High Hazard Research Articles

Analysis of Groundwater Chemical Characteristics and Health Risk Assessment: A Case Study of Water Sources in the Tailai Basin

Groundwater nitrate pollution is a pressing threat to public health. To analyze the chemical properties of groundwater across various sources, samples from 15 groundwater outlets within the Tailai Basin were collected during both the dry and wet seasons. An assessment of human health risks based on drinking water habits and skin contact with various water sources was conducted to provide a foundation for the rational development and utilization of groundwater. The results revealed that the main source of chemical components in the groundwater in the study area was evaporite dissolution. Rock weathering and cation exchange predominantly affected the chemical composition of groundwater. The groundwater samples primarily contained Ca2+ cations and HCO3− anions. The concentration of groundwater nitrate at each water source was relatively high. The single-factor water quality evaluation demonstrated that SO42−, NO3−, and TDS exceeded the standard, where NO3− severely exceeded the standard. The water supply and dry seasons were more than 10 times higher than the standard. The HI exceeded 1 for most water sources, and the non-carcinogenic risk index for children significantly surpassed that for adults. This high hazard quotient suggests that groundwater from the majority of sources in the Tailai Basin may adversely affect residents’ health. Water resource management authorities should address groundwater nitrate pollution to ensure the residents’ health and safety. Meanwhile, efforts should focus on preventing and controlling nitrogen pollution in groundwater to support its sustainable development.

Modeling the rupture dynamics of strong ground motion (> 1 g) in fault stepovers

Following the July 2019 Ridgecrest, California earthquakes, multiple field investigators noted that pebble- to boulder-sized rocks had been displaced from their position in the desert pavement within a stepover along the right-lateral strike-slip M7.1 rupture trace, without evidence of dragging or shearing. This implies localized ground motions in excess of 1 g, in contrast to the instrumentally recorded peak of 0.57 g. Similar rock displacement occurred in a stepover in the predominantly strike-slip 2010 M7.2 El Mayor-Cucapah earthquake. Together, these examples suggest that some aspect of how earthquake rupture negotiates a strike-slip fault stepover produces extremely localized strong ground acceleration. Here, we use the 3D finite element method to investigate how rupture through a variety of strike-slip stepover geometries influences strong ground acceleration. For subshear ruptures, we find that the presence of a stepover in general matters more than its dimensions; the strongest ground acceleration always occurs at the end of the first fault. For supershear ruptures, the stepover is effectively irrelevant, since the strongest particle acceleration occurs at the point of the supershear transition on the first fault. Our model subshear and supershear ruptures alike do produce horizontal particle acceleration above 1 g, but over a region so close to the fault (< 1 km) that a seismic network may not catch it. We suggest that the physics of rupture through a fault stepover could have been responsible for the displaced rocks in the Ridgecrest and El Mayor-Cucapah earthquakes, and that stepover regions may have particularly high ground motion hazard. Our study suggests that ground motion predictions and local hazard assessments should account for much stronger accelerations in the immediate near field of active faults, especially around stepovers and other geometrical discontinuities.

Projecting Future Chronic Coastal Hazard Impacts, Hotspots, and Uncertainty at Regional Scale

AbstractWhile there is high certainty that chronic coastal hazards like flooding and erosion are increasing due to climate change induced sea‐level rise, there is high uncertainty surrounding the timing, intensity, and location of future hazard impacts. Assessments that quantify these aspects of future hazards are critical for adaptation planning under a changing climate and can reveal new insights into the drivers of coastal hazards. In particular, probabilistic simulations of future hazard impacts can improve these assessments by explicitly quantifying uncertainty and by better simulating dependence structures between the complex multivariate drivers of hazards. In this study, a regional‐scale probabilistic assessment of climate change induced coastal hazards is conducted for the Cascadia region (Northern Washington to Northern California), USA during the 21st century. Three co‐produced hazard proxies for beach safety, erosion, and flooding are quantified to identify areas of high hazard impacts and determine hazard uncertainty under three sea‐level rise scenarios. A novel chronic coastal hazard hotspot indicator is introduced that identifies areas that may experience significant increases in hazard impacts compared to present day conditions. We find that beaches near the California‐Oregon border and in Northern Washington have larger hazard impacts and hazard uncertainty due to their morphologic setting. Erosional hazards, relative to beach safety and coastal flooding, will increase the most in Cascadia during the 21st century under all sea‐level rise scenarios. Finally, we find that hazard uncertainty associated with wave and water level variability exceeds the uncertainty associated with sea‐level rise for most of the 21st century.

Assessing Multi-Hazard Risk through Spatial Analysis: A Geographic Information Systems for Susceptibility Mapping in Java Island, Indonesia

Abstract The geographic location and population make Java Island a disaster-prone area with various threats, including earthquakes, floods, landslides, and volcanic eruptions. Based on historical data, these four types of disasters caused a total of US$24,303,159,688 in economic losses in the last 50 years. In regard to the big loss, it is considered important to identify potential disaster risks to avoid more sustainable economic losses in the future. By utilizing developments in Geographic Information Systems (GIS) technology, potential disaster risk mapping could be carried out. The process begins with preparing a map of the potential risk of earthquakes, floods, landslides, and volcanic eruptions by referring to the regulatory document of the head of the National Disaster Management Agency (BNPB) Number 2 of 2012 and Indonesian National Standard (SNI). Afterwards, the potential risk map for each type of disaster will be combined to determine the hazard level of each disaster in 1 square kilometer-sized pixels. The merging process uses annual economic loss data over a period of 50 years as a weighting factor. Based on the data, the results show that 11.554% (15.092 square kilometers) of the area of Java Island falls into the high hazard level class, 77.642% (101.413 square kilometers) into the moderate hazard level class, and 10.804% (14.112 square kilometers) into the low hazard level class. The resulting multi-hazard map could be further used for various specific purposes, such as creating an early warning system or estimating direct losses due to disasters.

Driving mechanisms of the spatial distribution of industrial parks and the relative hazard level of the surrounding environment.

Analyzing the formation mechanisms of industrial parks and quantitatively evaluating the related hazard levels are important for understanding the development and planning of industrial parks, but there is currently a lack of relevant research. In this study, Beijing was taken as a case study. The analysis results showed that (1) the overall spatial distribution of industrial parks in Beijing followed a clustering pattern, with nested spatial distribution pattern, where larger structures contributed 53.96% of the variance; (2) for the overall spatial distribution of industrial parks, kernel density of enterprises was the main influencing factor, which there were synergistic enhancement effects with almost all other influencing factors, especially urban construction, the number of financial institutions, the population density, this can share transportation and other resources, achieving coordinated development. According to these main factors, the prediction model of the future spatial distribution pattern of industrial parks in Beijing was established; (3) for site selection of each industrial park, twenty-two industrial parks near industrial enterprises in Beijing were more affected by industrial enterprise clustering, and the remaining 65 industrial parks were strongly affected by terrain, (4) The industrial parks in the central and southern parts of Beijing presented a relatively high hazard level to the surrounding sensitive receptors. These results provide theoretical support for the development and layout of industrial parks.

New insights into combined surfzone, embayment, and estuarine bathing hazards

Abstract. Rip currents are the single largest cause of beach safety incidents globally, but where an estuary mouth intersects a beach, additional flows are created that can exceed the speed of a typical rip current, significantly increasing the hazard level for bathers. However, there is a paucity of observations of surfzone currents at estuary mouth beaches, and our understanding and ability to predict how the bathing hazard varies under different wave and tide conditions are therefore limited. Using field observations and process-based XBeach modelling at an embayed, estuary mouth beach, we demonstrate how surfzone currents can be driven by combinations of estuary discharge and wave-driven bathymetric and boundary rip currents under various combinations of wave and tide forcing. While previous studies have demonstrated the high hazard that rip currents pose, typically during lower stages of the tide, here we demonstrate that an estuary mouth beach can exhibit flows reaching 1.5 m s−1 – up to 50 % stronger than typical rip current flows – with a high proportion (&gt; 60 %) of simulated bathers exiting the surfzone during the upper half of the tidal cycle. The three-dimensional ebb shoal delta was found to strongly control surfzone currents by (1) providing a conduit for estuary flows that connect to headland boundary rips and (2) acting as a nearshore bar system to generate wave-driven “river channel bathymetric rips”. Despite significant spatio-temporal variability in the position of the river channels on the beach face, it was possible to hindcast the timing and severity of past bathing incidents from model simulations, providing a means to forewarn bathers of hazardous flows.

A quantitative assessment of GeoNet earthquake location quality in Aotearoa New Zealand

ABSTRACT Tens of thousands of earthquakes are located by GeoNet across Aotearoa every year. However, spatial variability – both in station coverage and earthquake distributions – produce heterogeneity in earthquake location quality throughout the GeoNet catalogue. Here we consider simple, established criteria (including station azimuthal coverage, minimum station distance, phase arrival coverage and fixed location criteria) to score earthquakes on a network location Quality Score (QS) scale of QS0 (unconstrained) to QS6 (best constrained). Significant variation in QS exists nationwide; 48% and 20% of earthquakes score QS6 for the North and South Islands respectively. The Hawkes Bay region scores highest (68% QS6) closely followed by other Hikurangi regions. However, several regions score extremely poorly, with Fiordland, West Coast, Nelson, Otago-Southland and Auckland-Northland regions having ≤5% QS6 events and >75% of events scoring QS3 or lower. Low QS mostly arises from the failure of minimum distance criteria, whereby the closest station is too far from the earthquake to provide sufficient depth control. Our analysis quantitatively assesses the impact of network heterogeneity on GeoNet earthquake catalogue location quality to inform end users. This work also provides motivation for the expansion of the weak-motion network in critically under-instrumented regions, especially those with high seismic hazard.

Hydrochemical characteristics, cross-layer pollution and environmental health risk of groundwater system in coal mine area: a case study of Jiangzhuang coal mine.

Long-term coal mining activities have significantly disturbed the groundwater system, resulting in aquifer water characterized by high levels of Na+, SO42-, and total dissolved solid (TDS), posing environmental health risks. To investigate the disturbance effects of coal mining activities on the groundwater system and ascertain the goaf water (OGW) environmental impacts, this study focuses on the surface water (SW), major aquifers, and OGW of Jiaozhuang Coal Mine. Through ion analysis and self-organizing map (SOM) clustering, the study analyzes the hydrochemical characteristics of the aquifer water, summarizes the accumulation patterns of OGW, and evaluates water quality of irrigation and drinking using sodium adsorption ratio (SAR), sodium percentage (SSP), and comprehensive pollution index (F). The results show that the hydrochemical characteristics of the groundwater system are influenced by a combination of cation exchange, dissolution, and mixing processes, with deep aquifers exhibiting high Na+ and SO42- levels. The OGW mainly originates from the coal roof sandstone aquifers water (RSW) and 3rd limestone aquifer water (3LW). Additionally, the groundwater shows high alkalinity and salinity hazards, with irrigation water quality assessments falling into general and unsuitable water quality area. Moreover, the groundwater quality is below Class III standards, with the worst being Class V, rendering it unsuitable as a drinking water source. Untreated discharge of OGW to the surface can easily threaten human drinking water health. The study results are helpful in identifying and controlling groundwater pollution caused by coal mining, ensuring the safety and sustainable utilization of water resources in mining areas and surrounding regions.

Graphitic nanotubes confined with Ni nanocrystals: Artificial armor for ammonium polyphosphate towards fire-safe epoxy composite

With the ever-growing usages of epoxy resin (EP) in versatile aspects, its high fire hazard comes to prominence. How to improve the flame retardancy of EP at the least cost has been hotspot. In this context, we have constructed an artificial armor, namely N doped graphitic nanotubes confined with nickel nanoparticles (NGNTs@Ni), on the surface of ammonium polyphosphate (APP). Here, the ratios of NGNTs@Ni and APP are fixed at 1:9, 2:8, 3:7, acquiring the flame retardants of 1NGNTs@Ni/9APP, 2NGNTs@Ni/8APP, 3NGNTs@Ni/7APP. Compared with APP, 1NGNTs@Ni/9APP induces the superior inhibitions in heat, smoke and toxic gas releases. Concretely, the using of 15 wt% APP leads to reductions of 65.1 %, 22.8 %, 57.7 %, 40.1 % in peak heat release rate (PHRR), peak CO production rate (PCOPR), peak CO2 production rate (PCO2PR), peak smoke production rate (PSPR). By using 10 wt% 1NGNTs@Ni/9APP, the reductions in PHRR, PCOPR, PCO2PR, PSPR reach 75.6 %, 49.2 %, 70.4 %, 60.4 %. As anticipated, the high loading of APP triggers the decreases in mechanical properties while the using of modified APP results in the promotion in mechanical performances. In short, this work can provide inspirations for the facile design of APP based flame retardant, reducing its dosage and improving its flame retardation efficiency.

Seismic scenario simulation and ANN-based ground motion model development on the North Tabriz Fault in Northwest Iran

AbstractEarthquakes pose significant seismic hazards in urban regions, often causing extensive damage to the built environment. In regions lacking robust seismic monitoring networks or sufficient data from historical events, ground motion simulations are crucial for assessing potential earthquake impacts. Yet, validating these simulations is challenging, leading to notable predictive uncertainty. This study aims to simulate four scenario earthquakes with moment magnitudes of 6.8, 7.1, 7.4, and 7.7 in Iran, specifically investigating variations in fault plane rupture and earthquake hypocenter. The North Tabriz Fault (NTF), located within the seismic gap in northwest Iran, is selected as the case study due to the lack of well-recorded ground motions from severe earthquakes, despite historical evidence of large-magnitude events. Simulations are conducted using a stochastic finite-fault ground motion simulation methodology with a dynamic corner frequency. Validation of the simulations is performed by comparing estimated peak ground motions and pseudo-spectral ordinates with existing ground motion models (GMMs), supplemented by inter-period correlation analysis. Simulation results reveal high hazard levels, especially in the northeastern area near the fault plane. Intensity maps in terms of the Modified Mercalli Intensity (MMI) scale underscore the urgency for comprehensive preparedness measures. Finally, a region-specific GMM is developed using Artificial Neural Networks (ANN) to predict peak ground motion parameters with an online platform accessible to end-users.

On the use of displaced river terraces to characterize active tectonics of the Zagros orogenic belt, SW Iran

Investigating fault deformation in Late-Quaternary sediments provide valuable data to seismic hazard analysis especially relevant for the urban areas. Integration of displacement of geomorphic markers and ages of Quaternary sediment is needed to measure deformation rates accurately. In order to produce data on intermediate-term deformation rates along the Sabzpoushan Fault Zone (SFZ) situated in the Zagros Mountains of south-west Iran, the optically stimulated luminescence (OSL) dating technique was applied to the tectonically influenced terraces of the Mianrod River passing through the fault zone. Field evidence and satellite imagery revealed that geomorphic markers include strike-slip displacement of terraces, different levels of the fluvial markers, shifting in Bakhtiary Formation, fast change in trend of the river and expansion of erosional gully, deformed horizontally along the Fault Zone. These geomorphic indices suggest that Mianrod River deflected along the SFZ as a consequence of faulting during multiple faulting cycles. The OSL dates obtained from the study area indicate that strike-slip deformation rate along the Sabzpoushan Fault Zone is 1–2.8 ± 0.2 mm y−1 (for ∼100 ka). It is suggestive from the research that a significant part of this estimated rate of deformation results from aseismic crustal deformation, but the areas with the highest likelihood of the Sabzpoushan near-surface deformation, as well as the west parts of the city of Shiraz, should be considered as high seismic hazard areas.

Comprehensive drought risk assessment of the Yangtze River Basin considering socio-natural systems — Based on PCR-GLOBWB model

Against the backdrop of climate change and the impact of human activities, the regional and global risks of drought disasters are increasing. It is imperative to undertake thorough assessments of drought risks and delve into the underlying factors influencing them. This is essential for devising effective disaster risk management strategies and fostering sustainable development within the region. However, the spatial macroscopic nature of statistical data and the incomplete evaluation framework pose great challenges to finely quantify regional drought risks. In addressing these issues, with robust data support from the PCR-GLOBWB model and introducing more comprehensive evaluation indicators, we have developed a comprehensive drought risk assessment system covering the subsystems of drought hazard, vulnerability, and exposure. A comprehensive evaluation of drought risk in the Yangtze River Basin was conducted, and identifying the primary influencing factors. The results indicate that, (1) Areas with moderate or high drought hazard account for 58% of the Yangtze River Basin, while drought vulnerability exhibits a noticeable increasing trend towards the west, and regions with high drought exposure primarily concentrated in the midstream and downstream; (2) Areas with moderate or high drought risk are mainly distributed in the source area and central regions of the upstream of the basin, as well as in the densely populated and widely distributed farmland areas of the midstream and downstream. From upstream to downstream, the proportion of areas at high drought risk is 31.2%, 15% and 19.1%, respectively. (3) The hazard and vulnerability of drought are the main factors leading to high drought risk in the upstream, while higher drought vulnerability and exposure together contribute to drought risk in the midstream and downstream. Different sub-basins should develop tailored measures based on the specific factors contributing to drought risks to effectively mitigate and withstand these challenges.

Multi-criteria assessment of PDGLs for GLOFs hazards in the Bhut and Warwan sub-basins of the Chenab basin, Northwestern Himalaya

The current investigation has been carried out to determine the potentially dangerous glacial lakes (PDGLs) and glacier recession and in the Bhut and Warwen sub-basins of Chenab basin using the Landsat series of data. In order to assess the glacier dynamics from 2000 to 2020 the consecutive set of 5-year intervals data were used and it is found that, glaciers are shrinked in area as 1049.94 km2 in 2000, to 988.07 km2 in 2020, indicating a notable decrease in glacier extent over the twenty-year period. Further, an empirical approach was used to identify the PDGLs in the study area. The results of PDGLs shows that there are a total of 55 glacial lakes have the potential to be hazardous. Out of them, 11 are classified as high hazard, 18 as moderate hazard; and the remaining 26 are designated as low hazard. The PDGLs in the region have seen a surge in their numbers in the last few decades due to topographical as well as climate variables. The receding of glaciers and the risk of landslides in the region greatly influences PDGLs. The dangers among these lakes in the region have accumulated so much sediments and the glacial melt and their bearing capacity has come up to certain threshold causing the GLOFs and landslide lake outburst floods (LLOFs) in the region.

An interpretable (explainable) model based on machine learning and SHAP interpretation technique for mapping wind erosion hazard.

Soil erosion by wind poses a significant threat to various regions across the globe, such as drylands in the Middle East and Iran. Wind erosion hazard maps can assist in identifying the regions of highest wind erosion risk and are a valuable tool for the mitigation of its destructive consequences. This study aims to map wind erosion hazards by developing an interpretable (explainable) model based on machine learning (ML) and Shapley additive exPlanation (SHAP) interpretation techniques. Four ML models, namely random forest (RF), support vector machine (SVM), extreme gradient boosting (XGB), and quadratic discriminant analysis (QDA) were used. Thirteen features associated with wind erosion were mapped spatially and then subjected to a multivariate adaptive regression spline (MARS) feature selection algorithm, and then, tolerance coefficient (TC) and variance inflation factor (VIF) statistical tests were used to explore multicollinearity among the variables. MARS analysis shows that eight features consisting of elevation (or DEM), soil bulk density, precipitation, aspect, slope, soil sand content, vegetation cover (or NDVI), and lithology were the most effective for wind erosion, while no collinearity existed among these variables. The ML models were used for ranking the effective features, and the research introduces the application of an interpretable ML model for the interpretation of predictive model's output. The ranking of effective features by RF-as the most typical ML model-revealed that elevation and soil bulk density were the two most important features. According to the area under the receiver operating characteristic curve (AUROC) (with a value > 90%) and precision-recall (PR) (with a value > 90%) curves, all four ML models performed with great accuracy. According to the PR curve, the SVM model performed slightly better than others, and its results revealed that 20.9%, 23%, and 16.6% of the total area in Hormozgan Province is characterized by moderate, high, and very high hazard classes to wind erosion, respectively. SHAP revealed that soil sand content and elevation are the most important variables contributing to the predictive model output. Overall, our research is one of the pioneering applications of interpretable ML models in mapping wind erosion hazards in Southern Iran. We recommend that future research should address the aspect of interpretability in order to better understand predictive model outputs.

Monitoring soil salinization and waterlogging in the northeastern Nile Delta linked to shallow saline groundwater and irrigation water quality

Soil salinization and waterlogging are critical environmental issues affecting agricultural productivity and cultural heritage preservation, particularly in arid regions. This study investigated soil degradation processes in the archaeologically and agriculturally significant northeastern Nile Delta of Egypt. The objective was to assess the severity of soil degradation and identify key drivers related to water resources and soil characteristics to aid in the development of management strategies. The research employed a multi-faceted approach, including hydrochemical analyses (of groundwater, irrigation water, and soil), water quality indices calculations, statistical analyses, and satellite data. The results revealed high levels of soil salinization in the northern and central areas, with 64% of soil samples classified as strongly and very strongly saline. Soil chemistry indicated salinization sources linked to sodium chloride dominance. Satellite data from Sentinel-2 images and SRTM digital elevation data showed widespread severe waterlogging in the northern lowlands. The Irrigation Water Quality Index (IWQI) values indicated that 87.5% of irrigation water samples posed severe restrictions due to high salinity and sodium hazards, which were mismatched with the low soil permeability observed in 81% of the collected samples exhibiting clay texture and covering most of the study area. Furthermore, shallow groundwater at depths of 0.5–3 m with high salinity was detected, where total dissolved solids exceeded 20,000 mg/L, and Na-Cl water types prevailed, indicating saltwater intrusion. A strong positive correlation (r > 0.83) was found between shallow saline groundwater and soil salinity. The combination of poor irrigation water quality, shallow saline groundwater tables, and low-permeability soils created a synergistic effect that severely compromised soil health and agricultural productivity. It also posed severe risks to the structural integrity of archaeological sites and buried artifacts through accelerated physical and chemical weathering processes. This necessitates an urgent mitigation strategy to combat soil degradation in this critical area.

Before the fire: predicting burn severity and potential post-fire debris-flow hazards to conservation populations of the Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus)

Background Colorado River Cutthroat Trout (CRCT; Oncorhynchus clarkii pleuriticus) conservation populations may be at risk from wildfire and post-fire debris flows hazards. Aim To predict burn severity and potential post-fire debris flow hazard classifications to CRCT conservation populations before wildfires occur. Methods We used remote sensing, spatial analyses, and machine learning to model 28 wildfire incidents (2016–2020) and spatially predict burn severity from pre-wildfire environmental factors to evaluate the likelihood (%) and volume (m3) hazard classification of post-fire debris flow. Key results Burn severity was best predicted by fuels, followed by topography, physical ecosystem conditions, and weather (mean adjusted R2 = 0.54). Predictions of high or moderate burn severity covered 1.1 (15% of study area) and 1.5 (19% of study area) million ha, respectively, and varied by watershed. Combined high or moderate debris flow hazard classification included 80% of stream reaches with conservation populations and 97% of conservation population point nodes. Conclusions Predicted burn severity and potential post-fire debris flow indicated moderate to high hazard for CRCT conservation populations native to the Green and Yampa rivers of the Upper Colorado River Basin. Implications Future management actions can incorporate predicted burn severity and potential post-fire debris flow to mitigate impacts to CRCT and other at-risk resource values before a wildfire occurs.

Occurrence, spatiotemporal distribution, and health risk of antibiotics in the Wuhan section of the Yangtze River, China.

The occurrence, spatiotemporal changes, and health hazard of antibiotics in source water and finished water in the Wuhan section of the Yangtze River are not well understood. In this study, 43 source water and finished water samples were collected from 11 water plants in Wuhan in August 2021 and May 2022. Fifty-one antibiotics from eight categories were measured. A total of 41 antibiotics were detected in the source water samples, and 24 in the finished water samples. The total antibiotic concentration in source water ranged from 1.68 to 437.18 ng/L, which is significantly higher than that in finished water (2.04-87.25 ng/L). Sulfonamides and lincosamides were predominant, accounting for nearly 80% of the total antibiotic concentration. Lincomycin constituted nearly 30% of the total antibiotic concentration in the source water. In August 2021, the average total antibiotic concentration in source water was 107.12 ng/L, higher than in May 2022 (63.13 ng/L). Spatially, the total antibiotic concentrations in samples collected from the Han River, a tributary of the Yangtze River, were higher than those in the main stream of the Yangtze River. Ecological risk assessment indicated that the hazard posed by most antibiotics were negligible. Lincomycin potentially posed a high health hazard, and clarithromycin and roxithromycin posed a moderate hazard to infants.

An Appraisal Of The Impact Of Leachates From A Waste Dumpsite On Coastal Soils And Groundwater System Of The Metropolitan Area Of Lagos, Southwestern Nigeria

Open dump being the common waste disposal practice in most of the urban centres has posed serious challenges to groundwater quality especially within its vicinity. This study assessed the impact of solid waste disposal on the quality of groundwater and soils in Oke-Odo area of Metropolitan Lagos, Nigeria. Field physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature were measured using PC Testre Model 35. A total of 36 water samples, two leachate samples and 15 soil samples were analyzed for their major ions and trace metal components using titration and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) methods. Results revealed a decrease in concentrations of trace and major elements with respect to their distance from the waste dumpsite. A decrease in concentrations of Fe was observed with distances from the dumpsite with values ranging from 12.6 to 0.03mg/l and 4.3 to 0.03mg/l for samples within 500 m and 500-1,500 m, respectively. With exception of a few locations having higher concentrations of Fe, Al, Br, Cu, Mn and Pb, the groundwater sources in the study area are chemically potable with respect to their chemical compositions and generally conform to the World Health Organization and the Nigerian Standard for drinking Water Quality standards for drinking water; and thus, fit for domestic purposes. Sodium adsorption ratio ranges between 0.82 and 5.80 %, indicating low sodium and medium to high salinity hazards. This implies suitability of the water for irrigation purpose. The leachate from the active part of the waste dumpsite showed high concentrations of heavy metals such as Pb (4 mg/l), Cd (0.7 mg/l), Zn (6.54 mg/l) and Cu (3.57 mg/l), which indicates a potential environmental risk. The absence of these metals in the groundwater can be attributed to the attenuating role of the soil above the water table as confirmed by higher concentration of the measured trace metals in comparison to the control sites, with values ranging from 280 to 636 mg/l for Pb, 2 to 9.9 mg/l for Cd, 1041 to 10,000 mg/l for Zn and 102 to 1,307 mg/l for Cu. A total of 66.6 % of soil samples havevery high degree of contamination while 33.3% is considerably contaminated. Hydrochemical characterization of the water revealed predominant Na-K-Cl end-member water type and Ca-Mg-Cl water type which could be attributed to the influence of leachate from the waste dumpsite and possible contribution of seawater from the adjoining lagoons and cation exchange process. This study has revealed that soils and groundwater quality within the vicinity of Oke-Odo dumpsite has been impacted minimally.

Chemometric assessment of bioaccumulation and contamination pathways for toxic metals in diet and environment: implications for chronic kidney disease of unknown etiology (CKDu) in Sri Lankan agricultural regions.

Prolonged consumption of foods containing toxic metals can elevate the risk of noncommunicable diseases, including chronic kidney disease of uncertain etiology (CKDu). Despite the increasing number of CKDu cases in Maradankulama and Mahakanadrawa Grama Niladhari Divisions (GN) in Sri Lanka, no prior studies have examined the accumulation of heavy metal(loid)s and their potential association with CKDu prevalence. Furthermore, there is an absence of comprehensive analyses using chemometric techniques such as PCA and hierarchical studies regarding CKDu and heavy metal contamination in Sri Lanka. This study aims to provide initial insights into the accumulation and potential pathways of toxic metals in staple foods within local diets and their subsequent presence in the agricultural environment of examined GNs. Cr, Cd, As, and Ni concentrations in analyzed foods were within permissible limits (MPLs), whereas Pb levels exceeded MPLs in rice (Oryza sativa), gotukola (Centella asiatica), lime (Citrus crenatifolia), and inland fish (Etroplus suratensis). High target hazard quotient (THQt) values in polished rice suggest possible health risks with prolonged intake. Hierarchical analysis suggested a common source of Pb accumulation. PCA and hierarchical clustering revealed the intricate connection between As and Cd, with their concurrent clustering in samples suggesting a potential common origin. This indicates that while individual concentrations comply with acceptable standards, the potential synergistic effects of Cd and As accumulation might pose elevated health risks. Further, the gut tissues of inland fish exhibited pronounced metal concentrations and significant (p < 0.05) positive correlations with toxic metals in the tank sediments suggesting a diet-based bioaccumulation pathway through sediments.

Rock Slope Stability Assessment for Selected Sites at Imam Mohammed Road \ Sulaimaniyah Governorate \ Northern Iraq

A detailed engineering geological study was performed for rock slope stability for several selected sites at Imam Mohammed Road that connects Sulaimaniyah city and Darbandikhan town, the study included four sites in which a comprehensive survey was made for the rock slopes, the rocks forming them, and discontinuities affecting in them. The assessment of rock slope stability of the sites was executed through the stereographic projection, to determine the status of the slopes and discontinuities, field measurements revealed many occurred and probable failure types represented by the rock fall and sliding. The rock slopes were also classified based on three factors; divergence angle (parallel, oblique lateral, and orthogonal), Laterality (right and left emergent), and concordance (concordant and discordant). The rocks forming the slopes are described geometrically based on their color, grain size, texture, discontinuities, weathering, rock strength, lithology, and permeability. On the other hand, the risk of each site was also assessed depending on the Landslide Possibility Index (LPI), which showed that the first site lies within the (moderate hazard) category whereas the others lie within the (High hazard) category. Finally, some treatment strategies were proposed in order to stabilize the slopes and decrease the danger of their collapse on the road.