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Considered that human activities mostly occur below building heights, the objective of this study was to investigate the temporal variations of fine particular matter (PM 2.5 )-associated polycyclic aromatic hydrocarbons (PAHs) and benzo[a]pyrene-equivalent (BaP eq ) concentrations at four different elevations (6.1, 12.4, 18.4, and 27.1 m) in Kaohsiung City, the largest industrial city of southern Taiwan. Temperature variation was critical for the PM 2.5 -associated PAH concentrations, which were dominated by benzo[g,h,i]perylene (0.27 ± 0.04 ng m −3 and 24.43% of the total concentration) and other high molecular weight (HMW) species. The PM 2.5 -associated BaP eq was dominated by 5-ring PAH (36.09%). The PM 2.5 -associated PAH and BaP eq concentrations at all elevations were significantly increased in winter. In the night, the correlations between the PM 2.5 -associated PAH concentrations and atmospheric temperatures became negatively stronger, notably at lower elevations (r = − 0.73 ~ − 0.86), whereas the BaP eq during daytime and nighttime were not changed significantly in most months. The PAHs analysis with different PM sizes demonstrated the importance of smaller particles such as PM 2.5 . The meteorological variation was more important than elevation to influence the low-elevation PM 2.5 -associated PAH and BaP eq concentrations in an urban area like Kaohsiung City, as the two concentrations were dominated by the PAHs with HMWs and those 5-ring species, respectively.

Epidemiological studies have suggested the effects of ambient fine particles (PM 2.5 ) on asthma, but the effects of specific components of PM 2.5 on asthma remain to be explored. Here, we studied the effect of PM 2.5 -bound polycyclic aromatic hydrocarbons (PAHs) on asthma acute exacerbation. The data on daily counts of emergency room visits (ERVs) were obtained from Wan Fang Medical Center, Taipei, Taiwan, from 2012 to 2015. The daily concentrations of PM 2.5 and pollutant gases were obtained from a local air quality monitoring station. The levels of PM 2.5 -bound PAH were estimated by an established grid-scale model. Relative risks for ERVs as the increase in the level of ambient pollutants were calculated by using a generalized additive model of Poisson regression. In the present study, we observed statistically significant positive associations between PM 2.5 and asthma ERVs for all age groups. PM 2.5 -bound PAH was also associated with asthma ERVs for all age groups. In the adult subgroup analysis, there was a significant association between PM 2.5 -bound PAH and asthma ERVs at lags 1 and 2 (RR 1.289, 95% CI 1.050–1.582 and RR 1.242, 95% CI 1.039–1.485). The impacts of air pollution on the risk of pediatric asthma ERV were found to be significant for PM 2.5 at lag day 0 (RR 1.310, 95% CI 1.069–1.606). Moreover, pediatric asthma ERVs were significantly associated with the levels of PM 2.5 -bound PAH at lag 1 and 2 days (RR 1.576, 95% CI 1.371–1.810 and RR 1.426, 95% CI 1.265–1.607). The study provides evidence that PM 2.5 -bound PAHs were associated with an increased risk of asthma attacks. Our data further suggested that traffic exhaust is a primary source of PM 2.5 -bound PAHs.

Microplastics are a major environmental issue. In marine systems, these break down into small fragments that may lodge within organisms, but they behave as vectors for chemicals when pollutants such as metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, and pharmaceuticals are absorbed by the particles. The rate and extent of uptake of organic compounds onto microplastics is dependent on a range of factors such as the sites available on the surface, the type of plastic, and the compound being sorbed, with hydrophobicity an important property. Laboratory experiments determined the uptake of pyrene and acenaphthene (and sometimes phenanthrene) onto pellets of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyoxymethylene (POM), polypropylene (PP) and polystyrene (PS). The kinetics of uptake in the experiments reveals half-lives ~10 h. The extent of partition onto the plastic pellets was similar for pyrene and phenanthrene, though lower for acenaphthene. This was not surprising because the octanol-water distribution coefficient of acenaphthene is about an order of magnitude smaller than that of pyrene, suggesting it is less hydrophobic. The PAHs are distributed most strongly into PP but only weakly into PVC. The fragmentation and oxidation of microplastics means that they sorb increasing amounts of organic material as they age.

Chronic exposure to ambient polycyclic aromatic hydrocarbons (PAHs) is associated with asthma, but its regulatory mechanisms remain incompletely defined. We report herein that elevated levels of urinary 1-hydroxypyrene, a biomarker of PAH exposure, were found in asthmatic subjects ( n  = 39) as compared to those in healthy subjects ( n  = 43) living in an industrial city of Taiwan, where indeno[1,2,3-cd]pyrene (IP) was found to be a prominent PAH associated with ambient PM 2.5 . In a mouse model, intranasal exposure of mice with varying doses of IP significantly enhanced antigen-induced allergic inflammation, including increased airway eosinophilia, Th2 cytokines, including IL-4 and IL-5, as well as antigen-specific IgE level, which was absent in dendritic cell (DC)-specific aryl hydrocarbon receptor (AhR)-null mice. Mechanistically, IP treatment significantly altered DC’s function, including increased level of pro-inflammatory IL-6 and decreased generation of anti-inflammatory IL-10. The IP’s effect was lost in DCs from mice carrying an AhR-mutant allele. Taken together, these results suggest that chronic exposure to environmental PAHs may pose a significant risk for asthma, in which IP, a prominent ambient PAH in Taiwan, was shown to enhance the severity of allergic lung inflammation in mice through, at least in part, its ability in modulating DC’s function in an AhR-dependent manner.

The spatiotemporal distribution and chemical composition of atmospheric fine particles in areas around the Taiwan Strait were firstly investigated. Fine particles (PM 2.5 ) were simultaneously collected at two sites on the west-side, one site at an offshore island, and three sites on the east-side of the Taiwan Strait in 2013–2014. Field sampling results indicated that the average PM 2.5 concentrations at the west-side sampling sites were generally higher than those at the east-side sampling sites. In terms of chemical composition, the most abundant water-soluble ionic species of PM 2.5 were SO 4 2− , NO 3 − , and NH 4 + , while natural crustal elements dominated the metallic content of PM 2.5 , and the most abundant anthropogenic metals of PM 2.5 were Pb, Ni and Zn. Moreover, high OC/EC ratios of PM 2.5 were commonly observed at the west-side sampling sites, which are located at the downwind of major stationary sources. Results from CMB receptor modeling showed that the major sources of PM 2.5 were anthropogenic sources and secondary aerosols at the both sides, and natural sources dominated PM 2.5 at the offshore site. A consistent decrease of secondary sulfate and nitrate contribution to PM 2.5 suggested the transportation of aged particles from the west-side to the east-side of the Taiwan Strait.

BackgroundAdult asthma is phenotypically heterogeneous with unclear aetiology. We aimed to evaluate the potential contribution of environmental exposure and its ensuing response to asthma and its heterogeneity.MethodsEnvironmental risk was evaluated by assessing the records of National Health Insurance Research Database (NHIRD) and residence-based air pollution (particulate matter with diameter less than 2.5 micrometers (PM2.5) and PM2.5-bound polycyclic aromatic hydrocarbons (PAHs)), integrating biomonitoring analysis of environmental pollutants, inflammatory markers and sphingolipid metabolites in case–control populations with mass spectrometry and ELISA. Phenotypic clustering was evaluated by t-distributed stochastic neighbor embedding (t-SNE) integrating 18 clinical and demographic variables.FindingsIn the NHIRD dataset, modest increase in the relative risk with time-lag effect for emergency (N=209 837) and outpatient visits (N=638 538) was observed with increasing levels of PM2.5 and PAHs. Biomonitoring analysis revealed a panel of metals and organic pollutants, particularly metal Ni and PAH, posing a significant risk for current asthma (ORs=1.28–3.48) and its severity, correlating with the level of oxidative stress markers, notably Nε-(hexanoyl)-lysine (r=0.108–0.311, p<0.05), but not with the accumulated levels of PM2.5 exposure. Further, levels of circulating sphingosine-1-phosphate and ceramide-1-phosphate were found to discriminate asthma (p<0.001 and p<0.05, respectively), correlating with the levels of PAH (r=0.196, p<0.01) and metal exposure (r=0.202–0.323, p<0.05), respectively, and both correlating with circulating inflammatory markers (r=0.186–0.427, p<0.01). Analysis of six phenotypic clusters and those cases with comorbid type 2 diabetes mellitus (T2DM) revealed cluster-selective environmental risks and biosignatures.InterpretationThese results suggest the potential contribution of environmental factors from multiple sources, their ensuing oxidative stress and sphingolipid remodeling to adult asthma and its phenotypic heterogeneity.

This paper presents a methodology based on multivariate data analysis for characterizing potential source contributions of emerging contaminants (ECs) detected in 26 river water samples across multi-scape regions during dry and wet seasons. Based on this methodology, we unveil an approach toward potential source contributions of ECs, a concept we refer to as the \"Pharmaco-signature.\" Exploratory analysis of data points has been carried out by unsupervised pattern recognition (hierarchical cluster analysis, HCA) and receptor model (principal component analysis-multiple linear regression, PCA-MLR) in an attempt to demonstrate significant source contributions of ECs in different land-use zone. Robust cluster solutions grouped the database according to different EC profiles. PCA-MLR identified that 58.9% of the mean summed ECs were contributed by domestic impact, 9.7% by antibiotics application, and 31.4% by drug abuse. Diclofenac, ibuprofen, codeine, ampicillin, tetracycline, and erythromycin-H2O have significant pollution risk quotients (RQ>1), indicating potentially high risk to aquatic organisms in Taiwan.

Background DEHP, a common plasticizer known for its hormone-disrupting properties, has been associated with asthma. However, a significant proportion of adult asthma cases are “non-atopic”, lacking a clear etiology. Methods In a case-control study conducted between 2011 and 2015, 365 individuals with current asthma and 235 healthy controls from Kaohsiung City were enrolled. The control group comprised individuals without asthma, Type 2 Diabetes Mellitus (T2DM), hypertension, or other respiratory/allergic conditions. The study leveraged asthma clusters (Clusters A to F) established in a prior investigation. Analysis involved the examination of urinary DEHP metabolites (MEHP and MEHHP), along with the assessment of oxidative stress, sphingolipid metabolites, and inflammatory biomarkers. Statistical analyses encompassed Spearman’s rank correlation coefficients, multiple logistic regression, and multinomial logistic regression. Results Asthma clusters (E, D, C, F, A) exhibited significantly higher ORs of MEHHP exposures compared to the control group. When considering asthma-related comorbidities (T2DM, hypertension, or both), patients without comorbidities demonstrated significantly higher ORs of the sum of primary and secondary metabolites (MEHP + MEHHP) and MEHHP compared to those with asthma comorbidities. A consistent positive correlation between urinary HEL and DEHP metabolites was observed, but a consistent negative correlation between DEHP metabolites and selected cytokines was identified. Conclusion The current study reveals a heightened risk of MEHHP and MEHP + MEHHP exposure in specific asthma subgroups, emphasizing its complex relationship with asthma. The observed negative correlation with cytokines suggests a new avenue for research, warranting robust evidence from epidemiological and animal studies.

Marine plastic debris is an environmental problem, and its degradation into microplastics (1-5000 μm) introduces them into the food chain. In this study, small polyoxymethylene (global production ~3000 Tg per year) pellets were exposed in terrestrial and simulated marine environments to heat and light, resulting in cracking during decay with increasing IR absorption (OH-bonds). Furthermore, sunlight over three years reduced pellet mass and diameter (~10% and ~40%), initially yielding 100-300 μm fragments. Changes under UV irradiation were smaller as it could not penetrate into particle interiors. Characteristic spacing of surface striations (100-300 µm) initiated radial cracks to pellet interiors, and breakdown ultimately meant 95% of particles were <300 µm, which are potentially incorporated in marine turbidites.

The change in air quality in cities can be the product of regulation and emissions. Regulations require enforcement of emission reduction, but it is often shifting economic and societal structures that influence pollutant emissions. This study examines the long-term record of air pollutants in Kaohsiung, where post-war industrialisation increased pollution substantially, although improvements are observed in recent decades as the city moved to a more mixed economy. The study tracks both gases and particles across a period of significant change in pollution sources in the city. Concentrations of SO 2 and aerosol SO 4 2− were especially high ~1970, but these gradually declined, although SO 4 2− to a lesser extent than its precursor, SO 2 . While twenty-first century emissions of SO 2 and NO x have declined, this has been less so for NH 3 , because it arises from predominantly agricultural sources. The atmosphere in Kaohsiung continues to have high concentrations of O 3 , and these have risen in the city, likely a product of less titration by NO. The changes have meant that ozone has become an increasing threat to health and agriculture. Despite a potential for producing (NH 4 ) 2 SO 4 and NH 4 NO 3 aerosols, a product of a relatively constant supply of NH 3 , visibility has improved in recent years. Emissions of SO 2 and NO x should continue to be reduced, as these strongly affect the amount of fine secondary aerosol. However, the key problem may be ozone, which is difficult to control as it requires careful consideration of the balance of NO x and hydrocarbons so important to its production.