Severe Pollution Research Articles

Optimized fertilization using online soil nitrate data

Abstract. A new soil nitrate monitoring system that was installed in a cultivated field enabled us, for the first time, to control the nitrate concentration across the soil profile. The monitoring system was installed in a full-scale agricultural greenhouse setup that was used for growing a bell pepper crop. Continuous measurements of soil nitrate concentrations were performed across the soil profile of two plots: (a) an adjusted fertigation plot, in which the fertigation regime was frequently adjusted according to the dynamic variations in soil nitrate concentration, and (b) a control plot, in which the fertigation was managed according to a predetermined fertigation schedule that is standard practice for the area. The results enabled an hourly resolution in tracking the dynamic soil nitrate concentration variations in response to daily fertigation and crop demand. Nitrate–nitrogen (N–NO3) concentrations in and below the root zone, under the control plot, reached very high levels of ∼ 180 ppm throughout the entire season. Obviously, this concentration reflects excessive fertigation, which is far beyond the plant demand, entailing severe groundwater pollution potential. On the other hand, frequent adjustments of the fertigation regime, which were carried out under the adjusted fertigation plot, enabled control of the soil nitrate concentration around the desired concentration threshold. This enabled a substantial reduction of 38 % in fertilizer application while maintaining maximum crop yield and quality. Throughout this experiment, decision-making on the fertigation adjustments was done manually based on visual inspections of the soil's reactions to changes in the fertigation regime. Nevertheless, it is obvious that an algorithm that continuously processes the soil nitrate concentration across the soil profile and provides direct fertigation commands could act as a “fertistat” that sets the soil nutrients at a desired optimal level. Consequently, it is concluded that fertigation that is based on continuous monitoring of the soil nitrate concentration may ensure nutrient application that accounts for plant demand, improves agricultural profitability, minimizes nitrate down-leaching and significantly reduces water resource pollution.

Asphaltenes and hydrolysed polyacrylamide at the oil–water interface behaviour and emulsion stability

In the petroleum industry, polymer-containing oily sludge (PCOS) hindered oil extraction and caused severe environmental pollution and resource wastage to groundwater and the surrounding ecosystem. Asphaltenes and hydrolysed polyacrylamide (HPAM) were the key factors in treating PCOS. This study characterised asphaltenes extracted from PCOS and examined the oil–water interaction and emulsion stability with asphaltenes and HPAM. Asphaltenes were found to have a medium aromatic structure and reactive groups such as hydroxyl. Asphaltene molecules had strong π-π stacking interactions. The structure of asphaltenes were highly condensed, which formed aggregates at high concentrations. The optimal concentrations of asphaltenes and HPAM used in this study were CASP=300 ppm and CHPAM=300 ppm, which had a synergistic improvement in the stability of the emulsion. Asphaltenes and HPAM built a stable spatial network structure when the two ingredients exist. Asphaltenes were the primary interfacial active ingredient of emulsions. HPAM significantly increased the viscosity of the aqueous phase. Co-adsorption of asphaltenes with HPAM occurs, resulting in the adsorption sites of asphaltenes occupied by HPAM and the rearrangement of asphaltenes on the oil–water interface film. The decrease in adsorption sites for asphaltenes reduced the quantity of asphaltenes adsorbed at the oil–water interface. The yield stress of the emulsion could increase, and the interfacial film strength could decrease, which improved the initial emulsification degree and had a synergistic improvement in the oil storage capacity. This study is dedicated to establishing a theoretical framework for understanding the role of asphaltenes and HPAM in PCOS.

The role of air pollution in electric vehicle adoption: Evidence from China

This study provides a comprehensive analysis of the mechanisms through which air pollution influences consumer adoption of electric vehicles (EVs) in China. Utilizing the Air Quality Index (AQI) and EV sales data from 50 Chinese cities from 2010 to 2019, we apply a multiple regression model to investigate the direct and indirect impacts of air pollution on EV adoption. By analyzing data from the AQI and EV sales across 50 Chinese cities between 2010 and 2019, we apply a multiple regression model to dissect the direct and indirect effects of air pollution on the adoption of EVs. We find that the health risks associated with air pollution, such as respiratory and cardiovascular diseases, significantly sway consumer behavior towards EVs. Concerns over health and the financial burden of air pollution-related illnesses drive consumers, especially in wealthier regions, to choose EVs for healthier transportation. Additionally, we note an indirect mechanism: increased public and government awareness of environmental issues. This heightened awareness, coupled with policies promoting EV adoption, indirectly bolsters consumer interest in EVs, acknowledging their role in enhancing air quality. These findings offer vital insights for formulating sustainable transportation policies and urban planning strategies, especially in contexts of severe air pollution.

Sources and formation of fine particles and organic aerosols during autumn-winter period in the southern edge of northern China plain

The North China Plain (NCP) experienced significant improvements in air quality in 2018–2022. However, severe pollution episodes still occur frequently during the cold season. The limitations of highly time-resolved measurements hinder understanding the sources and formation mechanisms of pollution episodes, especially the role of organic aerosols (OA). Therefore, we used a Time-of-Flight Aerosol Chemical Speciation Monitor to characterize the aerosol chemical species, variation, and sources of OA during autumn and winter in Luohe, a city in the southern part of the NCP. The results showed that nitrates and organics were the main species of fine particles (PM2.5), accounting for an average of 38.4% and 29.6% of its total mass, respectively. Furthermore, the positive matrix factorization model analyzed the OA in PM2.5 and identified three primary OA and secondary OA related to photochemistry. Primary OA was the dominant contributor throughout the study period (55%), increasing from 50% during the non-heating period to 59% during the heating period. The contribution of photochemically generated oxidized OA remained high (41%) during heavy pollution episodes in the heating period, indicating strong photochemical production during winter. Additionally, most aerosol species and OA factors showed distinct diurnal variations, with lower concentrations during the day, suggesting the influence of the planetary boundary layer and primary emissions. By analyzing the chemical species features of five heavy particulate matter pollution episodes during the study period, we identified three main driving mechanisms for severe pollution events: photochemical processing, photochemical and aqueous-phase production, and local emissions.

Ozone pollution aggravated by mountain-valley breeze over the western Sichuan Basin, Southwest China

The impact of thermally driven mountain-valley breezes (MVB) on the atmospheric environment remains poorly understood, especially in ozone (O3)-polluted regions with complex underlying topography. To address this knowledge gap, we focused on the western Sichuan Basin (SCB), situated immediately east of the Tibetan Plateau (TP), which is considered susceptible to MVB coupled with severe O3 pollution in southwest China. We revealed the MVB driving diurnal O3 variations and meteorological mechanisms using surface observations and ERA5 reanalysis data. Local MVB days accounted for up to 47% of cases in the summers of 2015–2022. Driven by the MVB, the near-surface O3 concentrations increased by 8.8%, with 12.7% and 50.0% deterioration in the O3 light and moderate exceedance rates, respectively, on the western SCB edge. The daytime upslope valley breeze with 20% higher wind speed drove the westward transport of rich O3 and precursors from the upwind-polluted inner SCB towards its western edge, and the O3 photochemical production, followed by intensifying solar radiation and air temperature, gave rise to 14.8% of surface O3 concentrations over the western SCB edge. The nighttime downward mountain breeze with a 20% increase in wind speed could transport the rich O3 in the mountainous area to the basin edge, causing O3 levels to increase by 2.8%. In summary, we quantitatively assessed the impacts of MVB on changes in O3 concentrations and air quality along with its meteorological mechanisms, facilitating a comprehensive understanding of meteorological drivers in the atmospheric environment.

Spatially and Temporally Differentiated NOx and VOCs Emission Abatement Could Effectively Gain O3-Related Health Benefits.

The increasing level of O3 pollution in China significantly exacerbates the long-term O3 health damage, and an optimized health-oriented strategy for NOx and VOCs emission abatement is needed. Here, we developed an integrated evaluation and optimization system for the O3 control strategy by merging a response surface model for the O3-related mortality and an optimization module. Applying this system to the Yangtze River Delta (YRD), we evaluated driving factors for mortality changes from 2013 to 2017, quantified spatial and temporal O3-related mortality responses to precursor emission abatement, and optimized a health-oriented control strategy. Results indicate that insufficient NOx emission abatement combined with deficient VOCs control from 2013 to 2017 aggravated O3-related mortality, particularly during spring and autumn. Northern YRD should promote VOCs control due to higher VOC-limited characteristics, whereas fastening NOx emission abatement is more favorable in southern YRD. Moreover, promotion of NOx mitigation in late spring and summer and facilitating VOCs control in spring and autumn could further reduce O3-related mortality by nearly 10% compared to the control strategy without seasonal differences. These findings highlight that a spatially and temporally differentiated NOx and VOCs emission control strategy could gain more O3-related health benefits, offering valuable insights to regions with severe ozone pollution all over the world.

Visual effect of air pollution on the need for arousal and variety-seeking behavior

Research on air pollution, one of the most common environmental factors, has primarily focused on its effects on physical, mental, and cognitive health. However, air pollution-induced achromatic color of an environment, which is a prominent feature of air pollution, has received little attention. This study explored the visual effects of air pollution on the variety-seeking purchase behavior of consumers through two scenario-based experiments and primed manipulation (Study 1 and Study 2) and one natural experiment using data from a local fruit chain store (Study 3). Study 1 tested the main effect of air pollution on the variety-seeking behavior and found that primed air pollution increased variety-seeking when consumers purchased beverages. Study 2 broadened the category and tested the mechanism, and the results indicated that primed air pollution increased the variety of purchased chocolates and demonstrated the mediating effect of the need for arousal. Study 3 tested the boundary condition and extended the external validity with actual purchases. The results revealed that severe air pollution increased the purchased SKUs by 22.9% and visibility reduced the moderation effect. This research extended the literature on the visual effect of air pollution by providing evidence of the effects of air pollution on variety-seeking behavior through the need for arousal. And, product managers could leverage the results by offering a greater variety of goods on days with air pollution to increase sales.

Extended-spectrum β-lactamase-producing bacteria and their resistance determinants in different wastewaters and rivers in Nepal

Wastewaters serve as significant reservoirs of antibiotic resistant bacteria. Despite the evidence of antimicrobial resistance in wastewaters and river water in Kathmandu, direct linkage between them is not discussed yet. This study investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing bacteria and associated resistance genes in wastewaters and river water. Out of 246 bacteria from wastewaters, 57.72% were ESBL producers and 77.64% of them were multidrug resistant (MDR). ESBL producing E. coli was dominant in municipal and hospital wastewaters (HWW) as well as in river water while K. pneumoniae was common in pharmaceutical wastewater. The blaSHV and blaTEM genes were prevalent and commonly co-occurred with aac(6')-Ib-cr in K. pneumoniae isolated pharmaceutical wastewater. blaCTX-M carrying E. coli from hospital co-harbored aac(6')-Ib-cr while that from municipal influent and river water co-harbored qnrS. Whole genome sequencing data revealed the presence of diverse ARGs in bacterial isolates against multiple antibiotics. In average, an E. coli and a K. pneumoniae isolate contained 55.75 ± 0.96 and 40.2 ± 5.36 ARGs, respectively. Multi-locus sequence typing showed the presence of globally high-risk clones with wider host range such as E. coli ST10, and K. pneumoniae ST15 and ST307 in HWW and river indicating frequent dissemination of antimicrobial resistance in wastewater of Kathmandu. Whole genome sequence data aligned with phenotypic antibiograms and resistance genes detected by PCR in selected isolates. The presence of significant plasmid replicons (IncF, IncY) and mobile genetic elements (IS903, IS26) indicate high frequency of spreading antibiotic resistance. These findings indicate burden and dissemination of antimicrobial resistance in the environment and highlight the need for effective strategies to mitigate the antibiotic resistance.

Risk/benefit trade-off of habitual physical activity and air pollution on mortality: A large-scale prospective analysis in the UK Biobank

BackgroundPrevious observational studies have indicated associations of physical activity (PA) and air pollution with mortality. A few studies have evaluated air pollution and PA interactions for health. Still, the trade-off between the harmful effects of air pollution exposure and the protective effects of PA remains controversial and unclear. ObjectiveThis study aimed to investigate the joint association of air pollution and PA with mortality risks. MethodsThis prospective cohort study included 322,092 participants from 2006 to 2010 and followed up to 2021 in the UK Biobank study. The concentrations of air pollutants (2006–2010), including particulate matter (PM) with diameters <=2.5 mm (PM2.5), <=10 mm (PM10), and between 2.5 and 10 mm (PM2.5–10), and nitrogen oxides (NO2 and NOx) were obtained. Information on PA measured by the International Physical Activity Questionnaire short form (2006–2010) and wrist-worn accelerometer (2013–2015) were collected. All-cause and cause-specific mortalities were recorded. Cox proportional hazard models were used to investigate the associations of air pollution exposure and PA with mortality risks. The additive and multiplicative interactions were also examined. ResultsDuring a mean follow-up of 11.83 years, 16629 deaths were recorded. Compared with participants reporting low PA, higher PA was negatively associated with all-cause [hazard ratio (HR), 0.74; 95% CI, 0.71–0.78], cancer (HR, 0.85; 95% CI, 0.80–0.90), CVD (HR, 0.79; 95% CI, 0.71–0.87), and respiratory disease-specific mortality (HR, 0.51; 95% CI, 0.44–0.60). Exposure to PM2.5 (HR, 1.05; 95% CI, 1.00–1.09) and NOx (HR, 1.06; 95% CI, 1.02–1.10) was connected with increased all-cause mortality risk, and significant PM2.5-associated elevated risks for CVD mortality and NOx-associated elevated risks for respiratory disease mortality were observed. No obvious interaction between PA and PM2.5 or NOx exposure was detected. ConclusionsOur study provides additional evidence that higher PA and lower air pollutant levels are independently connected with reduced mortality risk. The benefits of PA are not significantly affected by long-term air pollution exposure, indicating PA can be recommended to prevent mortality regardless of air pollution levels. Our findings highlight the importance of public health policies and interventions facilitating PA and reducing air pollution in reducing mortality risks and maximizing health benefits. Future investigation is urgently needed to identify these findings in areas with severe air pollution conditions.

Influence of topography and synoptic weather patterns on air quality in a valley basin city of Northwest China

To clarify the mechanism underlying the effects of weather patterns and topography on air pollution, this study conducted the obliquely rotated principal component analysis in the T-mode to analyze ERA5 reanalysis data and categorize typical weather patterns at a 700-hPa geopotential height from 2015 to 2022. The probability of worsened air pollution attributable to weather patterns was quantitatively assessed using a generalized additive model. The results indicated that due to the influence of topography, Lanzhou was affected by an extended period of downdraft (with weak convective intensity) and the delayed formation of a convective boundary layer during the daytime by 1–2 h relative to other areas. Under the combined effect of low trough patterns (south low pressure type [SL] and south low weak pressure type [SL−]) and topography, the formation of a stable layer above the planetary boundary layer (PBL) would weaken the vertical exchange of the local airflow and inhibit the development of the PBL. The type of SL led to the most severe pollution, causing a 61.9 % (95 % confidence interval [CI]: 46.3 %–79.3 %) increase in PM2.5 concentration. For southwest high pressure patterns (south high [SH], southwest weak high [SWH−], southwest high [SWH], and southwest strong high [SWH+] pressure types), the prevailing northwest wind was the main transport path for pollutants. For the high pressure patterns (north high [NH] and northwest high [NWH] pressure types) and south wind patterns (southeast weak high [SEH−], southeast high [SEH], and northeast high [NEH] pressure types), the enhancement of vertical convection, deepening of the PBL, and reduction of pollution transport led to improved air quality. The NH, NWH, and NEH pressure types caused PM2.5 concentration to decrease by 18.4 % (95 % CI: 8.8 %–27.1 %), 14.9 % (95 % CI: 4.7 %–24.0 %), and 35.9 % (95 % CI: 9.7 %–54.6 %), respectively.

Rationally controlling interfaces and oxygen vacancies of CeO2@C core–shell nanorods/nanofibers for superior microwave absorption and thermal conduction

High-performance thermally conductive-microwave absorbing integrated materials are highly required to mitigate the severe electromagnetic pollution and overheating generated in electronic devices. However, the incompatibility between thermal conduction and microwave absorption impedes their collaborative development. Herein, an adjustment strategy for interface- and oxygen-vacancy-linkage was adopted to rationally construct CeO2@C core–shell nanorods/nanofibers (CSNRs/NFs) and cooperatively boost their electrical, thermal, and microwave absorption properties. A hydrothermal-annealing technique was employed to synthesize CeO2@C CSNRs/NFs. Their core–shell structure, oxygen vacancies/lattice defects, and length-to-diameter ratio were accurately adjusted by changing the annealed temperature (Ta) and toluene volume (V). The CeO2@C CSNRs/NFs produced under Ta = 600 °C and V = 1.5 mL exhibit high thermal conductivity (TC = 2.94 W/(m·K)) at a small load of 40 wt%. The large TC is mainly due to the weak phonon defect/interface scattering and electron/phonon co-transfer in a 3D continuous path consisting of a 1D structure. Furthermore, the CeO2@C CSNRs/NFs display strong microwave absorption (EABmax/d = 3.27 GHz/mm; RLmin=− 50.98 dB) due to their various polarizations, tunable conduction loss, and multiple internal reflections. These results demonstrate that the CeO2@C CSNR/NFs are an ideal multifunctional material that protects against concurrent EM interference and excess heat in electronic packaging materials.

Revisiting e-waste management: A review of global practices and sustainability

With rapid population growth, as well as, technological advancement, the generation of e-wastes is increasing day by day and has become a fact of emergent concern for scientific and research communities worldwide. Though the most developed territories generate the highest amount of e-wastes, little efforts has been put towards managing them. European countries, including United Kingdom, Germany, and France are managing significant amount of e-wastes responsibly. The informal and unscientific management of e-wastes led to severe health and environmental hazards. The traditional waste management methods, such as, landfilling, and incineration expels significant amount of heavy and toxic chemicals to the environment, leading to severe air, water, and soil pollution. However, proper management strategies for e-wastes not only inhibit the associated harmful effect towards the lives on earth, but also favor circular economy. The sustainability of the strategies for managing e-wastes lie in the responsibility of all stakeholders associated with it. In this review, we have discussed the statistics of global of e-wastes generation and recycling, effect of e-wastes towards lives and the environment, different methodologies of managing e-wastes, and strategies for sustainable e-waste management.

Geochemical Insights into Environmental Studies

Environmental pollutions are considered a significant challenge in all human societies. Heavy metals, recognized as fundamental environmental pollutants, enter the environment through human activities and can pose various environmental hazards. In this study, a comprehensive investigation of environmental pollutions in Aligudarz County is considered as a strategic point in Iran and serves as a model for similar studies worldwide. The research utilizes geochemical, mineralogical, and statistical approaches to examine pollutions, providing innovative and quantitative insights into understanding the geochemistry of the environment and the relationship between pollutions and environmental factors. The results indicate that the study area is subject to moderate to severe pollution from toxic elements, including molybdenum, lead, cadmium, and copper. These pollutions are correlated with the geochemical, mineralogical, and environmental analysis of the region, and the information derived from this study contributes to environmental management and protection. Considering the research findings, this research model can serve as a global template for environmental studies, playing a crucial role in enhancing understanding of pollutions and advancing knowledge in this field. Therefore, the current research has a broad impact on fostering innovations and advancing knowledge in pollution management and environmental conservation.

Aerosol-PM2.5 Dynamics: In-situ and satellite observations under the influence of regional crop residue burning in post-monsoon over Delhi-NCR, India

The increasing air pollution in the urban atmosphere is adversely impacts the environment, climate and human health. The alarming degradation of air quality, atmospheric conditions, economy and human life due to air pollution needs significant in-depth studies to ascertain causes, contributions and impacts for developing and implementing an effective policy to combat these issues. This work lies in its multifaceted approach towards comprehensive understanding and mitigating severe pollution episodes in Delhi and its surrounding areas. We investigated the aerosol dynamics in the post-monsoon season (PMS) from 2019 to 2022 under the influence of both crop residue burning and meteorological conditions. The study involves a broad spectrum of factors, including PM2.5 concentrations, active fire events, and meteorological parameters, shedding light on previously unexplored studies. The average AOD550 (0.79) and PM2.5 concentration (140.12 μg/m³) were the highest in 2019. PM2.5 was higher from mid-October to mid-November each year, exceeding the WHO guideline of 15 μg/m³ (24 h) by 27–34 times, signifying a public health emergency. A moderate to strong correlation between PM2.5 and AOD was found (r = 0.65) in 2021. The hotspot region accounts for almost 50% (2019), 47.51% (2020), 57.91% (2021) and 36.61% (2022) of the total fire events. A statistically significant negative non-linear correlation (r) was observed between wind speed (WS) and both AOD and PM2.5 concentration, influencing air quality over the region. HYSPLIT model and Windrose result show the movement of air masses predominated from the North and North-West direction during PMS. This study suggest to promotes strategies such as alternative waste management, encouraging modern agricultural practices in hot-spot regions, and enforcing strict emission norms for industries and vehicles to reducing air pollution and its detrimental effects on public health in the region and also highlights the need for future possibilities of research to attract the global attention.

Unveiling the emerging role of curcumin to alleviate ochratoxin A-induced muscle toxicity in grass carp (Ctenopharyngodon idella): in vitro and in vivo studies

BackgroundOchratoxin A (OTA), a globally abundant and extremely hazardous pollutant, is a significant source of contamination in aquafeeds and is responsible for severe food pollution. The developmental toxicity of OTA and the potential relieving strategy of natural products remain unclear. This study screened the substance curcumin (Cur), which had the best effect in alleviating OTA inhibition of myoblast proliferation, from 96 natural products and investigated its effect and mechanism in reducing OTA myotoxicity in vivo and in vitro.MethodsA total of 720 healthy juvenile grass carp, with an initial average body weight of 11.06 ± 0.05 g, were randomly assigned into 4 groups: the control group (without OTA and Cur), 1.2 mg/kg OTA group, 400 mg/kg Cur group, and 1.2 mg/kg OTA + 400 mg/kg Cur group. Each treatment consisted of 3 replicates (180 fish) for 60 d.ResultsFirstly, we cultured, purified, and identified myoblasts using the tissue block culture method. Through preliminary screening and re-screening of 96 substances, we examined cell proliferation-related indicators such as cell viability and ultimately found that Cur had the best effect. Secondly, Cur could alleviate OTA-inhibited myoblast differentiation and myofibrillar development-related proteins (MyoG and MYHC) in vivo and in vitro and improve the growth performance of grass carp. Then, Cur could also promote the expression of OTA-inhibited protein synthesis-related proteins (S6K1 and TOR), which was related to the activation of the AKT/TOR signaling pathway. Finally, Cur could downregulate the expression of OTA-enhanced protein degradation-related genes (murf1, foxo3a, and ub), which was related to the inhibition of the FoxO3a signaling pathway.ConclusionsIn summary, our data demonstrated the effectiveness of Cur in alleviating OTA myotoxicity in vivo and in vitro. This study confirms the rapidity, feasibility, and effectiveness of establishing a natural product screening method targeting myoblasts to alleviate fungal toxin toxicity.Graphical

Uncovering the evolution of ozone pollution in China: A spatiotemporal characteristics reconstruction from 1980 to 2021

Ozone pollution emerged as a significant environmental concern in China in recent years. Given the enduring impact of anthropogenic activities on the atmosphere, understanding the long-term evolutionary patterns of ozone pollution is crucial for effective pollution mitigation strategies. However, there have been limited studies to reconstruct spatiotemporal continuity ozone concentrations in China since 1980. In this research, monthly MDA8 ozone concentrations from 1980 to 2021 were first estimated by reproducing the numerical relations between ozone pollution and the atmospheric environment based on a machine learning approach. The verification results from temporal, spatial, and sample-based cross-validation methods demonstrated the model performance in simulating MDA8 ozone concentration spatiotemporally, with correlation coefficients (R) ranging from 0.76 to 0.79, mean square error (RMSE) ranging from 22.72 μg·m−3 to 24.28 μg·m−3, and mean absolute error (MAE) ranging from 17.06 μg·m−3 to 18.25 μg·m−3. The evolution of ozone pollution in China can be delineated into two phases, characterized by an increasing trend since 2001, coinciding with significant rises in average annual temperature and hot weather frequency over the past four decades. The 90th percentile of ozone concentration from 2001 to 2021 increased by 1.79% compared to the period from 1980 to 2001. Notably, ozone episodes have expanded beyond summer months, partly due to global warming and frequent extreme climate events, contributing to an annual temperature increase of 0.03 °C. Despite several pollutant emission restrictions since 2013, the ozone pollution in China has persisted due to the increased emissions of VOCs. Spatially, severe ozone pollution hotspots are evident in Xinjiang province, the Jing-Jin-Ji urban agglomeration, and Northeast China, with notable increases observed in Tibet and the Guangdong-Hong Kong-Macao Greater Bay Area over the past six years. Moreover, the influence factors were identified by the average reduction of node impurity calculation. The evolution of ozone pollution was inextricably linked to solar radiation and atmospheric temperature, which played pivotal positive roles in ozone formation. Whilst, there is significant heterogeneity in the effect of meteorological conditions on ozone concentrations due to the disparity between land and oceanic climates.

Potential ecological risk by metals in Sepetiba bay (SE Brazil): Exporting metals to the oceanic region

Sepetiba Bay (SB) is one of the Brazilian coastal regions most impacted by anthropogenic activities due to increased population density, the installation of tourist and industrial mega-developments, and essential port, agricultural and fishing activities. Given the great concern about its environmental quality, several studies have focused on it, especially since the 1980s. This study aims to analyze the current ecological risk by potentially toxic elements (PTEs) in the bottom sediments of Sepetiba Bay (SB). The work integrates numerous variables (physicochemical, textural, and geochemical) analyzed at 73 stations in SB and the transition area to Ilha Grande Bay. The results show that the sediments in the eastern-inner region of Sepetiba Bay, along the Itacuruçá coast, and in some areas near the Marambaia Barrier Island (MBI) are severely polluted by Cd (4.47 mg kg−1) > Sn (7.31 mg kg−1) > Zn (824 mg kg−1) > Co (12.50 mg kg−1) > Pb (36.6 mg kg−1) > Cr (65.0 mg kg−1) > Fe (4.98 %) > Ni (21.4 mg kg−1) > V (66.0 mg kg−1), (maximum values), and highly polluted by U (2.8 mg kg−1) > Mn (857 mg kg−1) > Sb (0.32 mg kg−1) > Tl (0.63 ppm) > Hg (170 μg kg−1) > As (11.2 mg kg−1), maximum values. The pollution load index (PLI) and contamination degree (Cdeg) indexes also indicate considerable to very high contamination, indicating severe pollution in that zone. The Potential Ecological Risk Index (PERI) suggests high (160≤RI < 320) and very high (RI ≥ 320) ecological risk in the inner and middle areas of Sepetiba Bay by Cd > Hg > Cu > Co > Pb > Sn > Tl > Ni. Relatively low pH and Eh values were identified in the inner region of Sepetiba Bay, indicating eutrophication processes. A comparison of the concentration factors in the surface sediments of SB in 2009–2011 and 2022 suggests that there has been a general increase in contamination by metals, namely Fe, Mn, Pb, Co, Cr, Ni, U, V, and Hg. Although metals accumulate more pronounced in the inner and the most impacted marginal areas of Sepetiba Bay, their enrichment factors (EF) indicate an increase in contamination in the outer sector. Metals are being imported from the nearby oceanic region, where there is a dredging site, to the outer sector of Sepetiba Bay. Thus, the choice of dredged spoil disposal sites and how contaminated dredged material is deposited needs to be better addressed and is still a challenging task. This aspect often results in problems being transferred from one region to another. The results suggest that mitigation measures must be adopted to prevent the situation from worsening.

Severe microplastic pollution risks in urban freshwater system post-landfill fire: A case study from Brahmapuram, India

To investigate the escalating issue of microplastic (MP), pollution in urban water bodies, this study focuses on the aftermath of the Brahmapuram landfill fire in Kochi, India, analyzing its impact on MP concentrations in nearby freshwater system. The study conducted sampling sessions at the landfill site immediately before and after the fire. Post-fire, findings demonstrated a substantial increase in MP concentrations in surface waters, with levels rising from an average 25793.33 to 44863.33 particles/m³, featuring a notable presence of larger, predominantly black MPs. Sediment samples showed no significant change in MP count, but there was a significant increase in mass concentration. SEM/EDS analysis revealed changes in surface morphology and elemental composition, suggesting thermal degradation. Risk assessment using the Microplastic Pollution Index (MPI) and Risk Quotient (RQ) methods indicated heightened MP pollution risk in surface water post-fire. Hierarchical cluster analysis revealed the landfill's proximity as a significant factor influencing MP characteristics in the aquatic system. The study highlights the escalated challenge of MP pollution in urban water bodies following environmental disasters like landfill fires, underscoring the urgent need for policy and environmental management strategies.

Role of self-actualization in green production behavior: Evidence from rice smallholders in China

Understanding who adopt green production and why they choose this strategy is an important issue that needs to be addressed in the context of increasingly severe agricultural pollution. Previous studies have generally investigated subsistence-oriented smallholders, typically employing profit maximization or risk minimization models. However, Chinese farmers have differentiated, and have unique characteristics. This study collected data from 960 random samples of rice farmers and conducted quantitative analysis. The findings reveal that 94.9 % of the farmers had less than 2-ha rice-planting area, and 80.21 % of farmers reported that their purpose of planting rice was for family self-feeding. Furthermore, the new standard to define smallholder based on whether their production purpose is self-feeding or selling and found that non-smallholders had an overall advantage and passed the t-test. Even more non-smallholder (76.32 %) intentionally chose green pesticide than smallholders (66.1 %), but their decision-making logic was different. Binary logistic regression results show that three aspects of self-actualization (environmental, market, and personal) positively and significantly affected the green production behavior of smallholders, but not significant for non-smallholders. This study suggests that in China, where smallholders are the mainstay of agriculture production, green production by smallholders will greatly improve the ecological environment and provide high quality agricultural products.

Health impact assessment of the surface water pollution in China

China suffers from severe surface water pollution. Health impact assessment could provide a novel and quantifiable metric for the health burden attributed to surface water pollution. This study establishes a health impact assessment method for surface water pollution based on classic frameworks, integrating the multi-pollutant city water quality index (CWQI), informative epidemiological findings, and benchmark public health information. A relative risk level assignment approach is proposed based on the CWQI, innovatively addressing the challenge in surface water-human exposure risk assessment. A case study assesses the surface water pollution-related health impact in 336 Chinese cities. The results show (1) between 2015 and 2022, total health impact decreased from 3980.42 thousand disability-adjusted life years (DALYs) (95 % Confidence Interval: 3242.67–4339.29) to 3260.10 thousand DALYs (95 % CI: 2475.88–3641.35), measured by total cancer. (2) The annual average health impacts of oesophageal, stomach, colorectal, gallbladder, and pancreatic cancers added up to 2621.20 thousand DALYs (95 % CI: 2095.58–3091.10), revealing the significant health impact of surface water pollution on digestive cancer. (3) In 2022, health impacts in the Beijing-Tianjin-Hebei and surroundings, the Yangtze River Delta, and the middle reaches of the Yangtze River added up to 1893.06 thousand DALYs (95 % CI: 1471.82–2097.88), showing a regional aggregating trend. (4) Surface water pollution control has been the primary driving factor to health impact improvement, contributing −3.49 % to the health impact change from 2015 to 2022. It is the first city-level health impact map for China's surface water pollution. The methods and findings will support the water management policymaking in China and other countries suffering from water pollution.