Environmental Protection Agency Research Articles

Qualitative and quantitative water investigation of Erin-Ijesha (Olumirin) Waterfall, Erin-Ijesha, Nigeria

This study focused on the assessment of water quality in Erin-Ijesha (Olumirin) Waterfall, a prominent natural attraction in southwestern Nigeria. The physiochemical parameters, heavy metal concentrations, and bacteriological characteristics were examined in the upstream, midstream, and downstream sections, to ensure the resource quality and safety from harm. The results revealed notable variations in water quality. The pH, Total Dissolved Solids, Electrical Conductivity, and Temperature were highest in the midstream while Total Hardness, Alkalinity, salinity, Chloride, sulphate, Phosphate, Nitrate, Calcium, and Magnesium were highest in the downstream section. The physicochemical parameters were within the acceptable limits of World Health Organization (WHO), United States Environmental Protection Agency (USEPA), and the Standard Organization of Nigeria (SON) standards, except the pH, temperature, and Total Hardness were higher than the acceptable limits of 6.5–8.5, <25 °C or >50 °C and 50 mg/L in all the sections. Iron was above the WHO, USEPA, and SON permissible limits of 3.0 mg/L in all the sections of the river while there was no indication of copper, lead, and cadmium. Bacterial contamination, particularly the presence of E. coli, exceeded recommended safety thresholds. The Total Bacterial Count (TBC) exceeded safety limits by 0.1 million cfu/mL in the downstream. The mean of the parameters was higher in some instances, and sometimes lower than the values in the various sections of the river. A significant relationship existed between most physical, chemical, and bacteriological parameters at p < 0.01. The appraisal of water quality in Olumirin Waterfalls emphasizes the need for proactive measures to ensure water safety, preserve ecosystems, and promote responsible water resource management.

Agricultural-Derived organochlorine pesticide residues impact on macroinvertebrate community in an Afrotropical Stream

This study evaluated the impact of pesticide application through agricultural activities in Chanchaga River, Nigeria, using macroinvertebrate data sets obtained for six months (September 2021–February 2022). Four (4) stations, characterized by various agricultural activities, were sampled along the river. Analysis of the water samples for organochlorine pesticide residues (OCP) using Gas Chromatography-Mass Spectrometry (GC/MS) at the peak of the two seasons revealed a high concentration of eleven isomers of organochlorine, which ranged from 0.01 to 0.81 μg/L, and a mean concentration that was above international drinking water standards set by the World Health Organization, the Federal Environmental Protection Agency, and the European Union. The mean concentration of detected OCP was recorded as DDT (0.72 μg/L), Dieldrin (0.59 μg/L), Paraquat (0.54 μg/L), Aldrin (0.49 μg/L), Metribuzin (0.48 μg/L), Butachlor (0.47 μg/L), Alachlor (0.28 μg/L), Atrazine (0.23 μg/L), Phenol (0.10 μg/L), Endrin (0.09 μg/L), and Benzene (0.08 μg/L). Atrazine, alachlor, metribuzin, aldrin, phenol, and endrin showed significant differences across the two seasons (p < 0.05), while dieldrin, butachlor, paraquat, benzene, and DDT showed no significant differences across the two seasons (p > 0.05). A total of 622 macroinvertebrate individuals from 19 species in 18 families from 8 orders were collected. More individuals were collected during the dry season (58.17 %) and the wet season (41.83 %). Canonical Correspondence Analysis (CCA) ordination revealed a strong relationship between species abundance and some organochlorine pesticide residues such as DDT, endrin, metribuzin, atrazine, benzene, and dieldrin. The response of macroinvertebrates to OCP indicates that Chanchaga River is a disturbed river, and the indicator organisms (Lestes sp., Coenagrion sp., Zyxomma sp., Appasus sp., Chironomus sp., Lymnaea natalensis, and Caridina nililotica) can also be used for further biomonitoring.

Exploring spatial and temporal symptoms of the freshwater salinization syndrome in a rural to urban watershed

The freshwater salinization syndrome (FSS), a concomitant watershed-scale increase in salinity, alkalinity, and major-cation and trace-metal concentrations, over recent decades, has been described for major rivers draining extensive urban areas, yet few studies have evaluated temporal and spatial FSS variations, or causal factors, at the subwatershed scale in mixed-use landscapes. This study examines the potential influence of land-use practices and wastewater treatment plant (WWTP) effluent on the export of major ions and trace metals from the mixed-use East Branch Brandywine Creek watershed in southeastern Pennsylvania, during the 2019 water year. Separate analysis of baseflow and stormflow subsets revealed similar correlations among land-use characteristics and streamwater chemistry. Positive associations between percent impervious surface cover, which ranged from 1.26 % to 21.9 % for the 13 sites sampled, and concentrations of Ca2+, Mg2+, Na+, and Cl− are consistent with road-salt driven reverse cation exchange and weathering of the built environment. The relative volume of upstream WWTP was correlated with Cu and Zn, which may be derived in part from corroded water-conveyance infrastructure; chloride to sulfate mass ratios (CSMR) ranged from ~6.3 to ~7.7× the 0.5 threshold indicating serious corrosivity potential. Observed exceedances of U.S. Environmental Protection Agency Na+ and Cl− drinking water and aquatic life criteria occurred in winter months. Finally, correlations between percent cultivated cropland and As and Pb concentrations may be explained by the persistence of agricultural pesticides that had been used historically. Study results contribute to the understanding of FSS solute origin, fate, and transport in mixed-use watersheds, particularly those in road salt-affected regions. Study results also emphasize the complexity of trace-metal source attribution and explore the potential for FSS solutes to affect human health, aquatic life, and infrastructure.

A New Chemical Inhibitor to Mitigate Swelling of Sodium and Calcium Bentonite during Drilling Process

Clay swelling during drilling operations is one of the challenges faced in the oil industry. While both oil-based and syntheticbased muds have been successful at reducing clay swelling, the environmental concerns of oil-based muds and the high cost of synthetic-based muds limit their usage. Commercial water-based inhibitors like sodium chloride (NaCl), potassium chloride (KCl), cesium formate (CHCsO2), ammonium chloride (NH4Cl), and tetramethylammonium chloride (C4H12NCl-) are commonly used. However, some inhibitors have limitations, such as the toxicity of KCl, which according to the Environmental Protection Agency, cannot be used at concentrations higher than 5%. Other limitations include their impact on the rheology of drilling mud, cost (CHCsO2, C4H12NCl-), and their limited behaviour at high temperatures and pressures (NaCl). In this study, novel clay inhibitors for water-based drilling muds were characterized. A capillary suction timer (CST), a filtration time test, energy dispersive spectroscopy (EDS), and a scanning electron microscope (SEM) were used for the experiments. Testing was conducted on Na and Ca bentonite mixed with water-based drilling mud (WBDM) and commercial inhibitors, as well as novel inhibitors at 3%, 4%, and 5% concentrations.

Chlorine levels and a Legionella outbreak

Background: Legionella, first identified in the 1970s, is increasingly recognized as an opportunistic pathogen in healthcare facilities.1 The National University Hospital (NUH) is a large quaternary level academic hospital with 1,200 beds located in equatorial Singapore. Its first building, completed in 1985, still serves patients today. In 2022, the infection prevention team (IPT) was informed of two cases of nosocomial legionella, which sparked the start of an extensive investigation consisting of water quality testing of multiple sources, case finding, and formation of a water management committee. Methods: 250mL water samples were collected and cultured by an external vendor using direct membrane filtration followed by plating on selective agar according to ISO 11731 standards. Bacterial colonies were then identified, quantified and speciated. At the same time, NUH’s facility management measured chlorine levels using a portable colorimeter. Results: In total, we cultured 34 samples taken from sinks, shower heads, potable water dispensers. 91.2% of samples were positive for legionella. Of the 91.2%, 35.3% of sites grew Legionella pneumophila serogroup 1 while 79.4% of sites grew Legionella pneumophila serogroup 2-15. We attributed our high rates of legionella positivity to an aging plumbing system and Singapore’s high humidity and temperatures. In addition, the maximal temperature of our hot water is only 48-50 °C. Although chlorine levels were generally low, they were still within the local recommendation of less than 2ppm (Singapore does not have guidance on minimum chlorine levels). We found no statistically significant correlation between the number of legionella colony forming units (CFUs) and chlorine levels (ranging between 0.02 to 0.14ppm). This supports the United States Environmental Protection Agency’s recommendation, as well as the findings from in vitro and in vivo studies, for a minimal chlorine of 0.2 PPM at the taps for acute care hospitals.2,3However, these levels may be inadequate in the presence of acanthamoeba or a high biofilm load within water systems.4,5 Conclusion: Hospital water management programs should require a minimal level of chlorine at hospital taps and at levels above those recommended by public water systems, in order to control legionella growth. In addition, the formation of a hospital water management committee is essential to improve hospital water quality and put mitigation measures in place.

Spatial distribution of physicochemical parameters and drinking and irrigation water quality indices in the Jhelum River, Pakistan.

Sustainable management of river systems is a serious concern, requiring vigilant monitoring of water contamination levels that could potentially threaten the ecological community. This study focused on the evaluation of water quality in the Jhelum River (JR), Azad Jammu and Kashmir, and northern Punjab, Pakistan. To achieve this, 60 water samples were collected from various points within the JR Basin (JRB) and subjected to a comprehensive analysis of their physicochemical parameters. The study findings indicated that the concentrations of physicochemical parameters in the JRB water remained within safety thresholds for both drinking and irrigation water, as established by the World Health Organization and Pakistan Environmental Protection Agency. These physicochemical parameters refer to various chemical and physical characteristics of the water that can have implications for both human health (drinking water) and agricultural practices (irrigation water). The spatial variations throughout the river course distinguished between the upstream, midstream, and downstream sections. Specifically, the downstream section exhibited significantly higher values for physicochemical parameters and a broader range, highlighting a substantial decline in its quality. Significant disparities in mean values and ranges were evident, particularly in the case of nitrates and total dissolved solids, when the downstream section was compared with its upstream and midstream counterparts. These variations indicated a deteriorating downstream water quality profile, which is likely attributable to a combination of geological and anthropogenic influences. Despite the observed deterioration in the downstream water quality, this study underscores that the JRB within the upper Indus Basin remains safe and suitable for domestic and agricultural purposes. The JRB was evaluated for various irrigation water quality indices. The principal component analysis conducted in this study revealed distinct covariance patterns among water quality variables, with the first five components explaining approximately 79% of the total variance. Recommending the continued utilization of the JRB for irrigation, we advocate for the preservation and enhancement of water quality in the downstream regions.

Utilizing Microbial Fuel Cells For Simultaneous Treatment Of Solid Waste Water And Energy Generation

The proposed biocatalyst utilized in the microbial fuel cell (MFC) experiment demonstrated exo-electrogenic activity, with species such as Mycobacterium and Shewanella (Pseudomonas) sourced from sewer wastewater. Chemical parameters from the initial experimental trial did not comply with Environmental Protection Agency (EPA) limits. The total suspended solids (TSS) in the second MFC trial were the only parameter to meet the EPA threshold of 50 ppm, with influent and effluent concentrations of 96 ppm and 23.1 ppm, respectively. Consequently, supplementary treatment methods are required to achieve EPA discharge standards. The second trial indicated that the MFC setup effectively reduced metal concentrations, including Cr, Mn, Pb, and Zn, to levels that satisfy EPA surface water effluent discharge criteria. Keywords: microbial fuel cell, anode chamber, cathode chamber, wastewater, energy generation. Aims Research Journal Reference Format: Adeniyi O. A., Bakri A.J., Samuel O. Fadipe, Shakirat B. A., Adebayo O.C. &amp; Oyetunde R.A. (2024): Utilizing Microbial Fuel Cells For Simultaneous Treatment Of Solid Waste Water And Energy Generationelta. Advances in Multidisciplinary and Scientific Research Journal Vol. 10. No. 2. Pp 55-69. www.isteams.net/aimsjournal. dx.doi.org/10.22624/AIMS/V10N2P6

Analysis of Total Microcystins using LC-MS/MS: Assessment of Pretreatment Technique for MMPB(2-methyl-3-methoxy-4-phenylbutyric acid)

Algal toxin analysis, particularly for microcystin (MC) variants, is commonly performed using LC-MS/MS as the standard method. In 2016, the environmental protection agency (EPA) published method 546 for the determination of total MCs by ELISA. However, the limited availability of commercial algal toxin standards limits the efficacy of the LC-MS/MS method. This study proposes a novel approach using the 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) structure generated by oxidizing MCs with potassium permanganate and sodium periodate. MMPB is formed through the oxidation of the common (all-S,all-E)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (ADDA) structure, eliminating the need for specific standard materials for each MC variant. This provides a method for measuring the total MCs. This study focused on optimizing sample pretreatment before oxidation, salt removal as a post-oxidation step, and the quantitative method to establish a comprehensive total MC detection approach applicable to surface water samples. The whole process included pretreatment using a freeze-drying method, purification using liquid-liquid extraction (LLE) for salt removal, and a comparison of quantitative methods using internal standards. Additionally, an evaluation of internal standards was conducted to assess availability during the oxidation process. In this study, an MMPB recovery rate of up to 50% was achieved, with an analysis precision of 14%. According to the results of QAQC, the satisfactory linearity of the calibration curve was a precision and the performance of the method for spiked samples was verified. The MMPB analysis method developed in this study showed relatively lower quantification limits and recovery rates than individual MC analysis methods. We believe these results stem from the inherent sensitivity differences between MCs and MMPB, as well as the complexity of the pre-treatment process centered around the oxidation process.

Per- and polyfluoroalkyl substances (PFAS) in paired tap water and house dust from United States homes

Most people in the United States have been exposed to per- and polyfluoroalkyl substances (PFAS) which have been linked to a wide array of adverse health conditions in adults and children. The consumption of contaminated drinking water is an important human exposure pathway to PFAS. Residential sources also contribute to PFAS exposure through dermal contact and ingestion of house dust, which acts as an aggregate of chemicals from sources like furnishing materials and consumer products. The U.S. Department of Housing and Urban Development (HUD) conducted the first nationwide survey of residential hazards called the American Healthy Homes Survey (AHHS) in 2005, followed by a second survey (AHHS II) in 2017. The U.S. Environmental Protection Agency (EPA) collaborated with HUD on both efforts and subsequently analyzed PFAS in household tap water and house dust collected from the same homes during the AHHS II study. This study leverages these paired samples to investigate potentially important exposure sources and pathways in the residential environment. Here we report results for paired household tap water and house dust samples from 241 homes for 13 and 16 PFAS chemicals, respectively. All 13 targeted chemicals were detected in the household tap water samples with detections ranging from 100 % for PFBS to 1 % for PFNS, and all 16 targeted chemicals were detected in the house dust samples with detections ranging from 97 % for PFOA to 9 % for PFNS. Four chemicals (PFOA, PFOS, PFHxS, and PFHpA) were measured above the limit of detection in at least 50 % of the samples in both media. All households had at least one of the targeted PFAS detected in both their tap water and house dust. Results provided evidence that geographical factors, such as proximity to ambient contamination sources, were main drivers of PFAS contamination in tap water, while PFAS contamination in house dust was driven mainly by within-home sources. Exposure estimates calculated from the measured PFAS concentrations highlight the importance of addressing potential sources of exposure to PFAS within homes in addition to ambient sources affecting communities’ drinking water, particularly to reduce children’s exposure to these chemicals.

Assessment of metals and other trace elements in the drinking water along River Indus, Allai and Nagar

Trace element contamination in water is a global issue due to its widespread occurrence and health effects. Regular intake of elevated metal levels in drinking water can unequivocally cause several types of cancers. This study was primarily focused to assess the quality of drinking water in Allai, Nagar and along River Indus. So for this study a total of 64 spring, 14 waterfall and 7 glacier water samples were collected. Additionally, 13 sediment samples were also collected from Allai and Nagar which were located in the vicinity of mountainous River Indus, Pakistan. The samples were tested for arsenic, calcium, chromium, copper, iron, lead, magnesium, potassium, sodium and zinc using inductively coupled plasma optical emission spectroscopy so as to get the elemental concentrations in parts per billion. The range of metals and other trace elements were compared with the guidelines of World Health Organization (WHO) and the standards laid down by Environmental Protection Agency of Pakistan. The results revealed the (minimum-maximum) concentrations (µg/L) of drinking water quality parameters as follows: arsenic 0-0.06, calcium 1.74-176.87, chromium 0-0, copper 0-0, iron 0-0.25, sodium 1.27-292, potassium 0-24.01, magnesium 0.05-120.22, lead 0-0 and zinc 0-0. Moreover, the (minimum-maximum) concentrations (µg/L) of sediment samples were recorded as arsenic 0-0. 88, calcium 42.98-2068, chromium 0.16-0.65, copper 0.12-1.76, iron 166-544, sodium 8.99-15.36, potassium 35.57-247, magnesium 47.14-453, lead 0-0.23 and zinc 0.67-1.66. The study concluded that all the samples collected from the vicinity of River Indus had elemental concentrations within the recommended guidelines set by the National Drinking Water Quality Standards of Pakistan and WHO. Furthermore, a detailed study encompassing samples from the springs, glaciers, waterfalls and lakes is recommended to evaluate the possible trace element contamination either due to deposition or mixing of metal bearing rocks with water both in the low lying and highland areas of Upper Indus Basin. The outcomes of this research can be useful for the concerned authorities of Gilgit Baltistan and Khyber Pakhtunkhwa Province in the provision of safe drinking water to the people living in the vicinity of River Indus, Pakistan.

Annual Effective Dose Estimation from Radon Concentration in Commonly Consumed Bottled Water in Northcentral Nigeria

Radon (222Rn), the heaviest among the noble gas in the periodic table of element, is radioactive nuclide that is naturally available in rocks, soil and water. In this study, a total of ten (10) brands of commonly consumed commercial bottled water in northcentral Nigeria were collected and assigned for their radon concentration using liquid scintillation counter (LSC). The highest radon (222Rn) concentration of 0.073 Bq/l was recorded in C Way bottled water while Mr. V bottled water recorded the lowest 222Rn concentration value of 0.016 Bq/l. These values were below the parametric reference level of 11.1 Bq/l set by United State of America Environmental Protection Agency and lower than the permissible limit of 100 Bq/l by World Health Organization (WHO) and European Union. Computed total annual effective dose due to ingestion and inhalation of waterborne radon recorded the highest mean value of 0.187 μSv/y in C Way Bottled water and lowest value of 0.041 μSv/y in Mr. V bottled water. Mean total annual effective dose recorded for all the bottled water samples were found to be significantly lower than the safety limit of 0.1 mSv/y recommended by WHO. The likelihood of any radiation incidence among the public due to consumption of commercial bottled water is therefore negligible.

Quality evaluation and health risk assessment of karst groundwater in Southwest China

Groundwater in karst regions is of immense value due to its vital support for regional ecosystems and residents' livelihoods. However, it is simultaneously threatened by multi-source pollution from agricultural non-point sources, industrial and domestic point sources, and mining activities. This study focuses on the Guangxi of China, which features typical karst topography, aiming to thoroughly assess the groundwater quality and related health risks in Guangxi, especially identifying the impacts of various key pollution sources on the groundwater environment. A total of 1912 groundwater samples were collected, covering an area of approximately 237,600 km2. The spatial distribution of pollutants was analysed using the Nemeroww index method and Kriging interpolation, while multivariate statistical and cluster analysis methods were employed to identify the main types of pollution sources. Furthermore, based on the human health risk assessment model of the U.S. Environmental Protection Agency (US EPA), a risk assessment was conducted for key pollutants. The results revealed widespread heavy metal contamination in Guangxi's groundwater, particularly with concentrations of Mn, As, Al, Pb reaching up to 9.4 mg/L, 2.483 mg/L, 37.95 mg/L, 4.761 mg/L, respectively, significantly exceeding China's national Class III groundwater quality standards. Cluster analysis indicated that mining and industrial activities are the primary sources of pollution. The health risk assessment demonstrated that these activities pose a significant risk to public health. The aim of this study is to provide a scientific basis for the protection of the groundwater environment in Guangxi and other karst areas, the formulation of pollution prevention and control strategies, and the optimization of urban and industrial land use layouts. Future research should focus on advanced isotopic and molecular biological techniques to trace pollution sources more precisely and evaluate the effectiveness of pollution control measures.

Impact of Non-Renewable Energy Consumption and Economic Growth on Carbon Emission in Nigeria

The study examines the impact of non-renewable energy consumption and economic growth on carbon emission using an annual data spanning from 1980 to 2022. The Autoregressive Distributed Lag Model was employed. From the analysis, the co-integration results reveal that there is a long-run relationship between the variables under study. Furthermore, both the long-run and short-run Autoregressive Distributed Lag (ARDL) estimates unequivocally demonstrate that both economic growth and the non-renewable energy consumption exert statistically significant, and positive impacts on CO2 emissions. In essence, they jointly contribute to the observed increase in CO2 emissions over the study period. Based on the findings, it is recommended that adequate regulations, restrictions and innovative ways in fostering economic growth through energy consumption from non-renewable energy sources are implemented alongside policies from energy regulatory Commission and environmental protection agencies, to explore avenues to invest in, and promote, carbon-reducing technology in production processes to mitigate against the effects and degradation of the environment.

Environmental management of the water supply of Cidade Universitária Prof. José da Silveira Netto (UFPA) and implementation model for granting water use

This study was carried out in the Prof. José da Silveira Netto University City, on the campus of the Federal University of Pará (UFPA), on the evaluation of the environmental management of water supply and the normative status of models for granting the right to use water resources in the administrative body, the State Secretariat for the Environment and Sustainable Development (SEMAS/PA). The aim of the study is to propose necessary procedures for implementing a project to support good environmental management of urban sanitation systems, based on SEMAS/PA Normative Instruction no. 3 of March 26, 2014. The methodology was developed through documentary/bibliographical research and visits to the competent bodies (SEMAS/PA, CPRM and FEMAC) and technical visits to the sectors of the university city. The studies show that the process of environmental management of water resources and the model for granting water rights need to be improved from the outset. The water resource use on the campus of the Federal University of Pará should meet this requirement and comply with the applicable regulations and any technical conditions proposed by the competent environmental protection agency.

Environmental fate of monosodium methanearsonate (MSMA)-Part 2: Modeling sequestration and transformation.

Monosodium methanearsonate(MSMA), a sodium salt of monomethylarsonic acid (MMA),is a selective contact herbicide used for the control of a broad spectrum of weeds. In water, MSMA dissociates to ions of sodium (Na+) and monomethylarsonate (MMA-)thatis stable and does not transform abiotically. In soils characteristic of MSMA use, several simultaneous processes can occur: (1) microbial methylation of MMA to dimethylarsinic acid (DMA), (2) microbial demethylation of MMA to inorganic arsenic (iAs), (3) methylation of iAs to MMA, and (4) sorption and sequestration of MMA and its metabolites to soil minerals. Sequestered residues are residues that cannot be desorbed from soil in environmental conditions. Sequestration is rapid in the initial several days after MSMA application and continues at a progressively slower rate over time. Once sequestered, MMA and its metabolites are inaccessible to soil microorganisms and cannot be transformed. The rate and extent of the sorption and sequestration as well as the mobility of MMA and its metabolites depend on the local edaphic conditions. In typical MSMA use areas, the variability of the edaphic conditions is constrained. The goal of this research was to estimate the amount of iAs potentially added to drinking water as a result of the use of MSMA, with models and scenarios developed by the US Environmental Protection Agency for pesticide risk assessment. In this project, the estimated drinking water concentrations (EDWCs) for iAs were assessed as the average concentration in the reservoir over a 30-year simulation with annual applications of MSMA at maximum label rates. When the total area of suitable land was assumed to be treated, EDWCs ranged from <0.001 to 0.12 µg/L. When high estimates of actually treated acreage are considered, the EDWCs are below 0.06 µg/L across all scenarios. Integr Environ Assess Manag 2024;20:2076-2087. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Mineralogical insights into anion and cation dissolution behavior in calcium arsenic residue from copper smelting: Implications for safe disposal

This study investigates the dissolution behavior of calcium-arsenic residue (CAR) sourced from a copper smelter in China, crucial for its safe disposal. Using mineralogical analysis, we identified fine powders, medium particles, and varying crystallinity in lumps, with calcium arsenate oxides comprising 56.03 % of the total weight. Arsenic dissolution is predominantly influenced by arsenic-containing mineral phases, with calcium arsenate oxides serving as the primary controlling phase. Other cations, including copper, zinc, calcium, and lead, behave according to their respective mineral phases. At a leaching pH of 3, concentrations of heavy metal ions such as As, Zn, Cu, and Pb exceed permissible limits set by the United States Environmental Protection Agency (USEPA), reaching approximately 3500, 155, 30, and 7.5 mg/L, respectively. The release of fluoride and chloride anions remains consistent throughout the system, largely unaffected by pH variations, at approximately 10 and 200 mg/L, respectively. Additionally, the competitive interaction between SO42- and AsO43- for Ca2+ ions promote SO42- dissolution, leading to morphological changes in gypsum (CaSO4·2 H2O). Under acidic conditions (pH=3), there's an increase in gypsum volume, with SO42- leaching concentration around 1100 mg/L, while under alkaline conditions (pH=12), the SO42- leaching concentration increases to around 4400 mg/L due to the dominance of AsO43-. Kinetic analysis suggests that arsenic release involves a combination of diffusion and interfacial mass transfer. Overall, this study provides valuable insights into the characterization and dissolution behavior of CAR-related minerals, offering comprehensive data support for their safe disposal and landfilling.

Assessment of traffic-related PAH in various environmental components and its associated health risk at a highway Toll Plaza

Introduction: This study investigated Polycyclic Aromatic Hydrocarbon (PAH) emissions from road traffic at the Surathkal toll plaza, in Karnataka, India. It focuses on two phases: when the toll station operated (Phase 1: January 2020 – March 2020) and when it was inactive (Phase 2: January 2023 – March 2023). Materials and methods: The research examines Suspended Particulate Matter (SPM) concentration, its elemental analysis, and various PAH concentrations in it during both phases. Ultrasonic extraction and Gas Chromatography (GC) analysis were used to study 16 priority PAHs recommended by the United States Environmental Protection Agency (US-EPA), identifying eight in samples like SPM, soot, and green leaves. Inductively Coupled Plasma Optical Emission Spectrophotometer (ICPOES) analysed 14 elements in SPM. Results: Results revealed higher PAH concentration during Phase 2, indicating that the presence of toll structure negatively affects air quality even when inactive. In contrast, SPM and its elements had higher mean concentrations during Phase 1, suggesting an inverse relationship between SPM and PAH levels. PAH diagnostic ratios showed different sources for each phase, including gasoline, diesel, fossil fuel, coal/biomass, and pyrogenic sources. Comprehensive health risk assessment using BaP equivalent concentration (BaPeq) to estimate Inhalation Life-time Cancer Risk (ILCR), revealed an Conclusion: This research underscores the toll plaza's significant influence on air quality and calls for the development of mitigation measures.

Spatial Distribution and Health Risk Assessment of Nitrate in Drinking Water: A Case Study in the Central Plateau of Iran

Introduction: This study aimed to determine nitrate levels in water wells supplying drinking water in Taft city, Iran, and assess the associated health risks using the method proposed by the US Environmental Protection Agency. Materials and methods: In 2021, the average annual nitrate levels were determined in 48 drinking water wells which were located in Zone 39 (Taft city). Health risk assessment and sensitivity analysis were conducted to identify the most influential variables. Results: The mean nitrate content in the water wells under study was 32.88 ± 18 mg/L. Out of the 48 examined water wells, 10 had nitrate levels higher than the standard value (50 mg/L) established by the Iranian Institute of Standardization (Standard No. 1053) and WHO. The calculated Hazard Quotient (HQ) for children and adolescents was greater than 1, while it was less than 1 for adults. Nitrate concentration in drinking water was found to be the most important influencing variable in the calculated HQ for children and adolescents. Conclusion: The results indicated that children and adolescents’ health in the studied area is at risk, and appropriate measures must be implemented to avoid and control the exposure of these vulnerable groups; they can be continuous monitoring of nitrate levels using on-site treatment methods where nitrate concentrations exceed the standard level, and decommissioning wells with high nitrate levels.

Leachate analysis of trace metals from e-waste disposed of in landfills and open dumps

Waste electrical and electronic equipment (WEEE, or e-waste) has been largely generated worldwide, but the estimated proportion of WEEE that undergoes the correct disposal is very low. The objective of this study was to evaluate e-waste trace metals in the leachate from disposal of WEEE in soil, using different analytical approaches to determine how these methods may interfere in the results. Different forms of WEEE and MSW landfilling and open dumping were simulated in column reactors to analyse the resultant leachates. Analyses of heavy metals in the leachates were performed in two ways: via inductively coupled plasma-mass-spectrometry with acid digestion of samples, following American Standard 3015A, and via inductively coupled plasma-optical emission spectrometry without acid digestion (US Environmental Protection Agency - USEPA, 2007). Metal concentrations found in the landfill and dumping simulations were similar, but a higher concentration of metals was found in samples with e-waste content, and those undergoing acid digestion prior to ICP analyses. Exceptions were Ba e Zn with a higher concentration without digestion, what may indicate the appearance of matrix effect. Concentrations of Pb, Cu and Mn in the leachates indicate possible interference with MSW. Additionally, it was evident that the timescale of observation influenced the results.

Residential proximity to toxic metal-emitting industrial sites and toenail metal concentrations in a United States-wide prospective cohort

BackgroundIndustrial facilities across the United States (US) release millions of pounds of toxic chemicals, including metals. Exposure to toxic metals has been associated with adverse health outcomes, but there is limited evidence on the association between living near metal-releasing facilities and the body burden of emitted compounds. ObjectiveTo investigate the association between residential proximity to toxic metal-emitting industrial facilities and toenail metal concentrations and to evaluate whether associations differed by race. MethodsIn a sample of 1556 non-Hispanic Black (32.5%) and non-Hispanic White (67.5%) women from the Sister Study, we used the US Environmental Protection Agency Toxics Release Inventory to identify metal-emitting facilities within 3, 5, and 10 km of participants’ baseline residences. We measured toenail concentrations (μg/g) of arsenic, cadmium, cobalt, chromium, and lead. Using multivariable linear regression, we examined associations between residential proximity to and emissions from metal-emitting facilities and toenail metal concentrations, stratifying by race. We explored modification of race-stratified associations by neighborhood deprivation, using the Area Deprivation Index (ADI). ResultsBlack participants were more likely to reside within 3 km of chromium-releasing facilities and 5 and 10 km of all observed metal-emitting sites. Living near metal-releasing facilities was not associated with higher toenail metal concentrations overall. Among Black women, higher chromium emissions exposure was associated with higher toenail chromium levels (βTertile3vs.non-exposed = 2.36 μg/g, 95% CI = 0.63, 4.10). An association with lead was observed among Black women residing in the most deprived areas (≥75th ADI percentile: β = 3.08 μg/g, 95% CI = 1.46, 4.71). No associations were observed for White participants. ConclusionsDespite low exposure prevalence, our findings suggest that living near chromium- and lead-releasing facilities, especially at shorter distances, may be associated with higher corresponding toenail metal levels among Black women, particularly those residing in the most disadvantaged areas.