ARTICLE | doi:10.20944/preprints201709.0048.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: microbial contamination; bacteria; contamination sources; small watershed; Tibetan Plateau
Online: 12 September 2017 (16:01:26 CEST)
Microbial contamination is now more common than chemical contamination in Tibet, and water-borne microbes can cause a number of diseases that threaten public health. Thus, in order to clarify the spatiotemporal distribution of bacteria in small watersheds for which there is no data in Tibet, we set up four sampling points along an upstream-downstream transect of the Xincang River Basin. We collected 239 water samples in 2014 and 2015, and evaluated their total constituent numbers of bacteria (TB) and coliforms (TC). The results of this study show that the microbial contamination of the Xincang River Basin is mild-to-moderate in terms of TB and TC contents, and that these concentrations vary significantly in different seasons. Results show that in summer TB and TC concentrations in the downstream section of this river were highest and that microbial contamination was most serious. Data also demonstrate that precipitation is the most important factor underlying increases in TB and TC concentrations during the summer months; both these variables are significantly correlated with precipitation, while animal husbandry and domestic sewage are the main sources of microbial contamination overall. The results of this study are likely to reflect the basic characteristics of small watersheds for which there is no data to some extent, and are thus of significant practical importance for protecting their ecological environments and promoting sustainable development.
REVIEW | doi:10.20944/preprints202309.0206.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: Hydraulic fracturing; Groundwater contamination; Earthquake; Air pollution; Soil contamination; Environmental impacts
Online: 5 September 2023 (04:03:15 CEST)
Recent scholarship highlights the significant environmental impact of the expanding hydraulic fracturing industry, necessitating up-to-date, comprehensive, national-scale assessments. Addressing this gap, this literature review provides a thorough analysis of the contamination and induced seismicity associated with shale-gas hydraulic fracturing in the United States. Employing systematic reviews of literature and federal reports up until July 2023, this study reveals multiple areas of concern. Notably, water and soil contamination, seismic activity, and air pollution are identified as significant challenges linked to shale gas extraction. However, ongoing studies are actively exploring remediation strategies, including advancements in monitoring and treatment technologies, aimed at mitigating the impact of contamination. These findings underscore the need for stringent regulations, continuous research, and effective management practices. This work emphasizes the importance of a collaborative approach that leverages field studies, experimental investigations, and computational advancements to ensure the responsible development of shale gas resources.
REVIEW | doi:10.20944/preprints202305.0450.v1
Subject: Engineering, Mechanical Engineering Keywords: varnish; lubricant; contamination; degradation; oxidation
Online: 8 May 2023 (05:04:38 CEST)
In this study, the literature on varnish contamination is investigated among the various con-taminations of lubricant. As the period of use of lubricant increases, the lubricant deteriorates and becomes contaminated. The varnish causes filter plugging, sticking of hydraulic valves and fuel injection pumps, obstruction of flow, reduction of clearance, poor heater and cooler perfor-mance, and increase of friction and wear in various lubrication systems. These problems also cause mechanical system failure, performance degradation, and increased maintenance and re-pair cost. To improve the problems causes by the varnish, an adequate understanding of varnish is required. Therefore, in this literature review, definitions and characteristics, generating ma-chinery, generating mechanisms, causes, measurement methods, and prevention or removal methods are summarized. Most of the data are reports of companies related to lubricant and machine maintenance, and are included in some papers. We hope that this summary of varnish will be helpful to those who are engaged in reducing or preventing varnish problems.
ARTICLE | doi:10.20944/preprints202304.1216.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: contamination; CFU/ml; biocide; microorganisms
Online: 29 April 2023 (05:36:38 CEST)
The proliferation of bacteria in fresh water-based paints is a concerning issue, as these microorganisms can utilize the organic materials in paint as a source of carbon to stimulate their growth, leading to the deterioration of painted surfaces. This study analyzed the bacterial quality and lead concentration of six paint samples collected from a manufacturing industry in Lagos. The total bacterial population monitored in the paint samples ranged from 1×106 CFU/ml to 7.8×109 CFU/ml, and while the population density decreased in all the samples throughout the 3-month study period, it was not uniform. The observed decrease in population density may be attributed to the biocide present in the paint samples and environmental factors such as heavy metal concentration. Interestingly, Pseudomonas oleovorans, P. luteola, Burkholderia cepacia, Sphingomonas paucimobilis, and Stenotrophomonas maltophilia were still able to grow in the paint samples from week 0 to week 10. The study highlights the potential for bacterial contamination of water-based paint, and the need for manufacturers to take measures to prevent this. The findings suggest that even fresh paint can serve as a substrate for bacterial growth, which can lead to issues such as loss of viscosity, discoloration, and malodor. Additionally, the presence of bacteria in paint can lead to degradation of painted surfaces, which can have economic and public health implications. The study emphasizes the importance of incorporating effective biocides in paint formulations, as well as communicating proper storage conditions to retailers, to help increase the shelf-life of paint and prevent bacterial contamination. Overall, the study provides important insights into the potential risks associated with bacterial contamination of paint and the need for proactive measures to prevent it.
ARTICLE | doi:10.20944/preprints202112.0169.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: Plumes; dynamics; resistivity; contamination; groundwater
Online: 10 December 2021 (11:28:20 CET)
The contamination of areas around solid urban waste dumps is a global challenge for the maintenance of environmental quality in large urban centres in developing countries. This study applied geophysical methods (electrical resistivity) to identify leachate contamina-tion plumes in the subsoil and groundwater, as well as to describe their temporal (2020 and 2021) dynamics in the lithology and groundwater around the Hulene - B waste dump, Maputo, Mozambique. Geophysical methods (electrical resistivity) were applied to identify possible groundwater contamination plumes, their dynamics, mechanisms of their enrichment and dispersion. Eight 400 m electrical resistivity profiles were performed, four profiles in January 2020 and four profiles in May 2021, overlapped, and the data were inverted with RES2D software. The electrical resistivity models indicate an E - W move-ment of large contamination plumes that dilute superficially into the natural surface wa-ter receiving basin and groundwater, creating zones of resistive anomalies. The thickness of the plumes in the subsurface environment was shown to be extensive in summer for profiles 1a and 2b and we associate it with the higher leachate production and migration mechanisms, which are intense in the hot and rainy season. Profile 4b showed the prop-agation of anomalous surface and subsurface areas, which was associated with higher leachate production and migration process in the new deposition zone (west). The spatial distribution of contamination plumes at both stations reduced significantly as we moved further away from the waste deposit, revealing the attenuating effect of groundwater and lithological substrate (Profile 3 a, b, and fig.7).
ARTICLE | doi:10.20944/preprints201906.0247.v1
Online: 25 June 2019 (08:43:15 CEST)
In this letter, we advocate that it is possible to mitigate Pilot Contamination in Massive MIMO systems by scrambling the pilot sequences with a Base Station (BS) scrambling sequence. It is possible if a set of sequences is carefully designed to meet the orthogonality property defined in this letter. Each BS possesses its own scrambling sequence that can be reused the same way frequency reuse is applied to cell deployment. The main advantage of the prosed pilot generation scheme is that the frequency reuse factor can be set to 1, the most aggressive one, while the scrambling sequences can be reused with much less aggressive reuse factors (e.g. 4, 7, 9, 12, etc.), which in consequence results in pilot contamination mitigation and increased system's performance.
ARTICLE | doi:10.20944/preprints201809.0015.v2
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: supply chains; simulation model; contamination; variability; inventory levels; shipments
Online: 29 December 2019 (08:36:38 CET)
This article aims to serve as a guide for the construction of supply chain simulation models designed with a lean approach, using Promodel software. To achieve this, a supply chain was designed for a fictitious company located in the City of Celaya, Guanajuato and a set of suppliers located in different cities within the same State. It was used as a google tool to define the distances between each of the companies. As a final result, a representative model of a supply chain was obtained, as well as a methodology that allows the construction of lean supply chains regardless of the number of companies that comprise it. The effect of the variability in the delivery times between suppliers was incorporated into the simulation model, as well as an equation that calculates the pollution emissions of the vehicles that integrate the network that moves the products between the companies. With this work it is possible to represent networks of supply chains of real world companies, where the variability and contamination factor is included, to facilitate the decision making regarding the number of vehicles, inventory levels, quantities to be shipped, frequency in the shipments, etc. with the purpose of contaminating as little as possible and at the same time preventing interruptions in the supply chain using the least amount of resources possible.
ARTICLE | doi:10.20944/preprints202307.0785.v1
Subject: Biology And Life Sciences, Toxicology Keywords: Aquatic contamination; Ecotoxicology; Environmental contamination; Enrichment analysis; Net-work biology; Neurodevelopmental disorders; Neurotoxicity of pesticides.
Online: 12 July 2023 (07:32:31 CEST)
Organophosphate pesticides (OPs) are toxic substances that contaminate aquatic environments, interfere with the development of the nervous system, and induce Neurodevelopmental Toxicity (NDT) in animals and humans. The canonical mechanism of OP neurotoxicity involves the inhibi-tion of acetylcholinesterase (AChE), but other mechanisms non-AChE are also involved and not fully understood. We used network toxicology and molecular docking to identify molecular targets and toxicity mechanisms common to OPs. Targets related to diazinon-oxon, chlorpyrifos oxon, and paraoxon OPs were predicted using the Swiss Target Prediction and PharmMapper databases. Targets related to NDT were compiled from GeneCards and OMIM databases. In order to construct the protein-protein interaction (PPI) network, the common targets between OPs and NDT were imported into the STRING. Networks topological analyses identified EGFR, MET, HSP90AA1, and SRC as hub nodes common to the three OPs. Using Reactome pathway and gene ontology we found that signal transduction, axon guidance, cellular responses to stress, and glutamatergic signaling activation play key roles in OP-induced NDT.
ARTICLE | doi:10.20944/preprints202310.0291.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: ocular infections; bacteria contamination; antibiotic resistance
Online: 5 October 2023 (13:33:16 CEST)
Periodic assessment of bacterial contamination is necessary as it allows proper guidance in cases of eye infections through the use of appropriate antibiotics. Due to the extensive use of antibiotic treatment, most of the contamination flora is resistant to the usual ophthalmic antibiotics. The present study shows an updated picture of the susceptibility of Gram-positive and Gram-negative bacteria found on the ocular surface to the most commonly used antibiotic agents in patients undergoing cataract surgery. A total of 993 patients were included in the study with ages between 44 and 98 years old. Conjunctival culture was collected 7 days before cataract surgery. The response of Gram-positive and Gram-negative bacteria to various antibiotic classes like glycopeptides, cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, phenicols, tetracyclines, rifamycins, macrolides and penicillins was assessed. From the tested antibiotics, vancomycin had 97.8% efficacy on Gram-positive bacteria. In the cephalosporin category, we observed an increased resistance of the cefuroxime for both Gram-positive and negative bacteria. Antibiotics that have more than 90% efficacy on Gram-positive bacteria are: meropenem, imipenem, netilmicin, amikacin and rifampicin. On Gram-negative bacteria, we found 100% efficacy of all tested fluoroquinolones, aminoglycosides (except for tobramycin), doxycycline, azithromycin, clarithromycin and chloramphenicol. The current study illustrates patterns of increased resistance of certain bacteria present on ocular surface to some of the commonly used antibiotics in ophthalmological clinical practice. One such revealing example is cefuroxime, which has been highly used as an intracameral antibiotic for the prevention of bacterial endophthalmitis after cataract surgery.
ARTICLE | doi:10.20944/preprints202312.0547.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: Rotavirus; Water contamination; Dry period; Rainy period
Online: 8 December 2023 (08:01:08 CET)
Abstract: Rotavirus (RV) it’s the agent of one of the main causes of severe viral gastroenteritis in the pediatric population, being responsible for a significant portion of deaths related to diarrhea among children under five years. RV are identified as a potential reference pathogen and it is known that the persistence and infectivity of the viral particles can be related to environmental factors. The aim of the study was to identify and correlate the presence of Rotavirus in collective and individual water sources (deep tubular wells, shallow tubular wells, shallow dug wells, springs, surface water, rainwater stored in cisterns and water trucks that were collected from surface water) of rural communities in the state of Goiás, with the seasons in which the collections were made (rainy and dry season). For this, 86 water samples in the dry period and 160 samples in the rainy period were collected. Concentration of water samples, extraction of viral genetic material, cDNA synthesis and molecular tests (qPCR) were performed. When analyzing the presence of RV in the samples in relation to the period studied, RV was found to be more prevalent in the dry season (54.7%) than in the rainy season (20%), showing a strong statistical association with the dry season (p-value < 0.001). The proportion of positive samples in the dry period, considering the type of source, resulted in higher in Shallow dug wells (p-value <0.001), higher in surface waters (p = 0.001) and higher in spring water (p-value = 0.02). The presence of pathogenic microorganisms in water is a public risk problem, enabling the emergence of outbreaks, endemics and epidemics. In the present research, there was an association among the presence of Rotavirus and the dry period of the year, when compared to the rainy period. Describing or identifying the seasonal behavior of pathogens is important for prevention and attention to water treatment and help in the monitoring of the virus in the water sources.
ARTICLE | doi:10.20944/preprints202108.0299.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: contamination; trace elements; metal concentration; environmental pollution
Online: 13 August 2021 (15:07:34 CEST)
The Katangese Copperbelt area (KCA) located south-eastern of D.R. Congo presents high concentration of metal trace elements (MTE) in several soils due to a rich natural geochemical background, and intense mining activities, causing serious health issues to humans and animals. However, the lack of data on specific baseline concentrations makes it difficult to properly assess and monitor the environmental quality of soils in the region. In this study, the baseline concentration of 11 potentially toxic MTE (i.e., Mn, Zn, Cu, Co, Cr, Pb, Cd, Ti, Ni, Al, and Fe) was assessed in topsoils of the KCA, and the possible influence of land uses (croplands, forest and mining areas) was examined. Results showed the following baseline concentrations, i.e. lower and upper limits (mg.kg-1) in cropland soils : Al (18.4–162.0), Cd (0.0–0.1), Co (0.1–3.5), Cu (0.8–17.7), Cr (0.0–0.2), Fe (4.7–233.8), Mn (3.5–575.6), Ni (0.1–1.9), Pb (0.2–2.4), Zn (0.1–20.3), Ti (0.0–392.6); in forests: Al (18.8–1167.1), Cd (0.02–0.48), Co (0.20–18.1), Cu (3.6–42.7), Cr (0.1–33.7), Fe (86.4–283.3), Mn (4.9–1538.9), Ni (0.05–24.2), Pb (0.3–13.7), Zn (2.0–7.0), Ti (0.2–0.8); and in mining areas: Al (7.4–241.2), Cd (0.01–164.8), Co (0.2–211.3), Cu (2.4–5485.4), Cr (0.03–0.4), Fe (5.9–481.6), Mn (7.1–95.9), Ni (0.1–1.9), Pb (0.2–390.8), Zn (1.5–5629.3), Ti (0.1–1.3). Cu and Zn were highest in mining areas demonstrating a prevalent influence of mining activities in altering the natural background of metals concentrations in the region. By contrast, croplands and forest shared a similar trend of Al and Mn contents, suggesting a mild influence of agricultural activity. Intriguingly, higher Cu and Co contents were found in forest compared to croplands. For all the three studied land uses, no straightforward relation was found between metal concentrations and soil total acidity. This study is the first attempt to establish reference values of MTE contents in the KCA soils and thus provides valuable information for legislative purposes and for soil quality assessment.
ARTICLE | doi:10.20944/preprints202311.1307.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: water contamination; fertilizer; degradation product; flatworm; regeneration; phototaxis
Online: 21 November 2023 (10:03:42 CET)
The widespread use of the herbicide glyphosate has resulted in the global presence of its degra-dation product, aminomethylphosphonic acid (AMPA), in the global environment. AMPA is commonly found in water bodies, including freshwater systems. We investigated the effects of chronic and acute AMPA exposure on the survivorship, regenerative abilities, and locomotion of the brown planarian (Girardia tigrina), a water-dwelling flatworm commonly found in freshwa-ter ecosystems. We exposed planarians to two concentrations of AMPA, consistent with the high and low ranges of concentrations observed in US water systems. We measured endpoints includ-ing survivorship, regenerative abilities of head and tail segments, eyespot regeneration, and swimming speed. Compared to the control group, we found that planarians chronically exposed to AMPA exhibited (1) modestly reduced survivorship while regenerating and (2) slower regen-eration from the tail segment. No significant differences were observed in intact body growth during chronic exposure. Our findings highlight the potential ecological impacts of AMPA con-tamination on planarian populations. Understanding the effects of AMPA exposure on planarians contributes to our understanding of the ecological consequences of glyphosate use in freshwater ecosystems.
ARTICLE | doi:10.20944/preprints202307.0543.v1
Subject: Biology And Life Sciences, Virology Keywords: human papillomavirus; tropism; contamination; cervical sample; vaginal sample
Online: 10 July 2023 (08:31:47 CEST)
The oncogenic potential of human papillomavirus (HPV) may be used to determine the tissue tropism of each HPV type. Cervical cancer develops in the squamo-columar junction of the cervices, and most such lesions are induced by high-risk (HR) HPV types. This suggests that HR types preferentially infect the cervix, whereas the preferential infection site for low-risk (LR) types is not well defined. Determination of HPV tropism when using cytology samples can be uncertain since it is difficult to avoid contamination of cell samples between the cervix and the vagina. Herein, cell samples were carefully collected by independently scraping the cervix and vagina, after which the HPV types were determined. HPV tissue tropism was determined by considering what HPV types were positive at only one of the sites (the cervix or the vagina) as the viruses that preferentially infected that site. This method revealed that all LR types were only identified in vaginal samples, whereas 87% of HR types were identified in cervical sites. Thus, LR types may preferentially infect the vagina, whereas HR types infect the cervix. These findings suggest that preferential tissue tropism of certain HPV types is a probable factor for malignant progression.
ARTICLE | doi:10.20944/preprints202307.0567.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: fluorescence polarization immunoassay; phthalates; dibutylphthalate; contamination; water safety
Online: 10 July 2023 (08:16:23 CEST)
Dibutyl phthalate (DBP) is widely used as a plasticizer in the production of polymeric materials to give them flexibility, strength and extensibility. However, due to its negative impact on human health, in particular, reproductive function and fetal development, the content of DBP must be controlled in food and environmental objects. The present study aims to develop a sensitive, fast and simple polarization fluorescent immunoassay (FPIA) using monoclonal antibodies derived against DBP (MAb-DBP) for its detection in open waters. New conjugates of DBP with various fluorescein derivatives were obtained and characterized: 5-aminomethylfluorescein (AMF) and dichlorotriazinylaminofluorescein (DTAF). The advantages of using the DBP-AMF conjugate in the FPIA method are shown, the kinetics of binding of this drug with antibodies is studied, the analysis is optimized, and the concentration of monoclonal antibodies is selected for sensitive analysis - 16 nM. The calibration dependence of the fluorescence polarization signal for the detection of DBP was obtained. The observed IC50 (40 ng/mL) and LOD (10 ng/mL) values were improved by a factor of 35 for the previously described FPIA using polyclonal antibodies. This technique was tested by the added/found method, the percentage of DBP discovery in water ranged from 85 to 110%. Using the developed method, real water samples from Lake Onega were tested, and a good correlation was shown between the results of the determination of DBP by the FPIA method and GC-MS/MS. Thus, the FPIA method developed in this work can be used to determine DBP in open water reservoirs.
ARTICLE | doi:10.20944/preprints202107.0236.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CPE; drains; hospital plumbing; environmental contamination; infection control
Online: 12 July 2021 (09:37:00 CEST)
Sink waste traps and drains are a reservoir for multi-drug resistant Gram-negative bacteria in the hospital environment. It has been suggested that these bacteria can migrate through hospital plumbing. Hospital waste traps were installed in a laboratory model system where sinks were connected through a common wastewater pipe. Enterobacterales populations were monitored using selective culture, MALDI-TOF identification and antibiotic resistance profiling before and after a wastewater backflow event. When transfer between sinks was suspected, isolates were compared using whole-genome sequencing. Immediately after the wastewater backflow, two KPC-producing Enterobacter cloacae were recovered from a waste trap in which Carbapenemase-producing Enterobacterales (CPE) had not been detected previously. The isolates belonged to ST501 and ST31 and were genetically indistinguishable to those colonising sinks elsewhere in the system. Following inter-sink transfer, KPC-producing E. cloacae ST501 successfully integrated into the microbiome of the recipient sink and was detected in the waste trap water at least six months after the backflow event. Seven weeks and three months after the backflow, other inter-sink transfers involving Escherichia coli ST5295 and KPC-producing E. cloacae ST501 were also observed.
ARTICLE | doi:10.20944/preprints201908.0173.v1
Subject: Engineering, Telecommunications Keywords: massive MIMO; multi-cell; pilot contamination; channel estimation
Online: 16 August 2019 (07:16:53 CEST)
Accurate channel estimation is of utmost importance for massive MIMO systems that allow providing significant improvements in spectral and energy efficiency. In this work, we investigate the spectral efficiency performance and present a channel estimator for multi-cell massive MIMO systems subjected to pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without prior knowledge of the inter-cell large-scale channel coefficients and noise power. The estimator approximates the performance of a linear Minimum Mean Square Error (MMSE) as the number of antennas increases. Following, we derive a lower bound closed-form spectral efficiency of the Maximum Ratio Combining (MRC) detector in the proposed channel estimator. The simulation results highlight that the proposed estimator performance approaches the linear minimum mean square error (LMMSE) channel estimator asymptotically.
ARTICLE | doi:10.20944/preprints201908.0169.v1
Subject: Engineering, Telecommunications Keywords: massive MIMO; multi-cell; pilot-contamination; channel estimation
Online: 15 August 2019 (14:59:58 CEST)
Accurate channel estimation is of utmost importance for massive MIMO systems to provide significant improvements in spectral and energy efficiency. In this work, we present a study on the distribution of a simple but yet effective and practical channel estimator for multi-cell massive MIMO systems suffering from pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without previous knowledge of the inter-cell large-scale channel coefficients and noise power, asymptotically approximating the performance of the linear MMSE estimator as the number of antennas increases. We prove that the distribution of the proposed channel estimator can be accurately approximated by the circularly-symmetric complex normal distribution, when the number of antennas, M, deployed at the base station is greater than 10.
ARTICLE | doi:10.20944/preprints201908.0165.v1
Subject: Engineering, Telecommunications Keywords: massive MIMO; pilot contamination; deep learning; machine learning
Online: 14 August 2019 (16:01:48 CEST)
In this brief letter we report our initial results on the application of deep-learning to the massive MIMO channel estimation challenge. We show that it is possible to estimate wireless channels and that the possibility of mitigating pilot-contamination with deep-learning is possible given that the leaning model underwent an extensive training-phase and that it has been presented with a large number of different channel conditions.
ARTICLE | doi:10.20944/preprints201807.0211.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: contamination; domestic use; Nandoni dam; salinity; water analysis
Online: 12 July 2018 (07:48:10 CEST)
The problem of limited water supply in the Vhembe District (Limpopo Province, South Africa) is exacerbated by a preponderance of dissolved salts, which cause disagreeable taste and odour in the water as reported by the communities using this water for drinking. The water treatment plant that supplies the treated water to the communities in the District sources this raw water from the Nandoni Dam at the Livhuvu river catchment. However, there are no scientific studies that have been reported in the literature which focused on determining the levels of water salinity from various water sources in the municipalities of the District. Water samples from various sites across the Nandoni Dam, a primary source of domestic water supply in the region, were collected during all the seasons basis over a period of twelve months in order to ascertain the concentrations of dissolved salts in the dam. Onsite analyses of the water samples were conducted using the YSI ProDSS multimeter, while the laboratory water analyses were conducted using the spectroquant and atomic absorption spectrometers. Although salinity tests seem to indicate that the water sampled across most of the Nandoni Dam is brackish during all seasons of the year with the highest being 750 mg/L, water samples from the dam mid-outlet and the treatment plant are slightly below the WHO brackish water bracket of 500 mg/L with unfavourable taste for drinking. Results from this study indicate that the water sourced from the Nandoni Dam is not suitable for human consumption and therefore requires integrated water resource management, as well as robust and cost-effective water desalination treatment.
CASE REPORT | doi:10.20944/preprints201806.0117.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: sulfur; reclamation; acid mine drainage; salinity; soil contamination
Online: 7 June 2018 (11:21:57 CEST)
Sulfur contamination of topsoil, spatial distribution of contamination and surface water chemistry were investigated on an area of over 200 ha of a new forest ecosystem. Common birch and Scots pine growth reaction, vitality and nutrients supply, as well as wood small-reed (Calamagrostis epigejos (L.) Roth) chemical composition were assayed. The chemistry dynamics of soil leaching and the sulfur load leached from the sulfur contaminated soil-substrates were analyzed. The remediation effect of the birch and pine litter was assayed in an experiment under controlled conditions. It was found that reclamation was effective in a majority of the post-mining site, however hot-spots with sulfur contamination reaching even 45,000 mg kg-1, pH <2.0, and EC 6,500 µS cm-1 were reported. Surface waters typically displayed elevated concentrations of sulfate ions (average 935.13 mg L-1), calcium ions (up to 434 mg L-1) and high EC (average 1.795 µS cm-1), which was connected both with sulfur contamination and sludge lime used in neutralization. Wood small-reed was found to be species adapting well to the conditions of elevated soil salinity and sulfur concentration. We noted that an addition of organic matter had a significant impact on the chemistry of soil solutions but did not indicate in short term experiment a remediation effect by increased sulfur leaching.
ARTICLE | doi:10.20944/preprints201802.0016.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: ground water; pit latrines; fecal contamination; common factors
Online: 2 February 2018 (09:06:10 CET)
The coastal dry zone areas of Sri Lanka mostly rely on ground water as the potable drinking water source because pipe born water is rarely provided. Most of the domestic units construct dug wells adjacent to houses where the ground water is exposed to fecal contamination due to pit – latrines. There available standards and commonly accepted factors regulating the construction of ground water extraction sources yet there is lack of evidence whether following them effectively prevent ground water fecal contamination. This research focus on applicability of commonly accepted factors on preventing the pit latrines correlated ground water contamination, taking twenty (20) sampling locations of Kalpitiya Peninsula of Sri Lanka as the case study area. The ground water was tested for Total coliform bacteria at 37 °C and E.Coil at 44 °C to identify the water quality level related to fecal contamination. The depth of water table, gap of infiltration layer, depth of latrine pit and distance between dug well and latrine pit were identified as the most commonly considered factors. Accordingly, case specific and area specific reasons apart from the ‘commonly accepted factors’ are highly influencing the pit latrines correlated ground water contamination in Kalpitiya Peninsula, Sri Lanka.
ARTICLE | doi:10.20944/preprints202311.1980.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: household washing machines; microbial contamination; metagenomics; pathogenic bacteria; biofilm
Online: 1 December 2023 (03:11:19 CET)
Washing machines are one of the tools that bring great convenience to people's daily lives. However, washing machines that have been used for a long time often develop issues such as odor and mold, which can pose health hazards to consumers. There exists a conspicuous gap in our understanding of the microorganisms that inhabit the inner workings of washing machines. In this study, samples were collected from 22 washing machines in Shanghai, China, including both water eluted from different parts of washing machines and biofilms. Quantitative qualitative analysis was performed using fluorescence PCR quantification and microbial communities were characterized by high throughput sequencing (HTS). It showed that the microbial communities in all samples were predominantly composed of bacteria, and they have a strong adhesion ability in the washing machine environment. HTS results showed that in the eluted water samples, the bacteria mainly included Pseudomonas, Enhydrobacter, Brevibacterium and Acinetobacter. On the contrary, in biofilm samples, Enhydrobacter and Brevibacterium were the predominant bacterial microorganisms. Correlation analysis results revealed that microbial colonies in washing machines were significantly correlated with years of use and the type of detergent used to clean the washing machine. As numerous pathogenic microorganisms can be observed in the results, effective preventive measures and future research are essential to mitigate these health problems and ensure the continued safe use of these household appliances.
ARTICLE | doi:10.20944/preprints202310.0622.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Aflatoxin B1; mycotoxins; various nuts; contamination; food safety; extraction
Online: 10 October 2023 (10:06:54 CEST)
Nuts are a staple food consumed throughout the world, and their purity is essential to maintaining human health. However, fungal mycotoxins pose one of the real challenges in keeping nuts clean for human consumption. The high cost of equipment, reagents used, standard samples, as well as increased requirements for personnel qualifications limit the use of chromatographic methods in testing laboratories, both manufacturing enterprises and organizations monitoring food safety. The present study aimed to test a new method for extracting aflatoxin B1 using sodium chloride and citric acid instead of methanol present in imported nuts obtained from local markets in Astana (Kazakhstan). The proposed method for extracting aflatoxin B1 from nuts is chemically safe, since the substances used belong to hazard class 3 of the international classification and do not require separate premises in food safety laboratories of the Astana markets and special training of specialists. The technical objective of the method is to replace the reagent (methanol) during the sample preparation process when conducting cocuret enzyme-linked immunosorbent assay. Aflatoxin B1 levels varied depending on the type of nut. Aflatoxin contamination was observed in 35.8% of samples analyzed. These levels of mycotoxin contamination are alarming and raise serious questions about the purity of imported nuts to ensure food safety.
ARTICLE | doi:10.20944/preprints202309.0772.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: removal; contamination; FTIR; regulatory standards; receiving bodies; tourist city
Online: 13 September 2023 (05:46:59 CEST)
Contamination by microplastics (MP) in aquatic ecosystems is largely due to the release of millions of these particles from treated effluents from Wastewater Treatment Plants (WWTP). Due to the lack of policies and regulations that establish criteria for the control and elimination of MP from WWTP effluents, this research evaluated the presence of MP for particle sizes of 38 and 150 µm in influents and effluents from three WWTP in the port of Acapulco, Mexico. Using optical microscopy and Fourier transform infrared spectroscopy (FTIR) techniques, the MP detected were polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) and polyvinyl chloride (PVC). MP removal efficiencies of 82.5 to 98.7% (38 µm) and 86.8 to 97.5% (150µm) were obtained; the MP average daily emissions to the receiving bodies of these three WWTPs were in the ranges of 9.5 x 106 - 4.70 x 108 particles and the annual emissions in the range of 3.05 x 109 - 1.72 x 1011 particles. This work reveals the urgency of implementing regulatory policies to avoid the continuous emission of MP to aquatic ecosystems from WWTPs in Acapulco, Mexico.
ARTICLE | doi:10.20944/preprints202308.1357.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: Recreational activities; water quality parameters; contamination; variation; Plettenberg Bay
Online: 21 August 2023 (03:09:55 CEST)
This study aimed to analyse the variation of recreational water quality in Plettenberg Bay in an attempt to comprehend the effects of pollution on the environment, and more specifically the potential impacts on the quality of surface water used for recreational activities. Plettenberg Bay is a major destination for tourists in South Africa, with recreational water activities representing an important attraction. For this study, data were obtained from Bitou Municipality, the local au-thority in charge of the water monitoring program in Plettenberg Bay. The selected datasets contained water quality data collected by the Bitou Municipality waterworks department in three sampling sites in Plettenberg Bay. The samples were tested for six water quality parameters namely, Ammonia, Suspended Solids, Conductivity, Nitrates/Nitrites, pH, and E coli. Water quality trends appeared stabile over the five years, with only a few parameters showing variation in their concentration levels. It is recommended that the Bitou Municipality increase the sampling frequency to allow a clearer understanding of water quality variation and to minimise potential uncertainties.
ARTICLE | doi:10.20944/preprints202207.0350.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: magnetic susceptibility; soil magnetometry; vertical profiles; soil contamination; Krakow
Online: 25 July 2022 (05:36:35 CEST)
The paper concerns the distribution of apparent magnetic susceptibility in soil profiles located in the areas of topsoil magnetic susceptibility anomalies in Krakow. The type of land use, possible sources of magnetic carriers, and the type of soil were taken into account. Additionally, at each soil profile, a comparison between soil magnetic susceptibility and the results of geochemical analyzes of soil samples was made. The study shows very characteristic changes in magnetic susceptibility with depth, reflecting the interdependencies between natural and anthropogenic factors. A visible magnetic susceptibility maximum at the depth of 10-30 cm is observed at each soil profile. The maximum is associated mainly with the deposition of atmospheric dust and its vertical range depends on the level of anthropopression and natural conditions of soils. At the depth above 40 cm in the eastern part of Krakow, a correlation between the magnetic susceptibility and the soil type (chernozems de-veloped on loess) was found. All indicates that the thicknesses of contaminated upper horizons are not accidental and they depend on human interactions with the environment and the type of soil. An attempt at template establishment with the sources of magnetic particle carriers for different places in the city was made. As the result, in high urbanized sites, the extreme values of magnet-ic susceptibility rapidly change in short vertical distances can identify the richness of anthropo-genic layers with various types of anthropogenic ferrous material and/or additionally Fe-carrying objects buried in soils. In industrialized sites, anthropogenic input plays the most important role in the creation of soil magnetic characteristics. What is more, industrial pollution hides the natural magnetic properties of chernozems. In opposite, the studies at the sites under low anthropopression (mainly located in forests) allow for better insight into magnetic proper-ties arising during pedogenic processes, indirectly giving information about soil conditions. In the forest areas, the lowest values of soil magnetic susceptibility were measured. Additionally, the influence of pedogenic and lithogenic factors on forest soils is manifested in the results. Among the sites concerned, particular attention should be paid to the vicinity of the steel plant because of the agricultural land in the surroundings.
REVIEW | doi:10.20944/preprints201910.0005.v1
Subject: Environmental And Earth Sciences, Space And Planetary Science Keywords: International Space Station; space missions; biomonitoring; water biological contamination
Online: 1 October 2019 (16:16:01 CEST)
Space exploration is demanding longer lasting human missions and water resupply from Earth will become increasingly unrealistic. In a near future, the spacecraft water monitoring systems will require technological advances to promptly identify and counteract contingent events of waterborne microbial contamination, posing health risks to astronauts with lowered immune responsiveness. The search for bio-analytical approaches, alternative to those applied on Earth by cultivation-dependent methods, is pushed by the compelling need to limit waste disposal and avoid microbial regrowth from analytical carryovers. Prospective technologies will be selected only if first validated in a flight-like environment, by following basic principles, advantages, and limitations beyond their current applications on Earth. Starting from the water monitoring activities applied on the International Space Station, we provide a critical overview of the nucleic acid amplification-based approaches (i.e., loop-mediated isothermal amplification, quantitative PCR, and high-throughput sequencing) and early-warning methods for total microbial load assessments (i.e., ATP-metry, flow cytometry), already used at a high readiness level aboard crewed space vehicles. Our findings suggest that the forthcoming space applications of mature technologies will be necessarily bounded by a compromise between analytical performances (e.g., speed to results, identification depth, reproducibility, multiparametricity) and detrimental technical requirements (e.g., reagent usage, waste production, operator skills, crew time). As space exploration progresses toward extended missions to Moon and Mars, miniaturized systems that also minimize crew involvement in their end-to-end operation are likely applicable on the long-term and suitable for the in-flight water and microbiological research.
ARTICLE | doi:10.20944/preprints201811.0445.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Contamination, Escherichia coli, fecal coliforms, Nakawa, Salmonella, Staphylococcus aureus
Online: 19 November 2018 (10:19:56 CET)
This study evaluated the microbial safety of vended boiled, pasteurized and UHT milk sold in Nakawa, Kampala-Uganda. 15 milk samples were analyzed; 2 samples had Salmonella, 5 had S. aureus with a count of 1.66 0.02 log10CFU/ml. E. coli was detected in 8 samples with 1.0 0.02 to 3.0 0.01log10CFU/ml count. A high load of 3.0 CFU/ml was obtained in 3 samples with E. coli. Four E. coli positive samples had a contamination load of 2.0 0.015log10 CFU/ml of which one was pasteurized milk. Only a pasteurized milk showed a low E. coli load at 1.0 0.02log10 CFU/ml. All UHT milk had no microbial contamination. Both boiled and pasteurized milk had Salmonella, S. aureus and E. coli in levels above the set threshold limits. Milk consumers in Nakawa stand a potential public health risk of food poisoning reflected by presence of Salmonella, S. aureus and E. coli in some milk sold in the area.
ARTICLE | doi:10.20944/preprints202307.0811.v1
Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: Heavy metals; Vegetables; Contamination; Pollution indicators; Cancer risk; Health risk
Online: 12 July 2023 (11:24:32 CEST)
Contamination of soil and crops with heavy metals (HMs) poses a significant environmental challenge in the United States. Hence, this study aimed to assess HM contamination levels from sampled Ohio and West Virginia soils using various pollution indicators analyses, including Enrichment Factor (EF), Geo-accumulation index (lgeo), Contamination Factor (CF), and Pollution Load Index (PLI) and identify the Translocation Factor (TF) of HMs in the edible part of the vegetables and further evaluate health risks associated with dietary exposure through estimations of Estimated Daily Intake (EDI), Hazard Index (HI), Target Hazard Quotient (THQ), Cancer Risk (CR) and Target Cancer Risk (TCR) on adults and children. In this study, Fe was the most predominant contaminant, ranging from 28.41 to 67.36 g/kg in the soil. Cancer risk assessment revealed that Ni poses significant risks. Therefore, regular monitoring of metal concentrations in soil and vegetables grown in these regions might mitigate potential health hazards in the future.
ARTICLE | doi:10.20944/preprints202209.0177.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: non-target action; soil microbiome; pesticide contamination; fungicide; soil quality
Online: 13 September 2022 (11:00:07 CEST)
Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil have an unintended impact on non-targeted microorganisms. In this study, we evaluated the impact of the combined fungicide (difenoconazole, epoxiconazole, and kresoxim-methyl) on fungal and bacterial communities of Phaeozem. In the fungicide-treated soil, the Shannon index of both fungal and bacterial communities was decreased, while Chao1 index did not differ compared to the control soil. Among bacterial taxa, the relative abundance of Athrobacter, Sphingomicrobium, and Sphingomonas increased in fungicide-treated soil due to their ability to utilize fungicides and other toxic compounds. Rhizopus and plant-beneficial Chaetomium were the dominant fungal genera, which increased 2-4 times in the fungicide-treated soil, while the relative abundance of Mortierella and Talaromyces decreased. Fusarium acuminatum was the most abundant phytopathogenic fungus that causes root rot disease of wheat, but applied fungicide treatment decreased their diversity in the soil 2 times, which is consistent on the observed plants.
ARTICLE | doi:10.20944/preprints202205.0250.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: beach; coastal sand; fecal contamination; FIB; microbial source tracking (MST)
Online: 19 May 2022 (04:18:30 CEST)
Beach sand may act as a reservoir for numerous micro-organisms, including enteric pathogens. Several of these pathogens originate in human or animal feces, which may pose a public health risk. In August 2019, high levels of fecal indicator bacteria (FIB) were detected in the sand of the Azorean beach Prainha, Terceira Island, Portugal. Remediation measures were promptly implemented, including sand removal and the spraying of chlorine to restore the beach sand quality. To determine the biological source of the contamination, during the first campaign, supratidal sand samples were collected from several sites along the beach, followed by microbial source tracking (MST) analyses of Bacteroides markers for five animal species, including humans. Some of the sampling sites revealed the presence of marker genes from dogs, seagulls, and ruminants. Making use of the information on biological sources originating partially from dogs, the municipality enforced restrictive measures for dog-walking at the beach. Subsequent sampling campaigns detected low FIB contamination due to the mitigation and remediation measures that were undertaken, thereby no longer requiring MST marker-gene analysis. This is the first case study where the MST approach was used to determine the contamination sources in the supratidal sand of a coastal beach. Our results show that MST can be an essential approach to determine sources of fecal contamination in the sand. This study shows the importance of holistic management of beaches that should go beyond water quality monitoring for FIB, putting forth evidence for the need for sands also to be monitored.
ARTICLE | doi:10.20944/preprints202111.0242.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: contamination in environmental media; ion flotation; rare-earth elements; removal
Online: 15 November 2021 (09:09:44 CET)
Considering the ever-increasing role of rare-earth elements (REE) in the modern hi-tech field, their effective use has a tremendous significance, although the production process is inevitably linked to the large volumes of industrial ammonia effluents and heavy metal wastes. In the process of metallurgical separation of metals, the emission of large volumes of noxious gases and radioactive substances is inevitable. Lean technogenic raw material processing is sensible under the condition of the development of non-waste technology. The lack of competent regulations governing the disposal of waste containing REE has an impact on adjacent territories, accumulating in water bodies and, as a result, in the human body. Such an impact cannot pass without a trace, however, the ambiguity of opinions in the scientific community regarding the toxic effects of REE on living organisms determines the relevance of a more detailed study of this issue. The paper presents experimental and theoretical results of studies of ion flotation in the aqueous solutions containing ytterbium cations and a surfactant as a collector - sodium dodecyl sulphate (NaDS).
ARTICLE | doi:10.20944/preprints202010.0166.v1
Subject: Social Sciences, Psychology Keywords: Health Belief Model; risk perception; behavioral intentions; lead contamination; mining
Online: 8 October 2020 (09:15:26 CEST)
Understanding the strength of the associations between perceived risk and individuals’ behavioral intentions to protect their health is important for determining appropriate risk communication strategies in communities impacted by lead contamination. We conducted a survey within communities of northern Idaho, USA (n = 306) near a Superfund megasite with legacy mining contamination. We empirically test a theoretical model based on the Health Belief Model. Survey respondents had higher intentions to practice health protective behaviors when they perceived the risk of lead contamination as severe, recognized the benefits of health protective behaviors, and considered the risks of lead contamination. Women reported higher behavioral intentions than men, but age and mining affiliation did not have an association. Survey comments indicated that perceptions about the long-term environmental remediation in the region influenced risk perceptions. Understanding risk perceptions, behavioral intentions, and related factors can aid public health agencies in tailoring risk communication for increasing protective behaviors in mining-impacted communities internationally.
ARTICLE | doi:10.20944/preprints201912.0217.v1
Subject: Business, Economics And Management, Business And Management Keywords: Creating Shared Value; university-business contamination; living lab; sustainability science
Online: 16 December 2019 (11:38:20 CET)
This paper presents and discusses the pedagogical implication of teaching Shared Value, presenting a case study about a contamination lab namely the case of the Shared Value Living Lab (SVLL) which took place at the University of Torino (UniTO) in Italy. The paper analyzes the pedagogical side of CSV (arguments, topics, learning methodologies, etc.) in the framework of recent theories and approaches of teaching sustainability in business school and in the cooperation between industry and academia, as well. Our research methodology relies on the analysis and comparison of one case study under an intrinsic as it enables researchers to find “interactivity” and connectedness between the individuals participating. The SVLL case is an interesting example of co-creation of social value between academia and its stakeholders. First, it represents an inclusive project linking society and business; second, SVLL acted as a hub putting in contact different interlocutors; third, SVLL training stimulated the acquisition of soft skill in students (interviews, managing relations, represents the project outside university, explaining the project to people, research curiosity) through contamination activities. With our study, we demonstrate the change in students participating in the SVLL may not only be cognitive but also affective, making students feel hopeful, empowered and liberated, and ready to contribute to a more profound change towards the vast array of pro-sustainability behaviors.
ARTICLE | doi:10.20944/preprints201908.0172.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: epidemiological survey; foodborne illnesses; food contamination; food safety; public health
Online: 16 August 2019 (05:50:39 CEST)
This study aimed to assess the foodborne diseases (FBD) outbreaks reported in Brazil between 2000 and 2018, based on data from the Brazilian Ministry of Health (official data) and from the scientific literature. According to official data, 13,163 FBD outbreaks were reported in the country during this period, involving 247,570 cases and 195 deaths. The largest prevalence of FBD outbreaks was observed in the Southeast region of Brazil (45.6%). In most outbreaks it was not possible to determine the food implicated (45.9%) but among those identified, water was the most frequently associated (12.0%). The etiological agent was not identified in most outbreaks (38.0%), while Salmonella (14.4%) was the most frequently reported, among those identified. Homes were the main site of FBD occurrence (12.5%). Regarding data obtained from the scientific literature, 57 articles dealing with FBD in the country throughout the same period were selected and analyzed. Based on these articles, mixed foods were the most prevalent in the outbreaks (31.6%), Salmonella spp. was the pathogen most frequently reported (22.8%) and homes were also the main site of FBD occurrence (45.6%). Despite under-notification, the records of FBD outbreaks that have occurred in Brazil in the past recent years show alarming data, requiring attention from health authorities. The notification of outbreaks is essential to facilitate public health actions.
ARTICLE | doi:10.20944/preprints201706.0086.v2
Subject: Biology And Life Sciences, Plant Sciences Keywords: arsenic pollution; differential display; genes; resistance; rice crop; soil contamination
Online: 22 June 2017 (05:16:08 CEST)
The main objective of the present study was to investigate arsenate [As (V)] resistance genes in rice cultivars grown in arsenic contaminated Egyptian soil in order to genetically induce resistance against arsenic in the local rice varieties as well as defining contaminated rice grains and/or soil. Three local rice cultivars; Sakha 102-104 were cultivated on modified Murashige and Skoog Basal Medium (MS medium) containing elevated concentrations of arsenate (0.1, 1 and 10 mg/l). The three varieties showed different resistant attitudes against arsenate with Sakha 104 being the most resistant. Extracted messenger RNA (mRNA) from treated and untreated Sakha 104 plantlets was scanned using differential display to demonstrate the arsenate resistant genes using three different arbitrary primers. About 100 different RNAs with (1500 bp - 50 bp) were obtained from which seven were up-regulated genes, subjected to DNA cloning using TOPO TA system and the selected clones were sequenced. The sequence analysis described four genes out of the seven namely disease resistance protein RPM1, Epstein-Barr virus EBNA-1-like, CwfJ family protein and outer membrane lipoprotein OmlA while the other three genes were hypothetical proteins. It is concluded the four induced genes in the resistant rice cultivar considered as a direct response to arsenic soil pollution. Genes detected in the present study can be used as geno-sensors for rice grains and soil contamination with As (V). Moreover, local rice cultivars may be genetically modified with such genes to induce high resistance and to overcome arsenic soil pollution.
ARTICLE | doi:10.20944/preprints201608.0137.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: heavy metal; contamination assessment; X-ray fluorescence; bus station dusts
Online: 13 August 2016 (09:41:18 CEST)
The objective of this study was to investigate the concentration and spatial distribution patterns of six potentially toxic heavy metal elements (Mn, Zn, Cr, Pb, Cu and Ni) in bus station dusts in the Xifeng district of Gansu province, NW China. The contents were analyzed for Mn, Zn, Cr, Pb, Cu and Ni by using S8 TIGER Brochures wavelength dispersive X-ray fluorescence spectrometry. Geoaccumulation index (Igeo ), enrichment factor (EF), pollution index (PI) and integrated pollution index(IPI) were calculated to evaluate the heavy metal contamination level of bus station dusts. The results indicate that, in comparison with the background values of local soil, bus station dusts in Xifeng have elevated metal concentrations as a whole. The concentrations of heavy metals investigated in this paper are compared with the reported data of other cities. The results show that the arithmetic means of Mn, Zn, Cr, Pb, Cu and Ni are 440.8, 137.9, 60.0, 42.8, 33.5 and 19.8mg kg−1 respectively. The mean values of Igeo reveal the order of Ni<Mn<Cr<Cu<Zn<Pb. The high Igeo and EF for Cu, Zn and Pb in bus station dusts indicate that there is a considerable Cu, Zn and Pb pollution, which mainly originate from traffic and industry activities. The Igeo and EF of Ni, Mn and Cr are low and the assessment results indicate an absence of distinct Ni, Mn and Cr pollution in bus station dusts. The assessment results of PI also support Cu, Zn and Pb in bus station dusts presented middle pollution, and IPI indicates heavy metals of bus station dusts polluted seriously.
ARTICLE | doi:10.20944/preprints202310.0457.v1
Subject: Physical Sciences, Applied Physics Keywords: microbial fuel cells; energy recovery; biosensors; bio-electrochemical sensors; Antibiotic contamination
Online: 9 October 2023 (04:34:31 CEST)
This work demonstrates that microbial fuel cells (MFCs), optimized for energy recovery, can be used as an effective tool to detect the presence of antibiotics in water-based environments. MFCs directly convert chemical energy of organic matter in electrical energy thanks to electroactive biofilms. The efficiency of the conversion process can be significantly affected by the presence of contaminants acting as toxicants for the biofilm. In the present work, we demonstrate that MFCs can successfully detect the presence of antibiotic residues in water and water-based electrolytes associated to the food industry, especially using honey as a new and more complex electron donor. The effectiveness of MFCs to sense antibiotics is here demonstrated for tetracycline that was added to both water and water/honey electrolytes with a minimum concentration close to 3.5 μg⁄kg. MFCs not only efficiently detect the presence of tetracycline in both the electrolytes, but also recover the same performance after each cycle of exposure, showing to a be very robust and reliable technology for both biosensing and energy recovery.
REVIEW | doi:10.20944/preprints202210.0184.v2
Subject: Environmental And Earth Sciences, Pollution Keywords: plastic contamination; cotton; gin; textile; round module; mitigation efforts; textile mills
Online: 19 January 2023 (08:26:21 CET)
Plastic contamination is a burning issue costing the global cotton and textile industries billions of dollars annually. Any time plastics from different sources end up in a cotton lint bale, the value to the textile mills plummets significantly. Various industry players have therefore made a concerted effort to find lasting solutions to the menace posed by plastic to cotton profitability and sustainability. Nevertheless, until now, there have been no up-to-date comprehensive documents detailing the numerous and ever-growing efforts committed to solving this challenge. Therefore, this article provides a detailed yet compact review of this highly dynamic subject matter. First, it puts into perspective plastic contamination in the cotton and textile industries. Then, the cotton value chain is subdivided into phases from pre-cultivation to textile mills. The root causes of plastic contamination are discussed in each stage, followed by discussions of some already developed and emerging solutions in response to the challenge by the affected industries and researchers. Concluding from the author’s perspective, the paper makes projections for the future directions of plastic mitigation efforts within the cotton and textile industries. This article also infers from the reviewed literature that research on finding alternative materials to plastic as module wrap, the development of new, effective, and all-condition plastic sensing techniques for ginning and spinning equipment, and standardized protocols for UAV in-field surveys of plastic trash are some of the areas that will be beneficial to finding a permanent solution to the challenge.
REVIEW | doi:10.20944/preprints202201.0400.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Aflatoxin contamination; Cereals; Intrinsic factors; Extrinsic factors; Climate change; Mitigation strategies
Online: 26 January 2022 (13:12:06 CET)
Aflatoxins (AFs) contamination of cereals is considered one of the greatest food safety concerns worldwide. Occurrence of AFs in maize, wheat, rice and sorghum is highly prevalent with each commodity accounting for more than 10% of world’s AF exposure. Their occurrence as food contaminants is also associated with huge economic losses. AFs are highly stable compounds that cannot be eliminated by regular processing of grains. Hence, prevention of AFs in food and feed is now considered more important than the subsequent interventions to mitigate the deleterious health effects of AFs in human and animals. However, the development of an effective preventive strategy hinges on a clear understanding of the underlying factors influencing AFs production. Therefore, the present review aims to highlight the most significant factors influencing AFs contamination of cereals at pre-and post-harvest stages. This is crucial for effective monitoring of critical control points and optimisation of preventive strategies in food and feed supply chains. Several intrinsic and extrinsic factors have been reported of which nutritional composition, environmental factors (temperature, water activity and relative humidity) and climate change have been identified as primary factors, while pH of the substrate, carbon dioxide (CO2) levels in the gaseous environment, and agronomic and socioeconomic status are the main secondary factors promoting AFs biosynthesis in cereals. Additionally, an overview of global occurrence of AFs in cereals, with their health impacts and various preventive measures have also been highlighted.
ARTICLE | doi:10.20944/preprints202002.0224.v2
Subject: Environmental And Earth Sciences, Environmental Science Keywords: soil; groundwaters; polycyclic aromatic hydrocarbons (PAHs); industrial complex; ecological risk; contamination
Online: 8 March 2020 (16:24:28 CET)
Research subjects of this study are four representative locations in the industrial complex, in the city of Banja Luka, Republic of Srpska, Bosnia and Herzegovina. 16 polycyclic aromatic hydrocarbons (PAHs) (∑16PAHs), humus and pH were determined. The main objective of the paper is to determine the concentration levels, to assess the probable sources of PAHs contamination in soil and groundwater and to determine the ecological risk. The ∑16PAHs in soil (at depths of 30 cm, 100 cm, 200 cm, 300 cm and 400 cm) ranged from 0.99 to 2.24 mg/kg, from 0.34 to 0.46, from 0.24 to 0.32, from 0.13 to 0.27 and from 0.13 to 0.47, with mean values of 1.70 mg/kg, 0.40 mg/kg, 0.28 mg/kg, 0.20 mg/kg and 0.26 mg/kg, respectively. The ∑16PAHs in groundwater ranged from 0.23 to 4.50 mg/m3, with a mean value of 1.42 mg/m3. Surface soil and groundwater are heavily contaminated. All values of ∑PAHs in soil layers were lower in the depths of the soil. Factor analysis indicates three sources of contamination, i.e. principal component (PC) PC1 (pyrogenic), PC2 (petrogenic) and PC3 (biomass), with 52.39%, 26.14% and 8.46% of the total variance, respectively. ∑PAH and PAHs indicate high ecological risk for most PAHs, which decreases with soil depth.
ARTICLE | doi:10.20944/preprints202308.1491.v1
Subject: Environmental And Earth Sciences, Other Keywords: Municipal water supply; intergranular aquifers; karstic spring; contamination of water sources; Albania
Online: 22 August 2023 (10:56:02 CEST)
The municipal water supply, related mainly to the cities of Albanian, began to develop in the second half of the 19th century and much intensively after 1945. Today the reported mean water production for the cities, on average, is about 300 l/capita/d including drinking and industrial water supply. The territory of Albania consists of uneven distribution of very heterogeneous aquifers conditioning the reach variety of the municipal water supply solutions. In this article are analyzed and classified the hydrogeological aspects of water supply sources of the settlements, which are summarized in five groups: (a) Wells in alluvial intergranular aquifers; (b) karst springs; (c) wells in karst aquifers; (d) springs in fissured rocks, and (e) mixed water sources. For each group of the water supply sources the main concerns regarding the quantity and quality problems are analyzed facilitated by the description of a variety of representative examples of different situations. Based on the gained experience important recommendation are given for the better understanding of hydrogeological aspects of water supply systems emphasizing the problematics along the river water recharge areas and on the seawater intrusion in coastal aquifers, as well as on transboundary aquifers. However, the main problems of public water supply of Albania remain the poor management of water supply systems which is reflected in the e high water losses, as well as the low public awareness of request for sustainable use.
ARTICLE | doi:10.20944/preprints202206.0064.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: domestic wastewater; biological contamination; wastewater treatment plant; Moringa oleifera; an-tibiotic resistance
Online: 6 June 2022 (06:19:40 CEST)
Developing countries are confronted with general issues of municipal wastewater management and treatment. Untreated faecal sludges and wastewaters from septic tanks and traditional toilet are rejected into rivers and sometimes using for urban agriculture without any treatment to reduce the biorisk. Consequently, there are potential environmental and public health risks. In this study, a wastewater treatment plant prototype coupled with Moringa Oleifera seeds treatment was developed to evaluate their effectiveness for the reduction of faecal indicator bacteria and antibiotics resistant bacteria in domestic wastewater. Results indicate that our performed prototype system presents high capacity to reduce bacteria with abatements up to 99.34%. High reductions of bacteria load were obtained after add of Moringa Oleifera seeds into waters, with reductions varied from 36.6-78.8% for E. coli, 28.3-84.6% for Faecal coliform, 35.3-95.6% for Vibrio cholerae and 32.1-92.4% for total flora. Same effects of Moringa Oleifera seeds were noted for reducing antibiotic resistant bacteria, Extended Spectrum Beta-lactamases and Carbapenem-Resistant Enterobacteriaceae with abatements up to 98% for E. coli and faecal coliform, 100% for Vibrio cholerae and 91.96% for total flora. Our results supported high capacity of Moringa Oleifera seeds as an excellent alternative for pathogens and antibiotics resistant bacteria reduction/purification from domestic wastewater
ARTICLE | doi:10.20944/preprints202112.0504.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: Atmosphere pollution; atmosphere contamination; hazardous substances; particulate matters; cancerogenic substances; automotive vehicles
Online: 31 December 2021 (10:52:33 CET)
The article analyzes two existing social, technical and economic problems which the world community shall focus on and pay special attention to.
REVIEW | doi:10.20944/preprints202010.0141.v1
Subject: Physical Sciences, Acoustics Keywords: space optics; mirrors; coatings; radiation; thin film; multilayer; degradation; contamination; optical systems
Online: 6 October 2020 (16:10:07 CEST)
Mirrors are a subset of optical components essential for the success of current and future space missions. Most of the telescopes for space programs ranging from Earth Observation to Astrophysics and covering the whole electromagnetic spectrum from X-rays to Far-Infrared are based on reflective optics. Mirrors operate in diverse and harsh environments that range from Low-Earth Orbit, to interplanetary orbits and the deep space. The operational life of space observatories spans from minutes (sounding rockets) to decades (large observatories), and the performance of the mirrors within the mission lifetime is susceptible to degrade, which results in a drop of the instrument throughput, which in turn affects the scientific return. Therefore, the knowledge of potential degradation mechanisms, how they affect mirror performance, and how to prevent them is of paramount importance to ensure the long-term success of space telescopes. In this review we report an overview on current mirror technology for space missions with a focus on the importance of degradation and radiation resistance of the coating materials. A special attention will be given to degradation effects on mirrors for the far and extreme UV as in these ranges the degradation is enhanced by the strong absorption of most contaminants.
ARTICLE | doi:10.20944/preprints201909.0175.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: water purification; developing countries; SDG-6; microbiological contamination; public health; membrane filtration
Online: 16 September 2019 (17:23:23 CEST)
Introduction: In rural communities in regions with limited resources the provision of clean water remains challenging. Fecal contamination of water is very common and results in a high incidence of diarrhea, subsequent acute kidney injury and mortality particularly in the very young and old. Membrane filtration is a practical solution to this problem and recent innovation allows membrane filtration using recycled hemodialyzers. We, Easy Water for Everyone, have quantified the systematic effect on health outcomes. Material and Methods: Between 02/2018 and 12/2018, 4 communities in rural Ghana (in the Greater-Accra region) were each provided with a high-volume membrane filtration devices (NUF 500; NuFiltration using recycled hemodialyzers). Health data from montly household surveys and chart review in local healthcare facilities were collected with approval from Ghana Health Services. Specifically, data was collected on gastrointestinal disease, acute kidney injury and therapeutic interventions. Incidence rates for a five-months period before and after implementation of the device were calculated and compared to rates during the same months from 4 neighboring communities that were not yet provided with the device. Results: Acceptance of the devices and the purified water in the studied villages was good and self-reported data of 1130 villagers over 10 months from 9 studied communities in rural Ghana (11% younger than 5 years and 14 % older than 65 years) were included in this analysis. The overall monthly incidence rate of diarrhea showed a decline following the implementation of the device in the 4 study villages from a mean of 0.18 to 0.05 cases per person-month for a reduction in rates by 72% (rate ratio = 0.27). By contrast, the control group of 4 villages in the same region showed no decline in mean rates during the same months as the study period with mean rates changing not significantly from 0.11 to 0.08 cases per person-month. Discussion: Provision of a hemodialyzer membrane filtration device markedly improves health outcomes as measured by diarrhea incidence within rural communities. While our data awaits confirmation in a larger population and further statistical analyses accounting for village characteristics, seasonality and subject demographics, the obvious decline in incidence rates supports widespread use of hemodialyzer membrane filtration devices, particularly in rural regions. Rollout of the device in further sites will likely increase our understanding in terms of risk and other preventive factors modifying the incidence of diarrhea and subsequent acute kidney injury.
ARTICLE | doi:10.20944/preprints202311.0085.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: seasonal variation; contamination factor; pollution load index; geo-accumulation index; enrichment factor; Narmada River
Online: 2 November 2023 (07:48:14 CET)
This study aimed to assess the presence of metal contamination in the sediments of the Narmada River by considering seasonal variations. In this context, samples were gathered from six stations along the river in 2021–22. To assess the various metals including Li, Na, Mg, Al, Ca, Fe, Cu, Zn, Co, and Ni by utilizing ICP-MS. Sediment contamination was assessed by utilizing indices like contamination factor (CF), pollution load index (PLI), geo-accumulation factor (Igeo), and enrichment factor (EF). The observed order of metals concentration revealed that metals Fe>Al>Mg>Ca>Na>Cu>Zn>Co>Ni>Li. The seasonal variation reveals metals Al, Fe, Cu, Zn, and Ni exhibit the highest concentrations during the monsoon and metals Li and Co, the highest concentration in the post-monsoon, while metals Na, Mg, and Ca, exhibit their peak concentration during the pre-monsoon. The findings from CF, PLI, Igeo, and EF indicate that there were low to moderate contaminations, metal pollution exists, uncontaminated to moderate contaminations, and minor enrichment. The cluster analysis revealed the source of contamination was anthropogenic, marine, and fertilizer activities. Additionally, Correlation matrix was employed to establish connections between metals. The findings of this research are to understand the metal contamination and potential carcinogenicity in the sediment of Narmada River.
ARTICLE | doi:10.20944/preprints202111.0240.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: pathogen detection, bacteria quantification, dark field imaging, hydrodynamic diameter, E.coli, biosensing, water contamination, magnetic microparticles
Online: 12 November 2021 (17:09:40 CET)
In this paper, we present a method for detecting and quantifying pathogens in water samples. The method proposes a portable dark field imaging and analysis system for quantifying E. coli concentrations in water after being labeled with magnetic particles. The system utilizes the tracking of moving micro/nano objects close to or below the optical resolution limit confined in small sample volumes (~ 10 µl). In particular, the system analyzes the effect of volumetric changes due to bacteria conjugation to magnetic microparticles (MP) on their Brownian motion while being suspended in liquid buffer solution. The method allows for a simple inexpensive implementation and the possibility to be used as point-of-need testing system. Indeed, a work-ing prototype is demonstrated with the capacity of quantifying E. coli colony forming units (CFU) at a range of 1x10³ - 6x10³ CFU/mL.
ARTICLE | doi:10.20944/preprints201911.0063.v2
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: contamination; pathogens; bacteria; escherichia coli; staphylococcus aureus; hygiene; shigella; salmonella; milk processing; foodborne infection; cfu
Online: 13 November 2019 (10:37:25 CET)
Pasteurized milks are still causing food borne illness. Milk contamination can occur at any stage from its way from cow to our tables. Usually milk is pure and sterile when produced in udder of a healthy cow. Like humans, cow are reservoirs of bacteria which are harmless to humans and some cows can harbour few bacteria that are harmful to humans even though they are not harmful to the cow. Milk can be contaminated during or after milking. Also, cow feeds can be contaminated with mycotoxins such as aflatoxins produced by the fungi, Aspergillus flavus. Four types of aflatoxins are known which are; aflatoxin B1, B2, G1, G2. Cows comsuming feeds contaminated with aflatoxin B1 leads to secretion in the milk of aflatoxin M1 and M2 causing aflatoxicosis. Microbial contamination of milk and dairy products is a universal problem and foodborne infections accounting for 20 million cases annually in the world have been identified as an important public health and economic problem in developed as well as developing nations. The main objective of this study was to determine milk microbial quality in Kicukiro district. The specific objectives are to identify bacteria pathogens in milk collected in Kicukiro district, to compare milk quality among sectors of Kicukiro district, to compare milk processed by industries and home-processed milk. The methodology employed in this research was cross-sectional and experimental as the study began with collection of raw data and went through laboratory analysis from July–August, 2018. The findings showed that 59.56% of the milk fell within Grade I – Grade III (< 200,000 ≤ 2,000,000 cfu/ml) and 40.42 % of the milk samples were not within the acceptable limit of total count quality as per COMESA and EAS, non-lactobacilli and fungi were present in most samples as examined through microscope and no Staphylococcus aureus was present in any sample as examined by catalase and coagulase tests.
ARTICLE | doi:10.20944/preprints201911.0008.v1
Subject: Engineering, Civil Engineering Keywords: hydroxyapatite; calcite; vivianite; onsite wastewater treatment; phreeqc; precipitation; groundwater contamination; septic tank; drainfield; reactive filter
Online: 1 November 2019 (11:21:52 CET)
The objective of this work was to evaluate the removal of phosphorus and carbon dioxide capture of a conventional septic system upgraded with a sidestream steel slag filter used in recirculation mode. A pilot scale sidestream experiment was conducted with two septic tank and drainfield systems, one with and one without a sidestream slag filter. The experimental system was fed with real domestic wastewater. Recirculation ratios of 25%, 50% and 75% were tested. Limestone soils and silica soils were used as drainfield media. The phosphorus removal efficiency observed in the second compartment of the septic tank was 30% in the slag filter upgraded system, compared to -3% in the control system. The drainfield of silica soils achieved very high phosphorus removal in both control and upgraded systems. In the drainfield of limestone soil, the slag filtration reduced the groundwater phosphorus contamination load by up to 75%. Phosphorus removal in the septic tank with a slag filter was attributed to either sorption on newly precipitated calcium carbonate or precipitation of vivianite, or both. Recirculation ratio design criteria were proposed based on simulations. Simulations showed that the steel slag filter partly inhibited biological production of carbon dioxide in the septic tank. The influent alkalinity strongly influenced the recirculation ratio needed to raise the pH in the septic tank. The control septic tank produced carbon dioxide, whereas the slag filter upgraded septic tank was a carbon dioxide sink.
ARTICLE | doi:10.20944/preprints201907.0327.v2
Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: El Teniente Cu-Mo deposit; Andean magmatism; subduction erosion; mantle source region contamination; hafnium isotopes
Online: 8 September 2019 (17:22:48 CEST)
We have determined Hf isotopic compositions of 12 samples associated with the giant El Teniente Cu-Mo deposit, Chile. The samples range in age from ≥8.9 to 2.3 Ma and provide information about the temporal evolution of their magmatic sources from the Late Miocene to Pliocene. Together with previously published data, the new analysis indicate a temporal decrease of 10 εHf(t) units, from +11.6 down to +1.6, in the 12.7 m.y. from 15 to 2.3 Ma. These variations imply increasing incorporation of continental crust through time in the magmas that formed these rocks. The fact that the samples include mantle-derived olivine basalts and olivine lamprophyres suggests that these continental components were incorporated into their mantle source, and not by intra-crustal contamination (MASH). We attribute the increase, between the Middle Miocene and Pliocene, of crustal components in the subarc mantle source below El Teniente to be due to increased subduction erosion and transport of crust into the mantle. The deposit formed above a large, long-lived, vertically zoned magma chamber that developed due to compressive deformation and persisted between the period ~7 to 4.6 Ma. Progressively more hydrous mantle-derived mafic magmas feed this chamber from below, providing heat, H2O, S and metals, but no unique “fertile” Cu-rich magma was involved in the formation of the deposit. As the volume of these mantle-derived magmas decreased from the Late Miocene into the Pliocene, the chamber crystallized and solidified, producing felsic plutons and large metal-rich magmatic-hydrothermal breccias that emplaced Cu and S into the older (≥8.9 Ma) mafic host rocks of this megabreccia deposit.
ARTICLE | doi:10.20944/preprints201812.0230.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: fish consumption; subsistence fishing; Detroit River; surveys; contamination; consumption advisories; environmental justice; mercury; PCBs; dioxins
Online: 19 December 2018 (03:15:20 CET)
Consumption guidelines are a common way to improve conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to measure. To increase the distribution and effectiveness of guideline information for the Detroit River, an educational campaign was launched in 2010, which included distribution of pamphlets with consumption information, posting of permanent signs at popular fishing locations, and hiring River Walkers to personally communicate with anglers. In 2013 and 2015, we conducted in-person surveys of active shoreline anglers to determine the effectiveness of education and outreach efforts. Results from the survey indicated that 55% of anglers were aware of the guidelines in 2013, and by 2015 36% had communicated the information to family or friends. However, anglers were often unwilling to reduce consumption of popular game species, despite high contaminant levels. Encouragingly, black anglers were most likely to supplement their diet with species lower in contaminants. Our results suggest that utilizing multiple educational strategies including reaching out directly to individual anglers may improve conscious consumption behavior among the targeted population, providing a template for educational campaigns to successfully target vulnerable populations.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: bovine colostrum; bacteria; pathogens; probiotic bacteria; cost-effective processing; heat treatment; pasteurization; contamination control; immunoglobulins; enzymes
Online: 17 September 2021 (11:51:18 CEST)
The main purpose of bovine colostrum, being the milk secreted by a cow after giving birth, is to transfer passive immunity to the calf. The calves have an immature immune system as they lack immunoglobulins (Igs). Subsequently, the supply of good quality bovine colostrum is required. The quality of colostrum is classified by low bacterial counts and adequate Ig concentrations. Bacterial contamination can contain a variety of human pathogens or high counts of spoilage bacteria, which becomes more challenging with emerging use of bovine colostrum as food and food supplements. There is also a growing risk for the spread of zoonotic diseases originating from bovines. For this reason, processing based on heat treatment or other feasible techniques are required. This review provides an overview of literature on the microbial quality of bovine colostrum and processing methods to improve its microbial quality and keep its nutritional values as food. The highlights of this review are: high quality colostrum is a valuable raw material in food products and supplements, the microbial safety of bovine colostrum is increased using appropriate processing-suitable effective heat treatment, which does not destroy the high nutrition value of colostrum, the heat treatment processes are cost-effective compared to other methods, and heat treatment can be performed in both small- and large-scale production.
ARTICLE | doi:10.20944/preprints202004.0265.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: epidemic; COVID-19; contamination kinetics; immunological response; dynamical systems; reproduction rate; critical state; attractor; stable cycle; chaos
Online: 16 April 2020 (08:20:50 CEST)
In the context of the COVID-19 epidemic, and on the basis of the Theory of Dynamical Systems, we propose a simple model for the expansion of contagious diseases, with a particular focus on viral respiratory tracts. The infection develops through contacts between contagious and exposed people, with a rate proportional to contact duration and turnover, inversely proportional to the efficiency of protection measures, and balanced by the average immunological response. The obvious initial exponential increase is readily hindered by the size reduction of the exposed population. The system converges towards a stable attractor whose value is expressed in terms of the ratio C/D of contamination vs decay factors. Decreasing this ratio below a critical value leads to a tipping point beyond which the epidemic is over. By contrast, significant values of C/D may bring the system through a bifurcating hierarchy of stable cycles up to a chaotic behaviour.
ARTICLE | doi:10.20944/preprints201706.0014.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: air pollution; soil hydraulic parameters; geochemical characterization of soils; aquifer vulnerability to contamination; health assessment; multi-criteria environmental analysis
Online: 2 June 2017 (06:25:00 CEST)
This paper deals with the environmental characterization of a large and densely populated area, with a poor reputation for contamination, considering the contribution of environmental features (air, soil, soil hydraulic and groundwater) and the potential effects on human health. The use of Geographic Information System (GIS) has made possible a georeferenced inventory and, by overlaying environmental information, an operational synthesis of comprehensive environmental conditions. The cumulative effects on environmental features were evaluated, taking into account superposition effects, by means of the spatial multicriteria decision analysis (S-MCDA). The application of the S-MCDA for converging the combination of heterogeneous factors, related to soil, land and water, deeply studied by heterogeneous groups of experts, constitutes the novelty of the paper. The results confirmed an overall higher potential of exposure to contaminants in the environment and higher mortality rates in the study area for some tumours, but hospital admissions for tumours were generally similar to the regional trend. Besides, mortality data may be strictly dependent on the poor socioeconomic conditions, quality of therapy and a lack of welfare in the area relative to the rest of Italy. Finally, as regards the possible relationship between presence of contaminants in the environment and health conditions of the population no definite conclusions can be drawn, although the present study encourages the use of the new proposed methods, that increase the possibilities for studying the combined effect of more environmental factors.
ARTICLE | doi:10.20944/preprints202303.0132.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Toxoplasma gondii; rodents; rodent-borne diseases; environment contamination; biomonitoring; wildlife; molecular detection; PCR assay; nested-PCR assay prevalence; serological detection; agglutination test; ELISA method; seroprevalence
Online: 7 March 2023 (09:38:21 CET)
Rodents are known to be reservoirs of Toxoplasma gondii and keep the parasite circulation in the environment. We conducted biomonitoring to assess the role of sylvatic rodents in maintaining T. gondii and to analyse the prevalence and seroprevalence of the parasite in seven wild rodent species. Rodents were collected in our study sites (woodland and open grasslands) located in northeastern Poland and dissected. We collected brain, spleen, blood and serum samples. We applied both molecular (PCR assay, nested-PCR assay) and serological (ELISA and agglutination tests) methods to indicate the best approach for application in the biomonitoring of T. gondii in small mammals. We screened samples from 95 individuals sing PCR assays and found no T. gondii DNA. The agglutination test showed no signal. We found antibodies against T. gondii in 6 sera samples out of 74 analysed (seroprevalence = 8.11% [4.0-17.1]). Our results confirm that rodents participate in the life cycle of T. gondii as reservoirs of this parasite in the sylvatic environment. However, biomonitoring should be performed with the ELISA tests to search for T. gondii antigens, rather than a molecular approach only.