m³ (ΣMCCPs)). Only SCCPs in the gas phase could be detected reliably during outdoor sampling and were considerably lower compared to indoor concentrations (0.27 ± 0.10 ng/m³). Separation of the gas and particle bound phase was found to be crucial in applying the appropriate response factors for quantification based on the deconvoluted S/MCCP sample profile, thus avoiding over- (gas phase) or underestimation (particle phase) of reported concentrations. Very short chain chlorinated paraffins (vSCCPs, C₅-C₉) were also detected at equal or higher abundance compared to SCCP congener groups (C₁₀-C₁₃) congener groups, indicating an additional human indoor inhalation risk.

Organophosphate esters in airborne particles from subway stations

For the first time, the concentrations of 19 organophosphate esters (OPEs) were measured in airborne fine particulate matter (PM2.5) from subway stations in Barcelona (Spain) to investigate their occurrence, contamination profiles and associated health risks. OPEs were detected in all PM2.5 samples with levels ranging between 1.59 and 202 ng/m³ (mean value of 39.9 ng/m³). Seventeen out of 19 tested analytes were detected, with TDClPP, TClPP and TCEP being those presenting the highest concentrations. OPE concentrations are not driven by the same factors that determine the ambient PM2.5 concentrations of other constituents in the subway. Newer stations presented higher OPE levels, probably due to the materials used in the design of the platforms, with greater use of modern plastic materials versus older stations with tiles and stones. Estimated daily intakes via airborne particles inhalation during the time expended in subway stations were calculated, as well as the carcinogenic and non-carcinogenic health risks (CR and non-CR), all being much lower than the threshold risk values. Thus, subway inhalation exposure when standing on the platform to OPE's per se is not considered to be dangerous for commuters.

Polybrominated diphenyl ethers quinone exhibits neurotoxicity by inducing DNA damage, cell cycle arrest, apoptosis and p53-driven adaptive response in microglia BV2 cells

Polybrominated diphenyl ethers (PBDEs) are world-wide used flame retardants before they were listed as Persistent Organic Pollutants (POPs) by the Stockholm Convention. Previously, our studies indicated that a quinone type of PBDE metabolite (PBDEQ) exposure was linked with neurotoxicity via excess free radical formation and oxidative stress. However, it is current unknown the effect of PBDEQ on genetic biomacromolecules DNA and corresponding biological consequences in neurological cells. Here, by employing phosphorylated histone H2AX in Serine 139 (γ-H2AX) and comet assay in microglia BV2 cells, our data suggested PBDEQ could triggered DNA damage. Furthermore, PBDEQ exposure led to the caspase 3-dependent cell apoptosis. Moreover, PBDEQ induced G2/M-phase cell arrest in a p53-dependent manner. Notably, p53 activation coordinated cell cycle progression, alleviated DNA damage and ultimately mitigated apoptosis in BV2 cells. Finally, antioxidant N-acetyl-l-cysteine (NAC) inhibited p53 activation upon PBDEQ exposure, and then ameliorated PBDEQ-induced DNA damage, cell cycle arrest and apoptosis, which illustrated that PBDEQ-induced DNA damage and p53 activation were mediated by reactive oxygen species (ROS). Together, the current findings unveil the fundamental toxicological mechanisms of PBDEQ, which propose a potential therapeutic strategy against the adverse effect caused by PBDE exposure.

Presence of emerging organic contaminants and solvents in schools using passive sampling

In this study, we report on the applicability of passive sampling with Carbopack X adsorbent tubes followed by thermal desorption gas-chromatography-mass spectrometry (TD-GC-MS) to monitor the concentrations of emerging organic contaminants (EOCs) and solvents in ten indoor environments in a conventional and a vocational training school. However, if passive sampling is to be used as a reliable sampling technique, a specific diffusive uptake rate is required for each target compound. Accordingly, the aim of the present study was twofold. The first was to determine the experimental diffusive uptake rates of the target EOCs and solvents in one of the sampling sites of the vocational training school using Carbopack X adsorbent tubes and active sampling as the reference technique. The results showed experimental diffusive uptake rates between 0.46 mL min^-1 and 0.94 mL min^-1 with RSD % below 5% for the 28 target compounds. The second was to apply the uptake rates obtained experimentally to determine EOCs and solvents in schools. The monitoring results showed that solvents were ubiquitous throughout the conventional school with a concentrations range between 51.93 μg m^-3 and 164.6 μg m^-3, while EOCs were detected to a lesser extent. Moreover, the concentrations of EOCs in the vocational training school were much higher than those in the conventional school with concentrations of up to 562.9 μg m^-3 for solvents and 344.3 μg m^-3 for acrylate polymer monomers. After actively sampling for seven days in each school, we concluded that the concentrations of EOCs and solvents found are mostly linked to cleaning products (conventional school) and the activities carried out in the classroom (vocational training school).

Air pollution caused by phthalates and cyclic siloxanes in Hanoi, Vietnam: Levels, distribution characteristics, and implications for inhalation exposure

Contamination status and distribution characteristics of ten phthalic acid esters (PAEs) and three cyclic volatile methyl siloxanes (CSs) were determined in the air (gas and particle) samples collected from indoor and outdoor spaces of several chemistry laboratories, offices, and homes from urban area of Hanoi, the capital city of Vietnam. Air concentrations of Σ10PAEs (median 688; range 142-2390 ng m^-3) and Σ3CSs (171; not detected-1100 ng m^-3) in the indoor air samples were significantly higher than those measured in the outdoor ones (Σ10PAEs: 161; 34.1-515 ng m^-3 and Σ3CSs: 43.2; not detected-258 ng m^-3), partly suggesting the predominance of indoor emission sources of these substances. There were significant positive correlations in total air concentrations of phthalates and siloxanes between the indoor and outdoor air samples. The most predominant phthalates were diethyl-, di-n-butyl-, diisobutyl-, and di(2-ethylhexyl) phthalate. For siloxanes, D5 and D6 were more abundant than D4 in most samples. Except for di(2-ethylhexyl)- and di-n-octyl phthalate in some locations, almost all the compounds were likely associated with gas phase than particle phase. Daily intake doses of airborne phthalates and siloxanes, and non-cancer and cancer risks of selected phthalates were estimated for different exposure groups such as adults, children, and university subjects (e.g., laboratory staff and students), indicating relatively low levels of risk.

Phthalate levels in indoor dust and associations to croup in the SELMA study

Phthalates are ubiquitous indoor pollutants which have been associated with child airway disease although results are inconclusive. This study examined associations between phthalate levels in residential indoor dust and croup during infancy. Settled indoor dust was collected in 482 homes of 6-month-old infants in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study and analysed for seven phthalates and one phthalate replacement using gas chromatography tandem mass spectrometry. The incidence of parental reported croup at 12 months was 6.4% for girls and 13.4% for boys. Associations between phthalate dust levels and croup were analysed by logistic regression adjusted for potential confounders. We found significant associations between di-ethyl phthalate (DEP) and di-ethyl-hexyl phthalate (DEHP) in residential dust and parental reported croup (adjusted odds ratio (aOR) = 1.71; 95% CI: 1.08-2.73 and 2.07; 1.00-4.30, respectively). Stratified results for boys showed significant associations between DEP and butyl-benzyl phthalate (BBzP) in dust and infant croup (aOR = 1.86; 95% CI: 1.04-3.34 and 2.02; 1.04-3.90, respectively). Results for girls had questionable statistical power due to few cases. Our results suggest that exposure to phthalates in dust is a risk factor for airway inflammatory responses in infant children.

Occurrence and partitioning of brominated flame retardants (BFRs) in indoor air and dust: a 15-month case study in a test home

Ten polybrominated diphenyl ethers (PBDEs) and 16 novel brominated flame retardants (NBFRs) were measured in air and dust samples collected in a test home in Harbin, China, from January 2017 to June 2018. The PBDE and NBFR concentrations in indoor air were in the ranges of 0.598-14.5 pg m^-3 and 9.28-686 pg m^-3, respectively. The ranges of the PBDE and NBFR concentrations in indoor dust were 221-1060 ng g^-1 and 71.9-1160 ng g^-1, respectively. Brominated flame retardant (BFR) concentrations in indoor air were affected by the temperature, relative humidity (RH), and ventilation. The BFR concentrations in indoor dust did not show temperature dependence. All dust samples were sieved into 6 size fractions (F1-F6: 1000-2000 μm, 500-1000 μm, 250-500 μm, 125-250 μm, 63-125 μm, and < 63 μm). The mass percentage of BFRs in F6 was the highest. The BFR concentrations did not increase constantly with a particle size decrease, and the concentrations in F2 were higher than those in F3. The partitioning behavior of BFRs illustrates that the dust-air partitioning coefficient approximately approached equilibrium within F5, F6, and the total dust fraction (FA) in the test home when logK_OA was between 9.1 and 11.32. Air-dust fugacity fractions were calculated, and the results suggested that most of the BFRs were mainly transferred from air to dust in the indoor environment for F1-F6.

Passive sampling to control air quality in schools: Uptake rate determination and application

In this paper, we provide a detailed description of the application of passive sampling with Carbopack X tubes followed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) to determine the concentrations of volatile organic compounds (VOCs) in different school environments. The main objective of the study was to monitor VOCs in seven indoor and three outdoor environments at a school in Tarragona, Spain. However, in order to obtain more accurate information, it was necessary to determine the experimental diffusive uptake rates of the target VOCs in indoor settings through parallel passive and active sampling in one classroom. The results showed experimental diffusive uptake rates in the range of 0.38 mL min^-1 and 0.95 mL min^-1 with RSD % below 5% for up to 44 VOCs. The monitoring results showed that ethanol (23.84-83.16 µg m^-3 ) and isopropyl alcohol (5.42-25.92 µg m^-3 ) were the most common compounds found in indoor environments, with cleaning products as the main emission source. The VOCs i-pentane and n-pentane were found at the highest concentrations in the three sampling sites set in the school's playground, and their concentrations were strictly related to combustion processes from automobile traffic.

Determination of organophosphate ester flame retardants and plasticisers in fish samples by QuEChERs followed by gas chromatography-tandem mass spectrometry. Exposure and risk assessment through fish consumption

The presence of organophosphate esters (OPEs) in everyday commodities such as furniture, household appliances and baby toys have rendered these contaminants ubiquitous in environmental fates such as air, water, soils and biota. Their presence in food-related species suggests that an additional route of exposure to these esters for the general population is fish intake through diet. Their incipient toxicity and carcinogenetic behaviour make it essential to develop methods for determining OPEs in fish samples. In this paper we have developed a new method for determining 9 OPEs based on the QuEChERS extraction method followed by a simple clean-up using a novel device for selective lipid removal (LipiFiltr) and GC-MS/MS to extract these compounds from fish samples regardless of lipid content. QuEChERS salt packet optimisation and clean-up strategies such as liquid-liquid extraction, dispersive-solid phase extraction and LipiFiltr were tested. Our results showed that EN 15662 method salts and Lipifiltr were the best combination to produce efficient analyte apparent recovery (67-116%) and negligible matrix effects (<10%). Limits of detection ranged from 0.05 ng g^-1 (dry weight) for TiBP and TBP to 2.00 ng g^-1 (dry weight) for TCEP. Fish samples from four fish species were determined with a median concentration of ΣOPEs 5.31 ng g^-1 on a wet weight basis, with TBP, TiBP and TCPP as the main contenders. Estimates of exposure and risk associated with consuming these compounds via dietary intake showed low levels of concern for the population of Tarragona.

Perinatal exposure to 2-Ethylhexyl Diphenyl Phosphate (EHDPHP) affected the metabolic homeostasis of male mouse offspring: Unexpected findings help to explain dose- and diet- specific phenomena

The environmental health risks of a new type of organophosphate flame retardant, 2-ethylhexyl diphenyl phosphate (EHDPHP), which is present in large quantities in various Nordic foods, have attracted the attention of scientists recently. In this study, the metabolic homeostasis of low-fat diet (LFD) and high-fat diet (HFD) fed male mice offspring was assessed after perinatal exposure to two doses (30 μg/kg bw/day and 300 μg/kg bw/day) of EHDPHP. Perinatal exposure to EHDPHP resulted in weight changes in male mice offspring, altered glucose tolerance and induced liver damage, and surprisingly these changes were dose- and diet- specific. Then the ¹H NMR-based metabolomics, 16S rRNA sequencing, and qRT-PCR techniques were used to explore the mechanisms of these specific changes. The results indicate that the increase in short-chain fatty acids and the increase in Clostridium in the high-dose group may be responsible for the dose-specificity, while the attenuation of the purine metabolic pathway and the decrease in glutamine levels in the HFD group are accountable for the diet-specificity. In addition, down-regulation of PPARG (peroxisome proliferator-activated receptor gamma) gene expression levels might have caused the decrease in body weight in the H + HFD (high dose exposure with HFD feeding) group. Over all, these results elucidated the effects of dosage and diet on the toxicology of EHDPHP.

The environmental distribution and toxicity of short-chain chlorinated paraffins and underlying mechanisms: Implications for further toxicological investigation

Short-chain chlorinated paraffin (SCCP) pollution has become a global threat. Much attention has been paid to their environmental occurrence and toxicity. In this review, we summarized the wide distribution of SCCPs in various environmental matrices and biota, including human beings. Toxicokinetics and the toxicities of SCCPs, including lethality, hepatotoxicity, developmental toxicity, carcinogenicity, endocrine- and metabolism-disrupting effects, and immunomodulatory effects have been considered. The mechanisms of SCCP toxicity are mainly related to oxidative stress, metabolic disturbance, endocrine disruption and binding to biomacromolecules. In the future, further studies of SCCPs should focus on searching for their novel toxicity targets, and uncovering their toxic effects using transcriptomics, proteomics, metabolomics, and mutigenerational toxicity.