Contamination Levels Research Articles

Effect of oil and diesel fuel pollution on enzymatic activity of meadow chernozem-like soil

In the laboratory experiment, the effect of oil pollution on the short-term dynamics of the activity of urease, phosphatase, catalase, peroxidase and polyphenol oxidase of the chernozem soil of the south of the Far East was studied. It was found that when soil was contaminated with oil and petroleum products, urease activity decreased by 20–44% at the end of incubation, peroxidase activity increased by 39–49% in the middle and end of incubation, polyphenol oxidase activity increased 1.6–2.0 times in the middle of incubation. The activity of phosphatase and catalase was stable at different levels of contamination throughout the experiment. Examining the effect of the incubation period, it was found that the maximum activity of urease was on the 10th day, phosphatase – on the 20th, peroxidase – on the 20th and 30th, polyphenol oxidase – on the 30th day of the experiment. Catalase activity was stable throughout all incubation periods. It was shown that in the case of contamination of chernozem-like soil with oil and diesel fuel in doses up to 5000 mg/kg, inhibition of enzymatic activity did not occur in the early stages.

Geochemical Profiles of Deep Sediment Layers from the Kolubara District (Western Serbia): Contamination Status and Associated Risks of Heavy Metals

Global awareness of the harmful effects of heavy metal contamination in soil has increased significantly. Understanding the vertical distribution of oxides and elements is vital for tracing the history of potential contamination. Thus, this study focuses on deep sediment cores primarily composed of quartz and clay minerals from a small village in the western Tamnava Basin of Serbia. The aim was to assess the vertical distribution of 11 oxides and 21 elements and the ecological risks of eight heavy metals by analyzing 250 sediment samples from 18 boreholes at depths ranging from 5 to 58.5 m. Deep sediment core samples were analyzed using energy-dispersive X-ray fluorescence spectrometry (ED-XRF). Potential contamination levels were evaluated within the study area. Additionally, samples were analyzed for total carbonate and organic carbon contents and particles retained on a 0.063 mm sieve. Higher than permitted concentrations of vanadium (V), thallium (Tl), and barium (Ba) were found. Notably, this zone is located above a proposed lithium and boron mine in Gornje Nedeljice, making it crucial for monitoring efforts. Even if mining operations do not commence, examining the deep sediment layers in this rural area remains important. This study offers novel and valuable data on the concentrations of potentially toxic elements in undisturbed deep sediment, serving as a benchmark for future comparisons.

Polymorphism of candidate genes MTNR1B C/G (rs10830963) and TCF7L2 C/T (rs7903146) in children as a risk factor for the development of hepatobiliary system pathology in conditions of contamination of biological media with heavy metals (using lead as an example)

Introduction. Lead impact on health considering likely pathways of its molecular interactions in the body have not been given sufficient attention by researchers. The aim of this study was to assess polymorphism of the MTNR1B C/G (rs10830963) and TCF7L2 C/T (rs7903146) genes in children as a risk factor of hepatobiliary pathology in case of heavy metal contamination in biological media (exemplified by lead). Materials and methods. We examined ninety three 3–6 years children (39 children had hepatobiliary pathology and 54 children were considered healthy) who were exposed to low-dose airborne lead (0.1MPLa.d.), the average daily dose being 0.4 ∙ 10–3 µg/kg ∙ day. We estimated frequency of alleles and genotypes of the candidate genes MTNR1B C/G (rs10830963) and TCF7L2-1 C/T (rs7903146) associated with levels of lead contamination in biological media and hepatobiliary pathology. Results. The children from the observation group were established to have authentically high frequency of the G allele (OR=1.92, CI: 1.04–3.54) and GG genotype (OR=7.80, CI: 1.58–38.51; p<0.05) of the MTNR1B gene, as well as C wild type allele (OR=2.07, CI: 1.02–4.20; p<0.05) and CC genotype (OR=2.42, CI: 1.02–5.70; p<0.05) of the TCF7L2-1 gene, which were risk factors (RR=1.20–1.43) of developing hepatobiliary pathology aggravated by lead contamination in blood. Limitations. Limited sampling, the need to verify the results in further observations. Conclusion. The study established children with hepatobiliary pathology who lived under long-term low-dose exposure to airborne lead at the dose of 0.4 ∙ 10–3 µg/kg ∙ day (0.1MPLa.d.) to have elevated lead levels in blood and impaired biorhythms of smooth muscles in the bile duct combined with the risk (RR=1.20–1.43) of developing hepatobiliary pathology in carriers of G allele (OR=1.92, CI: 1.04–3.54; p<0.05) of the MTNR1B gene as well as C wild type allele (OR=2.07, CI: 1.02–4.20; p<0.05) of the TCF7L2-1 gene.

Influence of Smoking and Paprika Spice on the Content of Polycyclic Aromatic Hydrocarbons (PAHs) in the Traditional Spanish Smoked Sausage ‘Botillo del Bierzo’

The content of polycyclic aromatic hydrocarbons (PAHs) in a traditional Spanish smoked sausage known as ‘Botillo del Bierzo’ was analysed. The determination and quantification of PAH4 (the sum of benzo[a]pyrene, benz[a]anthracene, benzo[b]-fluoranthene and chrysene) in the smoked sausage were performed using GC–MS. The results showed that smoking ‘Botillo del Bierzo’ for 24 h contributes very little to the increase in PAH levels in the product, with no significant differences (p < 0.05). The paprika used in the production of botillo also contributes to PAH content, depending on the paprika’s production process (smoked, low-smoked, mixed paprika (smoked + unsmoked or low-smoked + unsmoked), and unsmoked), with significant differences among them (p < 0.05). Using paprika with a lower PAH content (unsmoked or mixed) enables the production of ‘Botillo del Bierzo’, in accordance with Protected Geographical Indication specifications, with a lower PAH content while maintaining the organoleptic characteristics provided by the paprika. The contamination levels detected in ‘Botillo del Bierzo’ do not pose a risk to consumer health, as the benzo[a]pyrene and PAH4 values are well below the regulatory limits of 5 μg/kg and 30 μg/kg, respectively.

Production of face protectors by 3d printing: distribution of PPE to face the coronavirus

Purpose: The aim of this study is to produce face shields using 3D printing, contributing to the personal protection of healthcare professionals from both public and private health institutions amid the coronavirus pandemic. Theorical framework: At the beginning of the Covid-19 pandemic, it became common for health professionals to report on the scarcity of Personal Protective Equipment (PPE) in their work, which resulted in the high level of contamination of those involved in the front line. The face shield stood out as one of the missing PPEs, important for the health and safety of workers as they offer a physical barrier to contamination by secretions. Methodology/Approach: For this purpose, through the Center for Robotics, Innovation, and Entrepreneurship (CRIE), the prototyping laboratory of the Federal Institute of Minas Gerais campus Governador Valadares (IFMG-GV), different models of face shields were tested. The model that provided the greatest comfort for users was selected, while also requiring less printing time and using less raw material. The production was carried out in accordance with Resolution 356/2020 of the National Health Surveillance Agency (ANVISA), which authorized and decentralized the production of large industries in an extraordinary and temporary manner. Findings: Requirements for the manufacture, importation, and acquisition of medical devices were defined. In total, 223 face shields were produced and donated to the city's healthcare system, serving the Unimed Hospital, the Medical Association, and other local hospitals. Research, practical & social implications: From the action, the IFMG-GV, as a public educational institution, played its role by providing support to local society, influenced by the consequences of the pandemic. Keywords: Covid-19; Face shield printing; 3d printing.

Assessment of bacteriological contamination in coin currency in circulation

: The primary aim of this study was to identify the bacterial contaminants present on Indian currency coins, characterize the different types of bacteria isolated, and assess the antimicrobial resistance patterns of the bacteria within the Nagpur region of Maharashtra, India. Determining the isolation and identification of the various pathogens on coin surfaces is essential for addressing the potential spread of diseases through handling currency.: This cross-sectional study was conducted in the Department of Microbiology at Indira Gandhi Government Medical College & Hospital, Nagpur, spanning from 2015 to 2024. We collected 120 currency coin samples aseptically from individuals across various occupational groups. The culture and antimicrobial susceptibility patterns were analyzed following standard operating procedures.: A total of 50.83% of the coins exhibited bacterial contamination, with . identified as the most frequently isolated organism at 13.33%. The highest levels of contamination were found in lower-value coins. Notably, there was a significant decrease in coin contamination during and after the COVID-19 pandemic, likely due to a rise in online monetary transactions. The isolated bacteria demonstrated strong sensitivity to several antibiotics, including Ampicillin, Amikacin, Gentamicin, Ciprofloxacin, Ceftazidime, Cefotaxime, Doxycycline, and Ceftriaxone.: The present study finds that Indian currency coins often harbor pathogenic bacteria, especially enteropathogens, which play a significant role in the spread of diseases. It is essential to raise public awareness about the importance of maintaining good personal hygiene when handling coins. By practicing proper hand hygiene and adhering to sound sanitary practices, individuals can greatly reduce the risk of infection, particularly those who handle both food and money at the same time.

​Quantitative assessment of heavy metal concentrations, pollution levels, and sources apportionment in one of China's top 10 most livable cities.

Urban topsoil is not only an essential part of the urban ecosystem, but also a powerful carrier of pollutants in the urban environment. In this paper, 130 topsoil samples from urban area of Xinyang in central-eastern China were selected, the aim is to quantitatively investigate the concentrations, pollution levels, and sources apportionment of 8 heavy metals (HMs, encompassing arsenic (As), cobalt (Co), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), vanadium (V), and zinc (Zn)) via geochemical method. The main conclusions are as follows. (1) The eight HMs in the topsoil have been artificially enriched to varying degrees, which are lower than the street dust levels sampled in pairs. (2) Cu, Zn, and Pb were significantly contaminated, and As, Co, Ni, Cr, and V were relatively low levels of contamination. Overall, comprehensive pollution levels were particularly severe, with 30.0%, 39.2%, and 30.8% for slight, moderate, and serious pollution, respectively. (3) Co, Ni, V, and Cr predominantly originated from natural sources, the percentage contribution of which is 6.3%; Pb, As, Cu, and Zn were predominantly derived from traffic-derived sources, with a percentage contribution of 93.7%. Thus, the first-order source of HMs in the topsoil originates from traffic-induced activities, similar to the case of street dust. Our findings can be beneficial in providing local governments with a reference to formulate environmental pollution controls, and also provide a case study for environmental pollution control in the other livable cities in China.

ANÁLISE DA QUALIDADE DE LEITE EM TANQUES DE ORDENHA MECÂNICA, DE ORDENHA MANUAL E TANQUES COMUNITÁRIOS

This study aims to analyze bacterial contamination in milk produced by three different milking systems: manual, mechanical, and community tanks. The research involved collecting milk samples from rural properties in Presidente Médici, focusing on the count of mesophilic aerobic and facultative anaerobic bacteria. The analysis of results showed that the manual milking system had the highest contamination levels due to greater manipulation and the use of simple equipment. On the other hand, the mechanical milking system exhibited an intermediate level of contamination, while community tanks, which generally face challenges regarding hygiene and management, surprisingly showed lower contamination levels than expected. These findings indicate that proper hygiene and management practices are essential to ensure milk quality, regardless of the milking system used. The study emphasizes the importance of training producers and investing in infrastructure to enhance the competitiveness of Brazilian milk in both the domestic and international markets.

Enrichment Characteristics, Risk Evaluation, and Source Apportionment of Heavy Metals in Wabu Lake of Yangtze River to Huaihe River Water Diversion Project

Wabu Lake serves as a crucial junction within the Yangtze River to Huai River Water Diversion Project （Yangtze-Chao Lake-Wabu Lake-Huai River）, where clarifying the status and risk levels of heavy metal contamination in the lake is crucial for the aquatic ecological safety along the route of the project. Surface water and sediment samples from 24 locations in Wabu Lake were collected and analyzed for the contents of heavy metals （As, Zn, Pb, Ni, Cu, Cr, Fe, and Cd）. Risk evaluation and source apportionment of heavy metals in the lake were conducted using the human risk assessment （HRA） model, sediment quality guidelines （SQGs）, and positive matrix factorization （PMF） method. The results showed that the average concentrations of heavy metals （except for Cd and Pb） in the surface water were lower than the class III limits of the surface water quality standard （GB 3838-2002）. The average concentration of heavy metals （As, Zn, Pb, Ni, Cu, Cr, Fe, and Cd） in interstitial water were lower than the Criteria Continuous Concentration （CCC） of the National Recommended Water Quality Criteria. The average contents of As, Zn, Pb, Ni, Cu, Cr, and Cd in the sediment exceeded the background values by factors of 1.78, 1.85, 1.42, 1.77, 1.41, 1.38, and 3.46, respectively. In addition, the heavy metals Pb, Cd, and Cr in the Wabu Lake water posed severe risks to human health, with the cancer risk （CR） value for Cr reaching 6.14×10-5. The sediment quality guidelines （SQGs） indicated that the probability of adverse effects on lakes by As, Ni, and Cr was relatively high. The spatial distribution of risk areas showed that the risk control zones for As, Cr, and Ni in Wabu Lake covered almost the entire lake area. The PMF analysis indicated that the primary sources of heavy metals in Wabu Lake were exogenous inputs from industrial, agricultural, and residential activities in surrounding areas, followed by endogenous pollution caused by enclosed aquaculture. The subsequent focus should be on the pollution of heavy metals Cr, Cd, and Pb in the overlying water of Wabu Lake as well as the sediment ecological safety of As, Cr, and Ni in the sediment.

Temporal and Spatial Distribution and Risk Assessment of Volatile Chlorinated Hydrocarbons in Soils of Typical Industrial Parks in Chongqing Under the “Dual Carbon” Background

ABSTRACT In the context of China’s “Dual Carbon” initiative, controlling volatile compounds (VOCs) in industrial park soils was crucial for pollution control and carbon mitigation efforts. This study examined the distribution and risks of chlorinated hydrocarbons in the soils of Chongqing’s chemical and mechanical industrial parks. Through site surveys, in situ sampling, pollutant extraction and detection, and soil microbial diversity sequencing, we identified a higher pollution risk in chemical parks (detection rate of 18.5%) and compared to mechanical parks (1%). Surface soils exhibited greater pollutant concentrations (11.8%) than deeper soils (8.8%), with higher contamination levels in winter (27.8%) than in summer (9.3%). Microbial diversity analysis revealed richer microbial communities in summer, suggesting their role in the natural degradation of pollutants, with Proteobacteria dominating but remaining largely functionally uncharacterized. Trichloroethylene and tetrachloroethylene were the primary detected pollutants, though at concentrations below regulatory thresholds. These findings provided crucial data for refining carbon emission policies and environmental management strategies in industrial parks under the “Dual Carbon” framework.

The role of habitat preference and feeding strategy on exposure to microplastic pollution in freshwater fish species.

Microplastic (MP) pollution has been observed in a variety of ecosystems, but there is a limited number of studies on reservoir ecosystems. The aim of this study was to determine the levels of MP contamination in sediment, water and commercially important fish species (Cyprinus carpio, Perca fluviatilis, Atherina boyeri and Sander lucioperca) collected from the Yamula Reservoir in Türkiye. Water samples were collected at five stations. Four sediment samples were collected from the lake. As sediments from the lake represent a vital element of the lake ecosystem, they function as a historical archive that reflects alterations in land use and the characteristics of the lake over time. The average amounts of MPs observed in sediment and water samples were 0.12 MP/g and 0.58 MP/m3 respectively. The digestive systems of 30 individuals of each fish species were examined. The highest amount of MP was observed for C. carpio (6 ± 5.9 MP/individual), while the lowest amount of MP was observed for A. boyeri (1.8 ± 1.7 MP/individual). MP abundance in S. lucioperca and P. fluviatilis was 2 ± 2.8 and 4.6 ± 6.3 MP per individual. The most commonly observed polymer types were polypropylene (67%), polyvinyl alcohol (13%), polyethylene resin (13%) and high-density polyethylene (7%). The pollution load indexes determined for each fish species from the highest to the lowest were as follows: 1.83 (C. carpio) 1.6 (S. lucioperca) 1.05 (P. fluviatilis) and, 1 (A. boyeri). The findings of the study indicate that all sampling stations, including both sediment and water, are contaminated with MPs. Furthermore, the results demonstrate that all examined fish species ingest MPs. Additionally, the results indicate that fish inhabiting a wide range of habitats and consuming diverse diets are more susceptible to MP contamination.

Equity Assessment of Groundwater Vulnerability and Risk in Drinking Water Supplies in Arid Regions

Groundwater is a vital drinking water source, especially in arid regions, sustaining both urban and rural populations. Its quality is influenced by natural (hydrogeological) and human-driven (demographic, policy) factors, which may pose significant public health risks, especially for communities relying on unregulated water supplies. This study addresses critical gaps by examining groundwater vulnerability and contamination disparities, emphasizing their implications for public health and equitable resource management. It analyzes the impact of socio-hydrogeological factors on arsenic and nitrate levels in groundwater-supplied systems in Arizona, U.S. Methods include spatial analysis, ANOVA, multivariate regression, and cluster analysis. Significant disparities in arsenic and nitrate contamination, including exceedances of regulatory limits, were observed across supply types, aquifer characteristics, jurisdictional oversights, and groundwater management areas. Domestic wells and community water systems showed distinct contamination risks. Groundwater vulnerability was influenced by geological differences (karst vs. alluvial aquifers) and regulatory oversight, with Tribal and State systems facing unique challenges and resource needs. Socioeconomic disparities were evident, with minority communities, institutional facilities, rural areas, and specific housing types disproportionately exposed to higher contaminant levels. These findings unveil the intersection of race, socioeconomic status, and public health risks, offering an adaptable framework for addressing similar groundwater challenges in arid and semi-arid regions globally. This study is innovative in its focus on policy distinctions between private and regulated wells, karst and alluvial aquifers, and State and Tribal jurisdictions. It emphasizes the need for targeted vulnerability assessments and remediation strategies that integrate geological, hydrological, and regulatory factors to address risk disparities in vulnerable communities. These environmental inequities underscore the urgent need for stronger regulations and strategic resource allocation to support marginalized communities. The study recommends enhancing monitoring protocols, prioritizing resource distribution, and implementing targeted policy interventions to ensure equitable and sustainable access to safe drinking water in arid regions.

Geographical disparities in cancer and occupational exposure to pesticides in a French-West Indies territory (2006–2019)

BackgroundIn the French West Indies, previous studies have reported findings on pesticide exposure and cancer incidence. A new exploratory geographical study, including a more sensitive soil contamination indicator, will provide more detailed information on the link between cancer incidence and organochlorine pesticide exposure. This study aims to investigate the association between incident cases of cancer and chlordecone soil contamination at an IRIS scale over the period 2006–2019 in Martinique.MethodsData on the 18 most frequent cancer sites were collected from the Martinique Population Based Cancer Registry. First, smoothed standardized incidence ratios at the level of the 141 IRIS were estimated, and then regression models including the smoothed standardized ratios were performed between cancer incidence and soil contamination index by sex and cancer site, using the Besag, York and Mollié models. Models were adjusted using an index of social deprivation. Results23,218 cancer cases were eligible for this study, with 21,920 cases included in the final analysis. Soil contamination was associated with a higher relative risk of cancer in women than in men, but no significant correlation was found for breast cancer in women or for prostate cancer. Lung, thyroid, stomach and rectal cancers in women, and melanoma in men, all increase significantly with the level of contamination. There was a significant increasing gradient in the incidence of multiple myeloma in men, from reference to highly contaminated areas.ConclusionIntegrating the latest available data on soil contamination and cancer incidence will extend on-going knowledge of chlordecone exposure and cancer incidence, which remains a major environmental concern in Martinique. Unexpectedly, our results show that the female population of Martinique is the most affected by chlordecone soil contamination.

Assessment of mycotoxins in infant flour and their decontamination in raw material during production processes in Ouagadougou.

The infant flours produced in Burkina Faso are essentially a mixture of cereals and legumes. These raw materials are frequently contaminated with mycotoxins which pose a huge food safety and public health threat. The objective of this study was to determine mycotoxin levels in raw materials and infant flours in Ouagadougou and to investigate the impact of decontamination on the raw materials used in infant flour production. A total of 22 cereals and 17 legumes as raw materials and 26 infant flour samples were analysed for aflatoxins, fumonisin B1 (FB1), and ochratoxin A (OTA) by liquid chromatography coupled to tandem mass spectrometry, while saline treatment and hand-sorting of grains in mycotoxin reduction were tested. All the samples of raw materials and infant flours were contaminated with aflatoxins, whereas 20.5% and 38.5% of raw materials and 57.7% and 61.5% of infant flours, respectively, were contaminated by FB1 and OTA. These decontamination assays significantly reduced the levels of mycotoxins. AFB1 was reduced by 48% after soaking of maize for 6h in a 6% NaCl solution. Sorting resulted in a 92% reduction in AFB1 content in peanut. However, soaking in saline solution did not reduce the FB1 and OTA contents. Sorting did not also reduce FB1 contents in peanut. Sorting and soaking in 6% saline solution for 6h are production processes that lead to a reduction in the level of contamination by aflatoxins in maize and peanut used as raw materials for infant flour production.

Delayed environmental pollution caused by transient landscape storage - An example from the Lesser Antilles.

The strong pest pressure on intensive banana cultivation in the French West Indies led to the intensive use of chlordecone (an organochlorine insecticide) between 1972 and 1993. Due to its high toxicity for the population and the environment, many studies were conducted on the transfer of chlordecone over the last 20 years. However, most studies focused on the dissolved fraction of chlordecone, while the particle-bound fraction was understudied. Therefore, this study reconstructs pluri-decadal erosion rates (i.e. 1980-2023) and associated chlordecone particle-bound transfers from soil and sediment cores sampled in a cultivated headwater catchment (Saint-Esprit, Martinique). Based on sediment accumulation analysis in an agricultural reservoir, high erosion rates (i.e. 10 t ha-1 yr-1) were found in the investigated catchment during the study period, with values exceeding the estimated tolerable soil loss rate in tropical context (i.e. 2.2 t ha-1 yr-1). Based on the analysis of soil cores sampled along a banana plantation hillslope, this study highlights the formation of colluvial deposits with high levels of chlordecone contamination. When these areas are affected by erosion processes, this leads to massive remobilization of particle-bound chlordecone to water bodies. Indeed, in sediment sampled in the downstream reservoir, we observed a drastic increase in these transfers since 2006, synchronous with changes in agricultural practices. This study therefore highlighted the occurrence of legacy contamination at toeslope positions, which was estimated to potentially persist for 4000 to 11,000 years. Such a residence time highlights the need to implement changes in land management to effectively reduce agricultural soils erosion, particularly in areas identified as "temporary deposition zones" for chlordecone contamination, in order to protect downstream water bodies from chlordecone transfer. To achieve this, agricultural practices that may increase soil erosion, such as herbicide application or intensive ploughing, should be minimized. Overall, this study improved our understanding of erosion and associated chlordecone transfers in tropical environments.

Assessment of Carcinogenic and non-carcinogenic risk indices of heavy metal exposure in different age groups using Monte Carlo Simulation Approach

Dermal contact, ingestion and inhalation of heavy metal poses significant health risk in human subjects. The exposure could be via potable water, soil or air. The current experiment design focuses on soil media and exposure. Advanced probabilistic and geospatial methods are used in this study which evaluates contamination levels and health risks associated with iron (Fe), arsenic (As), zinc (Zn), copper (Cu), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd) in soil samples. The samples were collected and analysed using ICP-OES after tri-acid digestion, and indices such as Geoaccumulation Index (Igeo), Contamination Factor (CF), Pollution Load Index (PLI), Hazard Quotient (HQ), Hazard Index (HI), and Carcinogenic Risk (CR) were used to assess environmental impacts and health risks across the age groups via oral ingestion, inhalation and dermal contact. The current study indicates heavy metal concentrations follow the order Ni > Zn > Pb > Cu > Cr > As > Cd, with more than 60% of samples demonstrating significant pollution levels. The computational method used in the study revealed substantial non carcinogenic risk (HQ > 1) and carcinogenic risk (33%) in the population related to As exposure. Geospatial analysis and Monte Carlo simulations helped in identifying the hotspots in the tropical coastal area emphasizing need for targeted remediation focusing on As and Pb.

Modeling and predicting caffeine contamination in surface waters using artificial intelligence and standard statistical methods.

Caffeine, considered an emerging contaminant, serves as an indicator of anthropic influence on water resources. This research employs various modeling techniques, including Artificial Neural Networks (ANN), Random Forest (RF), and more, along with hybrid and ensemble methods, to predict caffeine concentrations (in regression and classification scenarios) using readily available water quality parameters. The results indicate Ensemble-RF as the most effective method for estimating caffeine concentrations, while classification scenarios highlight Ensemble-RF, ANN, and Ensemble-ANN as promising methodologies for predicting contamination levels. This study offers a valuable tool for swiftly assessing caffeine contamination in water, leveraging easily obtainable data, with implications for safeguarding water resource systems.

Assessing the Interrelationship Between Microplastics and Polychlorinated Biphenyls Contamination in Chinese Mangrove Sediment

Mangrove ecosystems, critical intertidal zones at the land–ocean interface, are increasingly recognized for their role in microplastic (MP) pollution dynamics. Despite extensive research on the interaction of MPs with various chemical contaminants, the specific contamination levels of polychlorinated biphenyls (PCBs) associated with MPs in mangroves remain poorly understood. In this study, we quantified the concentrations of PCBs on MPs extracted from representative mangrove sediment samples across China, revealing values ranging from 9.80 to 13.91 ng/g. In contrast, PCB concentrations in sediment samples were found to vary between 25.67 and 69.85 ng/g. Our findings indicate a consistent level of PCB contamination on MPs across different sites, although these levels were marginally elevated compared to those in the surrounding sediments. Notably, Penta-PCBs were detected with the highest frequency across all samples analyzed. This study provides crucial insights into the occurrence and distribution of PCBs on MPs within the mangrove ecosystem, highlighting their significance in environmental contamination assessments.

The Influence of Iron Particle Contamination on the Breakdown Characteristics of Circulating Mineral Oil under DC Voltage

The presence of metallic particles can lead to the degradation of transformer oil due to the intensification of the electric fields near the conductive components. The primary objective of this research was to investigate the impact of iron impurities on the electrical properties of Mineral Oil (MO), particularly under conditions of continuous flow. Five distinct samples with varying levels of contaminants were carefully prepared for analysis. A specialized chamber was designed to replicate the circulation conditions of oil within an operating transformer. The focus of the investigation was on the breakdown characteristics under DC voltages. The results indicated that higher concentrations of iron impurities were associated with a reduction in breakdown voltage although the circulation of oil exhibited a beneficial effect. To validate these findings, Finite Element Method (FEM)-based simulations were conducted. The analysis of the electric field distribution revealed that iron impurities amplified the electric field intensity, while circulation served to mitigate this effect. Furthermore, the simulations tracking the trajectory of iron particles demonstrated that circulation hindered the particles from reaching the electrodes, thereby diminishing discharge events and lowering the risk of dielectric failure. In conclusion, the circulation of MO enhanced its breakdown voltage, although the presence of iron contamination could still pose a risk under DC voltage conditions.

The disparities in health risks of multiple pollutants through soil and dietary exposure in a rural-urban area based on accessibility method.

Rapid urbanization has resulted in disparities in environmental conditions for different communities in suburban area. This study presents a comprehensive investigation into the occurrence of pollutants in the soil and dietary food, and associated health risks in an urban-rural transitional area. The levels of potential toxic pollutants, notably metals, organophosphate esters (OPEs), and agrochemicals in surface soil and dietary food were evaluated. Higher levels of metals and OPEs were found in soils of industrial area, and agricultural soils had an elevated level of agrochemicals. The highest health risk was found for Chromium (Cr) which exceeded 1, indicating a high probability of adverse non-cancer effect to local residents. The levels of contaminants in food showed higher variability in community market and farmers' market than in supermarket, while higher levels of OPEs were found in food from supermarkets. The accessibility to fresh food mainly determined the differences in health risks of different communities. For dietary exposure, residents of industrial areas have higher levels of risk than other neighborhoods, mainly due to the possibility of exposure of foodstuffs with higher metal contents. In terms of market type, community markets mainly contributed to the comprehensive health risk through dietary exposure, especially for industrial and agricultural communities. The findings of this study provided further understanding of the spatial distribution of various contaminants as well as their health risks for different communities, which could guide the monitoring and management of potential toxic pollutants to safeguard public health in rural-urban transitional regions.