Environmental science. Advances最新文献

In this research, activated carbon (AC) was prepared from date seed (DS) biomass using a chemical activation method for the removal of the Bismarck Brown R (BBR) dye and zinc metal ions from water. As-prepared AC was characterized using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analysis for understanding the porous carbon surface and pore structure, which are essential properties for removing organic and inorganic pollutants. DSs are complex and were selected to prepare AC as they can yield hard activated carbon and perform better in packed-bed and fluidized-bed adsorption columns. AC samples were prepared at different soaking temperatures, specifically at 45 °C, 55 °C, and 65 °C, and subsequently tested for the removal of both the BBR dye and Zn ions. Various parameters were studied to complete the batch adsorption process, including solution pH, initial concentration (BBR: 100–500 mg L⁻¹; Zn ions: 10–50 mg L⁻¹), contact time (0–240 min), and temperature (30–60 °C). The maximum monolayer adsorption capacity for BBR and Zn metal ions were found to be 192.31 mg g⁻¹ and 15.55 mg g⁻¹, respectively. The data was most accurately described by the pseudo-second-order and Elovich kinetics models. Analysis using the particle diffusion model indicated that both film-diffusion and pore-diffusion mechanisms governed adsorption. Thermodynamic assessments revealed the endothermic behavior of BBR dye adsorption and the exothermic behavior of Zn metal ion adsorption.

Concerns over environmental impacts resulting from the use of zinc oxide containing medicines for weaning piglets led to the withdrawal of the authorisations for these products in the EU. In order to better understand these issues more detailed assessments were conducted for the UK, taking account of the fate of zinc in the environment and its bioavailability to ecological receptors. Four regional scenarios covered the main pig farming areas in the UK and the emission scenario was based on current agricultural practices in the UK. The fate and transport of zinc in the environment was modelled using the Intermediate Dynamic Model for Metals, and the toxicity of zinc in the environment was assessed based on current UK regulatory practices. The model takes account of historic additions of metals to the soils to calculate current and future metal levels in the environment. Whilst three of the four regional scenarios predicted a marginal risk, or no risk, to soils after 50 years of use one of the scenarios indicated a risk to surface waters prior to the use of zinc oxide medicated treatments for weaning piglets, and risks to local soils within 10 years of use. Further site-specific assessments were conducted for this region and one of the other regions, based on site specific emission scenarios, soil and surface waters characteristics. These two site-specific assessments revealed that the modelling results were accurate or conservative depending on the assumptions made about historic inputs of metals to agricultural soils from manure spreading, and that the regional scenario that resulted in significant predicted risks to surface waters did not reflect the actual conditions at the local pig farming sites considered. Comparisons between measured concentrations of copper and zinc at pig farming sites suggest that historic agricultural inputs have been an important source of these metals to agricultural soils at some sites. The limited data available for validation suggest that the IDMM is able to provide accurate predictions of metal levels in both soils and surface waters, but that there is significant uncertainty associated with historic inputs of metals to the soils.

Air pollution is a major risk factor for neurological disorders. Both indoor and outdoor dusts comprise different types of iron oxides in the nano-scale range. Due to their small size and unique physico-chemical properties, iron oxide nanoparticles (IONPs) adopt the intracellular path to agglomerate inside the cell cytoplasm. Moreover, they can cross the blood–brain barrier to invade cortical tissues in the brain and impair neuronal functions. Hence, analysis of the effects of IONPs on the Central Nervous System (CNS) structure and functions is indispensable from medical perspective. A literature search was performed using three scientific databases: ScienceDirect, PubMed, and Google Scholar. Articles published till December, 2023 were screened for their relevancy. Analyses of the appropriate literature have revealed that IONPs are being employed in drug delivery systems and diagnosis of CNS-related ailments that favor neuroprotection. However, the inhalation of IONPs from air and other sources can lead to excessive accumulation of iron in the neuronal tissues, leading to a disturbance in neuronal signaling and augmenting the onset of neurodegenerative disorders. Therefore, it is essential to monitor and control the abundance of IONPs in the environment to combat adverse impacts on the human nervous system.

Poly- and perfluoroalkyl substances are a ubiquitous class of compounds which are considered persistent organic pollutants. Many of these compounds are unregulated and understudied but are still widely used. One group of these compounds are fluorotelomer ethoxylates, which recently emerged as compounds of interest following their detection in the environment. To determine the health impacts of these persistent compounds, healthy pregnant CD-1 mice were exposed to 0 ng L⁻¹ (n = 8), 5 ng L⁻¹ (n = 8), or 100 ng L⁻¹ (n = 7) fluorotelomer ethoxylates in drinking water throughout gestation. At gestational day 17.5 (term is 18.5 days), high-frequency ultrasound was performed to investigate the placental and fetal hemodynamic responses following exposure. Maternal exposure to fluorotelomer ethoxylates showed evidence of placental insufficiency, with a significant increase in placental weights (p < 0.05), a decrease in the umbilical artery blood flow (p < 0.01) and vasodilation of the cerebral circulation (p < 0.01), consistent with brain sparing to preserve oxygen delivery to the brain. These results demonstrate that fluorotelomer ethoxylates cause developmental toxicity and motivate further work to evaluate the risk to human pregnancies and other vulnerable populations.

Humans and other living species of the ecosystem are constantly exposed to a wide range of chemicals of natural as well as synthetic origin. A multitude of compounds exert profound long-term detrimental health effects. The chronic toxicity profile of chemicals is of utmost importance for long-term risk assessment. Experimental testing of the chronic toxicity of compounds is not always a feasible option considering the magnitude of the number of chemicals, resource intensiveness in terms of time, limited availability of experimental data, and associated cost, which therefore necessitates the use of in silico approaches to overcome the associated limitations. In this work, QSAR (quantitative structure–activity relationship) models were developed employing the regression-based PLS method with strict adherence to OECD guidelines. For this study, chronic and sub-chronic toxicity datasets with LOEL (lowest observed effect levels) and NOEL (no observed effect level) as endpoints were used for model development. The validated models are robust, reliable, and predictable. The statistical results of the models are as follows: R²: 0.6–0.71, Q_LOO²: 0.51–0.635, and Q_F1²: 0.52–0.658. From the validated models, it was concluded that lipophilicity, electronegativity, the presence of aromatic ethers or aliphatic oxime groups, the presence of complexity in structures, the state of unsaturation in molecules, and the presence of halogen and heavy atoms (phosphate, sulphur, etc.) are responsible for chronic/sub-chronic toxicity. The QSAR models developed in our study can be utilized for the effective gap-filling of toxicity data sets, categorization, and prioritization of chemicals, along with chronic toxicity prediction of new synthetic compounds. Furthermore, we used 2568 approved drugs from the DrugBank and PPDB databases for screening purposes using the validated models, which further corroborated the developed models based on the available toxicity data.

Organic effluents from industries, especially bisphenol A (BPA) and dyes, pose a growing threat to living creatures due to their resistance to biodegradation and carcinogenic nature. This research emphasizes the design and fabrication of an inexpensive and magnetically separable MnFe₂O₄/poly meta-aminophenol heterostructure as a catalyst for the mineralization of two persistent pollutants viz. BPA and Reactive Blue 19 (RB-19). The structural and magnetic properties of the MnFe₂O₄/PmAP heterostructure (MnP-10) revealed its potential as an efficient and magnetically recoverable catalyst highlighting its practical usability and repeated use in wastewater purification. The heterostructure of MnP-10 was confirmed through various techniques by XRD, XPS, SEM, TEM/HRTEM as well as BET surface area and optical property measurements. The stability and recyclability of the MnP-10 catalyst were confirmed through XRD and VSM studies of fresh and reused catalyst. The catalyst showed 100% efficiency for mineralization of BPA and RB-19 within 60 min of visible light illumination. The TOC and GC-MS analyses confirmed the efficient removal of organic contents after the reaction. The cost-effectiveness and stability of the developed catalyst make it an attractive contender for wastewater treatment applications, addressing the growing concerns connected with the removal of stubborn organic contaminants.

The Stockholm Convention on persistent organic pollutants is an effective global instrument for the eradication of hazardous chemicals known as persistent organic pollutants (POPs) in the environment. The Convention has so far been successful in the mitigation of worldwide POPs over 20 years of its entering into force. However, concerns still arise on POP-related waste management and elevating trend of POPs in Africa. Recent documents indeed indicated significant concentrations of POPs, particularly polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in a top global range or higher with a potential for this elevating trend to continue. The high concentrations and increasing trends are likely similar for the newly listed POPs, but current data are insufficient to examine this hypothesis. Several concerted efforts have been made by the Stockholm Convention Secretariat and relevant stakeholders to support POP eradication programmes in Africa but projections for the decline of many POPs are yet to be visible due to challenges of inadequate policy and regulatory frameworks, capacity to self-manage relevant socio-economic data and others as fully discussed in this review. Africa currently requires full range financial and technical support. We, however, highlight that for effective mitigation efforts, this support should be channelled into the development of capacity and competency to enable African-led programs for POP monitoring, waste disposal, and public awareness, rather than reliance on external groups. Harmonising economical, industrial development, scientific and political interests will be crucial to future self-sustainability of mitigation goals of the Stockholm Convention on POPs in Africa.

Soft tissue simulants are traditionally used to provide a post impact medium suitable for replicating human anatomy. Performance of materials is therefore paramount, and the analysis of such experimentation relies on responses that mimic the various tissue, bone and muscle groups contained within the human body. However, with an increasing global push to reduce carbon emissions and increase sustainability, current materials require examination to ensure research establishments remain at the forefront of environmentally friendly practices. To date, the literature contains little in relation to how environmentally friendly the use and supply of soft tissue simulants is. The aim of the research is to provide researchers with primary data to support decisions on material selection for ballistic simulation research. The need arises due to the high cost and environmental impact of existing materials. To explore this research gap, a series of 5.5 mm ball bearings were fired from a gas gun at velocity ranges between 122 and 526 m s⁻¹ to examine the performance characteristics of six commercially available soft tissue simulants and a foodstuffs grade gelatine that represented a more cost effective environmentally friendly alternative. A structured multi-criteria decision analysis approach was employed to compare the overall effectiveness of the alternative materials. It was found that whilst PermaGel, 20 and 10% ballistic gelatine performed the most advantageously respectively during experimental testing, qualitative environmental assessment showed ballistic soap, PermaGel and foodstuffs gelatine to be most advantageous. The information provided within this study will enable researchers to make more informed decisions on both economic and environmental implications when sourcing materials for use within survivability assessment, whilst further work would increase awareness and viability of alternative materials.

Addressing the climate crisis is one of the most pressing issues of our time. Confronting climate change and meeting the 1.5 °C target set by the Conference of Parties (COP 28) requires the implementation of long-term carbon-sink measures. Carbon farming (CF) is a scalable, cost-effective, and efficient approach to achieving negative emissions that aligns with the larger goals of sustainability and climate resilience. CF is a carbon management system that facilitates the accumulation and storage of greenhouse gases within the Earth's systems. Notably, one-third of the Earth's land is used for crops and grazing, creating a significant opportunity to capture atmospheric CO₂ and convert it into soil organic carbon (SOC). CF enables to establish a mechanism for sequestering carbon in long-term storage forms by improving soil health and agricultural output in the framework of nature-based solutions (NBS). In the midst of growing global efforts to combat climate change, the implementation of sustainable agriculture and soil conservation services (SCS) via ‘carbon farming’ is emerging as a critical approach to addressing environmental issues and promoting a resilient future. Voluntary participation in future carbon offset markets may provide incentives for this approach.

Abiotic and biotic components of Antarctic ecosystems are valuable archives of past and current trends in global processes and play an important role in assessing emissions and long-range transport of persistent contaminants. After the ban on the production and use of alkyl-lead fuel additives, lead concentrations in Antarctic environmental matrices (snow, ice, sediments and biota) have decreased, just as the hole in the Antarctic stratospheric ozone layer is slowly shrinking following the ban on ozone-depleting gases. With the entry into force of the Stockholm Convention, the occurrence of persistent organic pollutants (POPs) in the Antarctic ecosystems could also decrease. However, the increasing anthropogenic sources of POPs in the Southern Hemisphere and the remobilization of those previously deposited in Antarctic ice could counteract the possible decreasing trend. Legacy pollutant concentrations in Antarctica are among the lowest reported in the global environment, with an exception of the bioaccumulation in various marine organisms of mercury (Hg) and cadmium (Cd) naturally occurring in Southern Ocean waters, or that of POPs in some long-lived seabirds with particular migration routes and life histories. However, despite the protection guidelines, long-range transport processes and especially the increase in human activities in Antarctica are sources of many persistent contaminants not yet subject to regulatory criteria and often lacking standardized sampling and analytical procedures. Chronic exposure to anthropogenic contaminants (legacy and of emerging interest) and pathogenic microorganisms near coastal scientific stations could cause synergistic or additive effects on marine biota. Most Antarctic marine organisms are endemic, with unique ecophysiological adaptations, and are also exposed to climate-related stressors. Warming and acidification of Southern Ocean waters along with increased melting of ice will likely affect the transport, pathways and environmental fate of persistent contaminants and could interfere with the metabolic processes of Antarctic organisms involved in the uptake and detoxification of environmental contaminants. Therefore, to implement environmental protection protocols around the coastal stations, the Council of Managers of National Antarctic Programs should evaluate the possible cumulative impact on biotic communities in the context of changing climatic and environmental conditions.