Low Pollution Levels Research Articles

Study of Heavy Metal Removal with Porous Nanocomposite Scaffolds based on Hybrid Inorganic/Organic Nanoparticles (MSN@COF)

aims: Synthesis of organic-inorganic hybrids as 3D adsorbents for heavy metal removal background: Synthesis of organic-inorganic hybrids objective: Study of heavy metal removal with porous nanocomposite scaffolds based on hybrid organic/inorganic nanoparticles (MSN@COF) method: Using soluthermal methods for the synthesis of organic-inorganic hybrids and studying the removal of heavy metals in them result: Precise and defect-free synthesis of organic-inorganic hybrids Removal of over 90% of heavy metals conclusion: In this research work, in order to achieve the desired product, mesoporous silica nanoparticles were first synthesized based on TEOS, and then the surface modification of these nanoparticles was done with APTES in order to achieve MSN-NH2. Next, organic covalent frameworks based on cyanuric chloride were synthesized. The main goal in this research work was the synthesis of porous nanocomposites based on MSN and COF, so that it is possible to synthesize hybrid organic/inorganic porous nanocomposites by in situ growth of COF on porous silica nanoparticles. Therefore, after synthesizing both hybrid organic/inorganic porous nanocomposites (COF and MSN) and examining their morphology and how to identify them, porous nanocomposites (MSN@COF) resulting from the growth of COF on MSN were synthesized. To achieve a proper comparison of the porosity and nature of these nanocomposites, once this nanocomposite was synthesized using MSNs whose surfactant was not removed, the CTAB surfactant was removed after COF growth on it. In another synthesis, the nanocomposite was synthesized from the growth of COF on MSN-NH2 whose surfactant was removed. This nanocomposite, due to the open pores of the MSNs, the growth of COF started by connecting to the amino groups obtained from APTES from within the MSN-NH2 themselves. The nanocomposite had less porosity than the other composite due to the growth of COF inside it. But the remarkable thing was the growth and presence of COF with its constituent atoms inside the MSN cavities. Due to the fact that porous nanomaterials have their own unique morphology, nature, function, and application according to their constituents and porosity category, both porous nanoparticles used in the preparation of these nanocomposites are well-known and widely used porous nanomaterials. They are in industry and medicine, so we decided to synthesize porous nanocomposites that have the special characteristics, behavior, and ability of both MSN and COF. Relevant analyses confirmed the synthesis of these porous nano absorbents. The growth of COF on MSNs, according to the data obtained from BET, has reduced the surface area and volume of pores in porous nanocomposites, but on the other hand, the presence of COF with its constituent atoms definitely gives a special characteristic and ability to nanocomposites. Porous materials will give in exchange for a decrease in the surface area and volume of the initial MSN cavities. The results of this study demonstrated that MSN@COF(WC) absorbs a higher percentage of zinc and cadmium metal ions than other adsorbents at various levels of adsorbent consumption, demonstrating that hybrid adsorbents are more effective than COF and MSN in removing these heavy metals from the primary solution. Also, the evaluation of the equilibrium time showed that the adsorption of heavy metals zinc and cadmium by MSN, COF adsorbents has a greater speed, while the MSN@COF(NC) hybrid adsorbent needs the greatest time to reach equilibrium conditions. When hybrid absorbents and two other absorbents were compared at various pollution levels, it became clear that hybrid absorbents at low pollution levels and other absorbents at high pollution levels are more effective in removing metals heavier than the original solution. In conclusion, the results of this study showed that the hybrid adsorbents have a larger absorption amount and the other two adsorbents have a higher absorption speed to reach equilibrium conditions in the process of removing zinc and cadmium metals from the stock solution. other: All the necessary information is available inside the text.

THE ECOLOGICAL ASSESSMENT OF SMALL RIVERS IN UKRAINE UNDER CONDITIONS OF INTENSIVE WAR IMPACT

Aquatic ecosystems are perpetually exposed to anthropogenic sources of pollution, wherein the quality of subterranean and surface waters undergoes influence from both natural and anthropogenic processes. This interaction results in environmental predicaments and, occasionally, environmental crises. Small rivers, in particular, bear a pronounced impact from human interventions on the environment. The investigation undertaken by the researchers commenced in 2021 with the primary objective of scrutinizing the ecological condition of the Irsha River. Regrettably, due to the military aggression of the Russian Federation, the regions through which the river courses were temporarily occupied, subjecting it to considerable anthropogenic disturbances. Specifically, two bridges spanning the Irsha River in the Malyn area were demolished, and military operations transpired along the riverbanks, leading to the accumulation of damaged military equipment. Consequently, it was deemed imperative during the course of our study to conduct an analysis of the natural water in the Irsha River subsequent to the military activities. The outcomes of a comprehensive assessment of surface water quality, employing a graphical method, revealed that, during the period of 2021-2022, the river waters within the Irsha River exhibited an overall failure to meet quality standards in both monitoring locations. Elevated values of Maximum Permissible Concentration (MPC) exceeding the norm were noted for the Chemical Oxygen Demand (COD) indicator, the dissolved oxygen indicator, as well as the general iron and iron of permanganate oxidizability parameters in both samples. The highest degree of pollution was discerned in the Malyn Reservoir, whereas the Irsha Reservoir manifested comparatively lower pollution levels in the aquatic environment.

Assessing the risks associated with indoor and outdoor air quality in relation to the geographic placement of nursing home

Indoor air quality significantly impacts the well-being and health of elderly residents in nursing homes. This study was conducted to explore the connection between indoor and outdoor PM (Particulate Matter) concentrations in nursing homes and their association with the facilities' location and construction characteristics. The findings revealed that indoor PM2.5 and PM10 concentrations ranged from 0.2 to 124 μg/m3 and 2–188.4 μg/m3, respectively, which were approximately 12.67 and 1.25 times higher than their outdoor counterparts. A strong correlation (P < 0.05) was identified between indoor PM levels and various factors, including proximity to parks, passenger terminals, and gas stations, as well as building attributes such as single-glazed windows, ceramic floor coverings, and the use of radiators. The risk assessment indicated that carcinogenic risk factors were well within acceptable limits for all nursing homes. However, it's important to note that certain PM components, particularly polycyclic aromatic hydrocarbons (PAH), may have long-term adverse effects on the health of nursing home residents. Even though indoor PM levels met the standards established by the U.S. Environmental Protection Agency (USEPA) for particulate matter risk assessments, the study emphasized that even low levels of indoor air pollutants can affect the health and well-being of older adults, particularly considering the increased vulnerability associated with aging. Consequently, the study underscores the importance of nursing home location selection and the regular monitoring of particulate matter concentrations. These measures are essential for enhancing air quality within nursing homes, ultimately contributing to the improved well-being and health of their residents.

Sustainable Innovation and Economic Resilience: Deciphering ESG Ratings’ Role in Lowering Debt Financing Costs

AbstractThis study delves into the intricate dynamics between environmental, social, and governance (ESG) ratings and corporate debt financing costs among China’s A-share listed companies from 2010 to 2021. Analyzing a substantial dataset unveils a tangible link where higher ESG ratings correlate with significantly lower debt financing costs. This relationship manifests more prominently in enterprises with lower pollution levels, state ownership, and those in China’s central and western regions, especially under heightened economic policy uncertainty. The findings elucidate that improved ESG ratings, reflective of robust sustainability practices, diminish corporate agency costs and enhance financial stability, thereby reducing debt financing expenses. This research extends the discourse in the knowledge economy by offering empirical evidence on how ESG integration can serve as a lever for financial efficiency and sustainability in business operations. By spotlighting the financial merits of embracing ESG criteria, the study offers profound insights for policymakers, investors, and corporations, encouraging the acceleration of ESG disclosure and assessment frameworks. In doing so, it supports the cultivation of high-caliber, environmentally friendly enterprises, aligning with the broader objectives of innovation, entrepreneurship, and societal welfare within the knowledge economy paradigm.

Organic Emissions of Volatile Chemical Products in Canada: Emission Inventories, Indoor-to-Outdoor Transfer, and Regional Impacts.

The contribution of volatile chemical products (VCPs) to ambient air pollution has increased following decades of regulating combustion sources. There is a research gap concerning the impact of indoor physicochemical phenomena on VCP emissions. In this work, a bottom-up speciated VCP emission inventory with indoor-outdoor resolution was developed for Canada, an industrialized country with low air pollution levels, whose major cities are among the largest urban areas in North America. VCPs were estimated to account for about 290 kilotons of gaseous organic emissions for a typical year in the 2010s, with more than 60% of emissions occurring indoors. Coatings and cleaners were the most emissive VCP categories. Oxygenated species and saturated aliphatics dominated the chemical profiles of most emissions. Less than 5% of VCP emissions were impacted by indoor physicochemical phenomena. VCP emissions were predicted to account for 0.8-3.2 s-1 of OH reactivity and 0.22-0.52 μg/m3 of secondary organic aerosol formation potential in major urban areas in Canada. Our predictions aligned with previous measurements concerning indoor and outdoor organic pollutant levels, underscoring the important air quality impacts of VCPs relative to other sources. Our results provide helpful insights for future research regarding VCP emissions, especially from indoor spaces.

COMPETITIVE ENVIRONMENTAL STRATEGY OF AGRICULTURAL ENTERPRISES OF THE CARPATHIAN REGION OF UKRAINE

A comprehensive assessment of the level of environmental competitiveness of agricultural enterprises of the Carpathian region of Ukraine allows to recognise them as priority, important competitors of high quality and safe agricultural products with geographical indication. In this regard, the problem of developing and implementing an environmental competitiveness strategy of agricultural enterprises in the Carpathian region, which is characterised by a relatively low level of environmental pollution and has significant land and resource potential for the production of the main types of agricultural products, is being updated at the national level. Methodology. The article uses the methods of induction, deduction, analysis, synthesis, statistical sampling, comparison, expert opinions, associations and analogies. Results. The identified conceptual foundations of the competitive environmental strategy of agricultural enterprises at the regional level provide for improvement of the regulatory and legal support for their functioning. A grouping of farms in the Carpathian region of Ukraine was carried out according to two key criteria: the area of agricultural land and the number of farms. Based on the results of the analysis, a matrix of problematic aspects of the development of organic agriculture is formed, which is based on the following levels of management: legislative-institutional and organisational-economic. Practical implications. Implementation of a competitive environmental strategy in the Carpathian region of Ukraine requires active and coordinated work of government authorities, scientific institutions, NGOs and the private sector. This will help to preserve and rationally use the region's environmental resources, ensure its sustainable development and improve the quality of life. Value/Originality. The paper suggests and evaluates the environmental competitiveness of agricultural enterprises in the Carpathian region of Ukraine using the integrated index of environmental competitiveness based on the data of the State Statistics Service of Ukraine.

Long-term exposure to PM2.5 air pollution and mental health: a retrospective cohort study in Ireland

BackgroundMental illness is the leading cause of years lived with disability, and the global disease burden of mental ill-health has increased substantially in the last number of decades. There is now increasing evidence that environmental conditions, and in particular poor air quality, may be associated with mental health and wellbeing.MethodsThis cross-sectional analysis uses data on mental health and wellbeing from The Irish Longitudinal Study on Ageing (TILDA), a nationally representative survey of the population aged 50+ in Ireland. Annual average PM2.5 concentrations at respondents’ residential addresses over the period 1998–2014 are used to measure long-term exposure to ambient PM2.5.ResultsWe find evidence of associations between long-term exposure to ambient PM2.5 and depression and anxiety. The measured associations are strong, and are comparable with effect sizes for variables such as sex. Effects are also evident at relatively low concentrations by international standards. However, we find no evidence of associations between long-term ambient particulate pollution and other indicators of mental health and well-being such as stress, worry and quality of life.ConclusionsThe measured associations are strong, particularly considering the relatively low PM2.5 concentrations prevailing in Ireland compared to many other countries. While it is estimated that over 90 per cent of the world’s population lives in areas with annual mean PM2.5 concentrations greater than 10 μg/m3, these results contribute to the increasing evidence that suggests that harmful effects can be detected at even low levels of air pollution.

Urban environmental monitoring and health risk assessment introducing a fuzzy intelligent computing model.

To enhance the precision of evaluating the impact of urban environments on resident health, this study introduces a novel fuzzy intelligent computing model designed to address health risk concerns using multi-media environmental monitoring data. Three cities were selected for the study: Beijing (B City), Kunming (K City), and Wuxi (W City), representing high, low, and moderate pollution levels, respectively. The study employs a Fuzzy Inference System (FIS) as the chosen fuzzy intelligent computing model, synthesizing multi-media environmental monitoring data for the purpose of urban health risk assessment. (1) The model reliably estimates health risks across diverse cities and environmental conditions. (2) There is a positive correlation between PM2.5 concentrations and health risks, though the impact of noise levels varies by city. In cities B, K, and W, the respective correlation coefficients are 0.65, 0.55, and 0.7. (3) The Root Mean Square Error (RMSE) values for cities B, K, and W, are 0.0132, 0.0125, and 0.0118, respectively, indicating that the model has high accuracy. The R2 values for the three cities are 0.8963, 0.9127, and 0.9254, respectively, demonstrating the model's high explanatory power. The residual values for the three cities are 0.0087, 0.0075, and 0.0069, respectively, indicating small residuals and demonstrating robustness and adaptability. (4) The model's p-values for the Indoor Air Quality Index (IAQI), Thermal Comfort Index (TCI), and Noise Pollution Index (NPI) all satisfy p < 0.05 for the three cities, affirming the model's credibility in estimating health risks under varied urban environments. These results showcase the model's ability to adapt to diverse geographical conditions and aid in the accurate assessment of existing risks in urban settings. This study significantly advances environmental health risk assessment by integrating multidimensional data, enhancing the formulation of comprehensive environmental protection and health management strategies, and providing scientific support for sustainable urban planning.

Modern successful global solutions in environmentally friendly urban delivery and their application in Ukraine

Nowadays the issue of reducing environmental pollution is on the agenda of all countries. Among the areas that have huge negative consequences for nature, logistics and supply chains take their place. Today, there are many concepts and scientific currents that recognize the need to account for the environmental component in urban logistics. Environmental aspects are used when evaluating the efficiency of investment projects, developing new models of vehicles, calculating taxes and insurance payments, and when searching for the best delivery schemes. The goal of the work. Taking into account the world experience in research on the chosen topic, the purpose of this study is to consolidate the world's successful experience in environmentally friendly urban delivery and assess their applicability in Ukraine. Technologies and methods that allow reducing the negative impact of motor vehicles on the environment include: The technology of off-peak delivery, which allows you to improve the speed mode of the car. With off-peak delivery, the probability of traffic jams is minimized, which makes the speed of movement the maximum permissible in the city (and, accordingly, the most environmentally friendly). Although night delivery is currently not possible in Ukraine due to the curfew, late and early delivery is still available, allowing you to successfully bypass traffic jams. Use of consolidation centers. The economic idea of consolidation of freight transportation is to use the effect of scale - the greater the carrying capacity of the vehicle, the lower the specific costs for transportation of a unit of production. Currently, the construction of the consolidation center is being evaluated from the point of view of the impact of the supply chain on the environment. At the same time, the existence of a consolidation center near or within the city allows to organize delivery by vehicles with zero or low level of environmental pollution. Use of Parcel Delivery Lockers. Delivery lockers are usually installed in places where the maximum flow of residents is concentrated, which makes it possible to create additional comfort for users due to the possibility of choosing the point closest to their own home or place of work. This method eliminates up to two thirds of harmful emissions into the air. The number of post machines and the area covered by them increases year by year, which allows us to talk about the success of this technology. According to the results of 2022, such major players of express delivery as "Nova Poshta" (now “Nova”), "Ukrposhta" and "Meest" will continue to work with post delivery lockers in Ukraine. Use of more environmentally friendly types of transport. The use of hybrid, electric or non-motorized vehicles is increasingly used in last-mile logistics. Electric vehicles, mopeds, two- or three-wheeled bicycles with a large trunk or cargo body can be considered environmentally friendly types of urban logistics. Such vehicles have practically zero emissions of harmful substances, they are much more maneuverable and do not require a lot of space for unloading, loading and parking. Implementation of zones with low (zero) air pollution. Zones with zero or low emissions have long been used in developed countries. There are no generally accepted technologies for calculating the territory that requires restrictions on the movement of transport, as well as for calculating the cost of such movement. Usually it depends on the will of the local authorities, the wishes of the residents and the well-being of the region. Prohibition on the use of motor vehicles. Some local authorities introduce a complete ban on the use of motor vehicles within certain parts of the city. Usually these are historical centers with dense buildings and a large number of tourists. Sometimes such drastic measures are combined with night delivery technology. If this is not possible, the only alternative is delivery by small, usually two- or three-wheeled, zero-emission vehicles. Improvement of traffic management. Competently designed organization of road traffic can reduce the pressure on the environment. The use of an intelligent transport system in smart cities allows you to perform important tasks like detection of transport accidents; automated control of the ramp, traffic lights and parking, etc. Improvement of road conditions. This refers to the quality of the road surface, markings, cleanliness of the road surface, etc. Improvement of road conditions indirectly affects the improvement of environment of the region. Summing up the results of the research, successful global practices in environmental friendly urban logistics are highlighted, which are applied and have prospects for application in Ukraine. It was concluded that there is a huge potential of using world experience in urban logistics of Ukraine. This will bring Ukrainian logistics and urban supply chains to a new level, increasing the level of health and general satisfaction of the citizens.

Delayed effects of air pollution on public bike-sharing system use in Seoul, South Korea: A time series analysis

Background:As a complementary means to urban public transit systems, public bike-sharing provides a green and active mode of sustainable mobility, while reducing carbon-dioxide emissions and promoting health. There has been increasing interest in factors affecting bike-sharing usage, but little is known about the effect of ambient air pollution. Method:To assess the short-term impact of daily exposure to multiple air pollutants (PM2.5, PM10, NO2, and O3) on the public bike-sharing system (PBS) usage in Seoul, South Korea (2018–2021), we applied a quasi-Poisson generalized linear model combined with a distributed lag nonlinear model (DLNM). The model was adjusted for day of the week, holiday, temperature, relative humidity, and long-term trend. We also conducted stratification analyses to examine the potential effect modification by age group, seasonality, and COVID-19. Results:We found that there was a negative association between daily ambient air pollution and the PBS usage level at a single lag day 1 (i.e., air quality a day before the event) across all four pollutants. Our results suggest that days with high levels of air pollutants (at 95th percentile) are associated with a 0.91% (0.86% to 0.96%) for PM2.5, 0.89% (0.85% to 0.94%) for PM10, 0.87% (0.82% to 0.91%) for O3, and 0.92% (0.87% to 0.98%) for NO2, reduction in cycling behavior in the next day compared to days with low levels of pollutants (at 25th percentile). No evidence of effect modification was found by seasonality, age nor the COVID-19 pandemic for any of the four pollutants. Conclusions:Our findings suggest that high concentrations of ambient air pollution are associated with decreased rates of PBS usage on the subsequent day regardless of the type of air pollutant measured.

Measuring ecological quality status in low-diversity Arctic intertidal foraminiferal assemblages using a diversity-based index

EcoQS assessment of the marine intertidal zone based on its fauna is challenging because the assemblages have a low diversity and consist of stress tolerant species. The new approach we propose is to pool foraminiferal diversity (effective number of species exp(H'bc)) across the whole intertidal zone including the salt marsh and tidal flat. In seven fjordheads studied in northern Fennoscandia, polycyclic aromatic hydrocarbon (PAH) concentrations indicated low levels of pollution (EcoQSPAH Excellent to Moderate). Jadammina or Balticammina dominated the salt marsh, Elphidium albiumbilicatum, Elphidium williamsoni, Elphidium clavatum, and Buccella frigida occurred in the tidal flat. Ovammina opaca thrived in both belts. While foraminiferal test abnormalities are often proposed to measure pollution impacts, we did not detect any correlation with PAHs. EcoQS based on foraminiferal diversity (EcoQSforam Excellent to Good) matched EcoQS based on PAHs suggesting that pooled foraminiferal diversity reliably measures intertidal EcoQS.

Residual loads from tilapia farming on the sediment of a Brazilian reservoir

This study investigated the sediment geochemistry of a fish farming area in net cage tanks in the Rosário reservoir, Brazil. Three areas were investigated: reference (RA), fish farming (FFA), and dispersion (DA). The results were analyzed through correlation, similarity, principal component analysis, comparison with legislation, sediment quality guidelines, and sediment pollution indices. The mean concentrations for RA, FFA, and DA areas were respectively: Cu (mg.kg−1) 37.74, 62.23, and 71.83; Mn (mg.kg−1) 22.55, 66.48, and 55.90; Zn (mg.kg−1) 9.13, 114.83, and 94.27; Fe (%) 0.28, 0.40, and 0.43; OM (%) 15.84, 21.95, and 18.45; TOC (%) 1.86, 3.69, and 6.05; TN (mg.kg−1) 2365.00, 5015.00, and 3447.51; TP (mg.kg−1) 780.00, 6896.00, and 2585.50; ORP (mV) −95.50, −135.20, and −127.10; pH 6.60, 6.58, and 6.05; <63 μm 90.59, 78.68, and 87.30. Statistically, the influence of fish farming on sediment, organic matter, and pollutant sedimentation was demonstrated. Cu and Zn concentrations were below sediment quality guidelines. Regarding legal limits (resolution 454/2012/CONAMA), nutrients in the FFA area exceeded by 60% (TN) and 100% (TP), while in DA and RA areas they were 100% lower. TOC was 100% lower in all areas. Organic matter exceeded the limit by 100% in all areas. Pollution indices resulted in: low contamination factor 78%; unpolluted for 87% of pollution load and 83% of combined pollution; moderately polluted for 75% of the Nemerow index. The greatest impacts and influence of farming on pollutant sedimentation were more concentrated in the fish farming area. In terms of legal aspects and pollution indices, fish farming produced low levels of trace metal pollution and nutrient concentrations exceeded legal limits.

Distribution, source identification, and contamination level of trace metals in the sediment of the Shari-Goyain River in Bangladesh: Implications for ecological health risks

The major issue associated with coal mine drainage is its contribution to river pollution, which occurs at the local, regional, and global levels. The pollution of surface sediment by heavy metals is a major environmental and health concern in coal mining and downstream areas. This study explored the concentrations of eight metal components in the sediments from the Shari-Goyain River of Bangladesh. The trend of decreasing metal concentration was identified as Fe > Mn > Ni > Zn > Cu > Cr > Pb > Cd in sediment. The level of metal pollution in the study area was assessed by using various indicators like geo-accumulation index (Igeo), pollution load index (PLI), contamination factor (CF), potential ecological risk factor, and risk index (RI). The sediment in the river exhibited PLI values ranging from 0.133 to 0.543, suggesting a low level of pollution from the evaluated heavy metals (PLI < 1). The mean Igeo showed that the study area was unpolluted whereas Ni showed unpolluted to moderately polluted status. For most of the metals, the sediment samples recorded a low degree of contamination (CF < 1) except Pb, Cd, and Ni which exhibited moderate degree of contamination (1 ≤ CF < 3). Through the application of various statistical analyses, coal mine drainage has been identified as the possible source of pollution of the analyzed metals in the Shari-Goyain River. However, the risk index and RI suggested a low risk of metal pollution in the studied areas. To improve the environmental conditions of the Shari-Goyain River, it is crucial to construct permanent sediment quality monitoring stations and conduct extensive ecological investigations.

Surface water pollution by some heavy metals in a remote island, Hatiya, northern Bay of Bengal

IntroductionMetal contamination in surface water in urban cities has become a common scenario in underdeveloped and developing countries. Nowadays, the extent of this contamination is suspected to be traced in remote islands due to the transportation of metals with downward water flow. Unfortunately, we found a dearth of research on our remote island, where thousands of people live and use surface water for their daily needs. ObjectivesThe current study aims to investigate the status of heavy metals in surface water from a remote island, Hatiya Coast, to determine the existence of heavy metals and their risks to human health. Ten surface water samples were collected, and their concentrations were measured using AAS. Later, various pollution indices were analyzed to understand their pollution level. ResultsThe mean metal concentrations were ranked in descending order of Mg (65.44 mg.L−1)> Fe (0.375 mg.L−1)> Zn (0.139 mg.L−1)>Mn (0.016 mg.L−1)> and Cu was below the detection limit (BDL). According to different metal pollution indexes, the surface water of the Hatiya coast is low to moderately polluted. The standard HEI value was 1.58, and the range was 1.29–2.25, indicating that all sampling stations had a low level of metal contamination. The mean and range of HPI values were found at 44.58 and 34.33–69.33, respectively. All of the sampling stations indicated low pollution levels except sampling station 6. NPI values revealed moderate contamination in stations 2, 3, and 7. According to the hazard quotient (HQ) and hazard index (HI) for adults and children, heavy metals were found to have no carcinogenic risks for children and adults through dermal exposure. ConclusionAlong with the metals coming from upstream, several local sources of heavy metals were identified during fieldwork, including metallurgical businesses, oil spills from the ship, and some trawlers associated with fishing activities. Overall, these findings would be valuable for aquaculture sectors and future researchers to compare, correlate, and understand the pollution level of the island and serve as a foundation for conducting further investigations in similar island environments, both locally and globally.

Performance Evaluation of Low-Concentration Methane Combustion in a Four-Layer Gradually-Varied Porous Burner

ABSTRACT Porous media combustion (PMC) has made a comeback as a practical technology for the utilization of low-concentration methane (LCM) from coal mining. However, the conventional direct-fired PM burner still suffers from the rampart of flame stability and combustion efficiency not addressing industrial demands. Herein, a four-layer gradually-varied porous burner was innovatively developed for LCM combustion to investigate combustion performance under lean combustion conditions (CH4 volume fraction below 5%). The methane conversion, pollutant emissions, and flue gas temperature were also evaluated in detail. The results indicated that the burner offered a favorable combustion resistance due to the gradually-varied PM arrangement to heighten combustion stability with subtle temperature fluctuation and flame migration. The flammability limit of LCM was extended to the lowest equivalence ratio of 0.43 with stationary combustion at 240°C for 120 min. The energy efficiencies of the LCM combustion under lean combustion conditions were greatly boosted with the highest combustion and thermal efficiencies attained at 99.52% and 70.05%, respectively. The maximum 99.93% CH4 conversion was acquired at an equivalence ratio of 0.45 and a flow rate of 80 L/min. LCM combustion in the burner achieved extremely low pollutant emission levels and the overall CO and NOx emissions were 58.04 ppm and below 23 ppm respectively under the experimental conditions. In addition, the high-quality flue gas with an average temperature of more than 516°C was detected in the operating process, which allowed the available heat utilization at the coal mine scenes or in other industries.

Distribution, ecological, and health risk assessment of trace elements in the surface seawater along the littoral of Tangier Bay (Southwestern Mediterranean Sea)

In the current study, an environmental assessment of surface seawater in Tangier Bay was conducted by analyzing physicochemical parameters and trace elements, such as As, Cr, Zn, Cd, Pb, and Cu. The results showed mean concentrations (μg/l) of 22.50 for As, 0.46 for Cr, 8.57 for Zn, 15.41 for Cd, 0.23 for Pb, and 1.83 for Cu. While most trace elements met the guidelines, elevated levels of Cd raised concerns about long-term exposure. Pollution indices, including the contamination factor, degree of contamination, and water quality index, indicate the impact of human activities, dividing sites into arsenic‐cadmium contamination, wastewater influence, and low pollution levels. Statistical methods, such as ANOVA, revealed no significant differences in trace element levels across the bay. PCA and HCA revealed that Cr, Cu, and Zn originated from common anthropogenic sources, whereas Pb and Cd originated from distinct sources. As indicates that natural geological processes influence its origin.

Global trends and spatial drivers of diabetes mellitus mortality, 1990-2019: a systematic geographical analysis.

Diabetes mellitus is the leading cause of death worldwide, and multiple risk factors associated with diabetes mortality. Employing spatial statistics, we characterized the spatial distribution and patterns of diabetes mortality, and revealed the spatial relationship between diabetes mortality and 11 socioeconomic and environmental risk factors at the country level, from 1990 to 2019. Globally, significantly high rates of diabetes mortality were primarily clustered in countries with limited land areas or located on islands, such as Fiji, Kiribati, Eswatini, and Trinidad and Tobago. Countries with weaker economic independence are more likely to have higher diabetes mortality rates. In addition, the impact of socioeconomic and environmental factors was significant at the country level, involving health expenditure, number of physicians, household and ambient air pollution, smoking, and alcohol consumption. Notably, the spatial relationship between diabetes mortality and ambient air pollution, as well as alcohol consumption, showed negative correlations. Countries with high diabetes mortality rates generally had lower levels of ambient air pollution and alcohol consumption. The study highlights the spatial clustering of diabetes mortality and its substantial variation. While many risk factors can influence diabetes mortality, it's also essential to consider the level of these factors at the country level. Tailoring appropriate interventions based on specific national circumstances holds the potential to more effectively mitigate the burden of diabetes mortality.

Air pollution levels enhance green bond investment: green preference and environmental perception thresholds

Environmental change is a crucial factor influencing green investment, and air pollution affects green assets through green preference. This study analyzes the impact of air pollution levels on the green bond using the threshold model. Since investors have physiological thresholds for perceiving air pollution, green preferences change investor behavior once air pollution reaches a certain threshold. The empirical results confirm that at low air pollution levels, weak physical stimuli are not sufficient to induce strong environmental perceptions, resulting in an insignificant role for green preference. However, when air pollution exceeds the threshold, the effect of air pollution becomes significantly positive due to enhanced environmental perceptions. Additionally, major crisis events (e.g. COVID-19) may weaken the role of green preference by distracting investors, leading to an insignificant impact of air pollution on green bonds after the crisis. These findings help enterprises to achieve green transformation and sustainable development through green debt financing.

Under the dome: Air pollution and analyst forecast optimism

In this study, we investigate whether unpleasant mood caused by air pollution leads to lower analyst forecast optimism. Using a sample of 103,768 observations from 2014 to 2021, we show that there is a negative association between air pollution and analyst forecast optimism. Furthermore, we find that analysts become more optimistic forecasters after moving to a city with lower level of air pollution. Our results hold through various robustness tests including alternative measures of air pollution, controlling for various fixed effects, 2SLS by instrumenting for air pollution using thermal inversions and a placebo test by randomizing the headquarter locations of brokerage firms in our sample. Our paper provides plausibly causal evidence that air pollution lowers analyst forecast optimism.

Relationships between high-concentration toxic metals in sediment and evolution of microbial community structure and carbon-nitrogen metabolism functions under long-term stress perspective.

Microorganisms are highly sensitive to toxic metal pollution and play an important role in the material cycling and energy flow of the water ecosystem. Herein, 13 sediment samples from Junchong Reservoir (Guangxi Province, China) were collected in December 2021. The spatial distribution of pollution levels for toxic metals and the effects of toxic metals on the composition, functional characteristics, and metabolism of microorganisms were investigated. The results demonstrated that the area is a proximate area to industrial zones with severity of toxic metal pollution. Their mean concentrations of As, Cu, Zn, and Pb were up to 128.79mg/kg, 57.62mg/kg, 594.77mg/kg, and 97.12mg/kg respectively. There was a strong correlation between As, Cu, Zn, and Pb, with the highest correlation coefficient reaching 0.94. As the level of toxic metal pollution increases, the diversity and abundance of microorganisms gradually decrease. Compared to those with lower pollution levels, the Shannon index in regions with higher pollution levels decreases by up to 0.373, and the Chao index decreases by up to 143.507. However, the relative abundance of Bacteroidota, Patescibacteria, and Chloroflexi increased by 23%, 20%, and 5%, respectively, indicating their higher adaptability to toxic metals. Furthermore, microbial carbon and nitrogen metabolism were also affected by the presence of toxic metals. FAPROTAX analysis demonstrated an abundant reduction of ecologically functional groups associated with carbon and nitrogen transformations under high toxic metal pollution levels. KEGG pathway analysis indicated that carbon fixation and nitrogen metabolism pathways were inhibited with increasing toxic metal concentrations. These findings would contribute to a better understanding of the effects of toxic metal pollution on sediment microbial communities and function, shedding light on the ecological consequences of toxic metal contamination.