Environmental Science: Processes & Impacts最新文献

Firefighters are increasingly concerned about their exposure to per- and polyfluoroalkyl substances (PFAS). Polymeric PFAS are commonly used in the manufacturing and treatment of textiles designed for firefighters' turnout gear. This study was conducted to assess the effect of wear and tear on the concentrations and distribution of PFAS in used turnout gear by analyzing swatches taken from different areas from the different layers of the gear: the outer layer (OL), moisture barrier (MB), and thermal liner (TL). In the OL, samples collected from the bottom back of the pants showed higher concentrations of perfluoroalkyl acids (PFAAs) than samples taken from the knee, ankle, and groin areas. In the jacket, samples from the neck of the OL exhibited lower PFAA concentrations compared to samples taken from the back, elbow, and underarm areas. In addition, this study assessed PFAS profiles in the layers of five firefighter jackets (J) and four pants (P) manufactured between 2008 and 2019. The jacket manufactured in 2019, which had been in service for only one year, recorded the lowest PFAS concentration at 284 ng g⁻¹. Notably, fluorotelomer alcohols (FTOHs, including n = 6, 8, 10) were detected in all samples, accounting for over 50% of the total PFAS content. Generally, perfluorooctane sulfonate (PFOS) was found in older jackets, while perfluorobutane sulfonate (PFBS) was detected in newer jackets. Interestingly, the highest concentrations of FTOHs in the MB occurred in unused gear (DOM 2011), and these concentrations increased over time since manufacture, with the lowest levels found in newer and lightly used gear (DOM 2019). Moreover, the thermal liner from the unused gear had the lowest PFAS concentration.

Indoor environments host multiple sources of volatile organic compounds (VOCs) that influence the air quality, with cooking being one such significant and complex emission source. VOC emissions from cooking vary with the type of food cooked, ingredients used, cooking methodology, and ventilation, yet their speciation and impact on indoor air remain poorly understood. This study quantifies real-time emission rates of 39 VOCs from three frequently prepared UK meals: stir-fry, curry, and chilli, using a high-sensitivity selected ion flow tube mass spectrometer (SIFT-MS) in a room-scale, semi-realistic kitchen. Across 39 cooking experiments a distinct VOC emission profile for each meal was measured. The emissions were dominated by alcohols (methanol and ethanol, >50% of total emissions), harmful aldehydes (acetaldehyde, 7–23%), and highly reactive monoterpenes (up to 4%). The emissions were found to be influenced strongly by the use of different variants of the same ingredient (freshly chopped and packaged diced onions), spices and cooking behaviours. The secondary chemistry of the resultant VOC emissions was further investigated by simulating the hydroxyl (OH) reactivity and secondary product formation using INCHEM-Py. The model results show that the cooking plumes significantly perturbed the indoor chemistry, with OH reactivity ranging from 50–200 s⁻¹ depending on VOC composition. Further simulations of a typical urban London kitchen revealed recipe-dependent impacts on radical (HO₂, RO₂) and secondary pollutant (O₃, PAN, organic nitrates, formaldehyde) formation. Among the meals tested, chillies exhibited the highest potential for secondary pollutant production, followed by curries. These findings highlight the influence of cooking emissions on indoor air quality and secondary chemistry.

Water quality post-wildfire is often impaired by increased turbidity and elevated concentrations of elements such as manganese (Mn) and iron (Fe). Precipitation events exacerbate these issues, due in part to increased erosion and transport of sediment from hillslopes to surface water. Both Mn and Fe are major redox-active elements in sediments that drive a variety of biogeochemical cycles, precipitate adsorptive phases, and can themselves be drinking water contaminants. By investigating Mn and Fe sediment geochemistry in post-wildfire sediment deposits, related water quality hazards can be assessed. To establish and strengthen this connection, we analyzed the geochemistry of sediment deposits and surface water in the Gallinas Creek watershed, New Mexico over 1.5 years post-wildfire. Analyses included particle size analysis, water extractions, sequential extractions and aqua regia extractions to determine metal partitioning in sediment deposits. Data demonstrate Mn concentrations were distributed across labile and reactive fractions, such as the exchangeable and oxyhydroxide fractions, while Fe concentrations were mainly associated with the residual fraction. Manganese concentrations in aqua regia extractions and several fractions of sequential extractions were also strongly and significantly correlated with fine-grained sediment while the same pools of Fe concentrations were not. Dissolved Mn concentrations in surface water were elevated (>50 μg L⁻¹) multiple times over the 1.5 years post-wildfire, highlighting a relationship between sediment geochemistry and water quality. This work shows Mn in sediments mobilized post-wildfire has an influence on water quality and highlights how further investigation into Mn sediment redox processes and mineralogy post-wildfire can inform risk assessments and resource management.

Dust containing potentially toxic trace elements (TEs) from open pit mining, smelting of metallic ores, aggregate extraction, and road dust is a major concern worldwide. The potential ecological significance of TEs in these dusts, however, depends not only upon their concentrations, but also their physical and chemical forms. Here, dusty snow from the Athabasca River (AR) which bisects an open-pit bitumen mining and upgrading area in Canada was collected to perform size-resolved analysis of selected TEs. Conservative, lithophile (Al, Th, Y), bitumen-enriched (Mo, Ni, V), and chalcophile (As, Cd, Pb, Sb, Tl) elements were overwhelmingly found in the particulate fraction (>0.45 μm), with concentrations increasing toward industry. The mineralogical composition of this fraction was similar to dusts from natural and anthropogenic sources in the area. In the “filterable” fraction (<0.45 μm), Al, Mo, and V in snow were elevated near industry. Within the filterable fraction, TEs occur predominantly in the “truly dissolved” fraction (<300 Da): these are assumed to be ionic species and small molecules, and represent potentially bioavailable species. However, the concentrations of TEs in this fraction were extremely low: for perspective, Cd and Pb are similar to values reported for ancient Arctic ice. Within the filterable fraction at midstream sites, up to 30% of Ni and 37% of Y were associated with organic colloids (≈1 kDa) which may be from bitumen and soil-borne sources, respectively. Except for V, TE concentrations in the filterable fraction of snow were below the average values for the AR and the global average for uncontaminated river water. Consequently, the threat to aquatic life in the river by TEs in snowmelt may be limited.

Calibrated 3D-printed multi-modal passive sampler devices (3D-PSDs) were used herein both to monitor contaminants of emerging concern (CECs) in freshwater and to estimate in situ chemical toxic and effect units for the aquatic invertebrate, Gammarus pulex, to support prioritisation strategies. A six-month study of water, biota, and 3D-PSDs in a heavily wastewater-impacted urban river catchment in London revealed 112 CECs detected, including pesticides, pharmaceuticals, illicit drugs and transformation products (water = 50; 3D-PSDs = 99; and G. pulex = 58 CECs). In G. pulex, the top three most concentrated CECs were citalopram (an antidepressant, at 101 ± 11 ng g⁻¹), imidacloprid and clothianidin (both neonicotinoid pesticides, at 63 ± 12 and 52 ± 39 ng g⁻¹, respectively). Principal component analysis revealed that passive sampler data represented chemical occurrence in the G. pulex better than using water data. Strong correlations existed between the passive sampler and biomonitoring data (R² > 0.84, p < 0.05) indicating a possibility to infer risk from the device directly and without using calibrated PSD uptake rates (R_s). This new approach showed promise as a potentially cost-effective way to rapidly prioritise sites and CECs for large-scale risk assessment campaigns for these species.

Rare earth elements (REEs) are scarce in surface water, although areas impacted by acid mine drainage (AMD) display REE concentrations that are several orders of magnitude higher than those in freshwater and seawater. AMD neutralization as a result of mixing with seawater in estuaries induces a spontaneous precipitation of Fe- and Al-oxyhydroxysulfate nanominerals (i.e., schwertmannite and basaluminite, respectively). Although the affinity of REEs for these minerals under AMD conditions has been addressed, the effects of an increase in pH and ionic strength observed in AMD-impacted estuaries have not been investigated. In this work, REE adsorption onto schwertmannite and basaluminite has been studied in the pH range of 4.5–7 and ionic strength range of 0.25–0.5 M by batch experiments and extended X-ray absorption fine structure (EXAFS) analysis. Adsorption batch experiments show (1) that REEs have higher affinity for the schwertmannite surface than for basaluminite and (2) that the REE adsorption is strongly dependent on pH and weakly dependent on ionic strength. The log K_REE values calculated from the REE adsorption onto schwertmannite were implemented in a non-electrostatic surface complexation model (NESCM), reflecting that REEs are retained through monodentate and bidentate surface coordination at pH below and above 5.25, respectively. As for basaluminite, NESCM and EXAFS results indicate that REEs are retained by monodentate binuclear coordination in heavy and medium REEs, whereas light REEs form outer-sphere complexation with a resulting increase in the basaluminite adsorption capacity at higher ionic strength. Thus, the thermodynamic parameters provided in this study prove useful to predict the geochemical behaviour of REEs in AMD-impacted estuarine areas.

Cadmium (Cd)-bearing sphalerite occurs in carbonate-hosted zinc (Zn) deposits and can be deposited as particulate matter (PM) on the surrounding soils during mining activities. Weathering of the sphalerite-bearing PM releases Cd, yet the role of associated carbonates in controlling Cd mobility remains unclear. This study investigates Cd mobilization from carbonate-hosted sphalerite ore particles (SP) and Cd distribution between solid and aqueous phases in acidic and alkaline soils. At low Ca/S ratios, sphalerite dissolution led to similar annual Cd mobilization rates in acidic (1.41 μg Cd per g SP per a) and alkaline soils (1.29 μg Cd per g SP per a). However, higher Ca/S ratios significantly reduced Cd mobility due to Cd retention as CdCO₃ in both solid and solution phases. In acidic soils, Cd-bearing sphalerite weathering caused Cd depletion and enrichment in sulfide ore and CaCO₃ phases, respectively. In alkaline soils, CdCO₃ nanomaterials precipitated on zincite due to the incompatibility of Cd with the structure of ZnO and its desorption from the negatively charged Fe (hydr)oxide surfaces. For all characterized samples, nanoparticulate (nano)-Cd showed significant positive correlations with nano-Fe and nano-organic carbon (bulk chemical data) and was sequestrated as CdCO₃ nanomaterial by OM-Fe (hydr)oxide colloids in soil solutions (TEM data). These observations highlight that Cd-bearing nanomaterials control Cd mobilization in carbonate-rich soils affected by sphalerite-bearing PM deposition.

In many developing countries, increasing waste volumes are often dumped in unlined, poorly managed sites that are prone to frequent fires. Firefighting typically involves excessive water spraying, which produces large volumes of combustion derived runoff (CDR), a toxic liquid similar to landfill leachate. This runoff can severely pollute nearby ecosystems. This study presents the first comprehensive field assessment of CDR from a municipal solid waste (MSW) fire under tropical conditions. It combines ecotoxicological indicators, spatial modelling, and risk evaluation tools, based on the Brahmapuram dumpyard fire breakout in Southern India as a case study. This site, located in a tropical region, received about 400 m³ of water per day during the fire to suppress flames and smoke. While previous studies have focused on air emissions or general leachate, the environmental impact of CDR, particularly its flow into soil and water, has remained largely unexamined. This research fills that gap by analyzing fire residues, CDR, soil, sediment, and nearby surface and groundwater for contamination. Results showed that CDR had characteristics of stabilized landfill leachate, with low biodegradability (BOD : COD ratio is 0.11) and high toxicity, making it difficult to treat using conventional biological processes. Soils exposed to CDR had extreme heavy metal contamination, with a pollution load index over 100. The leachate pollution index was lower than those in past reports due to the dilution effect of water spraying. However, the overall mass of trace metals reaching downstream areas was higher due to the large CDR volume. Spatial mapping confirmed heavy metal enrichment in CDR affected zones. Leachability tests also suggested that up to 25% of metals in fire residues could percolate over time, posing serious long-term risks to soil and water. The study calls for immediate updates to fire suppression strategies, including engineered containment, environmental monitoring, and post-incident leachate management to reduce long-term ecological harm.

The long-term fate of tire and road wear particles (TRWP) significantly governs the distribution of tire-related chemicals. In addition to previous lab experiments a field study is performed, exposing TRWP and cryo-milled tire tread (CMTT) to sunlight for 20 months and to microorganisms in water in a sedimentation pond for 17 months. No indications of physical disintegration were obtained over all experimental times and conditions. The extractable concentration of 27 polar and moderately polar compounds was analyzed by liquid-chromatography-mass spectrometry (LC-MS), among them tire additives such as para-phenylenediamines, phenylguanidines, benzothiazoles and known transformation products. Total quantified extractables (TQE) decreased for about 62–92% within the first sampling period of 8–10 months. However, even after 17–20 months concentrations of 100–200 μg g⁻¹ of TQE remained in TRWP, mainly benzothiazolesulfonic acid (BTSA) and hydroxy-benzothiazole after sunlight exposure and N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine (6-PPD) after exposure in the sedimentation pond. For the sunlight exposure the results of this long-term field study are well comparable to the results of a previous lab study. A laboratory study on (bio) degradation in water with optimized conditions appears to overestimate both leaching and (bio) degradation occurring in the sedimentation pond. Despite these differences, this field study confirms the previous conclusion that, while a substantial part of the polar and moderately polar chemicals is rapidly released, tire particles can be a long-term source of tire-related chemicals. Preventing TRWP from entering aqueous environments would substantially reduce the load of polar and moderately polar compounds transported with them.

Oxidation flow reactors (OFRs) are essential tools for simulating atmospheric aging of aerosols, yet conventional laminar-flow designs often suffer from non-uniform oxidant exposure, broad residence time distributions (RTDs), and significant wall losses, limiting their ability to replicate real-world gas-and-particle-phase processes. Here, we present the design, hydrodynamic characterization, and experimental validation of a novel Annular Cylindrical Oxidation Flow Reactor (AC-OFR) featuring an optimized annular-flow geometry. Using computational fluid dynamics (CFD) simulations and a full factorial design of experiments, we identified reactor dimensions that minimize recirculation and dead volume, achieving RTDs approaching ideal plug flow for both gases and particles. Experimental measurements confirmed high transmission efficiencies for ozone, sulfur dioxide, and particles (50–800 nm), with strong gas-particle coupling and minimal wall losses. The AC-OFR enables precise, tunable oxidant exposures—reaching OH radical exposures equivalent to 0.5–15.3 days with 7 s⁻¹ of external OH reactivity added and ozone exposures up to 0.74 days of atmospheric aging—by adjusting the UV lamp free surface. Validation experiments with α-pinene demonstrated steady-state secondary organic aerosol (SOA) yields (0.11–0.14) consistent with or exceeding those reported for traditional OFRs and revealed robust nucleation and growth dynamics. The AC-OFR thus provides a flexible, high-performance platform for controlled gas and gas-particle oxidation studies, bridging laboratory experimentation and atmospheric processes.