Remedial Measures Research Articles

Enhancing remediation efficiency of cadmium-contaminated soil: integrating forage-microorganism systems with agronomic strategies.

Soil contamination due to heavy metals, especially cadmium (Cd), poses a growing concern. This study seeks to develop an economical and non-polluting sustainable remediation program for Cd-contaminated soil to address this issue. This study pioneered the exploration of Cd accumulation patterns in three forage species: Lolium multiflorum Lamk (LMJS), Sorghum bicolor × sudanense (SSBJ), and Sorghum sudanense (Piper) Stapf (SUJS) to identify their optimal harvest periods in Cd-contaminated soils. Additionally, a consortium of beneficial microorganisms (combinations of C, F, and H; C: 10% Bacillus subtilis; F: 20% Bacillus subtilis + 10% Bacillus cereus + 20% Citrobacter; H: 20% Deinococcus radiodurans + 10% Bacillus cereus) was implemented, with a focus on developing an efficient forage-microbial co-remediation system. Subsequently, agronomic strategies (mowing or chelating agents) were employed to improve the Cd enrichment capacity of the combined forage-microbe remediation system, offering sustainable field remediation strategies. The results indicate that the SSBJ + F combined remediation system was mowed on the 60th day (stubble left at 35cm, light mowing) and harvested on the 120th day as the optimal choice. The bioaccumulation quantity (BCQ) unit accumulation in Cd-contaminated soil at a concentration of 10mg/kg reached 0.397mg/kg, and the annual Cd removal rate was 9.23%, representing a 29.63% increase compared to the control group. The results of this study provide valuable insights into the development of practical, field-applicable remedial measures for cadmium-contaminated soils while minimizing environmental impacts.

Survey of nutritional intake status in college baseball players.

Diet is closely related to exercise performance. To improve athletes' performance and manage their condition, it is important to get sufficient energy and various nutrients. Thus, it is necessary that athletes understand their nutritional intake status to improve performance and maintain health. This study aimed to explore the nutritional intake status of college baseball players using the Food Frequency Questionnaire (FFQ). Furthermore, the characteristics of their nutritional intake status with respect to athletic performance were evaluated. The result of this studyprovide an opportunity for many under-developed college athletes with irregular lifestyles to recognize and improve their nutritional problems. In October 2022, a questionnaire survey of 116 male members of a college baseball club was conducted. Of whom, 100 (94.3%) members responded to the survey and 92 (92.0%) provided valid responses. The survey items included basic characteristics such as college grade and type of living arrangement, and information on living conditions, e.g. whether the participant ate breakfast. Nutritional intake was evaluated using the FFQ. Players were divided into the first (regular players in official games), second (bench players in official games), third (players who may join the second or higher team in the future), and fourth teams (players who do not belong to the first to third teams); these categories were used as a marker of performance level. The Kruskal-Wallis test was used to analyze the association between the performance levels of baseball players and the intake of each nutrient and food group obtained by the FFQ. For items that showed a significant association, inter-group comparison was performed using the Dunn-Bonferroni method. Carbohydrate intake was greater in the second team compared with the third and fourth teams; saturated and monounsaturated fatty acid intake was higher in the third team compared with the fourth team. Calcium, zinc, copper, manganese, insoluble dietary fiber, iodine, and molybdenum intake was higher in the second team compared with the fourth team. Intake of grains, sugar, dairy, and total energy was significantly higher in the second team compared with the fourth team. However, the protein intake ratio was significantly lower in the second team compared with the fourth team. Overall, energy deficiency and associated deficiencies in protein, fat, and carbohydrate were observed, in addition to dietary fiber and calcium deficiencies. The intake of several food groups appeared inadequate, such as potatoes, beans, vegetables, fruits, eggs, milk, and fats. The study showed deficiencies in the amount of energy and nutrients such as protein, fat, and carbohydrate in college baseball players. Differences in the intake of carbohydrate, calcium, and insoluble dietary fiber among different performance levels were observed, with significantly higher intake of carbohydrate, calcium, and insoluble dietary fiber in the second team. Implementing organized and strategic remedial measures and athletes' identification of nutritional problems are vital to overcome nutritional and energy deficiencies. This study provides useful information for the development of strategies to support nutritional intake in college baseball players.

Assessment and Evaluation of Consumer Awareness and Self-Medication Use Practices Towards Over the Counter (OTC) Analgesics. A Cross-Sectional Study in Abha-Saudi Arabia.

To assess and evaluate consumer awareness and common medication use practices towards OTC analgesics, with a focus on the impact of irrational drug use and its implications for public health and safety. This includes identifying gaps in knowledge, evaluating the potential consequences of misuse, and discussing how these findings can inform future educational initiatives and policy development to promote safer medication practices. This was a cross-sectional, semi-quantitative survey of 750 Saudi volunteers both males and females aged between 18 and 65 years. A validated self-administered questionnaire was used among randomly selected volunteers with a history of OTC analgesic use. A total of 750 questionnaires were administered and the response rate was measured to be 75.6%. More than 50% of the study population used OTC analgesics without a prescription and reported using analgesics as soon as they start experiencing any pain. Paracetamol was found to be the most predominantly used analgesic. The most common indication of OTC analgesic use was reported for headache and toothache whereas irrational use of analgesics in terms of dose, frequency and indication was found to be to the extent of 50%. Primary source of information related to OTC analgesic use was obtained from pharmacy personnel (31.7%), and Patient Insert Leaflets (PIL) (28.7%). Majority of the respondents (64.3%) didn't know the safe maximum dose of Paracetamol, whereas 73.3% used to stop medicine only after experiencing some side effects. 52.4% of the respondents were not aware about the most common side effects, and potential interactions of analgesic medications. Our study highlights the menace of self-medication practices and irrational use of OTC analgesic by the study participants. Immediate remedial measure need to be taken to discourage self-medication and improve rational use of OTC drugs which can be achieved by focusing on improving the consumers' awareness of self-medication and the rational use of medications.

The screening of priority pollutants in the Bohai Sea based on ecological risk assessment.

The Bohai Sea (BS) is a semi-enclosed inland sea and China's most polluted coastal sea. With the rapid economic development of the circum-Bohai Sea region, large amounts of pollutants have been discharged into the BS, posing a significant threat to human health and the ecosystem. Great efforts have been made on investigating the levels of various pollutants in the BS; however, the priority pollutants which are required for the implementation of suitable environmental management and remediation measures in this system remain unclear. By using the risk quotient method, this study evaluated the ecological risks of various pollutants (including antibiotics, heavy metals, total petroleum hydrocarbons (TPHs), endocrine disruptors, pesticides, and persistent organic pollutants) in BS water and sediments over the past twelve years to identify the priority pollutants in this system. The results showed that 8 and 10 pollutants were at risk in BS water and sediments, respectively. Overall, 13 pollutants (arsenic (As), copper (Cu), mercury (Hg), nickel (Ni), chromium (Cr), lead (Pb), zinc (Zn), cadmium (Cd), TPHs, bisphenol A (BPA), erythromycin, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs)) in the BS were identified to have potential risks and should be included in the list of priority pollutants. The monitoring of the changes in the contents of these pollutants in BS water and sediments needs to be strengthened in the future.

Two strains of cadmium (Cd)-resistant bacteria isolated from soils and their ability to promote oilseed rape (Brassica juncea L.) to grow and absorb Cd in soils.

As a highly toxic, mobile, and persistent heavy metal, cadmium (Cd) in soils is becoming a crucial environmental problem. Most of classical physical and chemical remediation measures for Cd-contaminated soils possibly cause some dangers to soil structure and characteristics and potential secondary pollution, however, Cd-resistant microbial which can sequestrate Cd by releasing extracellular polymeric substances (EPS) capable of ion exchange, coordination, and adsorption and improve plant growth should be favorable for remediation of Cd-contaminated soils due to being environmentally friendly and cost-effective. Therefore, the plant-microbe combination is becoming a priority option in the remediation of Cd-contaminated soils. Here, we isolated two strains of Cd-resistant bacteria from soils and investigated the ability of the two strains to promote growth of oilseed rape (Brassica juncea L.) and Cd uptake by the plants. Citrobacter farmeri and Cupriavidus gilardii were isolated from soils via culture media containing 30 and 50mg/L Cd, respectively, which could release EPS including proteins, polysaccharide, and DNA. The EPS from C. gilardii was significantly higher than that from C. farmeri, and the proportion of protein in EPS was the highest for two strains. Additionally, two strains secreted indole-3-acetic acid (IAA) and could solubilize phosphorus, and the ability of C. gilardii to secret IAA was significantly higher than that of C. farmeri. The pot experiment indicated that C. farmeri and C. gilardii significantly enhanced oilseed rape biomass (by 81.99% and 76.57%, respectively), C and N contents, Cd accumulation in plants by 229.03% and 264.63%, respectively, and remediation efficiency at 40 days after emergence (flowering stage). However, the difference in promoting plant growth and Cd uptake and phytoremediation efficiency of Cd-contaminated soils between the two strains was not significant. Overall, C. farmeri and C. gilardii isolated from soils might be promising strains in enhancing phytoremediation of Cd-contaminated soils.

Combining switching mechanism with re-initialization and anomaly detection for resiliency of cyber–physical systems

Cyber–physical systems (CPS) play a pivotal role in numerous critical real-world applications that have stringent requirements for safety. To enhance the CPS resiliency against attacks, redundancy can be integrated in real-time controller implementations by designing strategies that switch among multiple controllers. However, existing switching strategies typically overlook remediation measures for compromised controllers, opting instead to simply exclude them. Such a solution reduces the CPS redundancy since only a subset of controllers are used. To address this gap, this work proposes a multi-controller switching strategy with periodic re-initialization to remove attacks. Controllers that finish re-initialization can be reused by the switching strategy, preserving the CPS redundancy and resiliency. The proposed switching strategy is designed to ensure that at each switching moment, a controller that has just completed re-initialization is available, minimizing the likelihood of compromise. Additionally, the controller’s working period decreases with the number of involved controllers, reducing the controller’s exposure time to attacks. An anomaly detector is used to detect CPS attacks during the controller’s working period. Upon alarm activation, the current control signal is set to a predefined value, and a switch to an alternative controller occurs at the earliest switching moment. Our switching strategy is shown to be still effective even if the anomaly detector fails to detect (stealthy) attacks. The efficacy of our strategy is analyzed through three derived conditions under a proposed integrated attack-defense model for mean-square boundedness of the CPS states. Simulation results on a third-order system and a single-machine infinite-bus (SMIB) system confirm that our approach significantly bolsters CPS resiliency by leveraging the advantages of re-initialization, anomaly detection, and switching mechanisms.

Development and Validation of a Tool to assess the Retention of Clinical Anatomy Knowledge

Introduction: A thorough knowledge in anatomy is essential for the medical student and thereafter for the practicing doctor. Therefore, retention of knowledge acquired during formative years becomes valuable. Knowledge attrition may occur as students move from preclinical years towards clinical training. A tool to measure the level of retention becomes important to assess the level of attrition and apply remedial measures. Methodology: AKRA tool, a MCQ based tool was developed aligned to the learning objectives assessed and edited by opinions of clinicians. The AKRA tool was validated using expert opinion and statistical methods. For statistical assessment, it was administered to 100, 3rd year medical students and 20 recently passed out doctors and the scores calculated. Reliability was assessed using Cronbach alpha, and item discrimination using Pearson correlation. MCQs were graded into poor, marginal, good and excellent based on item discrimination and difficulty indices. Criterion validity was assessed by comparing the AKRA scores with those of an institutional examination. AKRA score was administered to students of two other institutions and scores were compared. Results: AKRA tool consisted of 42 MCQs. The reliability was high (Cronbach Alph = 0.81). The average score for AKRA was 61.78 (SD=12.3) %. The AKRA scores of the students correlated well with anatomy test scores achieved at the institutional examination (r=0.76). Scores between the other institutions did not show a significant difference. Conclusion: AKRA tool is a validated MCQ-based tool to assess the clinical anatomy knowledge in medical students and doctors.

Strata Control by Roof Blasting for Bord and Pillar Mining Method in Mechanized Depillaring Panels

This article discusses the challenges and remedial measures (roof blasting) adopted to deal with extremely difficult cavable roofs while working with Continuous Miner Technology (CMT) in Bord and Pillar mining method. The main objective of the roof blasting in the goaf is to induce caving to minimize the abutment load in and around the working face to prevent incidences of coal bumps, goaf swelling, pillar spalling, and air blasts. It was found that roof blasting is subjected to the nature of local roof falls, results of strata monitoring studies, and the hanging span of roof strata near the line of extraction. Efforts have been made to design different geotechnical elements and structures involved during the mechanized depillaring panel of the Tawa-I mine, using empirical methods to minimize the issues of roof overhang in the goaf. Numerical simulation studies were also performed to validate the design predicted by empirical methods. The Cavability Index indicated that the roof at Tawa-I mine is difficult to cave. To address this, roof blasting design strategies have been discussed to promote caving and minimize roof overhang, ensuring safe and efficient strata control while operating CMT in the challenging and complex geo-mining conditions of the mine.

Compliance with research participant protection guidelines by Nigerian medical journals

BackgroundStakeholders in medical research have roles in ensuring that research participants are protected. Medical journals play gatekeeping roles in the responsible conduct of research. They help guard against the publication of findings of unethical research, such as those with compromised participant welfare. Nigerian medical journals are being created to support the growing number of research enterprises. In this study, we aimed to determine the compliance of Nigerian medical journals with guidelines on research participant protection.MethodsThis was a descriptive cross-sectional study of Nigerian medical journals and articles. We used a checklist to obtain information on journal characteristics and the presence of recommendations from the International Committee of Medical Journal Editors (ICMJE) on the protection of research participants in the journal instructions to authors and articles. The data were analysed via IBM SPSS version 23.ResultsWe studied 40 journals and 350 journal articles. Thirty-one (77.5%) journals required ethical approval and the Declaration of Helsinki statement in their instructions to the authors, while informed consent was present in 26 (65.0%) journals; 6 (15.0%) journals had no participant protection guidelines. Forty-one (11.7%) articles complied with all three recommendations on research participant protection, whereas 60 (17.1%) articles did not. Ethical approval was most common in 268 (76.6%) articles, whereas it was least common in statements on the Declaration of Helsinki in 50 (14.3%) articles. The presence of participant protection recommendations in instructions to authors was not associated with compliance with these recommendations in published articles (p > 0.05).ConclusionAlthough there is fairly good compliance of Nigerian medical journals with research participant protection recommendations, there are still gaps, which highlight the need for remedial measures.

Assessment of heavy metal pollution of surface water through multivariate analysis, HPI and GIS techniques

ABSTRACT Presence of heavy metals in surface metals is the mounting concern in the world due rapid industrialization and modernization of society, and surface water is being utilized both as source and sink for water consumption and wastewater discharge, respectively. The chemometric method were applied on river for pre and post monsoon seasons to determine the potential heavy metals and development of heavy metal pollution index (HPI). The cluster and factor analysis were applied on thirteen heavy metals monitored over eleven locations for characterizing the highly correlating and potential, respectively heavy metals. The proliferation of health risks of heavy metals was determined through cluster analysis and GIS. The Fe and Mn found exceeding the permissible limits in river and drain samples for both the pre-monsoon and post-monsoon season, whereas other heavy metals were found within the permissible limits throughout the study period. The study suggested that classification of pollutants and assessment of associated risk to human health could provide a valuable insight for the development of remediation measures to minimize the degradation of public health and appropriate treatment technology for minimizing the contamination of water sources.

Response Mechanism of Plants to Cadmium Pollution in Soil

Cadmium (Cd), as a widespread heavy metal pollutant in soil, has become one of the globally recognized contaminants due to its high toxicity and bioaccumulative properties. Soil cadmium pollution not only hinders the normal growth of plants but also poses a threat to human health through the food chain. Microbe-plant combined remediation is an essential approach for the treatment of heavy metal contamination in soil. Plants primarily respond to cadmium stress through intrinsic physiological and biochemical adjustments, including inhibiting cadmium absorption, promoting cadmium compartmentalization in vacuoles, and facilitating cadmium efflux from cells. Moreover, plants enhance their tolerance to cadmium through mechanisms such as the regulation of plant hormones. Gene expression regulation is the molecular mechanism underlying plant cadmium tolerance. To date, multiple resistance genes, transcription factors, and microRNAs involved in cadmium tolerance have been identified. Exogenous additives mitigate the effects of cadmium stress on plants by chemical adsorption, enhancing plant cadmium tolerance, and improving the physical and chemical properties of the soil, as well as the structure of soil microbial communities. Investigating the mechanisms by which plants respond to cadmium stress and exploring remediation measures for cadmium pollution will provide a basis for developing effective pollution control and remediation strategies.

Feasibility study for providing remedial measures for overburden dump in new Majri Ug To oc mine, Wcl Majri area, Warora, Chandrapur

Feasibility study for providing remedial measures for overburden dump in new Majri Ug To oc mine, Wcl Majri area, Warora, Chandrapur

Assessment of Depression and Quality of Life among Elderly in a Rural Area of Goa, India

Abstract Background: By 2025, disability-adjusted life years attributable to depression are projected to rise by about 2.6 million (22.5%) due to population growth and aging. Assessing depression and analyzing the quality of life (QoL) among this vulnerable population are vital so that necessary measures to promote healthy aging can be implemented at the community level. Hence, our study was proposed to estimate the prevalence of depression and assess associated factors and QoL among the rural elderly population. Materials and Methods: A cross-sectional study was conducted among the elderly population of a rural area in Goa, India, over 1 year. Data were collected using a semi-structured questionnaire, including sociodemographic details, lifestyle factors, and medical history. Depression and QoL were assessed using the Geriatric Depression Scale-15 and short form-12 scale, respectively. Data were analyzed using SPSS version 22. Results: The total number of participants enrolled in the study was 384, of which majority, 60.2%, were in the age group of 60–69 years. The prevalence of depression in the current study was 29.2%. There was a statistically significant association between depression and the following variables: sex, self-reported insomnia, marital status, presence of major stressors, living arrangement, and physical activity. Among the study participants, 35.2% and 21.6% had low (<50) physical component summary and mental component summary scores, respectively. The association of depression and QoL was found to be statistically significant. Conclusion: Recognizing depressive symptoms among the elderly at an early stage is crucial for managing depression and providing timely remedial measures to improve their QoL.

A case study on risk assessment and novel anchoring technology for potential collapse of high and steep giant dangerous rock mass

Dangerous rock masses in mountainous areas seriously threaten the construction and operation of engineering with potential disaster hazards, especially the unpredictability and sudden occurrence of rockfall, which poses a huge challenge. This paper presents a systematic risk assessment and disposal of high and steep giant dangerous rock masses, which can pose a serious threat to railway operation. Using comprehensive methods such as on-site investigation, limit equilibrium method, and simulation analysis of rockfall trajectory, the possibility and potential harm of collapse and rockfall of giant dangerous rock masses are analyzed and corresponding remediation measures are proposed. Because of the huge size of the dangerous rock mass, the cracks behind the upper part of it are all penetrated; the overturning moment is 500,033.29kN·m, and the safety factor is only 0.744 under the most unfavorable working condition in terms of seismic action. Once the dangerous rock body collapses, most of the rockfalls occur near the tunnel portal and the railway bridge with large velocity and high kinetic energy and jump height. A safe and durable anchoring method of a prestressed anchor cable with double anchoring sections is proposed for in-situ reinforcement of giant dangerous rock masses to prevent the occurrence of collapse and rockfall disasters. The development of this method suggests new ideas and new methods for the reinforcement of similar dangerous rock masses.

Investigating the salinity distribution using field measurements in the semi-arid region of southern Ethiopia

This study investigated the distribution of salinity and sodicity in the irrigated areas of Abaya Chamo. Representative water and soil samples were collected from different soil depths (0–30 cm and 30–60 cm). Sodium absorption ratio (SAR), electrical conductivity (Ec), pH, exchange sodium, magnesium, calcium, and potassium cations, and exchange sodium percentage (ESP) of the sampled sites were analyzed for soil salinity classification and severity analysis. The spatial analysis revealed predominant strongly saline (72%) and sodic (71.1%) conditions in the surface layer (0–30 cm), intensifying very strongly saline (78.7%) and sodic (71.9%) conditions at 30–60 cm depth. Combined saline-sodic conditions dominated both layers, increasing from 91.2% at the surface to 97.1% in the deeper layer, indicating severe agricultural limitations. The results show that soil in the catchments of Lakes Abaya and Chamo suffer from different salinity and sodium content classes. Therefore, appropriate remedial measures based on soil salinity and sodium content should be developed to achieve better reclamation, agricultural production, and land sustainability.

Unlocking Biochar's Potential: Innovative Strategies for Sustainable Remediation of Heavy Metal Stress in Tobacco Plants.

Tobacco, being a globally cultivated crop, holds significant social and economic importance. Tobacco plants are susceptible to the adverse effects of heavy metals (HMs), particularly cadmium (Cd), which hinders root development, disrupts water balance, and impedes nutrient absorption. Higher concentrations of HMs, especially Cd, naturally accumulate in tobacco leaves due to complex interactions within the plant-soil continuum. The uptake of Cd by plants from the soil is influenced by several factors, including soil type, pH, irrigation water quality, and the chemical composition of the metal involved. Different techniques, such as bioremediation, phytoremediation, and mycoremediation, have been employed to tackle the issue of HMs. The use of biochar offers a practical solution to mitigate this problem. With its large surface area and porous nature, biochar can effectively alleviate HMs contamination. Under biochar application, metal adsorption primarily occurs through physical adsorption, where metal ions are trapped within the pores of the biochar. Additionally, electrostatic attraction, in which negatively charged biochar surfaces attract positively charged metal ions, is another major mechanism of metal remediation facilitated by biochar. In this review, we documented, compiled, and interpreted novel and recent information on HMs stress on tobacco plants and explored biochar's role in alleviating HMs toxicity. By providing a comprehensive review of the persistent threat posed by Cd to tobacco crops and exploring biochar's potential as a remediation measure, this work aims to enhance our understanding of HMs stress in tobacco and contribute to the development of sustainable agricultural practices.

Clinical practice guidelines on post-traumatic cognitive impairment: Assessment and remedial measures

Clinical practice guidelines on post-traumatic cognitive impairment: Assessment and remedial measures

A comprehensive analysis of the impact of arsenic, fluoride, and nitrate-nitrite dynamics on groundwater quality and its health implications.

Groundwater contamination is a growing global concern. The objective of the present study is to assess the groundwater quality of Khairpur district, Sindh, Pakistan-a region which is emblematic of broad environmental and public health challenges prevalent in South Asian countries. The study also aims to comprehend the impact of arsenic (As), fluoride (F-), and nitrate (NO3-) dynamics and its health implications. Additionally, this work is vital in shaping the policies of higher authorities to take actions regarding public health. The American Society for Testing and Materials (ASTM) methods and modern analytical techniques, such as Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES), Ion Chromatography (IC), and UV-Vis Spectrophotometry were employed to analyze a series of groundwater samples (n = 50), taken from various locations of Khairpur district. Present study reveals a high occurrence of arsenic (As) with mean concentrations of 26.05 µg/L, and low occurrence of fluoride (0.12-0.59 mg/L) in majority of samples (68 %), hence not according to the safe drinking limits of World Health Organization (WHO). The occurrence of low nitrate (range: 0.53-22.63; mean: 3.36 mg/L) and high nitrite (range: 10.23-30.3; mean: 20.48 mg/L) in 90 and 98 % of total samples respectively suggests that an active reduction process is taking place in the study area. A link was identified between numerous anthropogenic and natural geochemical processes, including As, F-, and NO3- contamination, which are contributing towards this groundwater pollution and significantly affecting the health of pediatric population in terms of skin manifestations like skin irritation, melanosis and keratosis which are early symptoms of skin cancer. Findings of present study emphasizes. Findings of the present study emphasizes an urgent need for remedial measures to mitigate the identified risk and call for a comprehensive plan to monitor and improve the quality of groundwater, in order to ensure the safety and well-being of the vulnerable communities. Our work also highlights the urgent need for environmental health awareness and policy reforms to prevent the long-term health repercussions from compromised groundwater quality.

Groundwater quality and associated health risks in the Eastern Region of Ghana.

In the Eastern Region of Ghana, 95% of residents have access to boreholes. However, approximately 30% of these boreholes are characterized by unpleasurable taste, odour, oily scum and particulate matter. Thus, this study aimed to assess water quality, predict the sources of groundwater contaminants, evaluate the human health risk and to generate spatial distribution and health risk maps. In achieving this, the water quality of 136 boreholes in the region was evaluated through Water Quality Index (WQI) and Groundwater Pollution Index (GPI) analyses. Multivariate statistical procedures, namely, principal component and correlation analyses were employed to define the major groundwater pollutants and their possible sources. Non-carcinogenic health risk to infants, children and adults through nitrates, iron, manganese and fluorides ingestion was also assessed. The results revealed that groundwater in the region is generally slightly acidic with a mean pH of 6.30. WQI analysis grouped 68% of the groundwater samples under the 'excellent' and 'good' water types with the remaining percent categorized under 'poor', 'very poor' and 'unsafe' drinking water types. GPI analysis classified 95%, 2.21% and 2.79% of the boreholes as 'insignificant', 'low' and 'highly' polluted zones. From the multivariate analyses, the dominant pollutants were iron, manganese, chlorides, sodium, fluorides, potassium, turbidity, total suspended and dissolved solids, hardness, alkalinity, sulphates, nitrates and phosphates. The sources of these contaminants are primarily from rock-water interactions and fertilizers. Health risk assessment for nitrates, fluorides, iron and manganese ingestion revealed that 23, 17 and 15 boreholes in the region are likely to pose non-carcinogenic health risk to infants, children and adults respectively. Health risk maps indicated that the most vulnerable districts were Atiwa East, Fanteakwa North, Achiase, Birim South, Akwapim, Suhum and Ayensuano. From these findings, it is imperative that appropriate groundwater remediation measures are implemented in the region to protect public health.

Combining sequential extractions with bulk and micro X-ray spectroscopy to elucidate iron and phosphorus speciation in sediments of an iron-treated peat lake.

In shallow lakes, mobilization of legacy phosphorus (P) from the sediments can be the main cause for persisting eutrophication after reduction of external P input. In-lake remediation measures can be applied to reduce internal P loading and to achieve ecosystem recovery. The eutrophic shallow peat lake Terra Nova (The Netherlands) was treated with iron (Fe) to enhance P retention in the sediment. This treatment, however, intensified seasonal internal P loading. An earlier study suggested that Fe addition led to increased P binding by easily-reducible Fe(III) associated with organic matter (OM), which readily releases P when bottom waters turn hypoxic. In this complementary study, bulk and micro Fe K-edge and P K-edge X-ray absorption spectroscopy and micro-focused X-ray fluorescence spectroscopy were applied to characterize the P hosting Fe(III) pool. Combined with sequential extraction data, the synchrotron X-ray analyses revealed that a continuum of co-precipitates of Fe(III) with calcium, phosphate, manganese and organic carbon within the OM matrix constitutes the reducible Fe(III) pool. The complementary analyses also shed new light on the interpretation of sequential extraction results, demonstrating that pyrite was not quantitatively extracted by nitric acid (HNO3) and that most of the Fe(II) extracted by hydrochloric acid (HCl) originated from phyllosilicate minerals. Formation of an amorphous inorganic-organic co-precipitate upon Fe addition constitutes an effective P sink in the studied peaty sediments. However, the high intrinsic reactivity of this nanoscale co-precipitate and its fine distribution in the OM matrix makes it very susceptible to reductive dissolution, leading to P remobilization under reducing conditions.