Environmental Science: Processes & Impacts最新文献

The release of microplastics (MPs) from nylon tea bags poses a critical concern for human exposure; however, their detection and quantification remain challenging especially in beverage matrices, and hence, this study pioneers the use of high-resolution optical coherence tomography (OCT) integrated with an image processing algorithm to rapidly detect and quantify the size and count of the MPs directly in the water extractions simulating tea brewing. The water extractions prepared by simulating tea brewing conditions, hot (100 °C, 1–5 min), cold (2 °C, 1 h), and ambient (30 °C, 1 h), were observed employing OCT imaging and validated through Nile Red (NR) staining and digital microscopy. The nylon tea bags steeped in hot water for 5 minutes released 16 000 to 24 000 LMPs (>30 µm) and SMPs (12–30 µm) per millilitre. The estimated daily intake (EDI) of MPs indicates a higher exposure for children (ranging from 0.201 to 0.349 mm³ kg⁻¹ day⁻¹) compared to adults (0.046 to 0.080 mm³ kg⁻¹ day⁻¹). In contrast, cold brewing for 1 hour released fewer LMPs but an equal quantity of small MPs (SMPs) compared to hot brewing. This OCT-based approach offers a rapid, versatile platform for the detection and quantification of MPs from diverse packaging materials and provides a powerful tool for comprehensive risk assessment when combined with chemical and toxicological analyses.

The environmental fate of tetracycline (TC, a widely used antibiotic) may be influenced by iron oxide particles and surfactants, which are common in aquatic systems. Currently, the impacts of co-existing surfactants (e.g., chemical and bio-surfactants) on TC adsorption to iron oxides remain poorly understood. This study employed two representative anionic surfactants—sodium dodecyl sulfate (SDS, a synthetic chemical surfactant) and rhamnolipid (Rha, a common glycolipid biosurfactant) to investigate their influences on TC adsorption behaviors onto two typical iron oxide minerals (goethite and hematite). Generally, goethite exhibited a higher affinity for TC than hematite, which was caused by the different surface area and surface charges of the two minerals. Interestingly, both surfactants facilitated TC adsorption through the surfactants' bridging effects. Meanwhile, the degree of the promotion impacts of surfactants (Rha or SDS) on TC adsorption was iron oxide type-dependent (goethite > hematite), which was related to diverse adsorbed amounts of surfactants on iron oxides. Note that SDS demonstrated a superior influence on TC adsorption than Rha, which was ascribed to the fact that more TC could be bound to iron oxides in systems containing SDS due to the stronger bridging effect. Additionally, the magnitude of the surfactant-mediated enhancement of TC adsorption decreased progressively from pH 5.0 to 9.0 because of the diverse surfactant-binding abilities of iron oxides under various pH conditions. These findings advance the fundamental understanding of antibiotic behaviors and fate in soil–water systems containing ubiquitous surfactants.

Predicting aquatic photodegradation remains challenging due to the simultaneous occurrence of multiple degradation pathways. While direct photolysis rates can be predicted from molar absorptivity and quantum yield, predicting indirect photodegradation requires quantifying both the bimolecular reaction rate constants with various photochemically produced reactive intermediates (PPRI) – including hydroxyl radicals (˙OH), singlet oxygen (¹O₂), and triplet excited states of chromophoric dissolved organic matter (³CDOM*) – and the steady-state concentrations of the PPRI. Yet, using laboratory measurements of these properties to predict photodegradation in environmental waters and quantify the relative contributions of individual pathways have not been evaluated across diverse chemical structures. In this study, photodegradation rates of 30 pesticides were measured in two CDOM solutions and compared to predicted values. The dominant degradation pathway was predicted to be direct photolysis for five pesticides, ˙OH reactions for five pesticides, and ³CDOM* reactions for 20 pesticides. Nevertheless, predicted rates often overestimated measured rates seemingly because of (1) higher reactivity of the selected triplet excited state model sensitizer (3-methoxyacetophenone, ³3-MAP*) relative to ³CDOM*, (2) the effects of antioxidants, and (3) overestimating reactive [³CDOM*]_ss due to using a probe compound that is more reactive with ³CDOM* than many organic pesticides. Adjusting for these factors, when possible, and accounting for quenching of ˙OH by the probe compound resulted in predicted rates 0.24–13.1 times the measured rates. Reactions with ˙OH became the dominant pathway for most of the pesticides previously predicted to primarily react with ³CDOM*. Based on these results, environmental half-lives under near surface conditions were predicted to range from 0.04 to 202 days across pesticides depending on the dominant pathway and environmental conditions. Notably, pesticides sharing the same dominant degradation pathway had similar t_1/2 ranges, indicating that environmental conditions will have a large influence on potential photodegradation rates. Consequently, identifying the relevant photodegradation mechanisms for a given chemical can be used to more accurately model environment-specific persistence, and this mechanistic approach should be integrated into regulatory frameworks.

Correction for ‘The sinking behavior of micro–nano particulate matter for bisphenol analogues in the surface water of an ecological demonstration zone, China’ by Yuanfei Cai et al., Environ. Sci.: Processes Impacts, 2021, 23, 98–108, https://doi.org/10.1039/D0EM00366B.

Climbing shoe abrasion generates fine rubber particles, leading to elevated concentrations of rubber-derived compounds (RDCs) in airborne particulate matter and settled dust of indoor climbing halls, in some cases comparable to levels measured near high-traffic roads. Indoor climbing halls therefore represent a hotspot of RDC exposure for visitors and employees. While the health implications remain uncertain, several RDCs present in climbing halls have demonstrated toxicity in vitro and in animal studies. Previous work, limited to a small number of facilities, left open whether climbing hall characteristics can mitigate RDC contamination. Here, we analyzed more than 200 samples of settled dust and foothold powder (abrasion material) collected from 41 climbing halls across 10 countries. RDCs were detected in every sample, confirming their ubiquity. Unsupervised analyses (hierarchical clustering, principal component analysis) revealed distinct patterns in concentrations and profiles, but supervised approaches (redundancy analysis, partial least squares, univariate correlations) showed only weak associations with hall characteristics. These results demonstrate that hall design and operation exert only a minor influence on RDC levels, underscoring that effective mitigation will require material-level solutions, specifically safe and sustainable-by-design (SSbD) innovations in the material used in climbing shoe soles to replace substances of concern with safer alternatives.

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.

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.

Calcium carbonate (CaCO₃) polymorphs are some of the most abundant minerals in natural environments on the Earth's surface. They are normally linked to fields including biomineralization, global CO₂ exchange or pollutant remediation due to the strong surface interaction with heavy metals in the environment. The aim of this work is to study the crystallization of CaCO₃ through precipitation experiments from aqueous solutions in the presence of different amounts of As(V), thus evaluating the capacity of the precipitating phases to remove As from solutions. Surprisingly, the results confirmed that, although the uptake mechanism operates relatively well, decreasing the initial concentration of arsenic in all the experiments conducted, the wonder is that the presence of this element controls the crystallization of calcium carbonate polymorphs by inhibiting the crystallization of calcite and stabilizing the vaterite, which is the least stable phase among those two. The combination of several techniques allowed us to confirm the increased uptake of As by precipitates from increased As-bearing supersaturated solutions. The gradual disappearance of calcite and the persistence of vaterite from precipitates in which As is present suggest that a potential incorporation of As into a crystalline CaCO₃ polymorph would be more likely in the vaterite. Even though the sequestering mechanism remains unclear, vaterite lattice distortions suggest that As could be absorbed inside the vaterite structure. Additionally, adsorption on the unstable polymorph would be the reason for the stabilization, by preventing its dissolution and therefore its transformation into calcite.

The growing demand for rare earth elements (REEs) in high-tech applications has elevated their concentrations in aquatic environments. However, comprehensive investigations into their ecological and human health risks remain limited. Forty-two river water samples from the Jiulong River basin, a representative coastal watershed, were analyzed to elucidate the occurrence, distribution, and risks of REEs. The inverse distance weighting (IDW) analysis revealed distinct spatial heterogeneity, typical fractionation between heavy and light REEs (HREEs and LREEs), and pronounced Ce and Eu anomalies. Redundancy analysis (RDA) indicated that REE concentrations were influenced by both natural geochemical processes and human activities. The key novelty of this work lies in the combined ecological risk assessment of ΣREE, highlighting the significance of mixture toxicity over individual-element evaluation. Additionally, the age-differentiated health risk assessment demonstrated that children are more susceptible to LREEs and Y exposure, although all hazard quotient (HQ) values remained below 1. Several tributaries (West river and upper North river) exhibited ΣREE risk quotient (RQ) values exceeding 1, indicating localized ecological concerns. These findings provide new insights into REE geochemical behavior and cumulative risk mechanisms in coastal rivers, establishing an integrated framework linking spatial geochemical characteristics with multi-scale risk assessments of REE contamination in coastal aquatic systems.

Biosolids have been identified as a major source of microplastics (MP) to the environment. While they have been heavily studied, the impacts biosolids have following their amendment to agricultural soils on the MP content of these soils is poorly understood. Eleven biosolid-amended and nine non-amended agricultural fields in Southern Ontario were sampled to compare the MP content between them. Biosolid-amended fields averaged 2441.82 ± 268.03 MP kg⁻¹, while non-amended fields averaged 775 ± 50.97 MP kg⁻¹. Additionally, MP abundance was correlated with the type of biosolid applied, with fields that received a single application of dewatered biosolids averaging 2412.14 ± 174.81 MP kg⁻¹, whereas fields that received a single application of liquid biosolids averaged 1689.83 ± 225.81 MP kg⁻¹. However, differences in MP abundance were primarily dictated by differences in application rate between dewatered and liquid biosolids. In addition to increasing overall MP content, biosolid amendments influenced MP composition. Biosolid amendment increased soil fibre content, as biosolids are rich in textile fibres derived from the laundering process. As a result, biosolid-amended soils primarily contained polyester, while unamended soils primarily contained polypropylene. Quantifying and characterizing MP content in biosolid-amended fields, and understanding how it differs from unamended fields, is crucial for accurately assessing the risks microplastics pose to terrestrial ecosystems.