High Pollutant Concentrations Research Articles

Preparation of rice-like WO2.92/Bi2WO6 nanoparticles and application in rapid restoration of sea water with high concentration of 4-nitrophenol pollutant

It is very needful to rapidly restore sea water with high concentration of 4-nitrophenol when a 4-nitrophenol pollution incident occurs. Driven by this requirement, we prepared rice-like WO2.92/Bi2WO6 nanoparticles. Meanwhile, their catalytic activity was explored. It was found that the as-prepared sample is an efficient catalyst which can be used in the fast restoration of highly concentrated 4-nitrophenol effluent. When the concentration of 4-nitrophenol is 1.0 × 10-3 mol L-1, almost 100% 4-nitrophenol can be removed within 1 min. In addition, when the WO2.92/Bi2WO6 nanoparticles are used to remove 4-nitrophenol in sea water (1.0 × 10-3 mol L-1), the removal efficiency of 4-nitrophenol is up to 100% within 8 min. Our work may put forward new insights for designing an efficient catalyst which is suitable for rapid removal of highly concentrated 4-nitrophenol from sea water.

Distribution of benzene and formaldehyde in tractor cabin: Effects of components, ventilation conditions, and vent positions

Tractor cabin is a relatively closed microenvironment in which operator is exposed to various pollutants that can adversely affect human health. In this study, the distribution of benzene and formaldehyde inside tractor cabin was investigated using computational fluid dynamics (CFD) method and verifying its effectiveness with field measurements. The effects of pollution source, ventilation, and vent position on the distribution of pollutants were discussed by using the validated CFD model. The results indicated that the areas with high concentration of pollutants are mostly distributed in the corners, and the ceiling contributes the most to its emission. The concentration difference of benzene and formaldehyde in the driver’s breathing area can reach a maximum of 20% by adjusting the air supply angle. It can also be reduced by 3.9% and 4.3% for every 1 m s−1 increase in air supply speed when the airflow angle emitted from the vent was 90°. In the common vent locations, the vent arranged on the front ceiling has the best pollutant reduction effect. This study provided a reliable CFD simulation method for benzene and formaldehyde distribution, offered a theoretical basis for the selection of ventilation conditions and the design of internal layout in tractor cabins for improving air quality. It also suggested that then environment and air quality of non-road mobile machinery cabs should be paid more attention in the future.

Vertical distribution of black carbon and its mixing state in the urban boundary layer in summer

Abstract. The vertical distribution of black carbon (BC), as well as its mixing state, is of great concern due to BC's strong regional climatic and environmental effects. In this study, vertical measurements were conducted through a moveable container based on a meteorological tower in the Beijing urban area during June and July. A total of 112 vertical profiles (0–240 m), including the concentrations of BC, O3, NOx and the optical properties of aerosols, were obtained. Based on BC concentration, the vertical profiles could be classified into four categories: uniform, gradual decrease, sharp decrease and sudden increase. The uniform type indicates strong vertical mixing with similar pollutant concentrations along the vertical direction. The gradual and sharp decrease types indicate stable vertical conditions with higher pollutant concentrations on the ground and lower concentrations at higher altitudes. Due to the strong radiation in summer, the vertical profiles exhibited a clear diurnal variation in which ∼ 80 % of profiles were uniform during the daytime and ∼ 40 %–90 % of profiles were of the gradual and sharp decrease types at night. O3 is an exception, and its concentration generally increases with height, even under strong vertical mixing conditions. The size distribution of the BC core varied slightly along the vertical direction, and the coating thickness, denoted by the diameter ratio between the BC-containing particle and BC core (Dp/Dc), of BC increased with height under stable conditions. Although the coating thickness could increase the absorption ability with an average absorption enhancement of 1.25 at 23:00 LT (local time: UTC+8), the vertical difference of Dp/Dc (2 %) was much lower than that of BC concentration (∼ 35 %). The vertical variation in absorption ability was mainly caused by the variation in BC concentration. In addition, O3 and Dp/Dc occasionally increased during 06:00–08:00 but remained stable during 08:00–10:00. Vertical mixing and transportation from upper heights, such as the residual layer, could significantly influence the pollutant properties on the surface during early mornings. This study exhibits a continuous vertical picture of BC and its mixing state in urban areas, which would be helpful for understanding BC's regional environmental effect.

Insights for Sea Outfall Turbid Plume Monitoring with High-Spatial-Resolution Satellite Imagery Application in Portugal

Coastal municipalities and industries often discharge poorly treated wastewater into proximate marine and estuarine environments. The urban and/or effluent input can lead to eutrophication and lower water quality, as it holds high concentrations of nutrients and pollutants. One widely applied tool to increase effluent dispersion and direct it away from coastal areas, thus causing fewer impacts on human activities, is sea outfall. In Aveiro, Portugal, the São Jacinto sea outfall construction was completed in 1998; however, limited literature regarding the sea outfall’s monitoring using satellite data is available. The methodology in this study involved collecting four years’ worth (2016–2019) of satellite data to investigate visible traces of the interaction between the S. Jacinto sewage water mass and the Ria de Aveiro lagoon ecosystem using ocean color and spectral analysis, and producing new qualitative data regarding sea outfall plume dispersion monitoring through high-resolution Sentinel-2 imagery. The results showed a clear spectral signature of the sewage water mass, and a seasonal pattern was observed in which the plume was more evident in winter and autumn. Additionally, the coastal longshore current and the Aveiro lagoon’s runoff were able to restrict the marine outfall’s dispersion superficially. Ocean color data were revealed to be a factual and cost-effective tool to monitor the plume water. Finally, an exchange between the marine outfall water mass and Ria de Aveiro lagoon could happen in high tide under northern wind conditions. Therefore, it is important to monitor the water quality to ensure the coastal ecosystem’s good environmental state.

Linking the shifts in the metabolically active microbiota in a UASB and hybrid anaerobic-aerobic bioreactor for swine wastewater treatment

Due to the high concentration of pollutants, swine wastewater needs to be treated prior to disposal. The combination of anaerobic and aerobic technologies in one hybrid system allows to obtain higher removal efficiencies compared to those achieved via conventional biological treatment, and the performance of a hybrid system depends on the microbial community in the bioreactor. Here, we evaluated the community assembly of an anaerobic-aerobic hybrid reactor for swine wastewater treatment. Sequencing of partial 16S rRNA coding genes was performed using Illumina from DNA and retrotranscribed RNA templates (cDNA) extracted from samples from both sections of the hybrid system and from a UASB bioreactor fed with the same swine wastewater influent. Proteobacteria and Firmicutes were the dominant phyla and play a key role in anaerobic fermentation, followed by Methanosaeta and Methanobacterium. Several differences were found in the relative abundances of some genera between the DNA and cDNA samples, indicating an increase in the diversity of the metabolically active community, highlighting Chlorobaculum, Cladimonas, Turicibacter and Clostridium senso stricto. Nitrifying bacteria were more abundant in the hybrid bioreactor. Beta diversity analysis revealed that the microbial community structure significantly differed among the samples (p < 0.05) and between both anaerobic treatments. The main predicted metabolic pathways were the biosynthesis of amino acids and the formation of antibiotics. Also, the metabolism of C5-branched dibasic acid, Vit B5 and CoA, exhibited an important relationship with the main nitrogen-removing microorganisms. The anaerobic-aerobic hybrid bioreactor showed a higher ammonia removal rate compared to the conventional UASB system. However, further research and adjustments are needed to completely remove nitrogen from wastewater.

Fabrication of durable self-cleaning photocatalytic coating with long-term effective natural light photocatalytic degradation performance

The practical application of photocatalytic coating has been greatly challenged in terms of its long-term effective natural light photocatalytic degradation due to its vulnerability and easy contamination caused by poor self-cleaning properties. In this work, photocatalytic coating with self-cleaning properties was prepared by spraying fluorinated dual-scale TiO2 on the inorganic lithium silicate adhesive, enabling excellent durability and long-term effective photocatalytic degradation performance under natural light. The coating exhibits superhydrophobic properties even after abrasion testing, acid and alkali immersion testing, and UV aging, laying a foundation for the practical use. Moreover, the coating can be applied to various substrates and its excellent self-cleaning properties make it resistant to particulate and liquid contamination that may occur in the environment. Besides, we evaluated the photocatalytic stability of the coating by subjecting it to acidic and alkaline environments and high pollution concentrations. Furthermore, benefiting from the synergistic effect of photocatalytic and self-cleaning properties, the coating achieves long-term effective photocatalytic degradation of dye wastewater under natural light, which still has a high removal rate of 95.8% for methylene blue even after 30 cycles of use. Meanwhile, due to the coating's excellent durability, the long-term quality loss rate of the coating still remained below 0.3%, which avoids the risk of secondary environmental pollution caused by nanoparticle leakage. Therefore, these excellent properties enable the coating to have a broad range of application prospects for the treatment of pollutants in water.

Seasonality of Polyaromatic Hydrocarbons (PAHs) and Their Derivatives in PM2.5 from Ljubljana, Combustion Aerosol Source Apportionment, and Cytotoxicity of Selected Nitrated Polyaromatic Hydrocarbons (NPAHs).

Airborne particulate matter (PM) is a vector of many toxic pollutants, including polyaromatic hydrocarbons (PAHs) and their derivatives. Especially harmful is the fine fraction (PM2.5), which penetrates deep into the lungs during inhalation and causes various diseases. Amongst PM2.5 components with toxic potential are nitrated PAHs (NPAHs), knowledge of which is still rudimentary. Three of the measured NPAHs (1-nitropyrene (1-nP), 9-nitroanthracene (9-nA), and 6-nitrochrysene (6-nC)) were detected in ambient PM2.5 from Ljubljana, Slovenia, along with thirteen non-nitrated PAHs. The highest concentrations of pollutants, which are closely linked with incomplete combustion, were observed in the cold part of the year, whereas the concentrations of NPAHs were roughly an order of magnitude lower than those of PAHs throughout the year. Further on, we have evaluated the toxicity of four NPAHs, including 6-nitrobenzo[a]pyrene (6-nBaP), to the human kidney cell line, HEK293T. The most potent was 1-nP (IC50 = 28.7 µM), followed by the other three NPAHs, whose IC50 was above 400 or 800 µM. According to our cytotoxicity assessment, atmospheric 1-nP is the most harmful NPAH among the investigated ones. Despite low airborne concentrations of NPAHs in ambient air, they are generally considered harmful to human health. Therefore, systematic toxicological assessment of NPAHs at different trophic levels, starting with cytotoxicity testing, is necessary in order to accurately evaluate their threat and adopt appropriate abatement strategies.

Characterization of pollutants and identification of microbial communities in the filter media of green infrastructures

Green infrastructure (GI) technologies use natural mechanisms and processes associated with microorganisms, plants, and filter media to facilitate mass circulation and energy flow in the ecosystem. Despite the numerous studies focused on the functions and pollutant treatment performance of nature-based stormwater treatment technologies, studies concerning the effects of filter media characteristics on the diversity and abundance of microorganisms in green stormwater infrastructures are still lacking. In this study, the physico-chemical characteristics of filter media and accumulated sediments in an infiltration trench (IT) and bioretention facility (BI) were investigated. Moreover, the composition and distribution of different microbial communities in GIs designed for stormwater treatment were identified. As compared with BI, higher pollutant concentrations were noted on the filter media and sediments accumulated in IT due to the higher degree of anthropogenic activities in IT's catchment area. Inorganic filter media (i.e., gravel) tend to have greater pollutant trapping efficiency due to the accumulation of sediments in the macropores. On the other hand, organic filter materials (i.e., woodchips) may serve as carbon sources for fueling microbial processes and promote better moisture retention in the facility. Proteobacteria, which constituted 38.6% to 43.0% of the total bacterial population in IT and 37.9% to 41.4% of the total bacterial population in BI, was found to be the most dominant type of bacteria in the facilities. In terms of microbial diversity, BI exhibited a higher diversity index, which is most likely due to the presence of vegetative components forming a symbiotic relationship with microbial colonies. Generally, inorganic filter media are mainly used for improving the GI technologies' drainage and infiltration functions, whereas organic filter media provide suitable growth environments for different bacterial communities involved in important biogeochemical cycles.

Smart solutions for urban health risk assessment: A PM2.5 monitoring system incorporating spatiotemporal long-short term graph convolutional network

Current spatial-temporal early warning systems aim to predict outdoor air quality in urban areas either at short or long temporal horizons. These systems implemented architectures without considering the geographical distribution of each air quality monitoring station, increasing the uncertainty of the forecasting framework. This study developed an integrated spatiotemporal forecasting architecture incorporating an extensive air quality PM2.5 monitoring network and simultaneously forecasts PM2.5 concentrations at all locations, allowing the monitoring of the health risk associated with exposure to these levels. First, this study uses a graph convolutional layer to incorporate the spatial relationship of the neighboring stations at their current state with real-time measurements. Then, it is coupled to a deep learning temporal model to form the long- and short-term time-series graph convolutional network (LSTGraphNet) model, anticipating high pollutant concentration events. This work tested the proposed model with a case study of an existing ambient air quality monitoring network in South Korea. LSTGraphNet model showed prediction performances of PM2.5 at multiple monitoring stations with a mean absolute error (MAE) of 1.82 μg/m3, 4.46 μg/m3, and 4.87 μg/m3 for forecasting horizons of one, three, and 6 h ahead, respectively. Compared to conventional sequential models, this architecture was superior among the state-of-the-art baselines, where the MAE decreased to 41%, respectively. The results of the study showed that the proposed architecture was superior to conventional sequential models and could be used as a tool for decision-making in smart cities by revealing hotspots of higher and lower PM2.5 concentrations in the long term.

Ventilation strategies and children's perception of the indoor environment in Swedish primary school classrooms

This study explored the relationship between children's subjective perception of indoor environmental quality in classrooms, measured thermal and air quality factors, and the type of ventilation. Environmental data were collected in 45 classrooms in 23 primary schools in Sweden during the heating season. Schools with three types of ventilation were recruited: natural or exhaust ventilation (category A), balanced supply-exhaust with constant air volume (category B), and balanced supply-exhaust with variable air volume or demand-controlled ventilation (category C). 796 children (8–14 years of age) answered a questionnaire about their perception of the classroom's indoor environment. Based on ten dichotomous questions, the children's overall perceptions and subjective well-being was scored (“Individual score”) from worst (0) to best (10) perception. A Perception Index (PI) was calculated as the arithmetic mean of the Individual scores from all children in a given classroom. We did not find statistically significant differences in the Individual scores or PI between the three ventilation categories. However, the PI of classrooms with ventilation category A, which also had lower ventilation rates and higher concentrations of pollutants, was noticeably lower than that in classrooms with ventilation category B or C. Correlations between the PI and most of the measured environmental parameters or the individual questions about perception were weak and not significant. The PI may be improved by including factors not considered in this study, such as those related to acoustic and lighting conditions.

Measurement Report: Wintertime new particle formation in the rural area of the North China Plain – influencing factors and possible formation mechanism

Abstract. The high concentration of fine particles and gaseous pollutants makes polluted areas, such as the urban setting of North China Plain (NCP) of China, a different environment for new particle formation (NPF) compared to many clean regions. Such conditions also hold for other polluted environments in this region (for instance, the rural area of NCP), yet the underlying mechanisms for NPF remain less understood, owing to the limited observations of particles in the sub−3 nm range. Comprehensive measurements, particularly covering the particle number size distribution down to 1.3 nm, were conducted at a rural background site of Gucheng (GC) in the North China Plain (NCP) from 12 November to 24 December 2018. In total, five NPF events during the 39 effective days of measurements for the campaign were identified, with the mean particle nucleation rate (J1.3) and growth rate (GR1.3–2.4) being 22.0 cm−3 s−1 and 3.9 nm h−1, respectively. During these 5 d, NPF concurrently occurred at an urban site in Beijing. Sharing similar sources and transport paths of air masses arriving at our site to that of urban Beijing, we hypothesize that NPF events during these days in this region might be a regional phenomenon. The simultaneous occurrence of NPF in both places implies that H2SO4-amine nucleation, concluded for urban Beijing there, could probably be the dominating mechanism for NPF at our rural site. The higher concentration of sulfuric acid during many non-event days compared to that of event days indicates that the content of sulfuric acid may not necessarily lead to NPF events under current atmosphere. Only when the condensation sink or coagulation sink was significantly lowered, atmospheric NPF occurred, implying that condensation sinks (CSs) and coagulation sinks (CoagSs) are the dominating factors controlling the occurrence of NPF for the present rural environment of the NCP, which is quite similar to the feature seen in urban Beijing.

PM2.5-bound trace metals in an urban area of Northern Mexico during the COVID-19 pandemic: characterization, sources, and health risk.

A field study was carried out in the Metropolitan Area of Monterrey (MAM), the second most populated city in Mexico, characterized by increasing urbanization, high traffic density, and intense industrial activity. These characteristics commonly present high concentrations of air pollutants leading to the degradation of air quality. PM2.5 was analyzed for heavy metals at two urban sites located within the MAM (Juarez and San Bernabe) in order to determine sources, health risk, morphology, and elemental content during the COVID-19 pandemic (autumn 2020 and spring 2021). Twenty-four-hour samples of PM2.5 were collected at each site during 30-day periods using high-volume equipment. Gravimetric concentrations and 11 metals were measured (Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Ni, Cr, and Pb) by different analytical techniques (flame atomic absorption spectroscopy, graphite furnace atomic absorption spectroscopy, and inductively coupled plasma optical emission spectroscopy). Selected samples were analyzed by scanning electron microscopy-energy-disperse spectroscopy in order to characterize their morphology and elemental content. PM2.5 concentrations exceeded the Mexican standard and WHO guidelines in Juarez during spring 2021. Cu, Cd, and Co were highly enriched by anthropogenic sources, and Ni, K, Cr, and Pb had a moderate enrichment. Mg, Mn, and Ca were of crustal origin. Bivariate statistics and PCA confirmed that alkaline metals originated from crustal sources and that the main sources of trace metals included traffic emissions, resuspension from soil/road dust, steel industry, smelting, and non-exhaust emissions at both sites. Lifetime cancer risk coefficients did not exceed the permissible levels established by EPA and WHO, implying that local residents are not at risk of developing cancer. Non-carcinogenic risk coefficients revealed that there is a possible risk of suffering cardiovascular and respiratory diseases due to inhalation of cobalt at the study sites. The online version contains supplementary material available at 10.1007/s11869-023-01372-7.

BOD/COD ratio as a probing index in the O/H/O process for coking wastewater treatment

Biodegradation of coking wastewater (CWW) containing high concentrations of toxic pollutants with nutritional imbalance is challenging. Biodegradability estimated as the ratio of 5-day biochemical oxygen demand (BOD5) to chemical oxygen demand (COD) was studied along with the influential operational factors in a full-scale oxic/hydrolytic & denitrification/oxic (O/H/O) plant for CWW treatment. The influential factors for the B/C ratio in each unit of the O/H/O provided by the experimental and theoretical BOD5 were elucidated. Batch experiment with various sludge inoculation settings showed that the B/C ratio of raw CWW increased from 0.38 ± 0.04 to 0.47 ± 0.05 after flocculation pretreatment due to the removal of sulfide and cyanide. In the O1 reactor, quickly depleted biodegradable pollutants resulted in a drastic decrease of the B/C ratio to 0.1 ± 0.02 together with a reduction in the CWW toxicity. In the H reactor, the B/C ratio increased to 0.28 ± 0.04 because of the hydrolysis of residual macromolecular organic matter and nitrite accumulation from the denitrification process. The B/C ratio in the O2 reactor dropped below 0.06 along with the complete nitrification. The relative abundance of organic pollutants, the structure and function of bacterial community were analyzed in each reactor to explain the changes in the B/C ratio. On the whole, the monitoring of the B/C ratio along different stages of the CWW treatment is an approach suitable to follow the efficacy of functional bacterial groups and their responses to the water characteristics. The B/C ratio thus becomes a marker of the extent of nitrogen transformations, CWW detoxification and mineralization of organic compounds. More broadly, the B/C ratio helps optimize the operation parameters of biological processes and indicate the functionality of each unit.

Tannery effluent treatment and its environmental impact: a review of current practices and emerging technologies

Abstract The tannery industry plays a significant role in the economy but poses a severe environmental threat due to its high water and chemical usage, leading to wastewater generation with a high concentration of pollutants. This wastewater contains a range of contaminants created throughout the leather manufacturing process, making effluent disposal a significant challenge for the industry. The tanning process also contributes significantly to the pH, biological oxygen demand (BOD), total suspended solids (TSS), chemical oxygen demand (COD), total dissolved solids (TDS), and concentrations of T Cr, Cr(III), Cr(VI), Cl−, sulfate, sulfide, and inorganic constituents in the wastewater. This review paper provides a concise overview of the origins and characteristics of post-tanning effluent, different treatment techniques, and applications of treated wastewater. Comparing the prominent tannery effluent technologies, adsorption and advanced oxidation processes (AOPs) effectively improved wastewater biodegradability before biological treatment. AOPs, enzymatic, adsorption, and coagulation treatment effectively upgraded the effluent to desired levels for disposal. Additionally, membrane separation processes have shown high pertinency in cases where the treated effluent is intended for reuse, whereas hybrid technologies can be the answer for better and cost-effective results.

Effective treatment of petroleum oil–contaminated wastewater using activated sludge modified with magnetite/silicon nanocomposite

The study aimed to optimize the treatment of oil refinery–contaminated wastewater through modification of the well-established activated sludge process with new nanocomposite (NC) materials to produce high-quality treated effluents for potential reuse. Refinery wastewater samples were collected from one of the major oil refineries, Alexandria, Egypt, where the operation, performance, and efficiency of the current activated sludge (AS) unit were evaluated for 6 consecutive months. Two AS bench scale PVC basins were constructed. Magnetite nanoparticles (Fe3O4 NPs) and magnetite silica (Fe3O4/silica) nanocomposite (NC) were prepared and characterized. Bioremediation trials were carried out in a sequential batch mode using Fe3O4/silica NC–modified AS and control (unmodified AS). The proposed treatment produced high-quality effluents in a very short time (2 h) despite the very high initial pollutant concentration accompanied with a reduction in the produced sludge. The highest removal of TSS, TDS, BOD, COD, and OG from raw industrial wastewater recorded 78.33, 3.6, 87.65, 85.17, and 92.92% compared to 55.3, 12.6, 50.0, 40.22, and 56.84%, respectively, achieved by the unmodified AS unit. The results confirmed that integration of the AS treatment with nanomaterial composite is highly effective, promising, and economic for the treatment of highly toxic and complicated industrial wastewater such as petroleum refinery effluents.

Detection of warning signal of particulate emission on the basis of fixed threshold in real-time using a lidar system

Monitoring pollutant emissions in an urban area is of primary importance in order to guarantee high levels of human health (by reducing the impact of respiratory diseases on urban inhabitants) and good preservation of objects (such as historical sites or buildings). The European Environment Agency (EEA) has established that the maximum concentration of PM2.5 concentration for long-term exposure is 10 μg/m3. By measuring the light that has been backscattered by atmospheric particulates, the lidar technique seems to be a valid method to provide a warning signal when a particulate concentration threshold is exceeded. In addition, the lidar system can also provide information about the distance at which the particulate threshold is exceeded. In this research measurements of traffic-originated particulate in the area near the University of Rome “Tor Vergata” is analysed at different times on a weekday to obtain continuous monitoring of its backscattering coefficient, values of particulate concentration and details about time and distance from the lidar system at which a warning signal is provided. The University of Rome “Tor Vergata” is in an area where traffic is very heavy, so high pollutant concentration values are to be expected.

Determinants of traffic related atmospheric particulate matter concentrations and their associated health risk at a highway toll plaza in India

People working at toll plazas are continuously exposed to high pollutant concentrations due to traffic congestion at toll booths. However, there are fewer studies available which focus on toll workers’ exposures. Therefore, a study was conducted at a toll plaza on a busy national highway (NH) in India to assess black carbon (BC), particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5), and ultrafine particles (UFP) concentrations and their associated health risks on the toll workers inside toll cabin and kerbside. Higher BC (34 μg m−3 vs. 18 μg m−3) and PM2.5 (86 μg m−3 vs. 79 μg m−3) concentrations were observed inside the cabin than at kerbside. On the contrary, UFP concentrations were higher at the kerbside (22,790 pt cm−3) than in-cabin (18525 pt cm−3). All pollutant concentrations were higher during evening hours than in the morning hours. BC and PM2.5 concentrations were found to be higher during the weekdays. Positive correlations were found between traffic volume and all pollutant concentrations. Negative correlations were observed for solar radiation and boundary layer height with pollutant concentrations. Additionally, it was found that the health risk of toll workers was higher (risk quotient, RQ range: ∼2–5) than the prescribed limit (RQ < 1). The present study demonstrates that there is a need to control personal exposure to pollutants in the workplaces, especially locations with traffic proximity.

Improving Air Pollution Modelling in Complex Terrain with a Coupled WRF–LOTOS–EUROS Approach: A Case Study in Aburrá Valley, Colombia

Chemical transport models (CTM) are crucial for simulating the distribution of air pollutants, such as particulate matter, and evaluating their impact on the environment and human health. However, these models rely heavily on accurate emission inventory and meteorological inputs, usually obtained from reanalyzed weather data, such as the European Centre for Medium-Range Weather Forecasts (ECMWF). These inputs do not accurately reflect the complex topography and micro-scale meteorology in tropical regions where air pollution can pose a severe public health threat. We propose coupling the LOTOS–EUROS CTM model and the weather research and forecasting (WRF) model to improve LOTOS–EUROS representation. Using WRF as a meteorological driver provides high-resolution inputs for accurate pollutant simulation. We compared LOTOS–EUROS results when WRF and ECMWF provided the meteorological inputs during low and high pollutant concentration periods. The findings indicate that the WRF–LOTOS–EUROS coupling offers a more precise representation of the meteorology and pollutant dispersion than the default input of ECMWF. The simulations also capture the spatio-temporal variability of pollutant concentration and emphasize the importance of accounting for micro-scale meteorology and topography in air pollution modelling.

Association of long-term ambient fine particulate matter (PM2.5) and incident non-alcoholic fatty liver disease in Chinese adults

Air pollution is increasingly recognized as an important environmental risk factor for non-alcoholic fatty liver disease (NAFLD). However, epidemiologic evidence on long-term exposure to high air pollution concentrations with incident NAFLD is still very limited. Here, we constructed a population-based dynamic cohort involving 17,106 subjects who were enrolled between 2005 and 2013 and subsequently followed until 2017, combined with a high-resolution ambient fine particulate matter ≤2.5 μm (PM2.5) dataset, to investigate the association of long-term PM2.5 exposure (cumulative annual average levels ranged from 36.67 to 111.16 μg/m3) with NAFLD incidence (N = 4,640). We estimated the adjusted hazard ratio (HR) for incident NAFLD among those exposed to the highest quartile of PM2.5 was 2.04 [95% confidence interval (CI), 1.80–2.30] compared with individuals exposed to the lowest quartile of PM2.5. The dose-response relationships for PM2.5 are non-linear for NAFLD across the exposure distribution. Further stratified analyses revealed that lean (<23 kg/m2), younger (<40-year-old), and women individuals appeared more vulnerable to the harmful effects of PM2.5 exposure. Our study suggests a greater long-term high ambient PM2.5 exposure is associated with an increased risk of NAFLD in Chinese adults, particularly in specific groups, including lean, women, and younger people.

Assessment of Wastewater Management at the Etoudi Slaughterhouse in the Municipality of Yaoundé - Cameroon

The management of wastewater in developing countries is a crucial challenge. The overall objective of this study was to evaluate the impact of discharges from the slaughterhouse Etoudi on physico-chemical and bacteriological water quality of the Ako'o. This study was conducted in two phases. The first phase (preliminary) in April 2022, during which a prospecting along the rivers and its watershed was performed. The second phase extended from May to October 2022, was dedicated in the collection of hydrological data, samples of water samples and bacteriological at each station coupled to the data analysis. This wastewater were collected from different stations, stored in refrigerated cooler and brought back to the laboratory for monitoring physical, chemical and bacteriological parameters according to standard protocols. The results show the effluent discharges from the slaughterhouse Etoudi exhibit high levels of pollution physicochemical (CND, MES, NO₃, NH₄⁺, PO₄^3ˉ, COD and BOD 5) and bacteriological (CF and SF) in the receiving environment having a negative impact on the watercourse Ako'o. negative impacts were increased to 90% by the dunghill faeces oxen or invading the rights of way areas. Existing gutters are littered with faeces of any kind and are not priests. Which causes recurring floods during the rainy season, the proliferation of insects and rodents and the emanation of foul odors and the persistence of certain diseases such as malaria typhoid fever, dysentery etc. this wastewater join the River Ako'o. This constitutes a major source of environmental pollution in general and rivers of waters Ako'o in particular. The positive impacts threshold is the use of cattle feces for farming populations who find themselves in different fields. Effluent discharges from the slaughterhouse Etoudi present an environmental and health risk because of high concentrations of physicochemical and bacteriological pollutants. A treatment system is needed to ensure environmental and health safety.