Transgenic Arabidopsis thaliana plants expressing bacterial γ-hexachlorocyclohexane dehydrochlorinase LinA.

BACKGROUND: γ-Hexachlorocyclohexane (γ-HCH), an organochlorine insecticide of anthropogenic origin, is a persistent organic pollutant (POP) that causes environmental pollution concerns worldwide. Although many γ-HCH-degrading bacterial strains are available, inoculating them directly into γ-HCH-contaminated soil is ineffective because of the low survival rate of the exogenous bacteria. Another strategy for the bioremediation of γ-HCH involves the use of transgenic plants expressing bacterial enzyme for γ-HCH degradation through phytoremediation. RESULTS: We generated transgenic Arabidopsis thaliana expressing γ-HCH dehydrochlroninase LinA from bacterium Sphingobium japonicum strain UT26. Among the transgenic Arabidopsis T2 lines, we obtained one line (A5) that expressed and accumulated LinA well. The A5-derived T3 plants showed higher tolerance to γ-HCH than the non-transformant control plants, indicating that γ-HCH is toxic for Arabidopsis thaliana and that this effect is relieved by LinA expression. The crude extract of the A5 plants showed γ-HCH degradation activity, and metabolites of γ-HCH produced by the LinA reaction were detected in the assay solution, indicating that the A5 plants accumulated the active LinA protein. In some A5 lines, the whole plant absorbed and degraded more than 99% of γ-HCH (10 ppm) in the liquid medium within 36 h. CONCLUSION: The transgenic Arabidopsis expressing active LinA absorbed and degraded γ-HCH in the liquid medium, indicating the high potential of LinA-expressing transgenic plants for the phytoremediation of environmental γ-HCH. This study marks a crucial step toward the practical use of transgenic plants for the phytoremediation of POPs.

Agricultural pesticides in feathers of the burrowing owl (Athene cunicularia) and its relationship to land-use in the argentinean pampas.

The pampas of South America represent one of the most productive lands for agriculture in the world, and consequently this activity has expanded throughout the region, especially in Argentina. In this context, native fauna faces various risks associated with agriculture, with exposure to pesticides being one of the most dangerous and deadly. Assessing the impact of pesticides on wildlife becomes fundamental and the use of sentinel species emerges as an important tool to monitor environmental health. In this study, we determined pesticide levels in the burrowing owl Athene cunicularia nesting in both rural and urban areas of the argentinean pampas. We used a multiple scale approach to evaluate the influence of land-uses (urban, crops, and grazing fields) at the nesting site on the contaminant load of A. cunicularia individuals, and assessed the potential use of this owl as a sentinel species. From March 2018 to January 2020, A. cunicularia feathers were collected at their nest sites in one urban and two rural areas. These samples were analyzed for the presence of contaminants, including chlorpyrifos and 18 organochlorine pesticides. All the compounds analyzed were detected in A. cunicularia samples. The chlorpyrifos showed the highest frequency of occurrence and concentration, thus denoting the exposure of owls to current-use pesticides. ∑DDTs showed the highest occurrence among organochlorines, followed by ∑HCHs > ∑Endosulfans > ∑Heptachlors > ∑Drins = ∑Chlordanes > methoxychlor. Principal Component Analysis showed that most of the compounds found in A. cunicularia samples showed a positive association with grazing fields, suggesting that exposure to contaminants does not depend on specific habitat use at the local scale, but probably the regional scale. Our results evidenced the exposure of A. cunicularia individuals to past and current-use pesticides in the pampas of Argentina, and indicate that this owl would be useful as a sentinel species.

Differentiated cognition of the effects of human activities on typical persistent organic pollutants and bacterioplankton community in drinking water source.

Accelerated urbanization in developing countries led to a typical gradient of human activities (low, moderate and high human activities), which affected the pollution characteristics and ecological functions of aquatic environment. However, the occurrence characteristics of typical persistent organic pollutants, including organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs), and bacterioplankton associated with the gradient of human activities in drinking water sources is still lacking. Our study focused on a representative case - the upper reaches of the Dongjiang River (Pearl River Basin, China), a drinking water source characterized by a gradient of human activities. A comprehensive analysis of PAHs, OCPs and bacterioplankton in the water phase was performed using gas chromatography-mass spectrometry (GC-MS) and the Illumina platform. Moderate human activity could increase the pollution of OCPs and PAHs due to local agricultural activities. The gradient of human activities obviously influenced the bacterioplankton community composition and interaction dynamics, and low human activity resulted in low bacterioplankton diversity. Co-occurrence network analysis indicated that moderate human activity could promote a more modular organization of the bacterioplankton community. Structural equation models showed that nutrients could exert a negative influence on the composition of bacterioplankton, and this phenomenon did not change with the gradient of human activities. OCPs played a negative role in shaping bacterioplankton composition under the low and high human activities, but had a positive effect under the moderate human activity. In contrast, PAHs showed a strong positive effect on bacterioplankton composition under low and high human activities and a weak negative effect under moderate human activity. Overall, these results shed light on the occurrence characteristics of OCPs, PAHs and their ecological effects on bacterioplankton in drinking water sources along the gradient of human activities.

Per- and polyfluoroalkyl substances, polychlorinated biphenyls, organochlorine pesticides, and polybrominated diphenyl ethers and dysregulation of MicroRNA expression in humans and animals-A systematic review.

BACKGROUND: Persistent organic pollutants (POPs) are chemicals characterized by their environmental persistence. Evidence suggests that exposure to POPs, which is ubiquitous, is associated with microRNA (miRNA) dysregulation. miRNA are key regulators in many physiological processes. It is thus of public health concern to understand the relationships between POPs and miRNA as related to health outcomes. OBJECTIVES: This systematic review evaluated the relationship between widely recognized, intentionally manufactured, POPs, including per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (dichlorodiphenyltrichloroethane [DDT], dichlorodiphenyldichloroethylene [DDE], hexachlorobenzene [HCB]), with miRNA expression in both human and animal studies. METHODS: We used PubMed and Embase to systematically search the literature up to September 29th, 2023. Search results for human and animal studies were included if they incorporated at least one POP of interest in relation to at least one miRNA. Data were synthesized to determine the direction and significance of associations between POPs and miRNA. We utilized ingenuity pathway analysis to review disease pathways for miRNA that were associated with POPs. RESULTS: Our search identified 38 eligible studies: 9 in humans and 29 in model organisms. PFAS were associated with decreased expression of miR-19, miR-193b, and miR-92b, as well as increased expression of miR-128, miR-199a-3p, and miR-26b across species. PCBs were associated with increased expression of miR-15a, miR-1537, miR-21, miR-22-3p, miR-223, miR-30b, and miR-34a, as well as decreased expression of miR-130a and let-7b in both humans and animals. Pathway analysis for POP-associated miRNA identified pathways related to carcinogenesis. DISCUSSION: This is the first systematic review of the association of POPs with miRNA in humans and model organisms. Large-scale prospective human studies are warranted to examine the role of miRNA as mediators between POPs and health outcomes.

Diabetes mellitus and serum organochlorine pesticides mixtures in Mexican women.

BACKGROUND: Very recently, it has been reported that exposure to different mixtures of organochlorine pesticides (OCP) is associated with the development of diabetes mellitus (DM). In Mexico, DM is a public health problem that might be related to the historical intense use of OCP. We aimed to evaluate, the association between DM and serum concentrations of OCP mixtures, and identify the main contributors within them. METHODS: We conducted a secondary cross-sectional analysis on the control group from a breast cancer population-based case-control study conducted from 2007 to 2011 in Northern Mexico. We identified 214 self-reported diabetic women and 694 non-diabetics. We obtained direct information about sociodemographic, lifestyle and reproductive characteristics. We determined 24 OCP and metabolites in serum by gas chromatography using an electron capture micro detector. We used Weighted Quantile Sum regression to assess the association of DM and exposure to multiple OCP, and the contribution of each compound within the mixture. RESULTS: We found a positive adjusted association between DM and an OCP mixture (OR: 2.63, 95%CI: 1.85, 3.74), whose primary contribution arose from p, p'-DDE (mean weight 23.3%), HCB (mean weight 17.3%), trans nonachlor (mean weight 15.4%), o, p'-DDE (mean weight 7.3%), heptachlor epoxide (mean weight 5.9%), oxychlordane (mean weight 4.7%), and heptachlor (mean weight 4.5%). In addition, these OCP along with p, p'-DDT and cis chlordane, were of concern and remained associated when excluding hypertensive women from the analysis (OR 2.55; 95% CI 1.56, 4.18). CONCLUSIONS: Our results indicate, for the first time in a Latin-American population, that the concomitant exposure to multiple OCP is associated with DM. Further research is needed since the composition of OCP mixtures may vary according to regional pesticides use patterns.

Organochlorine pesticides and risk of papillary thyroid cancer in U.S. military personnel: a nested case-control study.

BACKGROUND: The effects of organochlorine pesticide (OCP) exposure on the development of human papillary thyroid cancer (PTC) are not well understood. A nested case-control study was conducted with data from the U.S. Department of Defense Serum Repository (DoDSR) cohort between 2000 and 2013 to assess associations of individual OCPs serum concentrations with PTC risk. METHODS: This study included 742 histologically confirmed PTC cases (341 females, 401 males) and 742 individually-matched controls with pre-diagnostic serum samples selected from the DoDSR. Associations between categories of lipid-corrected serum concentrations of seven OCPs and PTC risk were evaluated for classical PTC and follicular PTC using conditional logistic regression, adjusted for body mass index category and military branch to compute odds ratios (OR) and 95% confidence intervals (CIs). Effect modification by sex, birth cohort, and race was examined. RESULTS: There was no evidence of associations between most of the OCPs and PTC, overall or stratified by histological subtype. Overall, there was no evidence of an association between hexachlorobenzene (HCB) and PTC, but stratified by histological subtype HCB was associated with significantly increased risk of classical PTC (third tertile above the limit of detection (LOD) vs.

Exploring the levels of persistent organic pollutants in umbilical cord blood and their connection to gestational age and birth weights in Sanliurfa, Turkey.

BACKGROUND: Controversy surrounds the impact of persistent organic pollutants (POPs) on fetal development. This study aimed to investigate levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in umbilical cord blood from Sanliurfa mothers in Turkey, exploring associations with gestational age and birth weight. METHODS: Participants included voluntary mothers pregnant with a single fetus, providing details on maternal factors. Cord blood samples were collected immediately after delivery. Samples were extracted with a modified QuEChERS method, and OCPs (17 pesticides) and PCBs (11 congeners) compound levels were analyzed with a gas chromatograph/mass spectrometry. Detection frequencies and levels of POPs by single pollutant type and pollutant groups were calculated and compared according to gestational duration and birth weight. We used partial least squares discriminant analysis to identify the key chemicals and distinguish their respective statuses. RESULTS: Among 120 infants, 35 were preterm but appropriate for gestational age, 35 were term but small for gestational age (SGA), and 50 were term and appropriate for gestational age (AGA). Beta HCH, Oxy-Chlordan, and PCB 28, were not detected in cord blood samples. Half of the samples contained at least 4 types of OCPs, with a median OCP level of 38.44 ng/g. Among the DDT, 2,4'-DDE was found at the highest concentration in cord plasma samples. The PCB congeners with a frequency exceeding 50% were ranked in the following order: 151, 149, 138, 146. The median level of ∑PCBs was 5.93 ng/g. Male infants born at term with SGA status exhibited lower levels of ∑DDTs, ∑OCPs compared to male infants born preterm or at term with AGA status. Di-ortho-substituted PCBs and hexachlorinated PCBs were higher in male infants born at term with SGA status than male infants born preterm with AGA status. CONCLUSION: Overall, exposure to DDT and PCBs demonstrates varying effects depending on gestational duration and birth weight, with exposure levels also differing by gender. This underscores the necessity for studies across diverse populations that investigate the combined effects of multiple pollutant exposures on gestational age, birth weight, and gender simultaneously.

Impact of Organochlorine Pesticides Exposure on Histone Modification H3K9ac: Implications for Unexplained Recurrent Miscarriage.

Epigenetic alterations, changes in gene expression without DNA sequence modifications, are associated with various health disorders, including reproductive health issues. These alterations can be influenced by environmental factors such as pesticides. This study aimed to explore the relationship between exposure to Organochlorine Pesticides (OClPs) and the histone modification mark H3K9ac in the placenta and fetal tissue, in the context of unexplained recurrent miscarriage (URM). In the case-control study, serum samples from 73 women with URM and 30 healthy women were examined for the presence of OClPs, which include 2,4-DDT, 2,4-DDE, 4,4-DDT, 4,4-DDE, α-HCH, ß-HCH, and γ-HCH, using gas chromatography. Western blot analysis was used to assess H3K9ac expression in placental and fetal tissues. In the URM group, significant increases were observed in the values of α-HCH, ß-HCH, 2,4-DDE, and 4,4-DDE, as well as in the concentration of total OClPs (Æ©3HCH, Æ©2DDE, Æ©2DDT, and Æ©7OClP), compared to controls. While H3K9ac levels in fetal tissue showed no significant difference, a notable decrease was found in the placental tissue of the URM. In the placenta tissue of URM, logistic regression analysis also revealed a significant inverse correlation between the toxins α-HCH, 2,4-DDE, 4,4-DDE, 4,4-DDT, total OClPs, and reduced H3K9ac expression. Our findings suggest that OClPs exposure may contribute to URM by reducing H3K9ac expression in the placenta, potentially affecting placental growth and immune tolerance. This underscores the need for further investigation into the involved mechanisms and potential therapeutic interventions, and the importance of OClPs regulation for reproductive health protection.

Pentachlorophenol affects doxycycline and tetracycline resistance genes in soil by altering microbial structure.

Tetracycline antibiotics play a vital role in animal husbandry, primarily employed to uphold the health of livestock and poultry. Consequently, when manure is reintegrated into farmland, tetracycline antibiotics can persist in the soil. Simultaneously, to ensure optimal crop production, organochlorine pesticides (OCPs) are frequently applied to farmland. The coexistence of tetracycline antibiotics and OCPs in soil may lead to an increased risk of transmission of tetracycline resistance genes (TRGs). Nevertheless, the precise mechanism underlying the effects of OCPs on tetracycline antibiotics and TRGs remains elusive. In this study, we aimed to investigate the effects of OCPs on soil tetracycline antibiotics and TRGs using different concentrations of doxycycline (DOX) and pentachlorophenol (PCP). The findings indicate that PCP and DOX mutually impede their degradation in soil. Furthermore, our investigation identifies Sphingomonas and Bacillus as potential pivotal microorganisms influencing the reciprocal inhibition of PCP and DOX. Additionally, it is observed that the concurrent presence of PCP and DOX could impede each other's degradation by elevating soil conductivity. Furthermore, we observed that a high concentration of PCP (10.7 mg/kg) reduced the content of efflux pump tetA, ribosome protective protein tetM, tetQ, and passivating enzyme tetX. In contrast, a low PCP concentration (6.4 mg/kg) only reduced the content of ribosome protective protein tetQ. This suggests that PCP may reduce the relative abundance of TRGs by altering the soil microbial community structure and inhibiting the potential host bacteria of TRGs. These findings have significant implications in understanding the combined pollution of veterinary antibiotics and OCPs. By shedding light on the interactions between these compounds and their impact on microbial communities, this study provides a theoretical basis for developing strategies to manage and mitigate their environmental impact, and may give some information regarding the sustainable use of antibiotics and pesticides to ensure the long-term health and productivity of agricultural systems.

Potential lethality of organochlorine pesticides: Inducing fatality through inflammatory responses in the organism.

BACKGROUND: Organochlorine pesticides, with their environmental persistence and bioaccumulation potential, have gained significant attention. This study explores the impact of organochlorine pesticides on mortality and chronic diseases, investigates their link to inflammatory states, and examines the role of anti-inflammatory diets in mitigating adverse reactions to these pesticides. METHODS: This study, with 2,847 participants, used gas chromatography and mass spectrometry to measure organochlorine pesticide exposure in NHANES data. Conventional statistical methodologies, encompassing survival curves, Cox proportional hazards regression, regression analysis, and restricted quadratic spline analysis, were employed to investigate the association between pesticides and mortality, chronic ailments, and inflammation. Furthermore, machine learning techniques, comprising RF, AdaBoost, Extra-Trees, LightGBM, and BPNN, were leveraged to evaluate the impact of pesticides on chronic disease and mortality prognostication. RESULTS: Organochlorine pesticides were significantly and positively correlated with increased mortality (p<0.05). Additionally, these pollutants were linked to the incidence of chronic diseases such as chronic kidney disease, diabetes, and hypertension (p< 0.05). Our study, utilizing various machine learning models, also showed a notable increase in the Area Under the Curve when incorporating organochlorine pesticide indicators into the model as opposed to excluding them. Furthermore, strong correlations were observed between serum c-reactive protein (CRP) and CRP to serum albumin ratio (CAR) concentrations with these substances, demonstrating their pro-inflammatory effects at specific concentrations. Interestingly, cutting down on dietary inflammation through changes in diet effectively reduced the risk of death at high organochlorine pesticide exposure levels, but the effect was less noticeable at low to moderate exposure levels. CONCLUSIONS: Exposure to organochlorine pesticides was linked to a higher risk of mortality, likely due to an increased prevalence of chronic diseases. In this context, inflammation played a crucial role, and adopting an anti-inflammatory diet significantly reduced the mortality risk associated with these pesticides.

Persistent organic pollutants and cognitive decline among middle-aged or older adults in the Hispanic Community Health Study/Study of Latinos.

Persistent organic pollutants may negatively impact cognition; however, associations between persistent organic pollutants and changes in cognition among United States Hispanic/Latino adults have not been investigated. Herein, we examined the associations between 33 persistent organic pollutants and cognitive changes among 1837 Hispanic/Latino adults. At baseline (2008-2011; Visit 1), participants provided biospecimens in which we measured levels of 5 persistent pesticides or pesticide metabolites, 4 polybrominated diphenyl ethers and 2,2',4,4',5,5'-hexabromobiphenyl, and 24 polychlorinated biphenyls. At Visit 1 and again at Visit 2 (2015-2018), a battery of neurocognitive tests was administered which included the Brief-Spanish English Verbal Learning Test, Word Fluency Test, and Digit Symbol Substitution Test. To estimate the adjusted associations between changes in cognition and each POP, we used linear regression for survey data. Each doubling in plasma levels of polychlorinated biphenyls 146, 178, 194, 199/206, and 209 was associated with steeper declines in global cognition (ßs range:-0.053 to -0.061) with stronger associations for the Brief-Spanish English Verbal Learning Test. Persistent organic pollutants, in particular polychlorinated biphenyls, were associated with declines in cognition over 7 years and may be a concern for Hispanic/Latino adults.

Environmental Exposure to Persistent Organic Pollutants and Its Association with Endometriosis Risk: Implications in the Epithelial-Mesenchymal Transition Process.

We aimed to explore the relationship of adipose tissue concentrations of some persistent organic pollutants (POPs) with the risk of endometriosis and the endometriotic tissue expression profile of genes related to the endometriosis-related epithelial-mesenchymal transition (EMT) process. This case-control study enrolled 109 women (34 cases and 75 controls) between January 2018 and March 2020. Adipose tissue samples and endometriotic tissues were intraoperatively collected to determine concentrations of nine POPs and the gene expression profiles of 36 EMT-related genes, respectively. Associations of POPs with endometriosis risk were explored with multivariate logistic regression, while the relationship between exposure and gene expression profiles was assessed through Spearman correlation or Mann-Whitney U tests. After adjustment, increased endometriosis risk was associated with p,p'-DDT, PCB-180, and ΣPCBs. POP exposure was also associated with reduced gene expression levels of the CLDN7 epithelial marker and increased levels of the ITGB2 mesenchymal marker and a variety of EMT promoters (HMGA1, HOXA10, FOXM1, DKK1, CCR1, TNFRSF1B, RRM2, ANG, ANGPT1, and ESR1). Our findings indicate that exposure to POPs may increase the risk of endometriosis and might have a role in the endometriosis-related EMT development, contributing to the disease onset and progression. Further studies are warranted to corroborate these findings.

Organochlorine pesticide residues and urinary arsenic and fluoride levels in mothers and their newborns who are residents of rural areas in Durango State, Mexico.

Maternal and prenatal exposure to organochlorine pesticides (OCP), arsenic (As), and fluoride (F-) is a critical public health concern. The present study assessed serum OCP residues and urinary As and F- levels in mother and newborn pairs who are residents of rural areas of Durango State, Mexico, from August 2018 to February 2019. Levels of OCP, As, and F- were measured in serum and urine samples by Gas chromatography - Tandem mass spectrometry (GC - MS/MS), Hydride generation - Atomic fluorescent spectrometry (HG-AFS, and ion-selective electron analysis (ISE), respectively, in 60 binomial mothers - newborns. Dieldrin, endrin aldehyde, and endosulfan-II were significantly higher in newborns than in mothers (p ˂0.05). Meanwhile, no significant differences were observed for As and F- concentrations between mother - newborn pairs. Differences were observed in ∑Dienes and ∑DDTs comparing newborns with normal and low birth weights and a positive relationship in Æ©Dienes, Æ©Chlordanes, and Æ©DDTs between mother and newborn pairs (p ˂ 0.05). These findings highlight the importance of extensive research regarding the influence of pollution.

Sediment-water exchange and risk assessment of pesticidal persistent organic pollutants in Bharathappuzha and Periyar Riverine region along the Arabian Sea.

Considering the extensive agricultural practices along the perennial rivers, viz. Periyar and Bharathappuzha of Kerala in the southwest coast of India, the first comprehensive surveillance of new and legacy organochlorine pesticides (OCPs) in surface sediment was conducted. Further, the sediment-water exchange fluxes have been elucidated. Mean concentrations of total HCH, DDT and endosulfan were 0.84 ng/g, 0.42 ng/g and 0.30 ng/g for Bharathappuzha Riverine sediment (BRS) and 1.08 ng/g, 0.39 ng/g and 0.35 ng/g for Periyar Riverine sediment (PRS). The dominance α-HCH and ß-HCH isomers in PRS and BRS reflect the ongoing use of technical HCH in Kerala. The calculated KSW in both rivers was very low in comparison with other Indian rivers. The average log K'OC for all the detected OCPs in both the rivers was lower than the predicted log KOC in equilibrium indicating the higher adherence of OCPs to sediment. Furthermore, fugacity fraction (fs/fw) was < 1.0 for all OCPs confirming the net deposition of OCPs into the sediment. Sediment concentrations for each of the OCPs in PRS and BRS did not surpass the threshold effect level and probable effect level as stipulated by the Canadian Council of Ministry of the Environment Guidelines. In addition, all the sites of both rivers had sediment quality guideline quotient (SQGQ) values below 0.1 indicating the absence of significant biological and ecological risks.

Vortex-assisted dispersive micro-solid-phase extraction using silica-supported Fe2O3-modified khat (Catha edulis) biochar nanocomposite followed by GC-MS for the determination of organochlorine pesticides in juice samples.

In this paper, dispersive micro-solid phase extraction technique was developed for the purpose of extracting and preconcentrating organochlorine pesticide residues in juice samples before their separation and quantitative analysis by gas chromatography-mass spectrometry. A sorbent composed of a silica-supported Fe2O3-modified khat leftover biochar nanocomposite (SiO2-Fe2O3-KLBNC) was implemented in the process. To improve the dispersion of the sorbent in the solution, vortex mixer was employed. Experimental parameters influencing the performance of the method were optimized, and the optimal conditions were established. With these conditions, linear dynamic ranges ranged from 0.003 to 100.0 ng/mL were achieved, with a correlation coefficient (r2) ≥ 0.9981. The limits of detection and quantification, determined by signal-to-noise ratios of 3 and 10, respectively, were found to be in the ranges of 0.001-0.006 ng/mL and 0.003-0.020 ng/mL. Intra- and inter-day precision, values ranging from 0.3-4.8% and 1.7-5.2% were obtained, respectively. The matrix-matched extraction recoveries demonstrated favorable outcomes, falling within the range of 83.4-108.3%. The utilization of khat leftover as an adsorbent in contemporary sample preparation methodologies offers a cost-effective alternative to the currently available, yet expensive, adsorbents. This renders it economically viable, particularly in resource-constrained regions, and is anticipated to witness widespread adoption in the coming future.

Carcinogenic, non-carcinogenic risk, and attributable cases to organochlorine pesticide exposure in women from Northern Mexico.

This study aimed to estimate the carcinogenic and non-carcinogenic risk as well as the attributable cases due to exposure to organochlorine pesticides (OCPs): hexachlorobenzene (HCB), dichlorophenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), heptachlor, and chlordane. From serum concentrations of pesticides of interest in a sample of 908 women from Northern Mexico, the risk for both cancer and non-cancer health effects was evaluated. The population attributable fraction (PAF) was also calculated based on summary association estimates between exposure to OCPs and different health events. Findings revealed that due to their OCP exposure slightly less than half of the women in the sample were at increased risk of developing non-cancerous diseases. Moreover, approximately 25% and 75% of participants were at risk of develop some type of cancer associated with their HCB and DDE concentrations, respectively. In addition, it was estimated that 40.5% of type 2 diabetes, 18.7% of endometriosis, and 23.1% of non-Hodgkin's lymphoma cases could have been prevented if women had not been exposed to these OCPs. Results suggest that the use of OCPs may have contributed to the disease burden in the study area and, based on the time required for these substances to be eliminated from the body, there are probably some women who are still at elevated risk of developing diseases associated to OCPs.

Monitoring of Organochlorine Pesticides (OCP) in Hair Samples of Wild Herbivorous Mammals Living in Remote and Protected Areas of the Far East and Siberia of Russia.

Monitoring wildlife exposure to biological hazards is a critical component of the wildlife risk assessment. In this study 38 hair samples were collected from 8 different species from ten districts of Russian Far East and Siberia and analysed for the presence of organochlorine pesticides (OCP). 50% of the samples were contaminated with - p, p'-DDT, α-HCH and DDD. DDT was the main contaminant found in 13 sample at concentrations range of 14.3 to 369.5 pg/mg hair, mean 91.9 ± 89.7 pg/mg. α-HCH was detected in three samples with the concentrations range 29.9-180.2 pg/mg. The p, p'-DDD was found only in one hair sample of Siberian roe deer from Altai region at 52.6 pg/mg. The exposure level is depended on animals habitat location. The most contaminated region is Terney district which is in the proximity to the borders with China and North Korea where OCP are still in use.

Viral and Bacterial Communities Collaborate through Complementary Assembly Processes in Soil to Survive Organochlorine Contamination.

The ecological drivers that direct the assembly of viral and host bacterial communities are largely unknown, even though viral-encoded accessory genes help host bacteria survive in polluted environments. To understand the ecological mechanism(s) of viruses and hosts synergistically surviving under organochlorine pesticide (OCP) stress, we investigated the community assembly processes of viruses and bacteria at the taxon and functional gene levels in clean and OCP-contaminated soils in China using a combination of metagenomics/viromics and bioinformatics approaches. We observed a decreased richness of bacterial taxa and functional genes but an increased richness of viral taxa and auxiliary metabolic genes (AMGs) in OCP-contaminated soils (from 0 to 2,617.6 mg · kg-1). In OCP-contaminated soils, the assembly of bacterial taxa and genes was dominated by a deterministic process, of which the relative significance was 93.0% and 88.7%, respectively. In contrast, the assembly of viral taxa and AMGs was driven by a stochastic process, which contributed 83.1% and 69.2%, respectively. The virus-host prediction analysis, which indicated Siphoviridae was linked to 75.0% of bacterial phyla, and the higher migration rate of viral taxa and AMGs in OCP-contaminated soil suggested that viruses show promise for the dissemination of functional genes among bacterial communities. Taken together, the results of this study indicated that the stochastic assembly processes of viral taxa and AMGs facilitated bacterial resistance to OCP stress in soils. Moreover, our findings provide a novel avenue for understanding the synergistic interactions between viruses and bacteria from the perspective of microbial ecology, highlighting the significance of viruses in mediating bioremediation of contaminated soils. IMPORTANCE The interaction between viral communities and microbial hosts has been studied extensively, and the viral community affects host community metabolic function through AMGs. Microbial community assembly is the process by which species colonize and interact to establish and maintain communities. This is the first study that aimed to understand the assembly process of bacterial and viral communities under OCP stress. The findings of this study provide information about microbial community responses to OCP stress and reveal the collaborative interactions between viral and bacterial communities to resist pollutant stress. Thereby, we highlight the importance of viruses in soil bioremediation from the perspective of community assembly.

Organochlorine pesticides in vegetable oils: An overview of occurrence, toxicity, and chromatographic determination in the past twenty-two years (2000-2022).

Organochlorine pesticides (OCPs) are used globally to control pests in the food industry. However, some have been banned due to their toxicity. Although they have been banned, OCPs are still discharged into the environment and persist for long periods of time. Therefore, this review focused on the occurrence, toxicity, and chromatographic determination of OCPs in vegetable oils over the last 22 years (2000-2022) (111 references).Literature search shows that OCPs kill pests by destroying endocrine, teratogenic, neuroendocrine, immune, and reproductive systems. However, only five studies investigated the fate of OCPs in vegetable oils and the outcome revealed that some of the steps involved during oil processing introduce more OCPs. Moreover, direct chromatographic determination of OCPs was mostly performed using online LC-GC methods fitted with oven transfer adsorption desorption interface. While indirect chromatographic determination was favored by QuEChERS extraction technique, gas chromatography frequently coupled to electron capture detection (ECD), gas chromatography in selective ion monitoring mode (SIM), and gas chromatography tandem mass spectrometry (GC-MS/MS) were the most common techniques used for detection. However, the greatest challenge still faced by analytical chemists is to obtain clean extracts with acceptable extraction recoveries (70-120%). Hence, more research is still required to develop greener and selective extraction methods toward OCPs, thus improving extraction recoveries. Moreover, advanced techniques like gas chromatography high resolution mass spectrometry (GC-HRMS) must also be explored. OCPs prevalence in vegetable oils varied greatly in various countries, and concentrations of up to 1500 µg/kg were reported. Additionally, the percentage of positive samples ranged from 1.1 to 97.5% for endosulfan sulfate.

Passive-Sampler-Derived PCB and OCP Concentrations in the Waters of the World─First Results from the AQUA-GAPS/MONET Network.

Persistent organic pollutants (POPs) are recognized as pollutants of global concern, but so far, information on the trends of legacy POPs in the waters of the world has been missing due to logistical, analytical, and financial reasons. Passive samplers have emerged as an attractive alternative to active water sampling methods as they accumulate POPs, represent time-weighted average concentrations, and can easily be shipped and deployed. As part of the AQUA-GAPS/MONET, passive samplers were deployed at 40 globally distributed sites between 2016 and 2020, for a total of 21 freshwater and 40 marine deployments. Results from silicone passive samplers showed α-hexachlorocyclohexane (HCH) and γ-HCH displaying the greatest concentrations in the northern latitudes/Arctic Ocean, in stark contrast to the more persistent penta (PeCB)- and hexachlorobenzene (HCB), which approached equilibrium across sampling sites. Geospatial patterns of polychlorinated biphenyl (PCB) aqueous concentrations closely matched original estimates of production and use, implying limited global transport. Positive correlations between log-transformed concentrations of Σ7PCB, ΣDDTs, Σendosulfan, and Σchlordane, but not ΣHCH, and the log of population density (p < 0.05) within 5 and 10 km of the sampling sites also supported limited transport from used sites. These results help to understand the extent of global distribution, and eventually time-trends, of organic pollutants in aquatic systems, such as across freshwaters and oceans. Future deployments will aim to establish time-trends at selected sites while adding to the geographical coverage.