Environmental Science: Processes & Impacts最新文献

Correction for 'Chemical fingerprints of cooking emissions and their impact on indoor air quality' by Ashish Kumar et al., Environ. Sci.: Processes Impacts, 2025, 27, 3665-3682, https://doi.org/10.1039/D5EM00385G.

Organic peroxides (POs) are an important component of secondary organic aerosol (SOA) and contribute to the generation of reactive oxygen species associated with adverse health effects. However, their molecular-level evolution upon atmospheric aging, particularly in SOA from typical terpenes like limonene, remains poorly characterized. In this study, limonene SOA was generated in an oxidation flow reactor under controlled OH exposure (equivalent photochemical age, PCA = 0.6-13.2 days). The SOA yield exhibited a nonlinear peak at PCA = 7.4 days, followed by a decline at 13.2 days, a trend that was accompanied by a shift in RO₂ reaction pathways from dimerization to reactions with excess oxidants. POs were quantified using iodometry-assisted high-resolution mass spectrometry (HRMS), and their yields decreased progressively with aging. It was found that 100% of highly oxygenated organic molecules (HOMs) were POs at low OH exposure (0.6 days), whereas only 27% of HOMs were POs at high OH exposure (13.2 days), indicating rapid conversion to non-peroxide, highly oxidized molecules (e.g., acids or esters). Key monomeric (C₈-C₁₀) and dimeric (C₁₅-C₁₉) species were identified at the molecular level. This work elucidates the fate of POs within aged SOA, highlighting the limitations of using HOMs as proxies for POs, and provides critical information for assessing the health risks of SOA.

Isocyanates are recognized as potent irritants and sensitizing agents. Accurate quantification of their airborne concentrations in occupational settings remains a significant analytical challenge due to their high chemical reactivity and semi-volatile nature, that is, their capacity to exist simultaneously airborne in both vapor and particulate phases. This study complements prior laboratory work by evaluating isocyanate sampling methods in an actual automotive repair facility. It investigates spatial distribution in samplers and assesses whether lab-based simulations yield comparable results to real-world conditions during HDI spray applications, supported by contextual analysis. This evaluation involved the comparison of three filter methods to the reference method-an impinger with a backup glass fibre filter (GFF) and 1,2-methoxyphenylpiperazine (MP) based on ISO 16702/MDHS 25- during the application of HDI based polyurethane coatings: (1) Swinnex cassette 13 mm GFF MP (MP-Swin); (2) closed-face cassette 37 mm GFF (end filter and inner walls) MP (MP-37); and (3) denuder and GFF dibutylamine (DBA) (ISO 17334-1 Asset). Using a cascade impactor, the particle-size distribution (MMAD) was determined to be 15 µm. The analysis identified distinct patterns in the distribution of HDI and isocyanurate across the sampler sections. These patterns were similar to those observed in the laboratory study, but consistent with the larger particle size observed in the tested environment. SEM imaging revealed substantial coating droplet accumulation on filters, potentially hindering derivatization efficiency. Of all the methods tested, only the MP-Swin method showed a significant negative bias for HDI (-47%). All filter methods underestimated isocyanurate levels compared to the reference, with a bias ranging from -40% to -59%. Using a low-speed activator reduced biases, suggesting that high reactivity limits isocyanate derivatisation, which leads to underestimation of the measurement. Field results were more variable and partially contradicted laboratory findings, which had shown no significant bias between tested methods and the reference. These findings emphasize the importance of field extraction in airborne isocyanate sampling and caution against relying solely on filter methods when fast-reacting compounds are present. The study underscores the complementary value of field and laboratory comparisons and highlights the influence of sampling device design and chemical reactivity on accurate isocyanate quantification.

Many industrial chemicals are recognized as carcinogenic to humans. In this study, we developed predictive models for binary carcinogenicity data in rats that are closely associated with human carcinogenicity. This study involves a range of feature-based and chemical language modeling approaches. After the training-test split and selection of essential structural and physicochemical descriptors, we developed a simple linear discriminant analysis model. Thereafter, we computed similarity- and error-based descriptors, pooled them with structural and physicochemical descriptors, and developed classification read-across structure-activity relationship (c-RASAR) models using a range of machine learning algorithms, including an artificial neural network (ANN). Additionally, the pooled feature matrix was used to compute two ARKA (arithmetic residuals in K-groups analysis) descriptors, and a simple logistic regression model was trained on the two-descriptor feature matrix. Moreover, we adopted the long short-term memory (LSTM) architecture to develop a model based on SMILES strings. The results suggested that the logistic regression RASAR-ARKA model was the best-performing, and it was subsequently used to predict external data efficiently, along with the ANN c-RASAR model. Moreover, the ARKA framework allowed us to identify activity cliffs and explain the reason for mispredictions. In addition to providing an efficient prediction framework, the structure-function analysis suggests that the presence of nitrogen atoms, including in hydrazine derivatives and nitrosamines, and greater branching are responsible for carcinogenicity, while increased molecular size reduces the carcinogenic potency.

We assessed potential exposures to a broad suite of contaminants (inorganic, organic and microbial) in culturally important surface waters from three watersheds in a northern plains Native American community (Apsáalooke [Crow Tribe of Montana]) in south-central Montana, United States, with water insecurity concerns. Inorganic (37), organic (435) and microbial (3) constituents were assessed in 12 surface water sites from the Pryor Creek (n = 2), Bighorn River (n = 2) and Little Bighorn River (n = 8) valleys. Twenty-six organics, 33 inorganics and Escherichia coli were detected. Despite relatively low concentrations in surface waters within the Crow Reservation, mixture toxicity indicated prevalent chronic ecological effects and human-health secondary contact (recreation) effects at multiple sites. Further, to address Tribal concerns over the prevalence and corresponding risks of per- and polyfluoroalkyl substances (PFAS), we sampled water, sediment, biofilms and fish at a limited number of locations in the Little Bighorn River. Results indicated that PFAS were prevalent in fish tissues, including whole blood and filets, and to a lesser extent in biofilms, despite few detections in water and sediment samples. This is the first attempt to document environmental PFAS contamination within the reservation and the potential human-health concerns for the general population from consumption of recreational/subsistence fish. Overall, this effort provided preliminary information on the contaminant mixtures present and their potential health implications, which can support the protection of community health and culturally meaningful resources across the Crow Reservation.

A total of 44 PM_2.5 samples were collected intermittently over three winter months (December 2021-February 2022) in the urban center of Chongqing, a city in southwestern China, and analyzed for per- and polyfluoroalkyl substances (PFAS, 20 species). The concentrations and compositions of the PFAS were analyzed by HPLC-MS/MS to determine their sources and potential human health risk. The PFAS concentrations ranged from 70.3 pg m^-3 to 404.9 pg m^-3, with an average of 197.1 ± 73.7 pg m^-3. Monthly variations were as follows: January (281.9 pg m^-3) > February (160.6 pg m^-3) > December (148.7 pg m^-3). The PFAS were dominated by perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and 2-perfluorohexyl ethanoic acid (6:2 FTCA). Positive Matrix Factorization (PMF) identified aqueous film-forming foam (AFFF) (43.2%) and precursor degradation (38.3%) as the main sources, followed by lifestyle-related pollution (18.5%). Median Estimated Daily Intake (EDI) for children (age-stratified: 0-6, 6-12, 12-15, 15-18 years) and adults for PFOA (7.69 pg per kg per day) and perfluorooctane sulfonate (PFOS) (0.52 pg per kg per day) was substantially below the U.S. EPA reference dosage (20 000 pg per kg per day). The Hazard Quotient (HQ) was far lower than 1, indicating negligible inhalation-related risk. The results of these two models both implied acceptable PFAS exposure levels. However, prolonged cumulative exposure via PM_2.5-bound PFAS inhalation warrants greater attention due to their lifelong health implications.

Dechlorane Plus (DP) is a widely used flame retardant in various electronic devices. E-waste (EW) dismantling workers could be widely exposed to DP, but related studies are still limited. Therefore, we conducted an extensive study on the levels of DP and its dechlorinated derivatives (anti-Cl₁₁-DP and Cl₁₀-DP) in various environmental and human samples from a typical e-waste dismantling site located in China. Paired hair, hand wipe, indoor air, and indoor dust samples were collected from EW workers, non-EW workers and nearby residents. Hair was divided into an external fraction (hair-Ex) from surface washing and an internal fraction (hair-In) from digested washed hair. Our findings indicated that the DP concentrations in air and dust samples varied between 7.44 and 6200 pg m^-3 and 0.355 and 7000 ng g^-1, respectively. The DP concentrations in hair-internal, hair-external, and hand wipe samples varied between 0.896 and 39.9 ng g^-1, 0.954 and 66.1 ng g^-1, and 1.25 and 1080 ng g^-1, respectively. The fractional abundance of anti-DP (f_anti) in hair-internal samples was significantly lower than in other samples (P < 0.05). Concentrations of anti-Cl₁₁-DP in both internal and external hair samples collected from EW recycling workers demonstrated statistically significant reductions relative to adult non-occupationally exposed individuals. This disparity may arise from the restricted metabolic clearance capacity of anti-Cl₁₁-DP in human physiological systems. The median proportion of anti-Cl₁₁-DP relative to ∑DPs was significantly elevated in hair-internal samples compared to both indoor dust samples (P < 0.05) and hair-external samples (P < 0.05), indicating a substantial enrichment of anti-Cl₁₁-DP in humans.

Continuous carbon (C) and nitrogen (N) inputs significantly affect cadmium (Cd) redistribution in soil aggregates, yet their impacts remain poorly understood. This study investigates Cd redistribution under labile C and two N sources (glucose + nitrate [CN], glucose + ammonium [CA], and glucose alone [CT]). CN and CA treatments increased Fe and Mn oxide-bound Cd (F3-Cd) by 99.7% and 38.7% in bulk soil, respectively, while CT reduced F3-Cd by 33.1%. Increased dissociative Fe oxides (DCB-Fe) and decreased Fe²⁺, coupled with NO₂^- consumption, confirmed enhanced NO₂^- reduction and Fe²⁺ oxidation in F3-Cd formation. Carbonate-bound Cd (F2-Cd) and organic matter-bound Cd (F4-Cd) also increased significantly (42.0-121.5%) across all treatments. Feature importance analysis highlighted dissolved organic carbon (DOC) as a key driver for F2-Cd, while DOC, amorphous Fe (oxalate-Fe), and soil organic carbon (SOC) influenced F4-Cd. Micro-aggregates (MAs) had higher F4-Cd levels compared to large macro-aggregates (LMAs) and small macro-aggregates (SMAs). Partial least squares path modeling showed that DOC influenced F2-Cd in LMAs, nitrate and ammonium cycling affected F3-Cd in SMAs, and genes related to Fe cycling and nitrification drove F4-Cd in MAs, potentially impacting mineral-associated SOC. Understanding C and N inputs' effects on Cd redistribution can improve remediation strategies for Cd pollution in agricultural soils.

Arsenic exposure is a major global health challenge. In addition to well-documented toxic effects in exposed people and animals, there is evidence that exposure to arsenic may lead to transgenerational effects. Transgenerational effects of low levels of exposure are challenging to study in species with long generation times. The model organism Caenorhabditis elegans offers the ability to quickly carry out transgenerational experiments with very large sample sizes of isogenic animals, reducing variation, and numerous biological replicates, to increase statistical rigor. An important challenge historically associated with this species for such work is uncertainty about internal dosimetry and toxicokinetics. Here, we report a 4-generation experiment in which C. elegans were exposed during larval development to sodium arsenite concentrations in the parental generation at concentrations resulting in no or mild growth inhibition up to significant growth inhibition. These exposures resulted in internal concentrations between 0.4 and 6.7 nM and rapid excretion (t_1/2 = 3 hours), despite the lack of arsenic methylation in this species. These exposures had strong and significant effects on the exposed generation later in life, but no transgenerational effects were detected. We discuss possible reasons for this "negative" result. We also report strong similarity of the nematode transcriptomic, metabolomic, and fat accumulation responses in the exposed generation to responses reported in other organisms, including persistent alterations in cysteine and fatty acid metabolism, phase II and III metabolic processes, and increased adiposity. Finally, we discuss ways to take advantage of this species difference in arsenic metabolism for the use of C. elegans in toxicology testing.

Fires in the wildland-urban interface (WUI) introduce pyrogenic organic contaminants to surface waters, but their impacts on microbial dynamics have not been evaluated. We studied the interactions between microbial communities and pyrogenic carbon during post-fire storms in a WUI fire-impacted creek in Orange County, CA. The first storms following the fire (low intensity) brought about the highest discharges of polycyclic aromatic hydrocarbons (PAHs), e.g. benzo[a]pyrene, benz[a]anthracene. Dissolved organic carbon (DOC) loads reached up to 11.2 g-C s^-1 during the more severe storms. PAHs correlated with each other but not with DOC or fluctuations in turbidity, suggesting these two variables might not be good predictors of PAH flushes, especially in low-intensity storms. Microbial genera with known PAH-degrading members were differentially abundant during post-fire storms (Pseudomonadota, Bacteroidota, Cyanobacteriota, Actinobacteriota, Bacillota). In addition, predicted metabolic pathways related to the PAH biodegradation intermediates, catechol and protocatechuate, increased significantly at sites downstream of the fire. Overall, our findings suggest pyrogenic carbon from the fire resulted in a detectable shift in microbial community function and composition to favor PAHs degradation just a few months after the fire. This response suggests that PAH-degrading microorganisms are readily found after WUI fires.