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Common carp (Cyprinus carpio) is extensively cultured and widely consumed in Heilongjiang Province, China. Due to the proximity of freshwater ponds to agricultural cultivated areas, these aquatic systems are inevitably influenced by the historical application of organochlorine pesticides (OCPs), due to their prolonged half-life and resistance to degradation. Gas chromatography-tandem mass spectrometry (GC-MS/MS) was utilized to quantify the levels of hexachlorocyclohexane (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in the muscle tissue of cultured common carp. This study examined the enrichment characteristics of HCHs and DDTs in fish muscle, as well as their correlation with sediment and associated risk assessments. The results showed that the residual levels of HCHs and DDTs in fish muscle ranged from 0.387 μg·kg−1 to 3.418 μg·kg−1 and from 0.114 μg·kg−1 to 0.420 μg·kg−1, respectively. They were all below the maximum residue limits specified in GB 2763-2021 (HCHs: 100 μg·kg−1, DDTs: 500 μg·kg−1). The concentrations of HCHs and DDTs in sediment were found to be lower than those in muscle tissue. Notably, the concentrations of HCHs were higher than those of DDTs in both muscle and sediment. Among the HCHs, γ-HCH was the predominant residual substance, contributing a significant proportion of 42.16% to 86.47%. No significant residues of DDT derivatives were detected. A significant correlation was observed between the concentrations of HCHs and DDTs in the muscle tissue and those present in the sediment (p < 0.01). The health risk assessment indicated that both the carcinogenic and non-carcinogenic risks associated with OCPs from common carp muscle and sediment were within acceptable limits. Therefore, it was recommended to regulate fish consumption during the breeding period. [ABSTRACT FROM AUTHOR]

One of the factors associated with increased morbidity of malignant neoplasms is environmental pollution with cancerogenic compounds including pesticides. Until recently, stable organic pollutant insecticide dichlorodiphenyltrichloroethane (DDT) was the single tool for fighting malaria carriers. Despite vast evidence of its negative effect on human health, DDT is still used in some countries.Aim. To perform a comprehensive analysis of the dynamics of DDT pesticide use and the consequences of its use on the global healthcare as well as to investigate the mechanism of its action on the human body including the endocrine system and cancerogenic effects.The review was composed using the PubMed (2853 publications), Elsevier (3139 publications), eLibrary (784 publications) biomedical literature databases. Full-text articles were retrieved through PubMed Central (PMC), Science Direct, Research Gate, CyberLeninka electronic resources.

Background: The escalation of insecticide resistance across the World Health Organization (WHO) African region calls for the routine monitoring of insecticide resistance in mosquitoes. While pyrethroids are recommended for use and dichlorodiphenyltrichloroethane (DDT) has been prescribed, it is imperative to reevaluate their efficacy across diverse geographical settings. The extent of resistance among mosquitoes to DDT and lambda-cyhalothrin remains understudied in Ika North East, Delta State, Nigeria, where the yellow fever virus was reported in 2019. Materials and Methods: We investigated the susceptibility of female mosquitoes to DDT (4%) and lambda-cyhalothrin (0.05%) in this specific study area. Adult female mosquitoes of Anopheles gambiae , Culex quinquefasciatus , and Aedes albopictus , aged between 2 and 4 days, were subjected to these insecticides utilizing the WHO bioassay method. The assessment of knockdown was done between 10 and 60 min, then mortality after 24 h. Results: C. quinquefasciatus and A. albopictus mosquitoes exposed to DDT and lambda-cyhalothrin exhibited high susceptibility, resulting in complete mortality (100%); however, A. gambiae displayed resistance, with mortality rates of 19% and 76%, respectively. Notably, A. gambiae mosquitoes exposed to piperonyl butoxide (PBO)-DDT and PBO-lambda-cyhalothrin exhibited enhanced mortality, reaching 95% (indicating suspected resistance) and 100% (indicating susceptibility), respectively. Knockdown time (KDT) for 50% in mosquitoes exposed to lambda-cyhalothrin ranged from 3.94 to 33.51 min. Similarly, KDT model for 95% ranged from 19.04 to 84.15 min. Among the tested mosquito species, Culex mosquitoes exhibited the shortest knockdown resistance time for lambda-cyhalothrin, recorded at 3.94 min. Similarly, the KDT for DDT ranged from 24.97 to 187.06 min for 50% mortality and from 61.04 to 431.03 min for 95% mortality, respectively. Anopheles mosquitoes exposed to PBO + DDT recorded the lowest KDT. Conclusion: Our study underscores the potential of exercising caution in the use of DDT and lambda-cyhalothrin insecticides for the control of mosquitoes due to emerging resistance. [ABSTRACT FROM AUTHOR]

Common carp (Cyprinus carpio) is extensively cultured and widely consumed in Heilongjiang Province, China. Due to the proximity of freshwater ponds to agricultural cultivated areas, these aquatic systems are inevitably influenced by the historical application of organochlorine pesticides (OCPs), due to their prolonged half-life and resistance to degradation. Gas chromatography-tandem mass spectrometry (GC-MS/MS) was utilized to quantify the levels of hexachlorocyclohexane (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in the muscle tissue of cultured common carp. This study examined the enrichment characteristics of HCHs and DDTs in fish muscle, as well as their correlation with sediment and associated risk assessments. The results showed that the residual levels of HCHs and DDTs in fish muscle ranged from 0.387 μg·kg−1 to 3.418 μg·kg−1 and from 0.114 μg·kg−1 to 0.420 μg·kg−1, respectively. They were all below the maximum residue limits specified in GB 2763-2021 (HCHs: 100 μg·kg−1, DDTs: 500 μg·kg−1). The concentrations of HCHs and DDTs in sediment were found to be lower than those in muscle tissue. Notably, the concentrations of HCHs were higher than those of DDTs in both muscle and sediment. Among the HCHs, γ-HCH was the predominant residual substance, contributing a significant proportion of 42.16% to 86.47%. No significant residues of DDT derivatives were detected. A significant correlation was observed between the concentrations of HCHs and DDTs in the muscle tissue and those present in the sediment (p < 0.01). The health risk assessment indicated that both the carcinogenic and non-carcinogenic risks associated with OCPs from common carp muscle and sediment were within acceptable limits. Therefore, it was recommended to regulate fish consumption during the breeding period.

Hexachlorobenzene （HCHs）, dichlorodiphenyltrichloroethane（DDTs） and poly-chlorinated biphenyls （PCBs） were determined in water, soil and mussel samples using GC-MS/MS, in order to investigate the concentrations, composition and distribution characteristics of legacy persistent organic pollutants （POPs） in different medium in the mussel mariculture area of the Huaniao Island, Yangtze estuary. The results showed that legacy POPs were widely detected in the samples, and the concentrations of HCHs, DDTs and PCBs ranged from 10. 8 to 49. 1, 169 to 900 and 10. 4 to 34. 4 ng/g（lipid weight） in mussel, 0. 22 to 1. 76, 0. 07 to 0. 29 ng/L and 9. 45-51. 8 pg/L in water, and 0. 18 to 10. 4, 2. 62 to 69. 6 and 0. 40 to 0. 69 ng/g（dry weight） in soil, respectively. DDTs were the main pollution compounds in mussel. The composition of target compounds in water and soil samples from the mariculture area reflected their exposure to residual pollutant emissions, with a dominance of highly chlorinated PCBs and DDT degradation products in mussels, which was associated with bioaccumulation characteristics. There were many significant positive correlations among HCHs, DDTs and PCBs in soils, as well as in mussels, reflecting the possible existence of similar sources of contaminants. The relationship between mussel tissues and non-biological medium can be seen in the principal component analysis. Health risk assessment showed that population ingestion of local mussels posed little risk of exposure and carcinogenic potential. This study can provide a basis for understanding the fate of legacy POPs among the different medium in the mussel mariculture area and the risk of mussel consumption by the population. [ABSTRACT FROM AUTHOR]

Environmental contamination with dichlorodiphenyltrichloroethane (DDT) has sever effects on the ecosystem worldwide. DDT is a recalcitrant synthetic chemical with high toxicity and lipophilicity. It is also bioaccumulated in the food chain and causes genotoxic, estrogenic, carcinogenic, and mutagenic effects on aquatic organisms and humans. Microbial remediation mechanism and its enzymes are very important for removing DDT from environment. DDT and its main residues dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) can biodegrade slowly in soil and water. To enhance this process, a number of strategies are proposed, such as bio-attenuation, biostimulation, bioaugmentation and the manipulation of environmental conditions to enhance the activity of microbial enzymes. The addition of organic matter and flooding of the soil enhance DDT degradation. Microbial candidates for DDT remediation include micro-algae, fungi and bacteria. This review provide brief information and recommendation on microbial DDT remediation and its mechanisms.

BACKGROUND: The World Health Organization recommends indoor residual spray (IRS) including dichlorodiphenyltrichloroethane (DDT), as a malaria vector control measure. OBJECTIVE: The objective was to assess the knowledge and practice of IRS with DDT in rural area of the West Tripura district. METHODOLOGY: A community based cross-sectional study was conducted in rural area of West Tripura District during the period of June to July 2019. Two hundred adult participants were interviewed from randomly selected families using multistage simple random sampling technique using a predesigned, pretested interview schedule. Data were analyzed using Microsoft excel 2007 and the Epi-info version 6.0 (CDC, Atlanta, Georgia, USA). RESULTS: More than 43% of the families knew that DDT spray was for malaria prevention and control measures. Reasons for not allowing DDT spray were due to stains of houses (35.13%), bad odors (3.5%), unpreparedness (3.5%), uninformed (3%), and 7% other reasons. CONCLUSIONS: Practice on indoor residual spray (DDT) was below the level of coverage required for mass effect recommended by the World Health Organization. However, the population had a good knowledge of the diseases spread by the mosquitoes.

Objective: Establish a high throughput method for the determination of 57 organic pollutants in edible vegetable oil. Methods: The target compounds were extracted by acetonitrile-hexane solution and purified by disperse solid phase extraction and solid phase extraction, after that the contents of 16 polycyclic aromatic hydrocarbons, 17 phthalates, 8 organochlorines and 16 polychlorinated biphenyls in edible oil were detected by gas chromatography triple quadrupole mass spectrometry. Results: All target components had an excellent linearity within the linear range of 0.001~0.1 μg/mL （r2＞0.998）, and the limits of detection was between 0.16~2.0 μg/kg, meanwhile the average recovery rate of matrix addition was between 71.0%~119.5%, and the relative standard deviation was below 12.6% （n=6）. Furthermore, the method was used to analyze 24 baches of edible oils, and 25 types of target substances were founded. Conclusion: This method is high efficiency, accuracy, high sensitivity, which has great significance for the monitoring of persistent organic pollutants and phthalates in edible oil.

BACKGROUND: The World Health Organization recommends indoor residual spray (IRS) including dichlorodiphenyltrichloroethane (DDT), as a malaria vector control measure. OBJECTIVE: The objective was to assess the knowledge and practice of IRS with DDT in rural area of the West Tripura district. METHODOLOGY: A community based cross-sectional study was conducted in rural area of West Tripura District during the period of June to July 2019. Two hundred adult participants were interviewed from randomly selected families using multistage simple random sampling technique using a predesigned, pretested interview schedule. Data were analyzed using Microsoft excel 2007 and the Epi-info version 6.0 (CDC, Atlanta, Georgia, USA). RESULTS: More than 43% of the families knew that DDT spray was for malaria prevention and control measures. Reasons for not allowing DDT spray were due to stains of houses (35.13%), bad odors (3.5%), unpreparedness (3.5%), uninformed (3%), and 7% other reasons. CONCLUSIONS: Practice on indoor residual spray (DDT) was below the level of coverage required for mass effect recommended by the World Health Organization. However, the population had a good knowledge of the diseases spread by the mosquitoes. [ABSTRACT FROM AUTHOR]

Abstract Exposure to certain chemicals in the environment may contribute to the risk of developing cancer. Although cancer risk from environmental chemical exposure among general populations is considered low compared to that in occupational settings, many people may nevertheless be chronically exposed to relatively low levels of environmental chemicals which vary by such various factors as residential area, lifestyle, and dietary habits. It is therefore necessary to assess population-specific exposure levels and examine their association with cancer risk. Here, we reviewed epidemiological evidence on cancer risk and exposure to dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFASs), cadmium, arsenic, and acrylamide. Japanese are widely exposed to these chemicals, mainly through the diet, and an association with increased cancer risk is suspected. Epidemiological evidence from Japanese studies to date does not support a positive association between blood concentrations of DDT, HCH, PCBs, and PFASs and risk of breast or prostate cancer. We established assessment methods for dietary intake of cadmium, arsenic, and acrylamide using a food frequency questionnaire. Overall, dietary intakes of cadmium, arsenic, and acrylamide were not significantly associated with increased risk of total cancer and major cancer sites in the Japan Public Health Center-based Prospective Study. However, statistically significant positive associations were observed between dietary cadmium intake and risk of estrogen receptor-positive breast cancer among postmenopausal women, and dietary arsenic intake and risk of lung cancer among male smokers. In addition, studies using biomarkers as exposure assessment revealed statistically significant positive associations between urinary cadmium concentration and risk of breast cancer, and between ratio of hemoglobin adducts of acrylamide and glycidamide and risk of breast cancer. Epidemiological studies of general populations in Japan are limited and further evidence is required. In particular, studies of the association of organochlorine and organofluorine compounds with risk of cancer sites other than breast and prostate cancer are warranted, as are large prospective studies of the association between biomarkers of exposure and risk of cancer.

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Dichlorodiphenyltrichloroethane (DDT) and its metabolite dichlorodiphenyldichloroethylene (DDE) are ubiquitous in the environment and detected in tissues of living organisms. Although DDT owes its insecticidal activity to impeding closure of voltage-gated sodium channels, it mediates toxicity in mammals by acting as an endocrine disruptor (ED). Numerous studies demonstrate DDT/DDE to be EDs, but studies examining muscle-specific effects mediated by nonhormonal receptors in mammals are lacking. Therefore, we investigated whether o,p'-DDT, p,p'-DDT, o,p'-DDE, and p,p'-DDE (DDx, collectively) alter the function of ryanodine receptor type 1 (RyR1), a protein critical for skeletal muscle excitation-contraction coupling and muscle health. DDx (0.01-10 µM) elicited concentration-dependent increases in [3H]ryanodine ([3H]Ry) binding to RyR1 with o,p'-DDE showing highest potency and efficacy. DDx also showed sex differences in [3H]Ry-binding efficacy toward RyR1, where [3H]Ry-binding in female muscle preparations was greater than male counterparts. Measurements of Ca2+ transport across sarcoplasmic reticulum (SR) membrane vesicles further confirmed DDx can selectively engage with RyR1 to cause Ca2+ efflux from SR stores. DDx also disrupts RyR1-signaling in HEK293T cells stably expressing RyR1 (HEK-RyR1). Pretreatment with DDx (0.1-10 µM) for 100 s, 12 h, or 24 h significantly sensitized Ca2+-efflux triggered by RyR agonist caffeine in a concentration-dependent manner. o,p'-DDE (24 h; 1 µM) significantly increased Ca2+-transient amplitude from electrically stimulated mouse myotubes compared with control and displayed abnormal fatigability. In conclusion, our study demonstrates DDx can directly interact and modulate RyR1 conformation, thereby altering SR Ca2+-dynamics and sensitize RyR1-expressing cells to RyR1 activators, which may ultimately contribute to long-term impairments in muscle health.

Persistent organic pollutants (POPs) are toxic chemical compounds that can bioaccumulate, adhere to lipid matrices, and affect human health. This study aimed to investigate the association between maternal pre-pregnancy overweight/obesity and dietary intake during pregnancy and POP concentrations in the human milk of women from Rio de Janeiro, Brazil. One hundred and forty-seven women were followed from the third trimester of pregnancy until 119 days postpartum, and 77 human milk samples were analyzed between 2 and 119 days postpartum. POP concentrations were analyzed using gas chromatography-triple quadrupole mass spectrometry. Pregnancy dietary intake was estimated using a semi-quantitative food frequency questionnaire, and pre-pregnancy body mass index at baseline was classified as normal or overweight/obesity. Multiple logistic and linear regression models were performed to investigate the association between pre-pregnancy overweight/obesity, dietary intake during pregnancy, and POP concentrations in human milk. The models were adjusted for maternal age, maternal schooling, total cholesterol serum concentrations, and time postpartum. The analyses were corrected for multiple comparisons using the Benjamini–Hochberg test. Significant associations were observed between pre-pregnancy overweight/obesity and dichlorodiphenyldichloroethane (ppDDE), polychlorinated biphenyl (PCB)74, PCB138, PCB153, PCB170, PCB180, total PCBs, total 4PCBs, total 2 organochlorine pesticides (OCPs), and total POP concentrations. Higher daily lipid intake during pregnancy increased human milk hexachlorobenzene (HCB). This study showed that pre-pregnancy overweight/obesity and total lipid intake during pregnancy were associated with POP concentrations in the milk of women from Rio de Janeiro, Brazil. To promote adequate nutritional status since preconception and surveillance and control of POP in the environment could be essential to ensure binomial mother-infant health and biomonitoring studies and programs for these POPs should be stimulated. [ABSTRACT FROM AUTHOR]

Exposure to certain chemicals in the environment may contribute to the risk of developing cancer. Although cancer risk from environmental chemical exposure among general populations is considered low compared to that in occupational settings, many people may nevertheless be chronically exposed to relatively low levels of environmental chemicals which vary by such various factors as residential area, lifestyle, and dietary habits. It is therefore necessary to assess population-specific exposure levels and examine their association with cancer risk. Here, we reviewed epidemiological evidence on cancer risk and exposure to dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFASs), cadmium, arsenic, and acrylamide. Japanese are widely exposed to these chemicals, mainly through the diet, and an association with increased cancer risk is suspected. Epidemiological evidence from Japanese studies to date does not support a positive association between blood concentrations of DDT, HCH, PCBs, and PFASs and risk of breast or prostate cancer. We established assessment methods for dietary intake of cadmium, arsenic, and acrylamide using a food frequency questionnaire. Overall, dietary intakes of cadmium, arsenic, and acrylamide were not significantly associated with increased risk of total cancer and major cancer sites in the Japan Public Health Center-based Prospective Study. However, statistically significant positive associations were observed between dietary cadmium intake and risk of estrogen receptor-positive breast cancer among postmenopausal women, and dietary arsenic intake and risk of lung cancer among male smokers. In addition, studies using biomarkers as exposure assessment revealed statistically significant positive associations between urinary cadmium concentration and risk of breast cancer, and between ratio of hemoglobin adducts of acrylamide and glycidamide and risk of breast cancer. Epidemiological studies of general populations in Japan are limited and further evidence is required. In particular, studies of the association of organochlorine and organofluorine compounds with risk of cancer sites other than breast and prostate cancer are warranted, as are large prospective studies of the association between biomarkers of exposure and risk of cancer. [ABSTRACT FROM AUTHOR]

ObjectiveRates of diabetes mellitus are higher in South Asians than in other populations and persist after migration. One unexplored cause may be higher exposure to persistent organic pollutants associated with diabetes in other populations. We compared organochlorine (OC) pesticide concentrations in South Asian immigrants and European whites to determine whether the disease was positively associated with OC pesticides in South Asians.Research design and methodsSouth Asians of Tamil or Telugu descent (n = 120) and European whites (n = 72) were recruited into the London Life Sciences Population Study cohort. Blood samples as well as biometric, clinical, and survey data were collected. Plasma levels of p,p'-dichlorodiphenyldichloroethylene (DDE), p,p'- dichlorodiphenyltrichloroethane, β-hexachlorohexane (HCH), and polychlorinated biphenyl-118 were analyzed by gas chromatography-mass spectrometry. South Asian cases and controls were categorized by binary exposure (above vs below the 50th percentile) to perform logistic regression.ResultsTamils had approximately threefold to ninefold higher levels of OC pesticides, and Telugus had ninefold to 30-fold higher levels compared with European whites. The odds of exposure to p,p'-DDE above the 50th percentile was significantly greater in South Asian diabetes cases than in controls (OR: 7.00; 95% CI: 2.22, 22.06). The odds of exposure to β-HCH above the 50th percentile was significantly greater in the Tamil cases than in controls (OR: 9.35; 95% CI: 2.43, 35.97).ConclusionsSouth Asian immigrants have a higher body burden of OC pesticides than European whites. Diabetes mellitus is associated with higher p,p'-DDE and β-HCH concentrations in this population. Additional longitudinal studies of South Asian populations should be performed.

Under insulin-stimulated conditions, skeletal muscle is the largest glucose consumer in the body. Mitochondrial dysfunction and damage to this tissue from oxidative stress are linked to the pathogenesis of type 2 diabetes. Environmental exposure to dichlorodiphenyltrichloroethane (DDT) and its metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), has been associated with the incidence of type 2 diabetes as well as altered oxidative stress and mitochondrial dysfunction in non-muscle tissues. We hypothesized that energy metabolism and insulin sensitivity in skeletal muscle will be altered with exposure to DDT and DDE. In this pilot study, mitochondrial function was measured in permeabilized muscle fibers from Sprague-Dawley rats after one week of exposure to a single injection of DDT (40 μg/kg), a dose comparable to DDT levels in the diets of the Inuit of Northern Canada. The levels of oxidative phosphorylation chain complexes and ROS detoxification enzymes were measured in muscle tissue from these specimens. This acute in vivo exposure to DDT decreased muscle mitochondrial function by 45% without affecting the levels of mitochondrial oxidative phosphorylation chain complexes nor levels of ROS detoxification enzymes. To isolate the effects of DDT and DDE exposure on muscle, L6 myotubes were exposed to DDT or DDE (0, 10, 100, 1000, 10 000 nM) for 24 h. Only very high concentrations of DDT and DDE (1 000 – 10 000 nM) altered maximal respiration with only DDT altering basal glucose uptake in L6 myotubes. This did not alter levels of ROS detoxification enzymes or malondialdehyde (MDA) in L6 myotubes. Altogether, acute exposure to environmentally relevant doses of DDT resulted in muscle mitochondrial dysfunction in vivo in rats, but not when muscle cells were directly exposed to the pollutant or its metabolite.

ObjectiveUsing data from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort study, we assessed the association of in utero exposure to dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenylethylene (DDE) with child adiposity at age 12.MethodsWe included 240 children with o,p'-DDT, p,p'-DDT, and p,p'-DDE concentrations measured in maternal serum collected during pregnancy (ng/g lipid) and complete 12-year follow-up data. Age- and sex-specific body mass index (BMI) z-scores were calculated from CDC growth charts. Children with BMI z-scores ≥ 85th percentile were classified as overweight or obese.ResultsAt 12 years, BMI z-score averaged 1.09 (±1.03) and 55.4% of children were overweight or obese. Prenatal DDT and DDE exposure was associated with several adiposity measures in boys but not girls. Among boys, 10-fold increases in prenatal DDT and DDE concentrations were associated with increased BMI z-score (o,p'-DDT, adj-β=0.37, 95% CI: 0.08, 0.65; p,p'-DDT, adj-β = 0.26, 95% CI: 0.03, 0.48; p,p'-DDE, adj-β = 0.31, 95% CI: 0.02, 0.59). Results for girls were nonsignificant. The difference by sex persisted after considering pubertal status.ConclusionsThese results support the chemical obesogen hypothesis, that in utero exposure to DDT and DDE may increase risk of obesity in males later in life.

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In this study, we evaluated the residual levels and distribution characteristics of 10 organochlorine pesticides (OCPs) in the soil of agricultural lands (paddy field, vegetable field, and orchard, n = 150) nationwide. As a result of the investigation, 3–10 types of OCPs were detected in combination in 144 locations (96%) of the total 150 locations. Among those OCPs, dichlorodiphenyltrichloroethane (DDT) and endosulfan were detected in high amounts. The geometric mean concentrations of DDT and endosulfan were ∑DDT 0.31 ng g−1 (ND-2187.18 ng g−1) and ∑endosulfan 0.33 ng g−1 (ND-312.68 ng g−1), respectively. OCP concentrations were generally higher in orchards than in other agricultural fields due to a large amount of pesticides used. DDT in two orchards was detected at 2187.18 ng g−1 and 1061.78 ng g−1, exceeding the levels stated in the Canadian DDT Soil Quality Guidance (SQG, 700 ng g–1). The result of applying the isomer ratio to evaluate the recent or past use of DDT, endosulfan, and hexachlorocyclohexane (HCH), which had a high detection rate, showed that it could be attributable to historical usage. DDT and HCH showed statistically similar residual distribution patterns; however, endosulfan did not show a clear correlation with DDT and HCH due to the effect of its recent use. Thus, the results of evaluation of OCP residual levels and distribution characteristics can be used for the soil management policy of OCPs in agricultural lands in Korea. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyltrichloroethane (DDT) is used for malaria control by 10 countries, nine of which are in Africa. Technical DDT contains various isomers with 65-80% insecticidal p,p'-DDT and 15-21% o,p'-DDT, an estrogenic chemical, while the persistent metabolite of p,p'-DDT, dichlorodiphenyldichloroethylene (p,p'-DDE), is an antiandrogen. In utero antiandrogenic exposure reduces anogenital distance in animal models and the anal position index in a single study. This study examined the associations between mother's serum DDT and DDE levels at delivery and anogenital distance in their children at birth and age 1 year. Data were collected as part of the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), a birth cohort study located in rural South Africa. DDT and DDE concentrations were measured in blood samples collected from 752 mothers at delivery. Anogenital distance measurements, taken at birth (n = 671) and age 1 year (n = 674), included anofourchette and anoclitoral distances in girls, and anoscrotal and anopenile lengths in boys. We also measured anococcygeal and coccyx-fourchette distances in girls, while in boys, we measured anococcygeal and coccyx-scrotal distances as well as penile length and penile width. The anal position index is calculated for both sexes as anoscrotal/coccyx-scrotal in boys and anofourchette/coccyx-fourchette in girls. We found no associations between p,p'-DDT/-DDE or o,p'-DDT and anogenital distance measurements at birth in either boys or girls. At 1 year, o,p'-DDE was negatively associated with anofourchette in girls (β =-1.32 mm, 95% confidence interval (CI) = -2.27, -0.38) and positively associated with penile width in boys (β = 0.30 mm, 95% CI = 0.00, 0.60). The results do not suggest an overt antiandrogenic or estrogenic effect on anogenital distance after long-term DDT exposure. These weak associations may be due to chance.

Tris(4-chlorophenyl)methane (TCPMe) is a byproduct of dichlorodiphenyltrichloroethane synthesis. TCPMe and its metabolite tris(4-chlorophenyl)methanol (TCPMOH) are environmentally prevalent and have been detected in wildlife and humans. Due to inadequate data addressing its toxicity, the National Toxicology Program (NTP) is testing TCPMe in Hsd:Sprague Dawley SD (HSD) rats following perinatal exposure. In support of the toxicology studies, a gas chromatography – mass spectrometry (GC-MS) method was validated to simultaneously quantitate TCPMe and TCPMOH in male Sprague Dawley rat plasma (primary matrix) over calibration standard ranges of 2–200 ng/mL and 1–100 ng/mL, respectively. The method was linear (r2 ≥ 0.9975), accurate (relative error (RE) ≤ ±12.8 (TCPMe) and ±14.5% (TCPMOH), and precise (relative standard deviation (RSD) ≤ 7.6 (TCPMe) and 3.8% (TCPMOH)). The limits of quantitation were 2 and 1 ng/mL and the limits of detection were 0.73 and 0.07 ng/mL for TCPMe and TCPMOH, respectively. Samples, as high as 2000 ng/mL for TCPMe (RSD ≤ 3.9, RE ≤ ±1.0) and 1000 ng/mL for TCPMOH (RSD ≤ 1.0, RE ≤ ±2.9), were successfully diluted with plasma into the validated concentration range. The method was selective and both TCPMe and TCPMOH were quantified in all secondary matrices (HSD male and female plasma, gestation day (GD)18 plasma, amniotic fluid, and fetus, postnatal day (PND)4 dam and pup plasma) using a primary matrix curve (RE ≤ ±14.4% and 11.5; RSD ≤ 7.6 and 11.8%, respectively). These results demonstrate that the method is suitable for simultaneous quantitation of TCPMe and TCPMOH in rodent plasma and fetuses for the evaluation of gestational and lactational transfer following perinatal exposure of TCPMe in NTP studies. [ABSTRACT FROM AUTHOR]

The level, composition, and distribution of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) residues were determined by GC-ECD technique in soil samples from the Soroca district, Republic of Moldova. The concentrations of DDTs and HCHs were up to 1100 and 640 mg/kg, respectively. The obtained results indicated that in 77% of analyzed soil samples the (DDE+DDD)/DDT ratios showed aged sources of DDT pollution, suggesting that in the studied area, the DDT residues have been transformed significantly into their degradation products. The α-HCH/γ-HCH ratios were generally high (in the range of 1-28) suggesting that technical HCH is the main source of contamination. The high concentration and the degradation rates of the pesticides in soil suggest that the contaminated sites are acting as continuous sources of pollution for the environment. Thus, remediation measures are required to reduce the level of the contaminants in soil.

Khat (Catha edulis) chewing is widespread in the region of East Africa. Even low levels of organochlorine pesticides (OCPs) in khat could induce public health concern. In a market-based study, from five popular khat varieties, a total of 35 composite khat samples were analyzed for dichlorodiphenyltrichloroethane (DDT) and its main transformation products, and four hexachlorocyclohexane (HCH) isomers. Extraction was carried out by quick, easy, cheap, effective, rugged and safe method (QuEChERS). OCP concentrations were determined by head space solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME–GC–MS). Every sample contained β-HCH above the maximum residue limit set by the European Commission. For total DDT, this was the case for 25.7% of the samples. The ratios of (p,p′-DDD + p,p′-DDE) to p,p′-DDT were less than one for 85% of khat samples, demonstrating recent use of DDT in khat farmlands. Conversely, the ratio of β-HCH to total HCH varied from 0.56 to 0.96, implying historical input of technical HCH. Assuming a daily chewable portion of 100 g, dietary intakes of p,p′-DDT, total DDT and total HCH by adults ranged from 3.12 to 57.9, 6.49 to 80.2 and 39.2 to 51.9 ng (kg body weight)−1 day−1, respectively. These levels are below acceptable levels suggested by international organizations. Chewing khat showed lower non-cancer health risk, but showed relatively higher cancer risk in terms of OCPs. Because khat is chewed without being subjected to any treatment, uncertainties associated with estimated intakes and health risks should be low. Therefore, this practice is of great concern. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyltrichloroethane (DDT) and its metabolites accumulate in adipose tissue through dietary exposure, and have been proposed to contribute to the development of abdominal obesity, insulin resistance and dyslipidemia. Toxicity may also result when DDT and its metabolites are released from adipose tissue into the bloodstream as a result of rapid weight loss. We hypothesized that DDT-exposed rats fed a high fat diet (HFD) followed by 60% calorie restriction would have an adverse metabolic response to rapid weight loss. To test this, we exposed obese Sprague-Dawley (SD) rats to DDT and a HFD over one month followed by 60% calorie restricted diet for two weeks, and examined metabolic parameters throughout the study. During the HFD feeding period, DDT-exposed rats had significantly elevated postprandial non-esterified fatty acids (NEFAs) and decreased body temperature compared with control rats. During calorie restriction, DDT-exposed rats had lowered food efficiency (weight gained/calories consumed), body temperature, and circulating TSH. Our findings suggest that exposure to DDT may impairs metabolic substrate utilization in rats during dynamic periods of weight gain and weight loss.

Although gas chromatography is the gold standard for detecting the persistent organic pollutant dichlorodiphenyltrichloroethane (DDT), a quick and easy alternative is needed to detect this highly toxic pesticide in food and household products. Therefore, we developed a monoclonal antibody (mAb)-based assay for the sensitive detection of DDT. The mAb used in our assay demonstrated favourable binding affinity in the nanomolar range against 2,2-bis(4-chlorophenyl)acetic acid (DDA), a DDT analogue, which is considered higher than commercially developed antibodies. By optimizing the assay conditions, we were able to detect DDT and its closely related compounds, including dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), and isomeric impurities. Our dot blotting assay demonstrated a detection limit of 0.9 ng/mL for DDT. Using computational modelling, we predicted the structure of the mAb and its interaction with DDT. Overall, this study provides insights for engineering mAb with improved sensitivity, facilitates point-of-care detection of toxic chemicals, including DDT, and offers a vital method for food safety monitoring and environmental protection. [Display omitted] • A sensitive monoclonal Ab-based assay detecting DDT and its derivatives is reported. • A detection limit of 0.9 ng/mL was demonstrated for DDT. • DDT spiked in milk and various juice samples was successfully quantified. • The antibody structure and its interaction with DDT were predicted. • This assay can be practically used to monitor potential DDT contamination in food. [ABSTRACT FROM AUTHOR]

The organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) is an endocrine-disrupting compound (EDC) that has been banned by most countries for decades. However, it continues to be detected in nearly all humans and wildlife due to its biological and environmental persistence. The ovarian dysgenesis syndrome hypothesis speculates that exposure to EDCs during sensitive developmental windows such as early gonadal differentiation lead to reproductive disorders later in life. Yet, mechanisms by which DDT affects developing gonads remain unclear due to the inherent challenge of getting developmental exposure data from adults presenting with reproductive disease. The Japanese medaka (Oryzias latipes) is a valuable fish model for sex-specific toxicological studies due to its chromosomal sex determination, external embryonic development, short generation time, and extensively mapped genome. It is well documented that medaka exposed to DDT and its metabolites and byproducts (herein referred to as DDT+) at different developmental time points experience permanent alterations in gonadal morphology, reproductive success, and molecular and hormonal signaling. However, the overwhelming majority of studies focus primarily on functional and morphological outcomes in males and females and have rarely investigated long-term transcriptional or molecular effects. This review summarizes previous experimental findings and the state of our knowledge concerning toxic effects DDT + on reproductive development, fertility, and health in the valuable medaka model. It also identifies gaps in knowledge, emphasizing a need for more focus on molecular mechanisms of ovarian endocrine disruption using enhanced molecular tools that have become increasingly available over the past few decades. Furthermore, DDT forms a myriad of over 45 metabolites and transformation products in biota and the environment, very few of which have been evaluated for environmental abundance or health effects. This reinforces the demand for high throughput and economical in vivo models for predictive toxicology screening, and the Japanese medaka is uniquely positioned to meet this need. [Display omitted] • We highlight the information known about the ovarian toxicity of DDT+ compounds in the Japanese medaka. • DDT + impact processes such as gonad development, ova-testis induction, fertility, egg quality, and steroidogenesis. • We need to better characterize mechanisms of DDT+ reproductive toxicity in aquatic models and their lasting health impacts. [ABSTRACT FROM AUTHOR]

In-utero exposure to endocrine-disrupting compounds, including dichlorodiphenyltrichloroethane (DDT) and its metabolite dichlorodiphenylethylene (DDE), has been hypothesized to increase the risk of obesity later in life. We examined the associations of maternal serum concentrations of DDT and DDE during pregnancy with body mass index, obesity, waist circumference, and percentage of body fat in 9-year-old children (n = 261) in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) Study, a longitudinal birth cohort study in the Salinas Valley, California (2000-2010). We found associations between prenatal exposure to DDT and DDE and several measures of obesity at 9 years of age in boys but not in girls. For example, among boys, 10-fold increases in prenatal DDT and DDE concentrations were associated with increased odds of becoming overweight or obese (for o,p'-DDT, adjusted odds ratio (OR) = 2.5, 95% confidence interval (CI): 1.0, 6.3; for p,p'-DDT, adjusted OR = 2.1, 95% CI: 1.0, 4.5; and for p,p'-DDE, adjusted OR = 1.97, 95% CI: 0.94, 4.13). The odds ratios for girls were nonsignificant. Results were similar for body mass index z score, waist circumference z score, and odds of increased waist circumference but were less consistent for percentage of body fat. The difference by sex persisted after considering pubertal status. These results provide support for the chemical obesogen hypothesis.

Endocrine disruptors are a major concern due to their possible association with hormone‐dependent carcinogenesis. Some examples of compounds with such properties are organochlorine pesticides (OCPs). OCPs are persistent pollutants with high lipophilicity, long half‐life, and bioaccumulation potential. In the past, some of the most commonly used OCPs were dichlorodiphenyltrichloroethane (DDT) and endosulfan. Here, we investigated the effects of o,p′‐DDT, p,p′‐DDT, and endosulfan and of hormones estradiol, testosterone, and progesterone on the expression of estrogen, progesterone, and androgen receptors (ER, PR, and AR) and of their target genes (KLF4, VEGFA, CCND1, PRLR, CDKN1A, and BCL6) in MCF‐7 and MDA‐MB‐231 cells. The results confirmed that under the action of the insecticides, there are dose‐ and time‐dependent changes in the expression of these receptors and target genes. As corroborated by an experiment with ER, PR, and AR negative MDA‐MB‐231 cells, the change in the expression of KLF4, VEGFA, CCND1, and PRLR in MCF‐7 cells treated with o,p′‐DDT and the change in CDKN1A and PRLR expression in MCF‐7 cells treated with p,p′‐DDT are likely mediated by ER, PR, and AR pathways. In conclusion, we have identified some targets of DDT and endosulfan and confirmed that the effects of insecticides on the expression of these target genes differ for breast cancer cell lines with different receptor statuses. [ABSTRACT FROM AUTHOR]

Abnormal amyloid beta (Aβ) clearance is a distinctive pathological mechanism for Alzheimer’s disease (AD). ATP-binding cassette transporter A1 (ABCA1), which mediates the lipidation of apolipoprotein E, plays a critical role in Aβ clearance. As an environmental factor for AD, dichlorodiphenyltrichloroethane (DDT) can decrease ATP-binding cassette transporter A1 (ABCA1) expression and disrupt Aβ clearance. Liver X receptor α (LXRα) is an autoregulatory transcription factor for ABCA1 and a target of some environmental pollutants, such as organophosphate pesticides. In this study, we aimed to investigate whether DDT could affect Aβ clearance by targeting LXRα. The DDT-pretreated H4 human neuroglioma cells and immortalized astrocytes were incubated with exogenous Aβ to evaluate Aβ consumption. Meanwhile, cytotoxicity and LXRα expression were determined in the DDT-treated cells. Subsequently, the antagonism of DDT on LXRα agonist T0901317 was determined in vitro. The interaction between DDT and LXRα was predicted by molecular docking and molecular dynamics simulation technology. We observed that DDT could inhibit Aβ clearance and decrease the levels of LXRα mRNA and LXRα protein. Moreover, DDT is supposed to strongly bind to LXRα and exert antagonistic effects on LXRα. In conclusion, this study firstly presented that DDT could inhibit LXRα expression, which would contribute to Aβ clearance decline in vitro. It provides an experimental basis to search for potential therapeutic targets of AD.

BackgroundIn utero exposure to endocrine disrupting compounds including dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) has been hypothesized to increase risk of obesity later in life.ObjectivesThe Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study is a longitudinal birth cohort of low-income Latinas living in a California agricultural community. We examined the relation of in utero DDT and DDE exposure to child obesity at 7 years of age. We also examined the trend with age (2, 3.5, 5, and 7 years) in the exposure-obesity relation.MethodsWe included 270 children with o,p´-DDT, p,p´-DDT, and p,p´-DDE concentrations measured in maternal serum during pregnancy (nanograms per gram lipid) and complete 7-year follow-up data including weight (kilograms) and height (centimeters). Body mass index (BMI; kilograms per meter squared) was calculated and obesity was defined as ≥ 95th percentile on the sex-specific BMI-for-age Centers for Disease Control and Prevention 2000 growth charts.ResultsAt 7 years, 96 (35.6%) children were obese. A 10-fold increase in o,p´-DDT, p,p´-DDT, or p,p´-DDE, was nonsignificantly associated with increased odds (OR) of obesity [o,p´-DDT adjusted (adj-) OR = 1.17, 95% CI: 0.75, 1.82; p,p´-DDT adj-OR = 1.19, 95% CI: 0.81, 1.74; p,p´-DDE adj-OR = 1.22, 95% CI: 0.72, 2.06]. With increasing age at follow-up, we observed a significant trend toward a positive association between DDT and DDE exposure and odds of obesity.ConclusionWe did not find a significant positive relation between in utero DDT and DDE exposure and obesity status of 7-year-old children. However, given the observed trend with age, continued follow-up will be informative.

Abnormal amyloid beta (Aβ) clearance is a distinctive pathological mechanism for Alzheimer's disease (AD). ATP-binding cassette transporter A1 (ABCA1), which mediates the lipidation of apolipoprotein E, plays a critical role in Aβ clearance. As an environmental factor for AD, dichlorodiphenyltrichloroethane (DDT) can decrease ATP-binding cassette transporter A1 (ABCA1) expression and disrupt Aβ clearance. Liver X receptor α (LXRα) is an autoregulatory transcription factor for ABCA1 and a target of some environmental pollutants, such as organophosphate pesticides. In this study, we aimed to investigate whether DDT could affect Aβ clearance by targeting LXRα. The DDT-pretreated H4 human neuroglioma cells and immortalized astrocytes were incubated with exogenous Aβ to evaluate Aβ consumption. Meanwhile, cytotoxicity and LXRα expression were determined in the DDT-treated cells. Subsequently, the antagonism of DDT on LXRα agonist T0901317 was determined in vitro. The interaction between DDT and LXRα was predicted by molecular docking and molecular dynamics simulation technology. We observed that DDT could inhibit Aβ clearance and decrease the levels of LXRα mRNA and LXRα protein. Moreover, DDT is supposed to strongly bind to LXRα and exert antagonistic effects on LXRα. In conclusion, this study firstly presented that DDT could inhibit LXRα expression, which would contribute to Aβ clearance decline in vitro. It provides an experimental basis to search for potential therapeutic targets of AD. [ABSTRACT FROM AUTHOR]

• Selected OCPs in placental tissue were quantified in OFC cases and controls. • No association between OCP concentrations and risk for OFCs was observed. • Women who took folic acid supplements had lower OCP levels than women who did not. Previous epidemiological studies have shown that prenatal exposure to organochlorine pesticides (OCPs) entails a variety of adverse impacts on fetal health, but it is not yet known whether it is associated with risk for orofacial clefts (OFCs). This study of 103 fetuses or newborns with a diagnosis of OFCs (cases) and 103 healthy newborns without malformations (controls) examined whether prenatal exposure to OCPs, as indicated by their concentrations in placental tissue, is a risk factor for OFCs. No differences were found in the median concentrations of OCPs between cases and controls, with exception of o,p'-dichlorodiphenyldichloroethylene, o,p'-dichlorodiphenyldichloroethane, and total o,p'-dichlorodiphenyltrichloroethane (DDTs), whose concentrations were higher in controls than in cases (Ps < 0.05). Although higher concentrations of placental δ hexachlorocyclohexane and isodrin were found to be associated with decreased risk for OFCs in logistic regression, no association was observed in the Bayesian kernel machine regression, a novel statistical model in analyzing exposure mixtures. Women who reported periconceptional folic acid supplementation had lower placental concentrations of DDTs than women who did not. In conclusion, no association between levels of OCPs in placental tissue and risk for OFCs was observed in this population. Supplementation with folic acid may help decrease the levels of DDTs in placental tissue, but further studies are needed to confirm this unexpected finding. [ABSTRACT FROM AUTHOR]

The present study is aimed to validate expression of transcriptional factors mediating postnatal development of adrenal zona fasciculata in rats exposed to low doses of endocrine disrupter dichlorodiphenyltrichloroethane prenatally and postnatally. Histological and immunohistochemical examination of the adrenals was performed. Impaired blood circulation, dystrophy and cell death were found in zona fasciculata of pubertal rats after developmental exposure to low doses of dichlorodiphenyltrichloroethane. Reparation of zona fasciculata was associated with increased number of Sonic hedgehog- and Oct4-expressing adrenal cortical cells but not in areas of regeneration. These data suggest that cell death may promote upregulation of factors inducing and maintaining pluripotent state in fasciculata cells for restoration of tissue homeostasis. Termination of growth of the adrenals after puberty was associated with upregulation of antiproliferative factor Hhex and decrease of cell proliferation. Dichlorodiphenyltrichloroethane exposure disrupted transcriptional control of cell proliferation by downregulation of Hhex expression in fasciculata cells. Decrease of proliferation in the exposed rats was mediated by inhibition of Sonic hedgehog and Oct4 expression and suppression of canonical Wnt signaling. The present study elucidated an alternative mechanism of proliferation control activated by endocrine disrupter dichlorodiphenyltrichloroethane through transition of fasciculata cells from pluripotent state and higher proliferative potential to differentiation. Activation of the alternative mechanism of growth control may probably affect maintenance of tissue homeostasis of zona fasciculata in postnatal development. [ABSTRACT FROM AUTHOR]

Fe/graphene oxide and Cu–Fe/graphene oxide nanocomposite were synthesized by the atomic implantation method to study the photocatalytic degradation of dichlorodiphenyltrichloroethane (DDT). The synthesized nanocomposites were characterized by the XRD, N2 isotherms, SEM with EDX, TEM and XPS analysis. Characterization results have reported that oxides of Cu and Fe were uniformly distributed on graphene oxide and exited in the form of Cu+ and Fe2+ ions in Cu–Fe/graphene oxide nanocomposite. The high photocatalytic DDT removal efficiency 99.7% was obtained for Cu–Fe/graphene oxide under the optimal condition of 0.2 g/L catalyst, 15 mg/L H2O2 and pH 5. It was attributed to the reduction of Fe3+ to Fe2+ by Cu+ ions and –OH radicals formation. However, it was dropped to 90.4% in the recycling study by leaching of iron and without a change in phase structure and morphology. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyltrichloroethane (DDT), a chlorinated insecticide served as a well-established tool against the Indian Visceral leishmaniasis (VL) or kala-azar vector, i.e. Phlebotomus argentipes (Diptera: Psychodidae) till infestation with insecticide resistance (IR) among these vector species, leading to the legacy of failure of major campaigns for global VL elimination via vector control strategy. Failing in the task of controlling the insect population, IR has definitely imposed a negative impact over the quality of mosquito vector species in terms of their physiological fitness and reproductive viability, but this has never been reported in the case of Indian VL vector. Therefore, to explore IR implications and comparative assessment over the physiological fitness and reproductive robustness within subsequent generations of laboratory- reared resistant sand flies, bioassay experiments have been performed up till the seventh generation of homozygous 4% DDT-resistant strained colony (DRC) of P. argentipes. With observed mean vector longevity ranging between 3 and 9 days (for male sand flies) as well as 5 and 13.5 days (for female sand flies) till their seventh generation, IR causes an abrupt decrease in fecundity (with mean potential fecundity per female from 60.72 to 6.44), fertility (with mean no. of eggs oviposited per female from 53.4 to 6.02 and mean no. of eggs hatching per female from 13.6 to 1.67) and greatly affecting reproductive fitness and behaviour throughout the studied generations of DRC sand flies. The affected DDT-modulated behavioural profile in terms of the studied four-pronged LF3 parameters (i.e. longevity, fitness, fecundity and fertility), revealed that the changed quality of DRC P. argentipes in the forthcoming generations to such an extent, that it might prove to be detrimental to the survival and fitness of the sand flies, if selection pressures maintained throughout their subsequent generations. The results of the present study provide the probable reasons and side effects associated with the developed resistance both at macroscopic and microscopic levels, which deserve additional attention for uprooting the disease from its end. [ABSTRACT FROM AUTHOR]

Evaluation of carcinogenic substances from the environment is a challenge for scientists. Recently, a novel approach based on 10 key characteristics of human carcinogens classified by the International Agency for Research on Cancer (IARC) has emerged. Carcinogenesis depends on different mechanisms and factors, including genetic, infectious (bacteria, viruses) and environmental (chemicals) factors. Endocrine disruptors are exogenous chemicals that can interfere and impair the function of the endocrine system due to their interaction with estrogen receptors or their estrogen signaling pathways inducing adverse effects in the normal mammary development, originating cancer. They are heterogeneous chemicals and include numerous synthetic substances used worldwide in agriculture, industry and consumer products. The most common are plasticizers, such as bisphenol A (BPA), pesticides, such as dichlorodiphenyltrichloroethane, and polychlorinated biphenyls (PCBs). Xenoestrogens appear to serve an important role in the increased incidence of breast cancer in the United States and numerous other countries. Several studies have demonstrated the role of organochlorine xenoestrogens in breast cancer. Therefore, the overall cumulative exposure of women to estrogens results in an increased risk for this type of cancer. Factors like lifestyle and diet also serve a role in the increased incidence of this disease. The aim of the present study was to analyze these chemical compounds based on the key characteristics given by the IARC, with a special focus on breast cancer, to establish whether these compounds are carcinogens, and to create a model for future analysis of other endocrine disruptors. [ABSTRACT FROM AUTHOR]

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ObjectivesDichlorodiphenyltrichloroethane (DDT) was used worldwide until the 1970s, when concerns about its toxic effects, its environmental persistence, and its concentration in the food supply led to use restrictions and prohibitions. In 2001, more than 100 countries signed the Stockholm Convention on Persistent Organic Pollutants (POPs), committing to eliminate the use of 12 POPs of greatest concern. However, DDT use was allowed for disease vector control. In 2006, the World Health Organization and the U.S. Agency for International Development endorsed indoor DDT spraying to control malaria. To better inform current policy, we reviewed epidemiologic studies published from 2003 to 2008 that investigated the human health consequences of DDT and/or DDE (dichlorodiphenyldichloroethylene) exposure.Data sources and extractionWe conducted a PubMed search in October 2008 and retrieved 494 studies.Data synthesisUse restrictions have been successful in lowering human exposure to DDT, but blood concentrations of DDT and DDE are high in countries where DDT is currently being used or was more recently restricted. The recent literature shows a growing body of evidence that exposure to DDT and its breakdown product DDE may be associated with adverse health outcomes such as breast cancer, diabetes, decreased semen quality, spontaneous abortion, and impaired neurodevelopment in children.ConclusionsAlthough we provide evidence to suggest that DDT and DDE may pose a risk to human health, we also highlight the lack of knowledge about human exposure and health effects in communities where DDT is currently being sprayed for malaria control. We recommend research to address this gap and to develop safe and effective alternatives to DDT.

Dichlorodiphenyltrichloroethane (DDT) is a recalcitrant synthetic chemical that threatens the environment. Despite being banned in most industrialized nations, DDT is still used as a pesticide to fight malaria and agricultural pests. The main objective of this study is to screen, characterize, and evaluate potential DDT-degrading fungi and their synergetic interaction effects for mycoremediation purpose. The soil and effluent samples were collected from Ziway, Koka, and Addis Ababa. Fungal isolation and screening were performed using a serial dilution on potato dextrose agar growth media. Matrix-Assisted Laser Desorption, Ionization, and Time of Flight Mass Spectrometry technology was used for fungal identification and the selected isolates AS1 and T1 were identified as Aspergillus niger and Trichoderma koningii. Fungal biomass production and sporulation capacity were examined and optimized using a Box-Behnken experimental design. The potential DDT-tolerant fungi were studied based on growth factor optimization. The optimization results revealed that the co-inoculated isolates AS1T1 had a maximum biomass (1.01 ± 0.16g) and spore count (5.74 ± 0.37 log spore/mL) and were selected as possible DDT-degrading fungi. Gas Chromatograph-Electron Capture Detector technology was used for the DDT degradation study. Its analysis confirmed that fungal-co-cultured Aspergillus niger and Trichoderma koningii in DDT-amended liquid medium were able to degrade DDT into its metabolites (DDE and DDD). The results also revealed that 99.5–99.99% of DDT and its metabolites degraded from initial concentrations of 1750, 3500, 5250, and 7000 ppm. The co-inoculated fungi Aspergillus niger and Trichoderma koningii are promising candidates for the removal of DDT and its metabolites from polluted environments. [Display omitted] • Dichlorodiphenyltrichloroethane is toxic, persistent organic pollutant synthetic chemical. • Dichlorodiphenyltrichloroethane is still employed for pest control, even though it has been banned. • Microbial degradation of Dichlorodiphenyltrichloroethane is an alternative treatment method. • A synergistic interaction between the fungal consortium Aspergillus niger and Trichoderma koningii was investigated as potential Dichlorodiphenyltrichloroethane degraders sequentially. • These fungal co-culture were capable of degrading 99.9–99.99% of Dichlorodiphenyltrichloroethane and its main metabolites between 1750 and 7000 ppm. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs) are considered as potential obesogens that may affect adipose tissue development and functioning, thus promoting obesity. However, various POPs may have different mechanisms of action. The objective of the present review is to discuss the key mechanisms linking exposure to POPs to adipose tissue dysfunction and obesity. Laboratory data clearly demonstrate that the mechanisms associated with the interference of exposure to POPs with obesity include: (a) dysregulation of adipogenesis regulators (PPARγ and C/EBPα); (b) affinity and binding to nuclear receptors; (c) epigenetic effects; and/or (d) proinflammatory activity. Although in vivo data are generally corroborative of the in vitro results, studies in living organisms have shown that the impact of POPs on adipogenesis is affected by biological factors such as sex, age, and period of exposure. Epidemiological data demonstrate a significant association between exposure to POPs and obesity and obesity-associated metabolic disturbances (e.g., type 2 diabetes mellitus and metabolic syndrome), although the existing data are considered insufficient. In conclusion, both laboratory and epidemiological data underline the significant role of POPs as environmental obesogens. However, further studies are required to better characterize both the mechanisms and the dose/concentration-response effects of exposure to POPs in the development of obesity and other metabolic diseases.

Many studies have shown that dichlorodiphenyltrichloroethane (DDT) exposure raises breast cancer risk. Another insecticide with similar properties is endosulfan, which has been actively used in agriculture after DDT prohibition. Previously, we have identified some estradiol-, progesterone-, and testosterone-sensitive microRNAs (miRNAs, miRs). Because DDT and endosulfan have estrogenic, antiandrogenic, and antiprogesterone properties, we hypothesized that these miRNAs are affected by the insecticides. We quantified relative levels of miRNAs and expression levels of their target genes in breast cancer MCF-7 cells treated with p,p′-DDT, o,p′-DDT, or endosulfan. We also quantified miR-19b expression, which, as previously shown, is regulated by estrogen. Here, we observed that miR-19b expression increased in response not only to estradiol but also to testosterone and progesterone. Treatment of MCF-7 cells with p,p′-DDT or endosulfan decreased the protein levels of apoptosis regulators TP53INP1 and APAF1. In cells treated with o,p′-DDT, the TP53INP1 amount decreased after 24 h of incubation, but increased after 48 h of incubation with insecticide. OXTR expression, which is known to be associated with breast carcinogenesis, significantly diminished under the exposure of all insecticides. In cells treated with p,p′-DDT or o,p′-DDT, the observed changes were accompanied by alterations of the levels of hormone-responsive miRNAs: miR-324, miR-190a, miR-190b, miR-27a, miR-193b, and miR-19b.

Dichlorodiphenyltrichloroethane (DDT) is an organochlorine insecticide that has been used for indoor residual spraying for the control of mosquito-borne diseases including malaria. However, due to its toxicity and environmental persistence, there are concerns about its potential deleterious effects in humans and wildlife. Therefore, the current study aimed to monitor and estimate the level of DDTs in human communities. The accumulation of DDT and its metabolites was evaluated in house rat (as sentinel) livers collected in an area where DDT was sprayed. DDTs were measured using a gas chromatography / Electron Capture Detector. The results revealed high concentrations of DDTs in the rat livers and the levels of DDTs were similar to findings reported from the same area in 2014. [ABSTRACT FROM AUTHOR]

Pesticides are unique environmental contaminants that are specifically introduced into the environment to control pests, often by killing them. Although pesticide application serves many important purposes, including protection against crop loss and against vector-borne diseases, there are significant concerns over the potential toxic effects of pesticides to non-target organisms, including humans. In many cases, the molecular target of a pesticide is shared by non-target species, leading to the potential for untoward effects. Here, we review the history of pesticide usage and the neurotoxicity of selected classes of pesticides, including insecticides, herbicides, and fungicides, to humans and experimental animals. Specific emphasis is given to linkages between exposure to pesticides and risk of neurological disease and dysfunction in humans coupled with mechanistic findings in humans and animal models. Finally, we discuss emerging techniques and strategies to improve translation from animal models to humans. [ABSTRACT FROM AUTHOR]

Behavioural assays are used as a tool to understand ecotoxicological effects on organisms, but are often not applied in an ecologically relevant context. Assessment of the effect of chemical contaminants on behaviours relating to fitness and trophic interactions for example, requires incorporating predator-prey interactions to create impact assessments. Dichlorodiphenyltrichloroethane (DDT) is a controlled substance but is still regularly used as a form of mosquito control. There is little explicit information on the effect of DDT on animal behaviour and the consequent effects upon trophic interactions. This study uses a 3 × 2 factorial design to assess the feeding behaviour of Xenopus laevis toward Culex sp. larvae when supplied with different prey cues. We also assess the behavioural responses of mosquito larvae when supplied with no threat cue and predator threat cues when exposed to 0 µg/L, 2 µg/L and 20 µg/L DDT. There was a significant "DDT exposure" x "prey cue" interaction whereby DDT significantly decreased the foraging behaviour of X. laevis towards live prey cues, however there was no effect of DDT on X. laevis response to olfactory prey cues. Dichlorodiphenyltrichloroethane exposure caused mosquito larvae to appear hyperactive regardless of DDT concentration. Mosquito larvae anti-predator response was significantly dampened when exposed to 2 µg/L DDT, however when exposed to 20 µg/L the anti-predator responses were not impaired. Our results indicate a complex interplay in trophic interactions under DDT exposure, wherein effects are mediated depending on species and concentration. There are possible implications regarding reduced anti-predator behaviour in the prey species but also reduced foraging capacity in the predator, which could drive changes in ecosystem energy pathways. We demonstrate that in order to quantify effects of pesticides upon trophic interactions it is necessary to consider ecologically relevant behaviours of both predator and prey species. [ABSTRACT FROM AUTHOR]

Pentachlorophenol (PCP) and dichlorodiphenyltrichloroethane (DDT) are organochlorine environmental contaminants found in human blood at very significant levels (as high as 5 μm for PCP and 260 nm for DDT). Cancers of the blood (lymphoma and myeloma) and kidney as well as others have been associated with exposure to these contaminants. Interleukin (IL)‐1β is a proinflammatory cytokine and is involved in stimulating cell proliferation. High levels of IL‐1β are associated with inflammatory diseases and tumor progression. Previous studies showed that PCP and DDT at certain concentrations were able to stimulate secretion of IL‐1β. This study shows that the increased secretion of IL‐1β seen with both contaminants is due to compound‐induced increases in the production of this cytokine. Increased production began within 6 hours of exposure to PCP and continued to increase up to 24 hours. DDT‐induced stimulation of IL‐1β appeared to be maximal after 6 hours of exposure and then diminished by 24 hours. The increases seen in IL‐1β production stimulated by PCP appear to be at least partially due to compound‐induced increases in IL‐1β mRNA. Although DDT caused increased production of IL‐1β, it did not appear to cause consistent increases in its mRNA. PCP‐ and DDT‐induced increases in IL‐1β production were dependent primarily on the p38 mitogen‐activated protein kinase pathway. These results indicate that both PCP and DDT are able to increase IL‐1β production in a p38 mitogen‐activated protein kinase‐dependent manner, which may have the potential to influence chronic inflammation. Production of interleukin (IL)‐1β stimulated by pentachlorophenol (PCP) began within 6 hours of exposure and continued to increase up to 24 hours and dichlorodiphenyltrichloroethane (DDT)‐induced stimulation appeared to be maximal after 6 hours of exposure. Increases in IL‐1β production by PCP are partially due to compound‐induced increases in IL‐1β mRNA. PCP‐ and DDT‐induced increases in IL‐1β production were dependent primarily on the p38 mitogen‐activated protein kinase pathway. These results indicate that PCP and DDT increase IL‐1β production and have the potential to influence chronic inflammation. [ABSTRACT FROM AUTHOR]