Polycyclic aromatic hydrocarbons (PAHs) of molecular mass (MM) 302 Da comprise numerous structural isomers that are of high concern for human health. Because of their multiplicity, low abundance in the environment, and limited availability of authentic standards, their occurrence, composition, and environmental health risk remain not well characterized. Here we extend the characterization of MM 302 Da PAH isomers in combustion-related particulate matter with the addition of four newly synthesized and previously unidentified MM 302 Da isomers: dibenzo[a,l]fluoranthene (DBalF), dibenzo[b,l]fluoranthene (DBblF), dibenzo[a,j]fluoranthene (DBajF), and naphtho[2,1-j]fluoranthene (N21jF). Using a coupled high-performance liquid chromatography/gas chromatography-mass spectrometric system with a 50% phenyl methylpolysiloxane stationary phase, 24 MM 302 Da isomers were annotated in four Standard Reference Materials, SRM 1648a, SRM 1649b, SRM 1650b, and SRM 2975, and in four combustion-related particulate matter samples consisting of two traffic-impacted filters and two laboratory-generated combustion samples. Three of the four previously unidentified compounds, DBalF, DBajF, and N21jF, were chromatographically resolved and quantified for the first time in these samples. Quantitative analysis of nine MM 302 Da PAHs (∑MM302Da) showed that these compounds accounted for roughly 0.66–4.1% of the total mass for 50 PAHs. The previously unidentified isomers were recurring but generally minor contributors to the ∑MM302Da burden, with N21jF representing 8–14%, DBalF typically 6–10% (but 23% in SRM 2975), and DBajF varying between 1 and 5%. These results demonstrate both the ubiquity and compositional variability of MM 302 Da PAHs in combustion-derived particulate matter and provide new reference data for analytical investigations of MM 302 Da PAHs.

Background: Textile chemicals may constitute a hazardous exposure and lead to skin sensitization or other health problems. Children, due to their thinner, less developed skin, are more susceptible to this exposure. Objectives: To investigate the occurrence and levels of 50 textile chemicals in childrens skin-close clothing. Further, to investigate the washout effect of these textile chemicals and their tendencies to migrate from the textile fibres into artificial sweat. Methods: Screening of 60 children's clothes purchased on the Swedish retail market was performed using coupled automated thermal desorption-gas chromatography/mass spectrometry (ATD-GC/MS). Results: Among the most frequently occurring chemicals were non-regulated quinolines, halogenated arylamines, phthalates, and nitrobenzenes. The highest concentrations were found for benzyl benzoate, 1400 mu g/g, and 2-bromo-4,6-dinitroaniline, 300 mu g/g. The highest number and levels of chemicals were detected in garments made of 100% polyester, while the fewest and lowest levels were determined in light-coloured cotton. Laundry experiments revealed that cotton garments had the greatest washout effect, whereas most of the chemical content remained in 100% polyester garments even after 10 laundry cycles. Conclusions: Results indicate a lower exposure from the investigated cotton garments, especially after laundry. On the other hand, cotton exhibited threefold greater chemical migration into artificial sweat than polyester. The strong dependence on fibre material is important to consider when estimating the bioaccessible chemical exposure from garments and related health risks.

The global production of textiles involves large amounts of health-hazardous chemicals, constituting possible health risks since residues usually remain in the finished garments. An analytical method based on automated thermal desorption (ATD) coupled online to GC/MS for screening of several classes of toxic chemicals in synthetic garments was recently published by us. In the present study, the ATD-GC/MS methodology is further extended to cotton and cotton blend materials. 

Different textile materials with a high content of cotton were found to exhibit large variations in adsorption strength for many chemicals frequently detected in textiles. This was shown to influence the thermal desorption efficiency strongly in ATD-GC/MS. By using absolute response factors from appropriate internal standards spiked directly onto the textile samples, the effects of these differences could be minimized. In this way, accurate quantification was made possible regardless of textile composition, and quantification of native textile chemicals in garments made with the ATD-GC/MS method agreed well with an offline method based on solvent extraction and GC/MS analysis.

The ATD-GC/MS method has now been shown to be applicable for quantitative screening of around 75% of [UN1] [TÅ2] all the textiles on the retail market. The simplified quantification method makes it suitable for screening many samples. For all textile chemicals and fibre materials investigated, the method limits of detection, using only 20 mg of textile, is at least 100 times lower than the current EU regulation for quinoline and several toxic arylamines.

Uncontrolled waste burning and accidental waste fires are an important source of emissions into the air. However, there are currently only few field studies providing data on these emissions. In this study, we investigated the emission rates, pollutant dispersion and particle composition for a large waste fire in Stockholm county, Sweden. Our results show that the waste fire, while burning, may have contributed as much as 5 times the mean PM₁₀ emissions from road traffic of the municipality it was located in (ca 95 000 inhabitants), which highlights the potential impact of temporary events such as waste fires on air quality. Gaussian dispersion calculations were used to model the spatial distribution of measured PM₁₀ data, demonstrating its use for assessment of exposure and deposition. Particles impacted by the waste fire were enriched in several potentially toxic metals and metalloids including arsenic, copper, cadmium and, in particular, lead when compared to particles collected after the fire. In addition, they may also pose an increased cancer risk on a per-mass basis compared to the post-fire period due to the larger mass fraction of relevant PAHs.

Comparative studies on traffic-derived particulate matter (PM) from fuel combustion and non-exhaust sources are scarce. This study compares cytokine release (CXCL8, IL-1α, IL-1β, TNFα) and expression of genes linked to inflammation (CXCL8, IL1A, IL1B, COX2, IL6), xenobiotic metabolism (CYP1A1) and redox responses (HMOX1) in human bronchial epithelial cells (HBEC3-KT) and THP-1-derived macrophages after exposure to samples of tire and road wear particles (TRWP) and diesel exhaust particles (DEP). CH223191 was used to assess the involvement of the aryl hydrocarbon receptor (AhR) in the cytokine responses. The results show that TRWP and DEP induced pro-inflammatory responses in both cell types. Moreover, exposure to TRWP and DEP in combination enhanced the pro-inflammatory responses in HBEC3-KT. While the relative potency of TRWP differed between the cell types and endpoints, pro-inflammatory responses of similar or greater magnitude than DEP were observed. The AhR inhibitor CH223191 attenuated the particle-induced cytokine release in HBEC3-KT, but not in the THP-1-derived macrophages. In conclusion, TRWP and DEP induced pro-inflammatory responses in human bronchial epithelial cells and macrophage-like cells, acting through different mechanisms. Responses of a similar magnitude as DEP were observed after exposure to TRWP, showing that TRWP constitutes a potential health hazard. Moreover, the enhanced responses following exposure to TRWP and DEP in combination suggest that the interplay between PM components could be a contributing factor in PM-induced health effects.

Air pollution is an example of a complex environmental mixture with different biological activities, making risk assessment challenging. Current cancer risk assessment strategies that focus on individual pollutants may overlook interactions among them, potentially underestimating health risks. Therefore, a shift towards the evaluation of whole mixtures is essential for accurate risk assessment. This study presents the application of an in vitro New Approach Methodology (NAM) to estimate relative cancer potency factors of whole mixtures, with a focus on organic pollutants associated with air particulate matter (PM). Using concentration-dependent activation of the DNA damage-signaling protein checkpoint kinase 1 (pChk1) as a readout, we compared two modeling approaches, the Hill equation and the benchmark dose (BMD) method, to derive Mixture Potency Factors (MPFs). MPFs were determined for five PM_2.5 samples covering sites with different land uses and our historical pChk1 data for PM₁₀ samples and Standard Reference Materials. Our results showed a concentration-dependent increase in pChk1 by all samples and a higher potency compared to the reference compound benzo[a]pyrene. The MPFs derived from the Hill equation ranged from 128 to 9793, while those from BMD modeling ranged from 70 to 303. Despite the differences in magnitude, a consistency in the relative order of potencies was observed. Notably, PM_2.5 samples from sites strongly impacted by biomass burning had the highest MPFs. Although discrepancies were observed between the two modeling approaches for whole mixture samples, relative potency factors for individual PAHs were more consistent. We conclude that differences in the shape of the concentration–response curves and how MPFs are derived explain the observed differences in model agreement for complex mixtures and individual PAHs. This research contributes to the advancement of predictive toxicology and highlights the feasibility of transitioning from assessing individual agents to whole mixture assessment for accurate cancer risk assessment and public health protection.

Atmospheric fine particulate matter (PM_2.5) is a critical indicator of air quality, with substantial implications for human health. Understanding the emission sources and chemical composition of PM_2.5 is crucial for mitigating possible adverse health effects. This study spans five diverse cities on three continents from north and south hemisphere: Stockholm (Sweden), Kyoto (Japan), Limeira, Ribeirão Preto, and Cáceres (Brazil). Our objective was to assess PM_2.5 chemical composition and regional and long-range transport influences to identify the main sources of particulate air pollution at these cities during the winter/dry seasons. All studied cities but Kyoto exhibited PM_2.5 levels above World Health Organization (WHO) guidelines, with the Brazilian cities experiencing the highest fine particle pollution levels, implying increased adverse health risks. We observed significant variations in concentrations of polycyclic aromatic compounds (PACs), monosaccharide anhydrides (MAs), and inorganic elements. Limeira exhibited the highest levels of total PACs (median level of 12.4 ng m⁻³), while Cáceres displayed high variability of PACs, most likely due to episodic regional wildfire events. MA concentrations were significantly higher in Limeira and Ribeirão Preto and together with elevated levels of retene and potassium (K) they suggested a substantial influence of biomass burning. Backward air mass trajectory analysis suggested widespread Amazon and Savanna wildfires along with local fires as main contributors for these sites. All source identification approaches highlighted differences among the cities, with Stockholm and Kyoto showing influence of sources related to traffic emissions, waste burning, and long-range transport, and Brazilian cities traffic, industrial, biogenic, and more evident biomass burning. This cross-continental study provides valuable insights into PM_2.5 composition and emission sources, emphasizing the impact of different emissions on air quality. Our findings underscore the importance of local strategies to mitigate air pollution and protect public health, especially in regions where PM_2.5 levels consistently exceed recommended guidelines.

Advanced materials are materials that have been engineered to exhibit novel or enhanced properties that confer superior performance when compared to conventional materials. Here, we evaluated the impact of Ti₃C₂ MXenes, a two-dimensional (2D) material, on the adverse effects caused by polycyclic aromatic hydrocarbons. To this end, we studied benzo[a]pyrene denoted here as B[a]P as a model compound. B[a]P was found to adsorb to MXenes as evidenced by UV–Vis spectroscopy. MXenes in the presence or absence of natural organic matter (NOM) were well tolerated by zebrafish embryos. The uptake (ingestion) of MXenes by zebrafish was determined by quantifying the Ti content using inductively coupled plasma mass spectrometry (ICP-MS) while Raman confocal mapping was applied for the label-free identification of MXenes in situ in exposed zebrafish. The body burden of B[a]P was determined by gas chromatography-mass spectrometry (GC-MS). The potential impact of MXenes on B[a]P triggered aryl hydrocarbon receptor (AhR) induction was assessed by evaluating the induction of downstream genes including cyp1a, and results were validated by using the transgenic zebrafish reporter tg(cyp1a-eGFP). The potential impact of MXenes on the genotoxicity caused by B[a]P was also assessed. MXenes were shown to ameliorate AhR induction and DNA damage caused by B[a]P. This was corroborated by using the human colon-derived cell line HT-29. Taken together, MXenes were found to be non-hazardous and alleviated the adverse effects caused by B[a]P in vitro and in vivo.

The environmental impact is a strong incentive for the development of upcycling processes for textile waste. However, toxic chemicals may occur in both brand-new textiles and post-consumer garments, and the chemical transfer in such routes is important to investigate. The present study applied non-target screening and quantification with liquid chromatography/mass spectrometry to follow the fate of hazardous chemicals from post-consumer polycotton garments to a new material, cellulose nanocrystals, in a chemical upcycling utilizing strongly acidic conditions. The majority of hazardous chemicals detected within the process were found to be transferred to a residual of polyester material and not to the enriched cellulose. However, phthalates were found to be mainly attached to the cellulose nanocrystals. The detected total concentration, in this case, was below 5 μg/g, at least 200 times lower than the limit set by the European Union. This indicates the importance of monitoring and controlling the phthalate content in the starting material of the process, i.e., the post-consumer garments. The chemical release into the process waste effluent could be estimated based on water solubility data for chemicals under the applied conditions. Three compounds, the water-repellent substance perfluorooctanesulfonic acid and the dyes Crystal Violet and Victoria Pure Blue, were almost entirely transferred into the process waste effluent. Although the levels detected were very low in the present pilot process, their presence eventually indicates the need for wastewater purification at further upscaling, depending on the exposure and dose in relation to toxicological relevant thresholds.

Air pollution is a complex mixture of gases and particulate matter (PM) with local and non-local emission sources, resulting in spatiotemporal variability in concentrations and composition, and thus associated health risks. To study this in the greater Stockholm area, a yearlong monitoring campaign with in situ measurements of PM₁₀, PM₁, black carbon, NO_x, O₃, and PM₁₀-sampling was performed. The locations included an Urban and a Rural background site and a Highway site. Chemical analysis of PM₁₀ was performed to quantify monthly levels of polycyclic aromatic compounds (PACs), which together with other air pollution data were used for source apportionment and health risk assessment. Organic extracts from PM₁₀ were tested for oxidative potential in human bronchial epithelial cells. Strong seasonal patterns were found for most air pollutants including PACs, with higher levels during the winter months than summer e.g., highest levels of PM₁₀ were detected in March at the Highway site (33.2 μg/m³) and lowest in May at the Rural site (3.6 μg/m³). In general, air pollutant levels at the sites were in the order Highway > Urban > Rural. Multivariate analysis identified several polar PACs, including 6H-Benzo[cd]pyren-6-one, as possible discriminatory markers for these sites. The main sources of particulate pollution for all sites were vehicle exhaust and biomass burning emissions, although diesel exhaust was an important source at the Highway site. In vitro results agreed with air pollutant levels, with higher oxidative potential from the winter samples. Estimated lung cancer cases were in the order PM₁₀ > NO₂ > PACs for all sites, and with less evident seasonal differences than in vitro results. In conclusion, our study presents novel seasonal data for many PACs together with air pollutants more traditionally included in air quality monitoring. Moreover, seasonal differences in air pollutant levels correlated with differences in toxicity in vitro.