HCH Isomers Research Articles

Хлорорганические соединения в атлантической треске (Gadus morhua) и морской камбале (Pleuronectes platessa) Баренцева моря

This paper studies the content of organochlorine pesticides and PCBs in muscle and liver of Atlantic cod and plaice, caught in the Barents Sea in 2016-2022. Chromatograph mass spectrometry is used to detect the content of organochlorine compounds in fish. The concentrations of HCB, α-HCH, β-HCH, γ-HCH, cis-chlordane, trans-chlordane, and trans-nonachlor in fish tissues are quantified, along with DDT and its metabolites, as well as PCB congeners with numbers 28, 31, 52, 99, 101, 105, 118, 138, 153, 156 and 180. The average content of ∑HCHs, HCB, ∑DDTs and ∑PCBs in cod muscle is 0.7, 0.06, 0.81 and 1.0 ng/g, and their average content in plaice muscle is 2.3, 0.66, 2.3 and 3.5 ng/g of wet weight, respectively. In cod liver, the average content of ∑HCHs, HCB, ∑DDTs, ∑PCBs, ∑chlordanes is 3.3, 3.0, 36.8, 65.4 and 30.9 ng/g, and their average content in plaice liver is 4.6, 6.5, 19.1, 10.9 and 4.8 ng/g of wet weight, respectively. The studies show that in fish tissue α-HCH predominates in ∑HCHs, ppꞌ-DDE — in ∑DDTs and PCB-118, PCB-138 and PCB-153 — in ∑PCBs. The accumulation of organochlorine compounds in fish tissue is found to be species-specific in terms of content level and ratio of HCH isomers, DDT isomers and metabolites, PCB congeners and chlordanes. The content of ∑HCHs, ∑DDTs and ∑PCBs in fish muscle and liver do not exceed the safe standards established for fish products.

The use of lichens and mosses as sentinel organisms for the determination of the airborne organic pollution in Western Pyrenees: the case of the Irati Forest

High mountain ranges are very sensitive environments. Due to their altitude, they are prone to receive pollution from long-range transport through the atmosphere. The Pyrenees is a good example of these mountain ranges that extend from the Matxitxako Cape (Basque Country) to the Creus Cape (Catalonia) with altitudes up to about 3400 m.In this article, the ability of lichens and mosses to accumulate Persistent Organic Pollutants (POPs) and consequently, to serve as indicators of atmospheric organic pollution is investigated. For this purpose, 50 lichens and mosses were collected in the Irati Forest (Western Pyrenees), one of the largest and best-preserved beech and fir forests in Europe. One species of lichens (Parmelia sulcata) and one species of mosses (Hypnum cupressiforme) were collected from 10 different beech trees at each sampling point. A microwave assisted extraction of the samples with a mixture of of 1:1 (v:v) acetone:hexane was done before the determination of 16 PAHs, 11 PCBs and 10 OCPs was determined by GC-MS.Generally, PAHs presented significantly higher concentrations (with a maximum concentration of 1190 ng/g in lichens and 585 ng/g in mosses) than PCBs (maximum concentration 220 ng/g in lichens and 587 in mosses) and OCPs (maximum concentration 550 ng/g in lichens and 692 in mosses) in both matrices. Regarding PAHs Ace, Flu, Flr, Nap and Phe presented in our study the highest concentrations in both mosses and lichens and with respect to PCBs and OCPs PCB-194 and HCH isomers stood out respectively.The spatial distribution of POPs revealed that generally the distribution of POPs obtained with both matrices was similar, with a common hotspot located in the centre area of the Forest. Despite pollution from long-range transport through the atmosphere cannot be underestimated, the work presented here revealed that the urban and agricultural activities carried out in the proximities of the Irati Forest during decades have still effect in the air quality regarding PCBs and OCPs. As the analysis of mosses showed, in order to avoid high presence of PAHs in the atmosphere of the Irati Forest, activities related with combustion processes carried out around the forest have to be controlled.

Biochar-Supported Phytoremediation of Dredged Sediments Contaminated by HCH Isomers and Trace Elements Using Paulownia tomentosa

The remediation of dredged sediments (DS) as a major waste generation field has become an urgent environmental issue. In response to the limited strategies to restore DS, the current study aimed to investigate the suitability of Paulownia tomentosa (Thunb.) Steud as a tool for decontamination of DS, both independently and in combination with a sewage sludge-based biochar. The experimental design included unamended and biochar-supplemented DS with the application rates of 2.5, 5.0, and 10.0%, in which vegetation of P. tomentosa was monitored. The results confirmed that the incorporation of biochar enriched DS with the essential plant nutrients (P, Ca, and S), stimulated biomass yield and improved the plant’s photosynthetic performance by up to 3.36 and 80.0 times, respectively; the observed effects were correlated with the application rates. In addition, biochar enhanced the phytostabilisation of organic contaminants and shifted the primary accumulation of potentially toxic elements from the aboveground biomass to the roots. In spite of the inspiring results, further research has to concentrate on the investigation of the mechanisms of improvement the plant’s development depending on biochar’s properties and application rate and studying the biochar’s mitigation effects in the explored DS research system.

Co-metabolic growth and microbial diversity: Keys for the depletion of the α, δ, β and γ-HCH isomers

The objective of this study was the isolation and enrichment of microbiomes capable of degrading the main hexachlorocyclohexane isomers quantified in environmental matrices, e.g.: the α, δ, β and γ-HCH isomers. Four microbiomes were isolated and enriched from an HCH-contaminated dumpsite in Italy, both in the presence of HCH isomers (1:1:1:1) as the sole carbon sources and under co-metabolic growth conditions in presence of glucose (0.1 % v/v). The microbiomes were assessed for their relevant metabolic capabilities. A quantitative metabarcoding approach was employed to analyze the compositional evolution of the four microbiomes during the enrichment phase and the phase of testing of the HCH isomers degradation kinetics. The use of a co-metabolic substrate during enrichment process was essential for selecting microbiomes with higher biodiversity. All microbiomes efficiently degraded the α, δ, and γ-HCH isomers. The highest efficiency in the β-HCH degradation capacity was positively correlated to the highest biodiversity of the microbiome, and the involvement of Chryseobacterium and Asinibacterium sps. have been proposed for a recorded increment in bacterial load during the HCH degradation process.

What potential do mosses have as biomonitors of POPs? A comparative study of hexachlorocyclohexane sorption

Persistent organic pollutants (POPs) pose a significant global threat to human health and the environment, and require continuous monitoring due to their ability to migrate long distances. Active biomonitoring using cloned mosses is an inexpensive but underexplored method to assess POPs, mainly due to the poor understanding of the loading mechanisms of these pollutants in mosses. In this work, Fontinalis antipyretica (aquatic moss) and Sphagnum palustre (terrestrial moss) were evaluated as potential biomonitors of hexachlorocyclohexanes (HCHs: α-, β-, γ-, δ-HCH), crucial POPs. Moss clones, grown in photobioreactors and subsequently oven-dried, were used. Their lipid composition and distribution were characterized through molecular and histochemical studies. Adsorption experiments were carried out in the aqueous phase using the repeated additions method and in the gas phase using an active air sampling technique based on solid-phase extraction, a pioneering approach in moss research. F. antipyretica exhibited greater lipid content in the walls of most cells and higher adsorption capacity for all HCH isomers in both gaseous and liquid environments. These findings highlight the need for further investigation of POP loading mechanisms in mosses and open the door to explore other species based on their lipid content.

Enhancing hexachlorocyclohexane solubility with surfactants and ionic liquids

Surfactant-enhanced remediation of soil can increase the solubility of hydrophobic organic contaminants in water and improve their removal. In this study, the effect of 24 traditional surfactants and surface-active ionic liquids (SAILs) on the solubility of hexachlorocyclohexane isomers (α-, β-, γ-, δ-HCH) was evaluated in batch-type experiments. The combination of two different proportions of a cationic SAIL and an anionic surfactant was also assessed. The solubilisation capacity of the surfactant varied depending on its concentration and structure, but also the HCH isomer considered. In general, the anionic surfactants yielded the best results, increasing solubilisation of HCH up to 2.4 times compared to the control (pure water). α-HCH and γ-HCH isomers were more easily solubilised than β-HCH and δ-HCH regardless of the surfactant’s type. The main advantage of ionic liquids being their tunability, some clues are given for formulating surfactants to enhance the solubilisation of HCH. The combination of a traditional surfactant and a SAIL influenced the critical micelle concentration, but not the solubilisation of the contaminant. Further studies on the use of blends for this application are required. The increase of solubility achieved with the studied surfactants encourages their application in washing HCH-contaminated soils through solubility enhancement.

ҚАЗАҚСТАН РЕСПУБЛИКАСЫНЫҢ СОЛТҮСТІК ӨҢІРІНІҢ ЖОҒАРҒЫ ТОБЫЛ ЖӘНЕ ҚАРАТОМАР СУ ҚОЙМАЛАРЫНЫҢ СУЛАРЫНДА ПЕСТИЦИДТЕР, ХЛОРОРГАНИКАЛЫҚ ҚОСЫЛЫСТАР ЖӘНЕ ОРГАНИКАЛЫҚ ТОКСИКАНТТАРДЫҢ ҚҰРАМЫН КЕШЕНДІ БАҒАЛАУ

The article presents the results of comprehensive studies of the Verkhnetobol and Karatomar reservoirs in Kazakhstan, focusing on the content of pesticides, organochlorides, and organic toxicants such as phenol, petroleum products, and surfactants. Various organochlorine pesticides (alpha, beta, and gamma isomers of HCH, heptachlor, DDT, DDE, DDD, aldrin, hexachlorobenzene, lindane, 2,4-D) were analyzed, as well as levels of bromodichloromethane, dibromochloromethane, carbon tetrachloride, benz(a)pyrene, atrazine, simazine, phenol, formaldehyde, and surfactants. Laboratory studies were conducted according to state, interstate, and international regulations on water sampling, quality control, and toxicology of drinking and natural waters using physico-chemical methods. There were no exceedances of the MPC standards for the content of pesticides, organochlorides and organic toxicants. According to the requirements of the unified water quality classification system of the Republic of Kazakhstan, the content of the studied toxicants does not exceed the values of the indicators of the first and second classes of water quality. The waters of these water use classes are suitable for all categories of water use. In case of use for household and drinking purposes, simple water treatment methods are required. The legal and regulatory documents governing state environmental water control in Kazakhstan and scientific recommendations on the quality and toxicology of drinking and natural waters, including hygienic standards for economic, drinking, and cultural use, are considered. The results serve as reference data and methodological recommendations for assessing reservoirs in the temperate climatic zone for pesticides and organic toxicants.

Lindane removal by membrane nanofiltration

Lindane is the γ-isomer of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) and it has been widely used in the pesticide industry due to its insecticide properties. In the production of lindane, significant quantities of other HCH isomers are generated as byproducts. All these compounds are typically stored in landfills, often with poor management practices. Polyamide membranes, two commercial membranes from Alfa Laval (NF99HF and NF99) and homemade thin film composite membranes prepared by interfacial polymerization on a porous polyimide support, were evaluated for water nanofiltration (NF) of HCH isomers, including lindane. Homemade membranes, with a lindane rejection of 91.3 % and a permeance of 2.7 L·m−2·h−1·bar−1, offered the highest performance in terms of both permeance and rejection. NF99 and homemade membranes were proven to be equally effective in removing α-HCH and β-HCH, showing similar results. Homemade membranes achieved 99.5 and 99.8 % rejections for α-HCH and β-HCH, respectively. Long-term experiments were carried out with NF99 and homemade membranes to assess their stability during filtrations with lindane solutions for up to 214 h. Homemade TFC membrane maintained its initial rejection (ca. 93.5 %) after 214 h, although its permeance decreased over time, ending in 2.5 L·m−2·h−1·bar−1.

Targets for pollutants in rat and human pancreatic beta-cells: The effect of prolonged exposure to sub-lethal concentrations of hexachlorocyclohexane isomers on the expression of function- and survival-related proteins

Decades after most countries banned hexachlorocyclohexane, HCH isomers still pollute the environment. Many studies described HCH as a pro-diabetic factor; nevertheless, the effect of HCH isomers on pancreatic beta-cells remains unexplored. This study investigated the effects of a one-month exposure to α-HCH, β-HCH, and γ-HCH on protein expression in human (NES2Y) and rat (INS1E) pancreatic beta-cell lines. α-HCH and γ-HCH increased proinsulin and insulin levels in INS1E cells, while β-HCH showed the opposite trend. α-HCH altered the expression of PKA, ATF3, and PLIN2. β-HCH affected the expression of GLUT1, GLUT2, PKA, ATF3, p-eIF2α, ATP-CL, and PLIN2. γ-HCH altered the expression of PKA, ATF3, PLIN2, PLIN5, and IDH1. From the tested proteins, PKA, ATF3, and PLIN-2 were the most sensitive to HCH exposure and have the potential to be used as biomarkers.

Levels of persistent organic pollutants (POPs) in the Antarctic atmosphere over time (1980 to 2021) and estimation of their atmospheric half-lives

Abstract. Persistent organic pollutants (POPs) are synthetic compounds that were intentionally produced in large quantities and have been distributed in the global environment, originating a threat due to their persistence, bioaccumulative potential, and toxicity. POPs reach the Antarctic continent through long-range atmospheric transport (LRAT). In these areas, low temperatures play a significant role in the environmental fate of POPs, retaining them for a long time due to cold trapping by diffusion and wet deposition, acting as a net sink for many POPs. However, in the current context of climate change, the remobilization of POPs that were trapped in water, ice, and soil for decades is happening. Therefore, continuous monitoring of POPs in polar air is necessary to assess whether there is a recent re-release of historical pollutants back to the environment. We reviewed the scientific literature on atmospheric levels of several POP families (polychlorinated biphenyls – PCBs, hexachlorobenzene – HCB, hexachlorocyclohexanes – HCHs, and dichlorodiphenyltrichloroethane – DDT) from 1980 to 2021. We estimated the atmospheric half-life using characteristic decreasing times (TD). We observed that HCB levels in the Antarctic atmosphere were higher than the other target organochlorine pesticides (OCPs), but HCB also displayed higher fluctuations and did not show a significant decrease over time. Conversely, the atmospheric levels of HCHs, some DDTs, and PCBs have decreased significantly. The estimated atmospheric half-lives for POPs decreased in the following order: 4,4' DDE (13.5 years) > 4,4' DDD (12.8 years) > 4,4' DDT (7.4 years) > 2,4' DDE (6.4 years) > 2,4' DDT (6.3 years) > α-HCH (6 years) > HCB (6 years) > γ-HCH (4.2 years). For PCB congeners, they decreased in the following order: PCB 153 (7.6 years) > PCB 138 (6.5 years) > PCB 101 (4.7 years) > PCB 180 (4.6 years) > PCB 28 (4 years) > PCB 52 (3.7 years) > PCB 118 (3.6 years). For HCH isomers and PCBs, the Stockholm Convention (SC) ban on POPs did have an impact on decreasing their levels during the last decades. Nevertheless, their ubiquity in the Antarctic atmosphere shows the problematic issues related to highly persistent synthetic chemicals.

Comprehensive study of acute toxicity using Microtox® bioassay in soils contaminated by lindane wastes

This research studies the acute toxicity of real contaminated soils (topsoil and subsoil) with hazardous chlorinated organic compounds (COCs) from lindane manufacturing wastes. The Microtox® bioassay was used to determine the toxicity of soils (modified Basic Solid Phase Test), soil elutriates (Basic Test), and organic extracts (adapted Organic Solvent Sample Solubilization Test), in which hydrophobic organic compounds are soluble. The acute toxicity of these persistent contaminants (hexachlorocyclohexanes, HCH isomers, as particulate matter in topsoil, and COCs, from dense non-aqueous phase liquid, DNAPL, in subsoil) and the commercial compounds were also measured. Soils tested showed different contaminant levels (topsoil: 0.9–1149 mg/kg and subsoil: 20–9528 mg/kg). Soil contaminants distribution, concentration and acute toxicity were highly related to the contamination source (HCHs or DNAPL). Soils, organic extracts, and subsoil elutriates presented high toxicity, highlighting the need for remediation of these sites. EC50 was calculated in the three-test applied for the soils tested. EC50 vs. COCs concentration in soils and soil elutriates showed an asymptotic trend, explained by the low pollutants solubility in the aqueous phase. Contrarily, EC50 vs. soil COCs concentration was more linear in the case of the organic extracts. This test was the most reliable from statistical analysis. The three methods reveal interesting and complementary information and are necessary for a complete overview of the acute toxicity of contaminated soils.

Uptake and Metabolization of HCH Isomers in Trees Examined over an Annual Growth Period by Compound-Specific Isotope Analysis and Enantiomer Fractionation.

To understand the role of plants for natural attenuation, a field study was conducted to characterize the fate of HCH in trees over an annual growth period using compound-specific isotope analysis and enantiomer fractionation. Stable and slightly higher δ13C and δ37Cl values of HCH of host soil samples compared to the muck (consisting nearly exclusively of HCH) revealed that masking isotope effects caused by the limited bioavailability may underestimate the real extent of HCH transformation in soil. In contrast, an increase of δ13C and δ37Cl values in trees indicated the transformation of HCH. A large variability of δ13C and δ37Cl values in trees over the growth period was observed, representing different transformation extents among different growth times, which is further supported by the shift of the enantiomer fraction (EF), indicating the preferential transformation of enantiomers also varied over the different growth periods. Based on dual-element isotope analysis, different predominant transformation mechanisms were observed during the growing seasons. Our observation implies that plants are acting as biological pumps driving a cycle of uptake and metabolization of HCH and refeed during littering to soil catalyzing their transformation. The changes of the transformation mechanism in different seasons have implications for phytoscreening and shed new light on phytoremediation of HCH at field sites.

HCH Removal in a Biochar-Amended Biofilter

This study evaluated the efficiency of two biofilter systems, with and without biochar chambers installed, at degrading and removing HCH and its isomers in natural drainage water. The biochar biofilter proved to be 96% efficient at cleaning HCH and its transformation products from drainage water, a significant improvement over classic biofilter that remove, on average, 68% of HCH. Although iron- and sulfur-oxidizing bacteria, such as Gallionella and Sulfuricurvum, were dominant in the biochar bed outflows, they were absent in sediments, which were rich in Simplicispira, Rhodoluna, Rhodoferax, and Flavobacterium. The presence of functional genes involved in the biodegradation of HCH isomers and their byproducts was confirmed in both systems. The high effectiveness of the biochar biofilter displayed in this study should further encourage the use of biochar in water treatment solutions, e.g., for temporary water purification installations during the construction of other long-term wastewater treatment technologies, or even as final solutions at contaminated sites.

Soil from a Hexachlorocyclohexane Contaminated Field Site Inoculates Wheat in a Pot Experiment to Facilitate the Microbial Transformation of β-Hexachlorocyclohexane Examined by Compound-Specific Isotope Analysis.

β-Hexachlorocyclohexane (β-HCH) is a remnant from former HCH pesticide production. Its removal from the environment gained attention in the last few years since it is the most stable HCH isomer. However, knowledge about the transformation of β-HCH in soil-plant systems is still limited. Therefore, experiments with a contaminated field soil were conducted to investigate the transformation of β-HCH in soil-plant systems by compound specific isotope analysis (CSIA). The results showed that the δ13C and δ37Cl values of β-HCH in the soil of the planted control remained stable, revealing no transformation due to a low bioavailability. Remarkably, an increase of the δ13C and δ37Cl values in soil and plant tissues of the spiked treatments were observed, indicating the transformation of β-HCH in both the soil and the plant. This was surprising as previously it was shown that wheat is unable to transform β-HCH when growing in hydroponic culture or garden soil. Thus, results of this work indicate for the first time that a microbial community of the soil inoculated the wheat and then facilitated the transformation of β-HCH in the wheat, which may have implications for the development of phytoremediation concepts. A high abundance of HCH degraders belonging to Sphingomonas sp., Mycobacterium sp., and others was detected in the β-HCH-treated bulk and rhizosphere soil, potentially supporting the biotransformation.

Contamination of Water, Sediment and Fish with Residues of Pesticides Used in Cotton Production in Northern Benin.

In Northern Benin, insecticides are used for cotton production. These insecticides can be easily transferred to water ponds close to cotton fields. To monitor insecticides levels in water, sediments and fish samples from water ponds, a GC-MS analytical method was developed to detect residues of endosulfan, DDT and its parent compounds, isomers of HCH, pyrethroids and chlorpyrifos. In addition, the influence of storage conditions of water sample on pesticides determination performance has been studied. The limits of quantification were between 0.16 and 0.32µg/L in water, 0.5 and 1μg/kg in sediment and 1 and 2μg/kg in fish. Twenty samples of water, twenty of sediments and forty of fish were taken in four different water reservoirs at five different times. Alpha-endosulfan, lambda-cyhalothrin and permethrin were identified in sediment while p,p'-DDE, α- and β-HCH, chlorpyrifos, lambda-cyhalothrin and permethrin were detected in fish. Only organochlorines were determined in water because of the lack of recovery of pyrethroids from water stored in glass. Concentrations of insecticide residues in sediment for all water ponds ranged from non-detected to 101µg/kg and from non-detected to 36µg/kg in fish. Preliminary risk assessment for consumers of the North of Benin showed that the Estimated Daily Intakes were lower than the Acceptable Daily Intakes and Acute Reference Doses for all consumers. However, as one fish can be contaminated by five pesticide residues at the same time, it is not possible to exclude a risk for the consumer due to his exposure to mixtures of pesticides.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Pacific salmon from the Kamchatka Peninsula and Sakhalin Island, Northwest Pacific

The purpose of the present study was to determine levels of POPs (dieldrin, endrin, HCH isomers, DDT metabolites, and PCB congeners) in organs of chum (Oncorhynchus keta), pink (O. gorbuscha), sockeye (O. nerka), masu (O. masou), and Chinook salmon (O. tshawytscha), and to identify the patterns of toxicants' distribution in organisms and the environment of the northwestern Pacific. Principal component factor analysis showed that all the salmon species typically exhibit relationships between the PCB congeners and are characterized by a similar pattern of entry of PCBs 101, 118, and 153. The OCPs levels in the organs of Pacific salmon are decreasing from 2012 to 2018, which suggests the elimination of these toxicants from the northwestern Pacific Ocean.

Human exposure to organochlorine, pyrethroid and neonicotinoid pesticides: Comparison between urban and semi-urban regions of India.

In developing countries, urban areas may be at greater risk of pesticide exposure compared to semi-urban agricultural regions. To investigate this, concentrations of selected pesticides were measured in 81 human milk samples collected in urban Kolkata and semi-urban Nadia in West Bengal, India. Three classes of pesticides were investigated - legacy organochlorines and emerging pyrethroids and neonicotinoids. The average concentration of the majority of the chemicals (DDT, its metabolites, HCH isomers, bifenthrin, endosulfan), showed a clear urban>semi-urban trend. Compared with previous measurements in other Indian cities and developing nations, current HCH and DDT concentrations in urban Kolkata were high. These chemicals were detected in 100% of the samples in both the urban and the semi-urban region. Also in both regions, the Estimated Daily Intake of DDTs, HCHs, aldrin, dieldrin and the pyrethroid bifenthrin for breastfed infants exceeded the Tolerable Daily Intake in a number of samples. Three pyrethroids were detected in human milk samples in India for the first time. This indicates a shift in the usage pattern of pesticides in India from organochlorines to pyrethroids. These findings may be used to drive targeted regulation of pesticides in developing countries with similar histories of pesticide use.

β-Hexachlorocyclohexane: A Small Molecule with a Big Impact on Human Cellular Biochemistry.

Organochlorine pesticides (OCPs) belong to a heterogeneous class of organic compounds blacklisted by the Stockholm Convention in 2009 due to their harmful impact on human health. Among OCPs, β-hexachlorocyclohexane (β-HCH) is one of the most widespread and, at the same time, poorly studied environmental contaminant. Due to its physicochemical properties, β-HCH is the most hazardous of all HCH isomers; therefore, clarifying the mechanisms underlying its molecular action could provide further elements to draw the biochemical profile of this OCP. For this purpose, LNCaP and HepG2 cell lines were used as models and were subjected to immunoblot, immunofluorescence, and RT-qPCR analysis to follow the expression and mRNA levels, together with the distribution, of key biomolecules involved in the intracellular responses to β-HCH. In parallel, variations in redox homeostasis and cellular bioenergetic profile were monitored to have a complete overview of β-HCH effects. Obtained results strongly support the hypothesis that β-HCH could be an endocrine disrupting chemical as well as an activator of AhR signaling, promoting the establishment of an oxidative stress condition and a cellular metabolic shift toward aerobic glycolysis. In this altered context, β-HCH can also induce DNA damage through H2AX phosphorylation, demonstrating its multifaceted mechanisms of action.

Prediction of Malignant Breast Cancer Cases Using Ensemble Machine Learning: A Case Study of Pesticides Prone Area

Cancer of the female breast is one of the leading types of cancers worldwide. This paper presents a case study of Malwa Belt in India that has witnessed the proliferation in the overall mortality rate due to breast cancer. The paper researches mortality aspect of the disease and its association with the various risk parameters including demographic characteristics, percentage of pesticides residue present in the water and soil, life style of the women in the affected area, water intake, and the amount of pesticide exposure to the patient. The levels of organochlorine pesticides like DDT and its metabolites and isomers of HCH in blood, tumor and surrounding adipose are estimated. Additionally, an extent of exposure of the subjects to environmental pollutants like heavy metals (Lead, Copper, Iron, Zinc, Calcium, Selenium, and Chromium etc.)are also examined. For the obtained experimental data, an efficient ensemble machine learning based framework called Bagoost is proposed to predict the risk of breast cancer in Malwa women. The performance of the proposed machine learning model results in an accuracy of 98.21 percent, when empirically tested using K-fold cross validation over the real time data of malignant and benign cases and is established to be efficacious than the existing approaches.

Seasonal levels of pesticide residues in the main and the Blue Nile waters in Sudan

Levels of twenty-two commonly used pesticides were monitored three times a year (autumn, winter, and summer) in 54 water samples collected from six sites representing the main and Blue Nile. These sites were selected to reflect any attributes from main drainage canals from agricultural schemes in Sudan as well as any impact from upstream sources. Collected samples were subject to gas chromatographic analysis equipped with FID/ECD, and results were expressed in ng/l water. Analysis of Blue Nile water indicated the presence of OCs in 45% of the samples, OPs in 11%, pyrethroids in 22%, and none of the tested herbicides. Heptachlor and DDTs were the most prevalent followed by the pyrethroids. Levels detected were not high. Water of the main Nile showed the presence of OCs in 22% of the samples, pyrethroids in 4%, and none of the tested OPs and herbicides. DDT is the most prevalent followed by heptachlor. Total concentration in main Nile is relatively higher than the Blue Nile. Residues of DDD, λ cyhalothrin, deltamethrin, oxyfluorfen, HCH, and endosulfan isomers were not detected in the analyzed samples. Generally levels were least in autumn, followed by summer and winter. Sources of contamination might include some drains from agricultural lands in central Sudan and/or upstream sources. Both recent and old contaminations were indicated.