Novel enhanced defluorination of perfluorooctanoic acids by biochar-assisted ultrasound coupling ferrate: Performance and mechanism.

An ultrasound (US)/biochar (BC)/ferrate (Fe (VI)) system was firstly proposed to enhance perfluorooctanoic acid (PFOA) defluorination. It achieved 93 % defluorination optimally, higher than the sum of 77 % (28 % and 49 % for US/BC and US/Fe (VI) respectively), implying synergistic effect. Besides, the mechanism study confirmed that, this system can not only increase the specific surface area of BC and the generation of reactive oxidant species (ROS), enriching the active sites and forming new oxygen-containing functional groups, but also promote the formation of intermediate iron species. The PFOA degradation in the US/BC/Fe (VI) was probably an adsorption-degradation process, both ROS and electron transfer promoted the defluorination. Additionally, its sustainability was also demonstrated with 14 % reduced defluorination percentage after five cycles of BC. Overall, the synergistic effect of the US/BC/Fe (VI) and its enhancing mechanism for PFOA defluorination were clarified firstly, which contributes to the development of biochar for assisting polyfluoroalkyl substances degradation.

How to Identify and Quantify Microplastics and Nanoplastics Using Raman Imaging?

While microplastics and nanoplastics are emerging as a big environmental concern, their characterization is still a challenge, particularly for identification and simultaneous quantification analysis where imaging via a hyper spectrum is generally needed. In the past few years, Raman imaging has been greatly advanced, but the analysis protocol is complicated and not yet standardized because imaging analysis is different from traditional analysis. Herein we provide a step-by-step demonstration of how to employ confocal Raman techniques to image microplastics and nanoplastics.

Is paper bag plastic-free, without plastic in colourful logo area?

The concern over plastic contamination has led to bans on plastic shopping bags, often replaced by paper ones. However, logos painted or printed on paper bags may still contain plastics, as investigated herein. In some logos, for example, white pigment of titanium dioxide (TiO2) nanoparticles are bound with plastic binder onto the cellulose surface of the paper. This hybrid of plastic and nanoparticle is examined using scanning electron microscope (SEM) to characterise morphology physically, and Raman imaging to identify and visualise them chemically. Raman imaging scans the sample to separate images and identify not only plastic but also the co-formulated pigment. The scan generates a hyperspectral matrix containing hundreds to thousands of spectra, and subsequent analysis can enhance the signal-to-noise ratio. Decoding the hyperspectral matrix using chemometrics like principal component analysis (PCA) can effectively map plastic and pigment separately with increased certainty. The image can be further refined through 3-dimensional surface fitting for deconvolution, providing direct visualisation of the plastic-nanoparticle hybrid at a density of approximately 7.3 million particles per square millimetre. Overall, caution should be exercised when using paper bags, as they may not be entirely free of plastics. Raman imaging proves to be an effective method for identifying and visualising complex components, including plastics and nanoparticles. ENVIRONMENTAL IMPLICATION: The concern over plastic contamination has led to bans on plastic shopping bags, replaced by paper alternatives. However, some logos on paper bags may still contain plastics, which is investigated to confirm the presence of plastic-nanoparticle hybrid using SEM and Raman imaging. By employing decoding algorithms such as PCA to separately map plastic and pigment, and utilising 3D surface fitting to deconvolute the image, the hybrid plastic-nanoparticle is estimated at a density of approximately 7.3 million particles per square millimetre. It's important to exercise caution and not assume these items are plastic-free. This aspect of plastics may have been overlooked as another potential source of contamination.

Toy building bricks as a potential source of microplastics and nanoplastics.

Microplastics and nanoplastics have become noteworthy contaminants, affecting not only outdoor ecosystems but also making a notable impact within indoor environments. The release of microplastics and nanoplastics from commonly used plastic items remains a concern, and the characterisation of these contaminants is still challenging. This study focused on evaluating the microplastics and nanoplastics produced from plastic building bricks. Using Raman spectroscopy and correlation analysis, the plastic material used to manufacture building blocks was determined to be either acrylonitrile butadiene styrene (correlation value of 0.77) or polycarbonate (correlation value of 0.96). A principal component analysis (PCA) algorithm was optimised for improved detection of the debris particles released. Some challenges in microplastic analysis, such as the interference from the colourants in the building block materials, was explored and discussed. Combining Raman results with scanning electron microscopy - energy-dispersive X-ray spectroscopy, we found the scratches on the building blocks to be a significant source of contamination, estimated several thousand microplastics and several hundred thousand nanoplastics were generated per mm2 following simulated play activities. The potential exposure to microplastics and nanoplastics during play poses risks associated with the ingestion and inhalation of these minute plastic particles.

The epidemiology of enterococci in a tertiary hospital and primary healthcare facilities in Fiji (2019-2022).

OBJECTIVES: We analysed 4 y of laboratory data to characterise the species and determine the antimicrobial susceptibility profiles of enterococci as human pathogens in Fiji. The study also investigated the molecular epidemiology amongst the subset of vancomycin-resistant enterococci (VRE). METHODS: This retrospective study reviewed bacteriological data from Colonial War Memorial Hospital (CWMH) and other healthcare facilities in the Central and Eastern divisions of Fiji. Phenotypic, antimicrobial susceptibility and vanA and vanB PCR testing were performed using locally approved protocols. The first clinical isolates per patient with antimicrobial susceptibility testing results in a single year were included in the analysis. Data was analysed using WHONET software and Microsoft Excel. RESULTS: A total of 1817 enterococcal isolates were reported, 1415 from CWMH and 402 from other healthcare facilities. The majority of isolates, 75% (n = 1362) were reported as undifferentiated Enterococcus spp., 17.8% (n = 324) were specifically identified as Enterococcus faecalis and 6.7% (n = 122) as E. faecium. Overall, 10% of the enterococci isolates were from blood cultures. Among isolates from CWMH, <15% of E. faecium were susceptible to ampicillin, and 17.2% were vancomycin resistant. Overall, 874 enterococcal isolates (including the undifferentiated species) were tested against vancomycin, of which 4.8% (n = 42) were resistance. All of the VRE isolates tested (n = 15) expressed vanA genes. CONCLUSIONS: This study demonstrates the clinical importance of VRE, particularly van A E. faecium in the national referral hospital in Fiji. Enhanced phenotypic and molecular surveillance data are needed to better understand enterococci epidemiology and help guide specific infection prevention and control measures and antibiotic prescribing guidelines.

Real-time monitoring and predictive analysis of VOC flux variations in soil vapor: Integrating PID sensing with machine learning for enhanced vapor intrusion forecasts.

In the rapidly evolving domain of vapor intrusion (VI) assessments, traditional methodologies encompass detailed groundwater and soil vapor sampling coupled with comprehensive laboratory measurements. These models, blending empirical data, theoretical equations, and site-specific parameters, evaluate VI risks by considering a spectrum of influential factors, from volatile organic compounds (VOC) concentrations in groundwater to nuanced soil attributes. However, the challenge of variability, influenced by dynamic ambient conditions and intricate soil properties, remains. Our study presents an advanced on-site gas sensing station geared towards real-time VOC flux monitoring, enriched with an array of ambient sensors, and spearheaded by the reliable PID sensor for VOC detection. Integrating this dynamic system with machine learning, we developed predictive models, notably the random forest regression, which boasts an R-squared value exceeding 79 % and mean relative error near 0.25, affirming its capability to predict trichloroethylene (TCE) concentrations in soil vapor accurately. By synergizing real-time monitoring and predictive insights, our methodology refines VI risk assessments, equipping communities with proactive, informed decision-making tools and bolstering environmental safety. Implementing these predictive models can simplify monitoring for residents, reducing dependence on specialized systems. Once proven effective, there's potential to repurpose monitoring stations to other VI-prone regions, expanding their reach and benefit. The developed model can leverage weather forecasting data to predict and provide alerts for future VOC events.

The changing epidemiology of antimicrobial resistance in Fiji: a descriptive analysis of antimicrobial susceptibility and trends of endemic and emerging pathogens, 2019-2022.

Background: There is a paucity of data on antimicrobial resistance in Fiji. The aim of this study was to determine the antimicrobial susceptibility profile of bacterial isolates from clinical samples at Colonial War Memorial Hospital in Fiji. Methods: This retrospective study reviewed four-year of data from January 1, 2019, through December 31, 2022. Laboratory testing was carried out using locally approved protocols. Selective antimicrobial susceptibility testing was performed whereby only isolates resistant to first line antimicrobials were tested against second line antimicrobials. Only the first isolate of a given species per patient in a single year were included in the analysis. WHONET software and Microsoft Excel were used for analysis. Findings: A total of 29,222 bacterial isolates were included, 62% (n = 18,084) were Gram-negative bacteria. K. pneumoniae was the most common (n = 5363), followed by E. coli (n = 4321). Extended spectrum beta lactamase (ESBL) production increased from 30% in 2019 to 43% in 2022 amongst K. pneumoniae, and 10%-23% in E coli. There were 733 carbapenem-resistant isolates identified from clinical samples, 61% (n = 445) were A. baumannii, 15% (n = 110) E. coli and 14% (n = 101) P. aeruginosa. Amongst the E. coli isolates tested, susceptibility to meropenem declined from 99% (272/274) in 2019 to 79% (255/325) in 2022. The rate of methicillin resistance amongst Staphylococcus aureus was steady, remaining between 11% and 13%. Interpretation: This study demonstrated a high rate of MDR amongst Gram-negative bacteria, especially ESBL producing K. pneumoniae and E. coli and carbapenem-resistant A. baumannii. The emergence and rapid spread of carbapenemase producing E. coli in Fiji's largest hospital is of particular concern. There is an urgent need to allocate resources to improve existing capacity and to develop effective multimodal strategies to detect, manage and control the spread of MDR organisms. Funding: This study was supported by the Medical Research Future Fund through the Australian government (grant number APP 1200970).

Herbicidal weed management practices: History and future prospects of nanotechnology in an eco-friendly crop production system.

Weed management is an important aspect of crop production, as weeds cause significant losses in terms of yield and quality. Various approaches to weed management are commonly practiced by crop growers. Due to limitations in other control methods, farmers often choose herbicides as a cost-effective, rapid and highly efficient weed control strategy. Although herbicides are highly effective on most weeds, they are not a complete solution for weed management because of the genetic diversity and evolving flexibility of weed communities. The excessive and indiscriminate use of herbicides and their dominance in weed control have triggered the rapid generation of herbicide-resistant weed species. Moreover, environmental losses of active ingredients in the herbicides cause serious damage to the environment and pose a serious threat to living organisms. Scientific advances have enabled nanotechnology to emerge as an innovation with real potential in modern agriculture, adding a new dimension in the preparation of controlled release formulations (CRF) of herbicides. Here the required amount of active ingredients is released over longer periods of time to obtain the desired biological efficacy whilst reducing the harmful effects of these chemicals. Various organic and inorganic carrier materials have been utilised in CRF and researchers have a wide range of options for the synthesis of eco-friendly carrier materials, especially those with less or no toxicity to living organisms. This manuscript addresses the history, progress, and consequences of herbicide application, and discusses potential ways to reduce eco-toxicity due to herbicide application, along with directions for future research areas using the benefits of nanotechnology.

Concentrations of per- and polyfluoroalkyl substances in vegetables from Sydney and Newcastle, Australia.

BACKGROUND: This study investigated per- and polyfluoroalkyl substances (PFASs) in 53 fruit and vegetable samples collected from a local wholesale and retail market in Sydney and a local supermarket in Newcastle. As there is limited information about PFAS levels in vegetables on the market, this study aimed to fill this gap and assess potential risks for humans through consumption of these vegetables. METHODS: QuEChERS extraction - a solid-phase extraction method, a portmanteau word formed from 'quick, easy, cheap, effective, rugged and safe' - followed by enhanced matrix removal-lipid cleaning and liquid chromatography-tandem mass spectrometry analysis were used to detect 30 PFASs in vegetables. RESULTS: PFOA was detected in 7 out of the 53 samples, with concentrations of 0.038-1.996 ng g-1 fresh weight; PFOS was detected in 2 samples only, with concentrations ranging from 0.132 to 0.911 ng g-1 fresh weight. PFHxS was not detected in any sample in this study. PFOA and PFOS concentrations measured in vegetables in this study constituted daily intake of 2.03 ng kg-1 body weight (BW) and 1.98 ng kg-1 BW, respectively, according to recommended daily vegetable intake and BW data from the Australian Bureau of Statistics. The most sensitive population group is girls of 4-8 years of age. These estimated exposure levels represent up to 1.3% of the tolerable daily intake for PFOA (160 ng kg-1 BW) and 9.9% for PFOS (20 ng kg-1 BW) according to Food Standards Australia New Zealand. Consumption of the vegetables from the study locations poses a marginal risk to human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Controlled release herbicide formulation for effective weed control efficacy.

Controlled release formulation (CRF) of herbicide is an effective weed management technique with less eco-toxicity than other available commercial formulations. To maximise the effectiveness of CRFs however, it is crucial to understand the herbicide-releasing behaviour at play, which predominately depends on the interaction mechanisms between active ingredients and carrier materials during adsorption. In this study, we investigated and modelled the adsorption characteristics of model herbicide 2,4-D onto two organo-montmorillonites (octadecylamine- and aminopropyltriethoxysilane-modified) to synthesise polymer-based CRFs. Herbicide-releasing behaviour of the synthesised CRF microbeads was then analysed under various experimental conditions, and weed control efficacy determined under glasshouse conditions. Results revealed that adsorption of 2,4-D onto both organo-montmorillonites follows the pseudo-second-order kinetics model and is predominately controlled by the chemisorption process. However, multi-step mechanisms were detected in the adsorption on both organoclays, hence intra-particle diffusion is not the sole rate-limiting step for the adsorption process. Both organoclays followed the Elovich model, suggesting they have energetically heterogeneous surfaces. Herbicide-releasing behaviours of synthesised beads were investigated at various pH temperatures and ionic strengths under laboratory and glasshouse conditions. Furthermore, weed control efficacy of synthesised beads were investigated using pot studies under glasshouse condition. Desorption studies revealed that both synthesised microbeads have slow releasing behaviour at a wide range of pHs (5-9), temperatures (25-45 °C), and ionic strengths. The results also revealed that synthesised microbeads have excellent weed control efficacy on different broad-leaf weed species under glasshouse conditions.

Residual hydrocarbons in long-term contaminated soils: implications to risk-based management.

Petroleum hydrocarbon (PHC) contamination is a widespread and severe environmental issue affecting many countries' resource sectors. PHCs are mixtures of hydrocarbon compounds with varying molar masses that naturally attenuate at different rates. Lighter fractions attenuate first, followed by medium-molar-mass constituents, while larger molecules remain for longer periods. This results in significant regulatory challenges concerning residual hydrocarbons in long-term contaminated soils. This study examined the potential risks associated with residual PHC and its implications for risk-based management of heavily contaminated soils (23,000-26,000 mg PHC/kg). Ecotoxicological properties, such as seedling emergence and growth of two native plant species-small Flinders grass (Iseilema membranaceum) and ruby saltbush (Enchylaena tomentosa)-and earthworm survival tests in PHC-contaminated soils, were assessed. Additionally, the effects of aging on the attenuation of PHC in contaminated soils were evaluated. Toxicity responses of plant growth parameters were determined as no-observed-effect concentrations: 75%-100% for seedling emergence, < 25%-75% for plant shoot height, and 75%-100% for earthworm survival. After 42 weeks of aging, the total PHC levels in weathered soils decreased by 14% to 30% and by 67% in diesel-spiked soil due to natural attenuation. Dehydrogenase enzyme activity in soils increased during the initial aging period. Furthermore, a clear shift of bacterial communities was observed in the soils following aging, including enrichment of PHC-resistant and -utilizing bacteria-for example, Nocardia sp. This study underscores the potential of natural attenuation for eco-friendly and cost-effective soil management, underlining that its success depends on site-specific factors like water content and nutrient availability. Therefore, we recommend detailed soil assessments to evaluate these conditions prior to adopting a risk-based management approach.

Chemical methods to remove microplastics from wastewater: A review.

Microplastics (Mps) have emerged as a pervasive environmental concern, with their presence detected not only in freshwater ecosystems but also in drinking and bottled water sources. While extensive research has centered on understanding the origins, migration patterns, detection techniques, and ecotoxicological impacts of these contaminants, there remains a notable research gap about the strategies for Mps removal. This study reviews existing literature on chemical approaches for mitigating microplastic contamination within wastewater systems, focusing on coagulation precipitation, electrocoagulation, and advanced oxidation methods. Each approach is systematically explored, encompassing their respective mechanisms and operational dynamics. Furthermore, the comparative analysis of these three techniques elucidates their strengths and limitations in the context of MPs removal. By shedding light on the intricate mechanisms underlying these removal methods, this review contributes to the theoretical foundation of microplastic elimination from wastewater and identifies future research trajectories and potential challenges.

Bushfire-smoke trigger hospital admissions with cerebrovascular diseases: Evidence from 2019-20 bushfire in Australia.

INTRODUCTION: Exposure to ambient air pollution is strongly associated with increased cerebrovascular diseases. The 2019-20 bushfire season in Australia burnt 5.4 million hectares of land in New South Wales alone, with smoke so severe it affected cities in Argentina, 11,000 km away. The smoke emitted by bushfires consists of both gaseous and particle components. It is important to note that exposure to particulate matter has been shown to be linked to a heightened risk of stroke, which is the primary kind of cerebrovascular illness, as well as an increased likelihood of hospitalisations and mortality. However, the available data is inadequate in terms of documenting the response of patients diagnosed with a proven cerebrovascular illness to bushfire smoke. Additionally, there is a lack of information about the health effects associated with particulate matter throughout the bushfire season and on days when smoke was present in 2019 and 2020.Therefore, we aimed to determine the effects of (i) short-term air pollution triggered by bushfires and (ii) high smoke days in increasing the daily number of hospital admissions with cerebrovascular diseases. MATERIALS AND METHODS: Hospitalisation data were accessed from the admitted patient dataset from seven local Government areas of Hunter New England Local Health District. The bushfire period was defined from 1 October 2019 to 10 February 2020, and a same period from 2018-19 as the control. High bushfire smoke days were days when the average daily concentration of particulate matter was higher than the 95th percentile of the control period. Poisson regression models and fixed effect meta-analysis were used to analyse the data. RESULTS: In total, 275 patients with cerebrovascular admissions were identified, with 147 (53.5%) during the bushfire (2019-20) and 128 (46.5%) in the control period (2018-19). There was no significant increase in daily admissions for cerebrovascular disease (Incidence Rate Ratio, IRR: 1.04; 95% CI: 0.81-1.34; p-value: 0.73), acute stroke (IRR: 1.15; 95% CI: 0.88-1.50; p-value: 0.29) or acute ischaemic stroke (IRR: 1.18; 95% CI: 0.87-1.59; p-value: 0.28), over the entire bushfire period. However, the high bushfire smoke days were associated with increased acute ischaemic stroke-related hospital admissions across lead 0-3 and the highest cumulative effect was observed with lead 0 (IRR:1.52; 95% CI: 1.01-2.29; p-value: 0.04). In addition, during the bushfire period, particulate matter, both PM10 and PM2.5 (defined as particulates that have an effective aerodynamic diameter of 10, and 2.5 microns, respectively), were also associated with increased acute ischaemic stroke admissions with a lag of 0-3 days. DISCUSSION AND CONCLUSION: The results suggested a possible association between particulate matter and high smoke days with increased hospital admissions due to acute ischaemic stroke during the recent Australian bushfire season.

Advancements in Raman imaging for nanoplastic analysis: Challenges, algorithms and future Perspectives.

BACKGROUND: While the concept of microplastic (<5 mm) is well-established, emergence of nanoplastics (<1000 nm) as a new contaminant presents a recent and evolving challenge. The field of nanoplastic research remains in its early stages, and its progress is contingent upon the development of reliable and practical analytical methods, which are currently lacking. This review aims to address the intricacies of nanoplastic analysis by providing a comprehensive overview on the application of advanced imaging techniques, with a particular focus on Raman imaging, for nanoplastic identification and simultaneous visualisation towards quantification. RESULTS: Although Raman imaging via hyper spectrum is a potentially powerful tool to analyse nanoplastics, several challenges should be overcome. The first challenge lies in the weak Raman signal of nanoplastics. To address this, effective sample preparation and signal enhancement techniques can be implemented, such as by analysing the hyper spectrum that contains hundred-to-thousand spectra, rather than a single spectrum. Second challenge is the complexity of Raman hyperspectral matrix with dataset size at megabyte (MB) or even bigger, which can be adopted using different algorithms ranging from image merging to multivariate analysis of chemometrics. Third challenge is the laser size that hinders the visualisation of small nanoplastics due to the laser diffraction (λ/2NA, ∼300 nm), which can be solved with involving the use of super-resolution. Signal processing, such as colour off-setting, Gaussian fitting (via deconvolution), and re-focus or image re-construction, are reviewed herein, which show a great promise for breaking through the diffraction limit. SIGNIFICANCE: Overall, current studies along with further validation are imperative to refine these approaches and enhance the reliability, not only for nanoplastics research but also for broader investigations in the realm of nanomaterials.

A modified TOP assay to detect per- and polyfluoroalkyl substances in aqueous film-forming foams (AFFF) and soil.

Total oxidisable precursor (TOP) assay can oxidise some per- and polyfluoroalkyl substances (PFASs) and their precursors, most of which cannot be quantitatively detected so far, and convert them to detectable PFASs, such as perfluoroalkyl acids (PFAAs). However, the conversion is constrained by the complexity of the target samples, including co-existent organics, unknown PFAS precursors, and background. In this study, the TOP assay is modified to increase the oxidation and conversion efficiency by changing the initial concentration of target sample, increasing oxidising doses, time, temperature, etc. The modified TOP assay is applied to test several aqueous film-forming foams (AFFF) and a PFAS-contaminated soil extract. The sum concentrations of the detectable PFASs are increased by up to ∼534× in the AFFF samples and ∼7× in the PFAS-contaminated soil extract. The detectable fluorotelomer sulfonate (FTS, such as 6:2/8:2 FTS) is accounted as an oxidation indicator to monitor the oxidation and conversion progress of the oxidisable PFASs precursors to the detectable PFASs. Overall, the modified TOP assay could be an appropriate method for identifying missing PFASs mass in complex matrices by detecting the PFASs precursors effectively.

Super-resolution Raman imaging towards visualisation of nanoplastics.

Confocal Raman imaging can potentially identify and visualise microplastics and nanoplastics, but the imaging lateral resolution is hampered by the diffraction of the laser, making it difficult to analyse nanoplastics that are smaller than the laser spot and the lateral resolution limit (λ/2NA). Fortunately, once a nanoplastic is scanned to collect the spectrum via a position/pixel array as a spectrum matrix, akin to a hyperspectral matrix, the nanoplastic can be imaged by mapping the spectrum intensity as a pattern that is transcended axially and can be fitted as a 2D Gaussian surface. The Gaussian fitting and image re-construction by deconvolution can precisely predict the nanoplastic's position and approximate size, and potentially enhance the signal intensity. Several algorithms are also employed to decode the spectrum matrix, to improve the Raman images before the subsequent image re-construction. Overall, general confocal microscopy can also break through the diffraction limit of the excitation light by using algorithms, resulting in super-resolution Raman imaging to capture nanoplastics.

Effect of short-term exposure to air pollution on daily cardio- and cerebrovascular hospitalisations in areas with a low level of air pollution.

Exposure to air pollution is associated with increased cardio- and cerebrovascular diseases. However, the evidence regarding the short-term effect of air pollution on cardio- and cerebrovascular hospitalisations in areas with relatively low air pollution levels is limited. This study aims to examine the effect of short-term exposure to different air pollutants on hospital admissions due to cardio- and cerebrovascular diseases in rural and regional Australia with low air pollution. The study was conducted in five local Government areas of Hunter New England Local Health District (HNE-LHD). Hospitalisation data from January 2018 to February 2020 (820 days) were accessed from the HNE-LHD admitted patients' dataset. Poisson regression model was used to examine the association between the exposure (air pollutants) and outcome variables (hospitalisation due to cardio- and cerebrovascular disease). The concentrations of gaseous air pollutants, Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone (O3), Carbon Monoxide (CO), and Ammonia (NH3) were below national benchmark concentrations for every day of the study period. In single pollutant models, SO2 and NO2 significantly increased the daily number of cardio- and cerebrovascular hospitalisations. The highest cumulative effect for SO2 was observed across lag 0-3 days (Incidence Rate Ratio, IRR: 1.77; 95% Confidence Interval, CI: 1.18-2.65; p-value: 0.01), and for NO2, it was across lag 0-2 days (IRR: 1.13; 95% CI: 1.02-1.25; p-value: 0.02). In contrast, higher O3 was associated with decreased cardio- and cerebrovascular hospitalisations, with the largest effect observed at lag 0 (IRR: 0.94; 95% CI: 0.89-0.98; p-value: 0.02). In the multi-pollutant model, the effect of NO2 remained significant at lag 0 and corresponded to a 21% increase in cardio- and cerebrovascular hospitalisation (95% CI: 1-44%; p-value = 0.04). Thus, the study revealed that gaseous air pollutants, specifically NO2, were positively related to increased cardio- and cerebrovascular hospitalisations, even at concentrations below the national standards.

Raman imaging to identify microplastics released from toothbrushes: algorithms and particle analysis.

Microplastics are small plastic fragments that are of increasing concern due to their potential impacts on the environment and human health. The source of microplastics is not completely clear and might originate in daily lives such as from toothbrushes. When toothbrushes are used to clean teeth, small plastic debris and fragments can be potentially released into mouths directly or environment indirectly. This study aims to examine the release of microplastics from toothbrushes, using Raman imaging to identify and visualise the plastic debris with an increased signal-noise ratio via hyper-spectrum analysis. Using algorithms to convert the hyper-spectrum to an image, the plastic can be distinguished from the co-formulated titanium oxide particles that are not uniformly distributed along the plastics. The non-uniform distribution can lead to the bias results if a single spectrum analysis is conducted at one position rather than imaging analysis to scan an area. The potential false image originating from the off-focal position for the confocal Raman is overcome using the terrain map to guide the Raman imaging. The imaging analysis balancing between the low magnification to capture the overview and the high magnification to test the details is also discussed. While the release amount of microplastics from the toothbrush is estimated at thousands daily with the expected variation, the results of this study have confirmed the release of microplastics in daily lives. The imaging analysis approach along with algorithm can help to identify the chemical elements of microplastics from the complex background, which can benefit the further research on microplastics towards risk assessment and remediation.

Multigenerational effects of TiO2 rutile nanoparticles on earthworms.

Nanoparticles have gained considerable attention as one of the pollutants released into the environment through consumer products. This study describes the sub-chronic and generational effects of TiO2 (rutile) nanoparticles on earthworms over a 252-day duration, with exposure ranging from 0.1 to 1000 mg kg-1. Results indicate that sub-chronic exposure (28 days) of TiO2 nanoparticles did not cause notable adverse effects on the weight, reproduction, and tissue accumulation in parent earthworms. However, the F1 generation displayed remarkable growth and maturity retardation during their early developmental stages, even at lower nano-TiO2 (rutile). Significant impacts on the reproduction of the F1 generation were observed solely at the highest concentration (1000 mg kg-1), which is predicted to be below the highest exposure scenario. Moreover, long-term (252 days) exposure resulted in considerable bioaccumulation of Ti metal in the F1 generation of E. fetida. This study uncovers the negative effects of TiO2 rutile nanoparticles on earthworms across two generations, with pronounced effects on the growth, maturity, and bioaccumulation in the F1 generation compared to the parent generation. These findings suggest the potential induction of toxic effects by TiO2 rutile nanoparticles, emphasizing the sensitivity of juvenile parameters over adult parameters in toxicity assessments. Furthermore, the study highlights the urgent need for comprehensive evaluations of the longer-term toxicity of nanoparticles on terrestrial organisms. Implementing multigenerational studies will contribute significantly to a better understanding of nanoparticle ecotoxicity on environmental organisms.