Environmental Risk Research Articles

Towards just cities: an environmental justice analysis of Aligarh, India

ABSTRACT Environmental justice (EJ) is crucial for sustainable urban development. With about 44 per cent of the Indian population projected to live in cities by 2035, the infrastructure and the management systems are yet to catch up with the growing population. This has exacerbated environmental problems, with the impacts disproportionately affecting certain sections of the population. EJ studies have explored the unequal distribution of environmental benefits and burdens along socio-economic lines, but such studies in India remain limited, particularly outside major metropolitan and industrial cities. This study investigates the link between EJ and social inequality in Aligarh, focusing on how different social groups experience environmental risks and access to resources. The findings provide clear evidence that Aligarh is both environmentally vulnerable and unjust. There is a clear disparity in the distribution of environmental goods and services, with socially and economically disadvantaged neighbourhoods facing the greatest risks. A strong association exists between socio-economic status and environmental vulnerabilities, indicating that marginalised and minority groups face higher environmental risks than the general population. This highlights the need for inclusive policies and management practices to address environmental injustices in urban India, ensuring equitable access to resources and a healthier environment for all groups and communities.

An exploratory study of volatile and semi-volatile organic compounds in PM2.5 atmospheric particles from an outdoor environment in Brazil.

The development of methods for determining volatile and semi-volatile organic compounds in public spaces has become necessary to identify potential health and environmental risks. This study presents a practical methodology for sampling, extracting, detecting, and identifying these compounds in a vehicular traffic region in Belo Horizonte, Brazil. The methodology uses direct-immersion solidphase microextraction (DI-SPME) and static headspace (SHS) to extract SVOCs/VOCs. Comprehensive time-of-flight gas chromatography mass spectrometry (GC×GC/Q-TOFMS) and gas chromatography coupled to mass spectrometry (GC/MS) were used to detect and identify compounds. The analysed samples, collected with a high-volume sampler (Hi-Vol) with quartz filters and in which particulate matter (PM2.5) was retained, showed the presence of more than 200 compounds, both biogenic (natural origin) and anthropogenic (human origin). Regarding the distribution of chemical classes, aromatic compounds were predominantly found at 29.2%, followed by esters at 20.8%, non-aromatic hydrocarbons at 5.6%, and carboxylic acids at 9.4%. Static headspace gas chromatography (HS-GC) enabled the identification and quantification of 21 volatile compounds, including BETX, dichloromethane, chloroform, and naphthalene, which are currently regulated by the US Environmental Protection Agency (EPA).

Pesticide contamination and associated ecological risks in estuarine waters of Brazil's Legal Amazon.

Pesticide contamination remains a significant environmental concern globally, with important implications for aquatic ecosystems. Despite being one of the world's largest pesticide consumers, monitoring and assessment of pesticide pollution are limited in Brazil, especially in sensitive regions like the Amazon. In this study, the occurrence and environmental risks of 8 pesticides of different classes, namely alachlor, atrazine, chlorfenvinphos, isoproturon, irgarol, simazine, diuron, and its transformation product DCPMU (1-(3,4-dichlorophenyl)-3-methyl urea) were analysed in surface water of the São Marcos Estuarine Complex (SMEC) in two consecutive years. The quantification of the target compounds was performed using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Suspected and untargeted screening analyses with ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was also conducted to identify transformation products (TPs) and additional pesticides in water samples. All target pesticides, except for alachlor, were found in at least one sampling campaign. The antifouling biocides irgarol and diuron were ubiquitous in 2018 and 2019, with detection frequencies varying between 81 and 100% and maximum concentrations of 13.6ng L-1 and 17.1ng L-1, respectively. In 2019, the detection frequencies of the target pesticides were considerably higher than in 2018, with atrazine, isoproturon, and DCPMU being found in 100% of the samples. In 2019, chlorfenvinphos and isoproturon were the pesticides with the highest levels, reaching 48.6ng L-1 and 44.6ng L-1, respectively. The UHPLC-HRMS analysis showed the presence of the pesticides DEET (N,N-diethyl-meta-toluamide), octhilinone (2-Octyl-4-isothiazolin-3-one), and cyprodinil (4-cyclopropyl-6-methyl-N-phenylpyrimidin-2-amine) in water samples. Additionally, the TPs 2-hydroxy-atrazine, didemethylisoproturon (1-(4-isopropylphenyl)urea) and M1 (2-methylthio-4-tert-butylamino-6-amino-s-triazine) were found. The environmental risk assessment showed that irgarol was the primary contributor to the global risk quotient in the SMEC region. Similarly, chlorfenvinphos also showed a high risk to the local aquatic biota, especially in 2019. This research not only highlights the urgent need for improved pesticide monitoring in Brazil but also establishes a baseline for future studies and environmental management efforts in SMEC. We emphasize the importance of prioritising pollutants and implementing effective mitigation strategies to protect the fragile aquatic ecosystems of the Brazilian Amazon.

Rainwater Quality in Southern Europe: Insights and Challenges Regarding Potential Toxic Elements

Rainwater is a source of freshwater that affects the aquatic and terrestrial ecosystems, and consequently human health. Since potential toxic elements (PTEs) have been found in rainwater in Southern Europe, its quality should be evaluated. This review assesses the current knowledge of the quality of rainwater in Southern Europe concerning PTEs, as well as its impact on the environment and human health. The presence of PTEs in rainwater poses challenges and simultaneously an opportunity for innovation in environmental management, particularly in water management. Further monitoring of rainwater quality, research, and policy development are needed to ensure that rainwater remains a viable and safe water resource. The challenges of rainwater quality regarding PTEs and of rainwater harvesting as a measure of drought mitigation, as observed in Southern Europe, require investing in rainwater treatment technologies. The treatment of rainwater harvested in Southern Europe can reduce environmental and health risks posed by PTEs, while enhancing the region’s resilience to climate change and water scarcity.

Spatial and temporal distribution of arsenic concentration in rural drinking water and health risk assessment in Northern China from 2013 to 2022: a case study of Inner Mongolia Autonomous Region

BackgroundBy monitoring arsenic levels in rural drinking water in Inner Mongolia Autonomous Region from 2013 to 2022 and evaluating their health risks, this study provides a basis for further developing strategies to promote public health.MethodsOne stable centralized water supply point was randomly selected in each township of Inner Mongolia Autonomous Region. One finished water sample and 1–3 tap water samples were collected at each supply point. Water samples were collected once during the dry season (May) and once during the rainy season (August-September). Mann-Whitney U test was used to compare arsenic concentrations in drinking water from different types of water sources, and Kruskal-Wallis test was used to compare arsenic concentrations in drinking water across different years. Environmental health risk assessment was conducted using the health risk assessment model recommended by the US Environmental Protection Agency (USEPA).ResultsOverall, arsenic concentrations in rural drinking water were higher in the central-western part of Inner Mongolia Autonomous Region compared to the eastern part. From 2013 to 2022, there was a notable decreasing trend in arsenic concentrations in rural drinking water, with over 98% of water samples meeting arsenic standards by 2022. During 2013–2019, arsenic concentrations in drinking water sourced from groundwater were consistently higher than those from surface water sources (P < 0.05). Hazard quotient (HQ) values for the entire population were below 1, and lifetime cancer risk (LCR) values exceeded 1 × 10− 6. Sensitivity analysis indicated that drinking water arsenic concentration contributed the most to health risks for the population.ConclusionDuring 2013–2022, through concerted efforts by the government and the people, excessive arsenic levels in rural drinking water have been significantly reduced, resulting in decreased health risks for the population. However, some carcinogenic risks still exist.Therefore, the next critical step in improving water quality in the region involves further optimizing methods such as coagulation, adsorption, or ion exchange to remove arsenic from drinking water.

Enhanced Anticancer Efficacy of Alkaline Plasma-Activated Water through Augmented RONS Production.

Despite notable advances in anticancer drug development, their manufacture and use pose environmental and health risks due to toxic byproducts, drug residue contamination, and cytotoxicity to normal cells. Therefore, developing cost-effective anticancer treatments with fewer toxic side effects and higher selectivity is essential to the advancement of highly effective anticancer therapies. Plasma-activated water (PAW) offers a green alternative to conventional chemical treatments as it reverts to water within days. However, the limited duration and dose of reactive oxygen and nitrogen species (RONS) in acidified PAW restrict its clinical deployment and the full understanding of their mechanism. In this study, we propose alkaline PAW as an innovative enhancement of the RONS technology. The alkaline PAW generated markedly superior RONS, with about 10 times higher levels of NO2-, H2O2, and ONOO-/O2•- than acidic PAW. The possible RONS generation pathways in alkaline PAW are analyzed by scavengers. In conventional acidic PAW, 70% of the H2O2 concentration is contributed by •OH but only about 20% in alkaline PAW. ONOO- is mainly formed through the reaction of O2•- with NO in alkaline pH, while in acidic PAW, it mainly forms from NO2- and H2O2. The results unveiled the synergistic and formidable anticancer effects of alkaline PAW against cancer cells, typified by an increase in intracellular ROS/RNS levels. Furthermore, alkaline PAW injection also effectively prevented xenograft tumor growth in mice. We systematically investigated this high-dose anticancer solution without using noble gases, toxic reagents, or extra energy consumption and successfully demonstrated the possibility of alkaline PAW being an effective and environmentally friendly therapeutic technology. The activity is closely linked to the RONS dose, and the generation pathway provides much-needed insight into the fundamental aspects of PAW chemistry required for the optimization of the biochemical activity of PAW.

Comprehensive Multidimensional Analysis of Metal(loid)-Containing Dust in Plastic Sports Facilities: Insights into the Potential Sources and Health Risks.

Dust released from widely established plastic sports courts and synthetic turf poses potential environmental and health risks. Herein, we systematically investigate the metal(loid) characteristics, potential sources, and health risks of 162 dust samples from 17 campuses in Beijing, using complementary analytical techniques. Bulk analysis revealed higher levels of Zn, Pb, Cu, Sb, Cd, and Cr than background values, suggesting excessive anthropogenic contamination. Pb and Cr in plastic basketball court and track dust and Zn and Sb in synthetic turf dust were higher than those in other sports facilities. Multielement single-particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOF-MS) revealed more Fe-, Al-, Si-, Ti-, and Pb-containing particles in the dust. At least 92% toxic Pb-containing particles were composed of multiple elements. The significant correlations between Pb and Cr contents on individual dust particles support their common potential source from inorganic pigments (crocoite, PbCrO4). Pb, Sb, As, and Cr in the dust pose higher health risks through intake. The risks were estimated to be approximately 3-5 times higher for children than for adults. Additionally, highly toxic Cr(VI) and As(III) species were observed in the sweat and gastric juice leachate of dust, highlighting severe threats of the metal(loid)s to human health.

Vitamin D Receptor TaqI Gene Polymorphism and Risk of Type 2 Diabetes Mellitus: A Case-Control Study Among Ethiopian Population.

Background: Type 2 diabetes mellitus (T2DM) is a complex and diverse illness that is influenced by several vulnerable genes as well as environmental risk factors. The aim of this study was to ascertain the relationship between the vitamin D receptor TaqI gene polymorphisms and the risk of T2DM at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia. Methods: An age- and sex-matched hospital-based case-control study involved 70 patients with T2DM and 70 nondiabetic healthy controls. Demographic information was assessed in order to identify the associated risk variables. To ascertain the TaqI genotypes, DNA was taken from blood samples and used in a polymerase chain reaction and agarose gel electrophoresis analysis. Results: The frequency of the homozygous TaqI-tt genotype [odds ratios (OR): 2.69; 95% confidence level (CL): 1.05-6.44; P = 0.38], and the t allele (OR: 1.90; 95% CL: 1.16-3.12; P = 0.0099) was significantly higher in patients with T2DM compared to nondiabetic controls. Conclusion: The results suggest that the TaqI gene polymorphism may be related to the onset of T2DM in the Ethiopian population under study.

Impact of Endocrine-Disrupting Chemicals, Climate, and Air Pollution on Pregnancy Outcomes: A Scoping Review.

Environmental pollutants, including endocrine-disrupting chemicals (EDCs), air pollution, and climate change, are increasingly recognized for their potential impact on pregnancy outcomes. EDCs, found in pesticides, industrial chemicals, and personal care products, are associated with preterm birth and fetal growth restriction, primarily through hormonal interference. Air pollution, notably PM2.5, NO2, and O3, has been linked to increased rates of preterm birth, low birth weight, and stillbirth. Climate factors, such as extreme heat, elevate risks of pregnancy loss and preterm birth, with significant impacts on vulnerable populations across diverse socioeconomic and geographic regions. These exposures contribute to adverse pregnancy outcomes through mechanisms involving oxidative stress, inflammation, and endocrine disruption. The interplay among these environmental factors underscores the need for integrated, longitudinal studies to understand their combined effects on pregnancy outcomes better. Future research should focus on region-specific impacts, cumulative exposure, and policy-driven interventions to mitigate these environmental risks, especially in vulnerable populations disproportionately affected by these hazards. This scoping review synthesizes recent findings from 2019 to 2024 to highlight these associations and identify research gaps.

Lateral collision avoidance stability control study of intelligent vehicles on low adherence roads

To enhance lateral collision avoidance safety for intelligent vehicles on various road surfaces, this paper proposes a collision avoidance algorithm specifically designed for low-adhesion roads. The study begins by a fuzzy control lane change decision model that considers the relative state information between the ego vehicle and the front vehicle. Next, the environment risk potential field is modeled, with multiple lane change paths of varying parameters considered as candidate trajectories. Critical risks during vehicle steering are analyzed, leading to the design of a dynamic instability boundary risk point potential field. Trajectory optimization is then performed using the Particle Swarm Optimization (PSO) algorithm. Finally, a fuzzy PID controller is developed to track the optimal trajectory. Simulation results demonstrate that, compared to the traditional artificial potential field method, the proposed collision avoidance algorithm provides better lateral stability in the planned paths. Additionally, the fuzzy PID controller designed in this study outperforms the Quantitative Feedback Theory (QFT) controller in terms of tracking accuracy.

Emerging Perfluorinated Chemical GenX: Environmental and Biological Fates and Risks

Emerging Perfluorinated Chemical GenX: Environmental and Biological Fates and Risks

Analysis of changes and influencing factors of stablization treatment effects and bioavailability after freeze-thaw: a case study of Pb-contaminated soil in a non-ferrous metal factory in Northeast China

IntroductionSolidification/Stabilization techniques are commonly used for the containment and isolation of Pb-contaminated soil, but they cannot reduce the amount of contaminants. Freeze – thaw after stabilization may affect Pb’s environmental behavior and increase the uncertainty of environmental risk.MethodsIn vitro experiments can simulate the bioavailability of heavy metals to the human body, accurately assessing their environmental health risks. In this study, soil samples from Pbcontaminated site are collected from a non-ferrous metal plant in Northeastern China. Through the results of stabilization and freeze–thaw after stabilization experiments, analyzing the changes of physicochemical property, Pb treatment effects (total concentration, leaching concentration, and occurrence forms) and microbial communities, and studying the influencing factors of Pb’s bioavailability.Result and discussionThe results show that stabilization and freeze – thaw after stabilization directly alter soil physicochemical property, thereby affecting the leaching and occurrence form of Pb and microbial communities, and closely related to changes in bioavailability of Pb. Both stabilization and freeze–thaw treatment reduced the leaching concentration of Pb, decreased the proportion of available Pb (acid-soluble state, oxidation state and reduction state), increased the bioavailability of Pb in the gastric phase, but decreased in the intestinal phase; And the dominant bacterial phylum in the soil changed to Firmicutes, the dominant bacterial genus changed to Bacillus; The analysis of the results shows that the bioavailability of Pb is related to soil pH, cation exchange capacity (CEC), soil organic matter (SOM), soil moisture content (SMC), Pb (leaching, acid soluble state, oxidation state, residual state), types of microorganisms in soil.

Heat Stress Prevention in Construction: A Systematic Review and Meta-Analysis of Risk Factors and Control Strategies

In hot and humid work environments, construction workers can experience heat stress and heat-related illnesses (HRIs). While several studies have investigated engineering and administrative control methods to prevent certain heat stress risk factors, a comprehensive understanding of all existing risk factors and their corresponding control strategies is still lacking. It is crucial to identify gaps in current control strategies and develop a safety management framework for effective heat stress control by implementing existing measures. In addition, the effectiveness of the most common control strategies must be rigorously evaluated to ensure their efficacy and to guide future research aimed at enhancing these strategies or developing more effective ones. This study employed a mixed literature review methodology to address this knowledge gap. A structured literature review investigated and synthesized heat stress risk factors and control methods to find the gaps in control options to address underestimated risk factors. Furthermore, a comprehensive systematic literature review, including trend analysis, scientometric analysis, and meta-analysis, determined research foci and evaluated the effectiveness of the heat stress control methods. The scientometric analysis identified 11 clusters, encompassing key research themes such as environmental risk factors (e.g., high-temperature environments, climate change), administrative controls (e.g., work–rest schedules, climate change risk assessment), and personal interventions (e.g., cooling vests and sleep-related strategies). These findings highlight that the most commonly studied control methods are cooling vests, work–rest schedules, and cooling interventions. According to these results and the availability of quantitative results, the meta-analysis evaluated nine datasets of reductions in core body temperature by using types of cooling vests and anti-heat-stress uniforms and established the significant effectiveness of this control strategy in mitigating heat stress with a medium effect size. Moreover, five potential research studies have been identified to address gaps in control strategies for certain underestimated risk factors, including leveraging sensor technologies, conducting control training, dynamic work–rest schedules, using cutting-edge PPE, and governmental initiatives. Insights gained from this study enhance decision making for resource allocation, selection of control options, and intervention prioritization within a heat-stress-control framework based on the safety management system. The findings also highlight the effectiveness of cooling vests and areas that need to be developed, and evaluate potential heat-stress-control methods in construction.

Serological Evidence of Cryptic Rift Valley Fever Virus Transmission Among Humans and Livestock in Central Highlands of Kenya

Although the highlands of East Africa lack the geo-ecological landmarks of Rift Valley fever (RVF) disease hotspots to participate in cyclic RVF epidemics, they have recently reported growing numbers of small RVF clusters. Here, we investigated whether RVF cycling occurred among livestock and humans in the central highlands of Kenya during inter-epidemic periods. A 2-year prospective hospital-based study among febrile patients (March 2022–February 2024) in Murang’a County of Kenya was followed by a cross-sectional human–animal survey. A total of 1468 febrile patients were enrolled at two clinics and sera tested for RVF virus RNA and antiviral antibodies. In the cross-sectional study, humans (n = 282) and livestock (n = 706) from randomly selected households were tested and questionnaire data were used to investigate sociodemographic and environmental risk factors by multivariate logistic regression. No human (n = 1750) or livestock (n = 706) sera tested positive for RVFV RNA. However, 4.4% livestock and 2.0% humans tested positive for anti-RVFV IgG, including 0.27% febrile patients who showed four-fold IgG increase and 2.4% young livestock (&lt;12 months old), indicating recent virus exposure. Among humans, the odds of RVF exposure increased significantly (p &lt; 0.05, 95% CI) in males (aOR: 4.77, 2.08–12.4), those consuming raw milk (aOR: 5.24, 1.13–17.9), milkers (aOR: 2.69, 1.23–6.36), and participants residing near quarries (aOR: 2.4, 1.08–5.72). In livestock, sheep and goats were less likely to be seropositive (aOR: 0.27, 0.12–0.60) than cattle. The increase in RVF disease activities in the highlands represents a widening geographic dispersal of the virus, and a greater risk of more widespread RVF epidemics in the future.

Global Burden of Disease from Environmental Factors.

Estimation of the disease burden attributable to environmental factors is a powerful tool for prioritizing environmental and pollution management and public health actions around the world. The World Health Organization (WHO) has been estimating the environmental disease burden since 2000, which has formed the basis for the modern estimation approach conducted in the Global Burden of Disease, Injuries, and Risk Factor (GBD) study. In 2021, environmental and occupational risk factors in the GBD were responsible for 18.9% (12.8 million) of global deaths and 14.4% of all disability-adjusted life years (DALYs), led by ambient PM2.5 air pollution (4.2% DALYs, 4.7 million deaths) and household air pollution (3.9% DALYs, 3.1 million deaths). Climate change exacerbates many environmental hazards, leading to increased disease burdens from heat, air pollution, vector-borne diseases, storms, and flooding. Other environmental risk factors not included in the GBD, such as poor indoor air quality, various chemical exposures, and environmental noise pollution, also significantly contribute to disease burden in many countries, though more efforts are needed to generate and integrate data resources for inclusion in global estimations.

USE OF GEO-INFORMATION SYSTEMS FOR GROUNDWATER MONITORING

Abstract . The article is devoted to the study of the possibilities of using geographic information systems (GIS) for monitoring the state of groundwater, which is important for ensuring environmental safety and sustainable management of water resources. Groundwater is an important source of fresh water for the population, industry and agriculture, but it is vulnerable to various pollutions caused by both natural and anthropogenic factors. Therefore, the implementation of reliable monitoring systems that allow timely detection, assessment and forecasting of changes in water quality is necessary to prevent the deterioration of the ecological situation and prevent the spread of pollution. Geographic information systems (GIS ) offer significant opportunities for the collection and integration of large volumes of spatial data, including satellite images, remote sensing results, automated sensor data, and field observations. GIS allow creating multi-layered maps reflecting the ecological state of underground aquifers, modeling pollution processes and predicting their possible impact on nearby ecosystems and water sources. Thanks to the use of GIS, it is possible to combine data from different sources in a single interactive system, which simplifies analysis and provides the ability to quickly respond to any detected deviations. The article examines in detail the key methods used within GIS for groundwater monitoring, including satellite sounding to analyze changes in the earth's surface, spectral indices to assess the state of vegetation and soil salinity, and radar methods to determine soil electrical conductivity. Particular attention is paid to the application of three-dimensional modeling, which allows visualization of the spread of pollution in underground aquifers, which facilitates decision-making regarding the optimal location of monitoring stations and the design of protective structures. In combination with automated sensors recording water parameters in real time, GIS provides continuous monitoring of the physico-chemical indicators of groundwater and allows for prompt assessment of their condition. The article also analyzes the possibilities of using predictive modeling in GIS to assess the further spread of pollution and develop environmental risk management measures. It is described how mathematical models in GIS can help predict the impact of anthropogenic and natural factors on groundwater, which ensures the development of scientifically based solutions to reduce pollution and maintain water quality at a safe level. The implementation of GIS in groundwater monitoring is an important step towards increasing the efficiency of water resources management, ensuring their protection from pollution and preserving the ecological stability of the regions.

THE IMPACT OF THE URBANIZED ENVIRONMENT ON PUBLIC HEALTH

The scientific and technological progress of modern society is an objective process that cannot be stopped. Currently, cities occupy about 0.3% of the earth's surface area, but they are home to more than 40% of the population. Large cities are expanding their functional properties and becoming stimulators of the growth of new industries, integration and focus of human economic activity. The concen-tration of a large number of equipment, buildings, and population in one area of a modern city has led to the fact that the urbanized environment is significantly different from the natural environment in terms of quality. In the context of large cities, humans deform the environment and feel the consequences of deformation acutely.Consideration of environmental problems from a modern perspective allows us to assert that envi-ronmental degradation is not inevitable and does not necessarily accompany human economic activity. At the same time, the author emphasizes the lack of unity of methodological approaches to the identification of environmentally caused diseases, contradictions in assessing the role of environmental factors, insufficient development of criteria for identifying environmentally caused pathology, imperfection of the system of envi-ronmental risk assessment and management, and the need for scientific substantiation of the system of legal and economic compensation for health damage associated with the impact of environmental factors. The process of urbanization and its related qualitative characteristics can be effectively considered only when studying the human-society-environment system. The most important task of studying the afore-mentioned system is to investigate the continuous process of urbanization and the increasing anthropogenic impact on the environment and public health. In these conditions, it is important to understand the sequence and features of the urbanization process, to study the impact of climate change, the development of anthro-pogenic factors, their impact on the environment and public health.The paper discusses the main hygienic and environmental problems associated with the process of urbanization and climate change, and proposes comprehensive measures to prevent and reduce the nega-tive consequences for the population. It is demonstrated that the management of the processes of formation of the urbanized environment is an important component of urban life and the main task of ensuring comfort-able living conditions for the population.

Transformation behavior and toxicity assessment of beaytlmethodeyammonNium chbride (BAC-12) disinfectant during hospital wastewater treatment.

This work focused on the transformation behavior of the emerging beaytlmethodeyammonium chbride (BAC-12) disinfectant existed in the treatment of medical sewage during its disinfection treatment. The degradation ability of ozone (O3) to BAC-12 was the best, followed by UV/NaOCl, UV, and NaOCl. The enhancement of BAC-12 in UV/NaOCl system is caused by the combined effect of UV photolysis, reactive chlorine species (RCS), and •OH. The transformation products of BAC-12 in the disinfection treatment were detected, and the chemical structure of products was rationalized by frontier molecular orbital and transition state theory methodologies. According to the ecological structure-activity relationship (ECOSAR) assessment, the intermediates of BAC-12 in UV, NaOCl, and UV/NaOCl treatments had lower half lethal concentration (LC50) and chronic toxicity (ChV) values with a higher ecotoxicity than BAC-12. O3 disinfection treatment of these toxic intermediates can significantly reduce the toxicity of the BAC-12 solution. This work provides necessary information on the potential environmental risks of BAC-12 arising from different disinfection methods in the treatment of medical wastewater.

Estimating the Volume of Water Torrents in the Rizan River Basin and its Environmental Risks

Estimating the Volume of Water Torrents in the Rizan River Basin and its Environmental Risks

Effect of Tannery Organic Matter on the Migration and Transformation of Chromium in Soil

ABSTRACT Chromium (Cr) contamination is one of the main pollution issues in the soils of tanning industries. Nevertheless, it is unclear how tannery organics affect the movement and transformation of Cr in soil. Column leaching tests were carried out to investigate the impact of various tannery organics, such as phenol, dyes, and surfactants on Cr mobility in tannery soil. The cumulative release of Cr from the soil was less in the presence of tannery organics than that from the non-tannery organics treated group. This suggests that the tannery organics enhanced the fixing of Cr in the soil. Cr was poured from the top of the soil column in the form of Cr (III) solution for leaching, and the concentration of Cr decreased with the increase of soil depth regardless of the presence of tannery organic matter. After leaching, the residual Cr concentration in the soil was 59%−78% of the total Cr concentration. The potential risk of Cr in the soil/groundwater system decreased in the presence of the tannery organics, which decreased the bioavailability of Cr and increased the percentage of Cr in residual state. Understanding the relationship between Cr migration and tannery organics in soil is helpful for soil environment risk assessment of tannery site.