Environmental science. Advances最新文献

The environmental impact of microplastics is increasingly being recognized, leading to their inclusion as contaminants of emerging concern. Consequently, it is essential to identify and monitor microplastics and their impact on the ecosystem. In this study, a ball miller was employed to process plastic waste, generating microplastics for the optimisation of separation methods. Microplastics of various sizes and shapes were produced and used to spike the sediments for optimisation of the density separation method. The recovered microplastics ranged from 0.74–5 mm, as confirmed by stereomicroscopy. In addition, the types of polymers present in microplastics were confirmed using Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR). The developed analytical method was employed to study the occurrence of microplastics in river sediments passing through informal settlements after floods. Moreover, the evaluated data confirmed that informal settlements are a major source of microplastics found in the ocean after a flood. Microplastics in river and ocean sediments were predominantly composed of polypropylene, polyethylene, and polystyrene with a size range of 0.90–5 mm. To the best of our knowledge, this study is the first to report the impacts of informal settlements on the ocean during floods in Africa.

The objective of this study was to investigate the occurrence, spatial distribution, and ecotoxicological risk of pesticides and transformation products in surface waters of western Montérégie (Quebec, Canada). A total of 29 samples were collected from 11 rivers during the summers of 2019 and 2021, and the samples were analyzed for 48 pesticides and 8 transformation products. The downstream data were used to assess the ecotoxicological risks based on Quebec's acute or chronic aquatic life criterion (AALC or CALC). Overall, 9 herbicides (glyphosate, S-metolachlor, 2,4-D, metribuzin, atrazine, MCPA, prometryn, dimethenamid, simazine), 3 insecticides (clothianidin, imidacloprid, chlorantraniliprole), and 4 fungicides (azoxystrobin, fluxapyroxad, tebuconazole, carbendazim) were detected at all sampling sites, demonstrating their widespread use in western Montérégie. Glyphosate (87–4095 ng L⁻¹), S-metolachlor (6–2519 ng L⁻¹), and 2,4-D (6–1094 ng L⁻¹) were identified as the most abundant pesticides in surface water. Furthermore, 6 pesticide transformation products (metolachlor ESA, AMPA, metolachlor OA, desethylatrazine, atrazine-2-hydroxy, desisopropylatrazine) were detected at all sampling sites. The concentration of transformation products accounted for 51% on average of the total concentration, demonstrating the abundance of transformation products in surface waters. Neonicotinoids exhibited the highest ecotoxicological risk in the surface water samples with an average CALC risk quotient of 28 for 2019 and 12 for 2021, respectively. The present study offers insights into pesticides occurrence and their ecological impacts on surface waters of western Montérégie and allows for supporting future pesticide management and ecotoxicological risk mitigation strategies.

Antibiotic resistance is a public health crisis. Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are present in drinking water distribution systems. Metals are known selective pressures for antibiotic resistance, and metallic corrosion products are found within drinking water distribution systems due to the corrosion of metal pipes. While corrosion products are a source of metals, the impact of specific corrosion products on antibiotic resistance has not been investigated. The objective of this study was to determine the impact of six corrosion products—CuO, Cu₂O, Pb₅(PO₄)₃OH, β-PbO₂, Fe₃O₄, and α-FeOOH—on the abundance of ARB and ARGs. Lab-scale microcosms were seeded with source water from Lake Michigan and amended with individual corrosion products. In general, copper and lead corrosion products increased antibiotic resistance, although not universally across different ARB and ARG types. Concentration and speciation of copper and lead corrosion products were found to have an impact on antibiotic resistance profiles. Meanwhile, iron corrosion products had minimal impact on antibiotic resistance. Overall, this study sheds light on how pipe materials may impact antibiotic resistance as a result of corrosion products.

The Global Atmospheric Passive Sampling (GAPS) network and GAPS Megacities network (GAPS-MC) are the only global-scale air monitoring programs for persistent organic pollutants (POPs), which support the Global Monitoring Plan (GMP) of the Stockholm Convention on POPs. The GAPS data represents all five United Nation regions and informs the spatial and temporal trends of listed POPs, their long-range transport in air, and new priorities for POPs monitoring and research. This information contributes to the Effectiveness Evaluation of the Stockholm Convention, which is assessed every six years. To ensure its long-term sustainability and relevance, the GAPS network is engaging in cross-cutting studies across fields of science and policy – leading to more holistic and integrative work on air pollution, health, climate science, and biodiversity. Future work under GAPS will continue to advance areas of intersection and tap-into topics and expertise in areas such as non-target analysis (chemical mixture approaches including transformation products in air), advanced data analysis and land-use assessment methods, top-down and inverse global modeling, global air health assessment/warning systems, and citizen science and outreach.

A novel sensitive, specific, and reversible optical sensor for the palladium(II) ion was created by impregnating an agarose membrane with 4-(2-amino-3-hydroxypyridine-4-ylazo)1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one (AHDDO). Spectrophotometric studies of complex formation between the AHDDO base ligand and Mn²⁺, Cd²⁺, Co²⁺ Hg²⁺, Zn²⁺, Cu²⁺, Pd²⁺, Sr²⁺, Al³⁺, Fe³⁺, Au³⁺, and Ag⁺ metal ions in an ethanolic solution indicated a substantially larger stability for the palladium ion complex. Therefore, the AHDDO was immobilized on a clear agarose film and used as a suitable ionophore for building a selective Pd²⁺ optical sensor. By combining the sensing membrane with Pd²⁺ ions at pH 5.75, a transparent color change from orange to violet was observed. On the immobilization of AHDDO, the effects of ionophore concentration, pH, temperature, stirring, and reaction time were investigated. A linear relationship was observed between the membrane absorbance at 633 nm and Pd²⁺ concentrations in a range from 15 to 225 ng mL⁻¹ with detection (3σ) and quantification (10σ) limits of 4.25 and 14.25 ng mL⁻¹, respectively. For the determination of Pd²⁺ ions, no significant interference from at least 400-fold excess concentrations of a number of possibly interfering ions was found. The sensor exhibits remarkable selectivity for Pd²⁺ ions and can be regenerated through exposure to 0.15 M HNO₃. The sensor has been successfully used to find palladium in biological, soil, road, and water samples.

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Stormwater ponds (SWPs) alter the export of the macronutrient phosphorus (P) from urban landscapes, hence impacting the trophic state and water quality of downstream aquatic environments. Despite an increasing number of studies reporting P load reduction by SWPs, the mechanisms responsible for P retention remain unclear. We analyzed P chemical speciation and fluxes in the inflow and outflow of a SWP in the Toronto metropolitan area. In addition, we collected sediment cores to determine under what forms P accumulates in the SWP. The resulting P mass balance for the SWP yielded an average annual retention of 62% for total P (TP). Retention efficiencies varied significantly among the various TP fractions, however: 53% for particulate P (PP), 67% for total dissolved P (TDP), 66% for dissolved unreactive P (DUP), and >80% for dissolved reactive P (DRP), with DRP representing the most bioavailable TP fraction. Sequential chemical extractions performed on the sediment cores indicate that, with increasing sediment depth, the concentration of mineral-bound P increases while that of organic P decreases. We therefore attribute the efficient retention of DRP to biosynthesis of P-containing organic compounds followed by their post-depositional degradation and sequestration of the released phosphate ions by in situ precipitation of inorganic phases, primarily calcium (Ca) minerals. The conditions in the SWP are favorable to the formation of common Ca minerals, such as hydroxyapatite and calcite, including near-neutral to moderately alkaline pH values and high dissolved Ca²⁺ concentrations. In areas where urban runoff does not meet these conditions, interventions that stimulate P-containing mineral formation in SWPs may help reduce the export of DRP, hence, protecting receiving water bodies from eutrophication.

Nitrophenol wastewater treatment and extracting and reusing precious metals from electronic wastewater have recently gained considerable attention. In this study, polyaniline-based membranes showcased remarkable gold recovery capability from electronic wastewater, effectively reclaiming 100% of gold on the membrane surface even in the presence of competing metal cations. The prepared Au@PmPD membrane, characterized by its high specific surface area and abundant Au nanoparticles (NPs), demonstrated excellent catalytic activity and stability, maintaining near 100% conversion efficiency in reducing 4-NP to 4-AP in the presence of NaBH₄ over extended durations. Compared with the conventional physical mixing method, our in situ formation of the Au@PmPD membrane highlights the superior distribution of Au NPs and active sites for enhanced catalytic efficiency. It eliminates the need for additional steps to load Au NPs onto the membrane, resulting in a more straightforward and efficient process. Overall, this research provides a sustainable approach to repurposing waste into precious resources and offers a promising solution for the efficient treatment of persistent organic pollutants in wastewater, aligning with the principles of a circular economy.

Polycyclic aromatic hydrocarbons (PAHs) pose health risks to children, potentially resulting in stunted growth, obesity, and cognitive deficits, but lack of reliable and noninvasive means to measure PAHs results in poor understanding of exposure patterns and sources in this vulnerable population. In this study, 24 children aged ∼7 years (9 boys and 15 girls) from Montevideo, Uruguay wore silicone wristbands for 8 days to monitor the exposure of 27 PAHs. Wristbands were extracted using a modified ethyl acetate tandem solid phase extraction clean up and then analyzed via gas chromatography with tandem mass spectrometry. This analysis has reported LODs for 27 PAHs between 0.05 and 3.91 μg L⁻¹. Eighteen PAHs were detected in >50% of the samples with concentration medians ranging 1.2–16.3 ng g⁻¹ of wristband. Low molecular weight PAHs (2–3 rings) such as naphthalene and its alkyl derivatives were highly correlated (0.7–0.9) in the wristbands, suggesting exposure from related sources. Exposure source exploration focused on secondhand tobacco smoke, potentially through caregivers who reported on smoking habits in an associated survey. A principal components analysis (PCA) was conducted to examine patterns in PAH compounds detected in the wristbands; subsequently, the resulting components were compared according to current smoking among caregivers. The PCA analysis revealed a grouping of participants based on higher exposure of 1-methyl naphthalene, pyrene, fluoranthene, 1-methylphenanthrene, dibenzothiophene and 2-phenyl naphthalene. The derived components did relate with parental smoking, suggesting that some participants experienced exposure to a common source of certain PAHs outside of parental smoking. This is the first study to assess PAH exposure in young children from South America. Using wristbands, our study indicates exposure to multiple, potentially harmful chemicals. Wristbands could provide a comprehensive picture of PAH exposure in children, complementing other non-invasive biomonitoring approaches.