Environmental Science: Processes & Impacts最新文献

In the indoor environment, occupants are exposed to air pollutants originating from continuous indoor sources and exchange with the outdoor air, with the highest concentration episodes dominated by activities performed indoors such as cooking and cleaning. Here we use the INdoor CHEMical model in Python (INCHEM-Py) constrained by measurements from the House Observations of Microbial and Environmental Chemistry (HOMEChem) campaign, to investigate the impact of a bleach cleaning event and cooking on indoor air chemistry. Measurements of the concentrations of longer-lived organic and inorganic compounds, as well as measured photolysis rates, have been used as input for the model, and the modelled hydroxyl (OH) radicals, hydroperoxyl radicals, and nitrous acid (HONO) concentrations compared to the measured values. The peak modelled OH, , and HONO concentrations during cooking and cleaning activities are about 30%, 10%, and 30% higher than the observations, respectively, within experimental uncertainties. We have determined rates for the rapid loss of HONO formed through cooking activities onto a wet surface during the cleaning events and also for the subsequent slow release of HONO from the cleaned surface back into the gas-phase. Using INCHEM-Py we have also predicted peak concentrations of chlorine (Cl) atoms, (0.75–2.3) × 10⁵ atom per cm³ at the time of cleaning. Model predictions of the Cl atom and OH radical reactivities were also explored, showing high Cl atom reactivity throughout the day, peaking around 5000–9000 s⁻¹. The OH reactivity was found to increase from a background value close to urban outdoor levels of 20–40 s⁻¹, to levels exceeding observations in outdoor polluted areas following cooking and cleaning activities (up to 160 s⁻¹). This underlines the high oxidation capacity of the indoor atmospheric environment through determining the abundance of volatile organic compounds.

Correction for ‘Fluorinated aromatic PCBTF and 6:2 diPAP in bridge and traffic paints’ by Mitchell L. Kim-Fu et al., Environ. Sci.: Processes Impacts, 2024, https://doi.org/10.1039/D4EM00546E.

Per- and polyfluoroalkyl substances (PFAS) are a resilient class of anthropogenic contaminants of emerging concern with over 12 000 individual compounds that have been noted for industrial applications, consumer goods, and food packaging materials. In general, the most common contributors to PFAS environmental pollution are aviation facilities, specifically those that use aqueous film forming foams (e.g., at military bases and airports). In this study, we examined the presence of PFAS across Okinawa Island (Japan) due to its large-scale U.S. military presence throughout the island. Surface water was collected at 61 sites across the island to achieve maximum geographical coverage of the island while also collecting near suspected PFAS sources; 31 PFAS were monitored using a 12 min HPLC-MS/MS method. A total of 15 PFAS were detected and quantified around the island with a mean Σ₁₅PFAS of 16.3 ng L⁻¹ and a maximum site concentration of 164.3 ng L⁻¹. Region-specific PFAS profiles were observed across the island, including the overwhelming presence of PFHpA in the northern region of the island, revealing the possibility of multiple PFAS source points in Okinawa. The resultant data herein provides the first island-wide examination of PFAS “hotspots” across Okinawa and is a critical first step toward increasing PFAS awareness and action.

Urinary hydroxylated-polycyclic aromatic hydrocarbons (PAHs), with half-life less than 2 days, are established biomarkers of short-term exposure to PAHs, a ubiquitous constituent of air pollution mixture. In this study, we explore the use of PAHs-hemoglobin adducts as biomarkers of longer-term exposure to air pollution by leveraging an extant resource of blood samples collected from 235 pregnant women residing in Rochester, NY. We measured red blood cells for benzo[a]pyrene-tetrols (BaPT) and phenanthrene-tetrols (PHET), both of which are hydrolysis products of PAH-hemoglobin adduct. We utilized previously estimated PM_2.5 and NO₂ concentrations within the 1 km² grid surrounding each participant's residence, calculated for up to 20 weeks before the blood collection date. Associations between PAHs tetrols and cumulative exposures to ambient PM_2.5 or NO₂ over different time periods were examined using a linear mixed-effects model with participant-specific random intercepts adjusting for season, gestation age, maternal age, maternal income level, and pre-pregnancy BMI. We observed positive associations between PHET concentration and cumulative PM_2.5 exposure over gestational weeks 12–17, and between BaPT concentration and cumulative PM_2.5 exposure over gestational weeks 3–16 prior to sample collection. Each interquartile range (IQR) increase in 14 week PM_2.5 exposure (1.26 μg m⁻³) was associated with a 9.02% (95% CI: 0.30%, 17.7%) increase in PHET and a 12.8% (95% CI: 1.09%, 23.5%) increase in BaPT levels. In contrast, no associations were observed between either biomarker and cumulative NO₂ exposures. These findings underscore the potential of PAH-hemoglobin adducts as longer-term (weeks to 4 months) exposure biomarkers of ambient PM_2.5.

Background and objective: Coke oven emissions (COEs) are formed in the process of coking production, mainly composed of polycyclic aromatic hydrocarbons (PAHs) and benzene; however, the health impacts of COE exposure in coking workers are not fully clear so far. We aimed to explore the associations of occupational COE exposure with pulmonary function, blood pressure, blood cell parameters, and blood biochemical indices, and to bolster health surveillance and disease prevention and control in coking workers. Methods: We investigated 566 coking workers at a large state-owned enterprise coking plant in Taiyuan, Shanxi, China, measured the concentrations of plasma 16 PAHs and urinary phenol, assessed the health outcomes including pulmonary function, blood pressure, the levels of peripheral hematologic parameters and biochemical indices, and examined the associations of PAH and phenol concentrations with the health outcomes using multiple linear regressions, least absolute shrinkage and selection operator regression (LASSO), and Bayesian kernel machine regression (BKMR). Results: After adjustment for confounders, plasma ∑₁₅PAH concentration was significantly associated with increases in hemoglobin (HGB) and triglyceride (TG) levels in coking workers, and urinary phenol concentration was significantly associated with increases in the diastolic blood pressure (DBP) level, and decreases in platelet (PLT) count. When phenol concentration and PAH concentration were simultaneously included in the multiple linear regression model, both of them were associated with the level of HGB. LASSO and BKMR indicated that the PAHs with four rings and above contributed to the HGB level. Conclusion: PAH exposure could damage hematological parameters and blood lipids, and benzene exposure could increase blood pressure and decrease PLT count.

Siderite (FeCO₃) is an important reservoir of mineral-bound ferrous iron in non-sulfidic, reducing soils and sediments. It is redox sensitive, and its oxidation may facilitate the reduction of a range of pollutants, produce reactive oxygen species, or induce the formation of oxidation products with large surface areas for contaminant sorption. However, there is currently a limited understanding of the stability of siderite in complex environments such as soils and sediments. Here, we use a series of batch experiments complemented with thorough characterisation of mineral oxidation products to investigate the oxidation of siderite in the presence and absence of the low molecular weight organic acids (LMWOAs) citrate, tiron, salicylate, and EDTA as analogues for naturally occurring compounds or functional groups of natural organic matter that ubiquitously coexist with siderite. Our results show that siderite alone at pH 7.5 was completely oxidised to form ferrihydrite, nanocrystalline lepidocrocite, and nanocrystalline goethite in less than 6 hours. However, in the presence of LMWOAs, up to 48% of the siderite was preserved for more than 500 hours and the formation of goethite was inhibited in favour of ferrihydrite and lepidocrocite. Using experimental data from electron microscopy and chemical speciation modelling, we hypothesise that the siderite may be preserved through the formation of an Fe(III)-passivation layer at the siderite surface.

Correction for ‘Exploring the variability of PFAS in urban sewage: a comparison of emissions in commercial versus municipal urban areas’ by N. Krlovic et al., Environ. Sci.: Processes Impacts, 2024, 26, 1868–1878, https://doi.org/10.1039/D4EM00415A.

Per- and polyfluoroalkyl substances (PFAS) are reported in residential and commercial paints, but there are no data for paints used in the transportation sector. From 2023 to 2024, 16 traffic paints and 10 bridge paints were collected from Pacific Northwest regional transportation facilities or purchased and analyzed for total fluorine by ¹⁹F-nuclear magnetic resonance (NMR) spectroscopy, volatile PFAS by gas chromatography-mass spectrometry (GC-MS), and ionic target and suspect PFAS by liquid chromatography-quadrupole time-of-flight mass spectrometry. The only target PFAS identified was 6:2 fluorotelomer phosphate diester (diPAP) which ranged in concentrations from 0.065 to 13 μg g⁻¹. While 6:2 diPAP is not regulated in paints, it can undergo environmental transformation to act as a source of perfluoroalkyl carboxylic acids. A combination of ¹⁹F-NMR and GC-MS was used to quantify and identify the fluorinated aromatic PFAS, parachlorobenzotrifluoride (PCBTF), at concentrations from 440 to 16 000 μg g⁻¹ in bridge paints, thus PCBTF may contribute to work exposure and levels in urban air. Additionally, evolved gas analysis with mass spectrometry and pyrolysis-GC-MS established that the insoluble fraction of paints is not comprised of fluoropolymers. Based on the amount of paint required per kilometer, we estimate up to 0.20–2.30 g 6:2 diPAP per kilometer depending on marking type. Therefore, traffic paint may be a potential source of the PFAS detected in urban runoff.

This study investigated microplastic polyester fibres representative of those shed during laundering as sorbents for metal ions. During sewage distribution and treatment, microplastics are exposed to elevated concentrations of metal ions, typically for several days. Cryogenic milling was used to generate polyethylene terephthalate (PET) fibres. Characterisation using optical microscopy and Raman spectroscopy revealed that milling did not cause significant chemical alteration to the fibres. Milled fibres were subsequently assessed in screening tests for their capacity to retain 12 metal ions—Sb(III), As(III), Cd(II), Cr(VI), Cu(II), Co(II), Pb(II), Hg(II), Mo(VI), Ni(II), V(V) and Zn(II)—at pH 8. All metal ions were sorbed onto PET fibres. The highest distribution coefficient (K_d) was observed for Pb²⁺ (939 mL g⁻¹), followed by Cd²⁺ (898 mL g⁻¹), Cu²⁺ (507 mL g⁻¹), Hg²⁺ (403 mL g⁻¹), and Zn²⁺ (235 mL g⁻¹). The extent of sorption is largely explicable by electrostatic interactions between the PET surface (1.95 point of zero net charge) and the predicted metal ion species. The sorption behaviour of Cd²⁺ and Hg²⁺ was examined in more detail since both showed high sorption capacity and are highly toxic. Kinetic experiments revealed that the sorption of both elements was relatively fast, with a steady state reached within six hours. Experimental data from isotherm tests fitted well to the Langmuir sorption model and demonstrated that PET fibres had a much greater sorption capacity for Hg²⁺ (17.3–23.1 μg g⁻¹) than for Cd²⁺ (4.3–5.3 μg g⁻¹). Overall, the results indicate that retention of metal ions onto PET fibres originating from laundry is expected during full-scale sewage treatment, which facilitates the subsequent transfer of metals into the terrestrial environment, given that sewage sludge is commonly applied to agricultural land.

As microplastic (MP) particles continue to spread globally, their pervasive presence is increasingly problematic. Analyzing MPs in matrices as varied as soil, river water, and biosolid fertilizers is critical, as these matrices directly impact the food sources of plants, animals, and humans. Current analytical methods for quantifying and identifying MPs are limited due to labor-intensive extraction processes and the time and effort required for counting and analysis. Recently, Machine Learning (ML) has been introduced to the analysis of MPs in complex matrices, significantly reducing the need for extensive extraction and increasing analysis speeds. This work aims to illuminate various ML techniques for new researchers entering this field. It highlights numerous examples in the application of these models, with a particular focus on spectroscopic techniques such as infrared and Raman spectroscopy; tools which are used to quantify and identify MPs in complex matrices. By demonstrating the effectiveness of these computer-based tools alongside the hands-on techniques currently used in the field, we are confident that these ML methodologies will soon become integral to all aspects of microplastic analysis in the environmental sciences.