Development of a Simple Dipstick Assay for Operational Monitoring of DDT

PubMed Central

Ismail, Hanafy M.; Kumar, Vijay; Singh, Rudra P.; Williams, Christopher; Shivam, Pushkar; Ghosh, Ayan; Deb, Rinki; Foster, Geraldine M.; Hemingway, Janet; Coleman, Michael; Coleman, Marlize; Das, Pradeep; Paine, Mark J. I.

2016-01-01

Background Indoor residual spraying (IRS) of DDT is used to control visceral leishmaniasis (VL) in India. However, the quality of spraying is severely compromised by a lack of affordable field assays to monitor target doses of insecticide. Our aim was to develop a simple DDT insecticide quantification kit (IQK) for monitoring DDT levels in an operational setting. Methodology/ principle findings DDT quantification was based on the stoichiometric release of chloride from DDT by alkaline hydrolysis and detection of the released ion using Quantab chloride detection strips. The assay was specific for insecticidal p,p`-DDT (LoQ = 0.082 g/m2). Bostik discs were effective in post spray wall sampling, extracting 25–70% of active ingredient depending on surface. Residual DDT was sampled from walls in Bihar state in India using Bostik adhesive discs and DDT concentrations (g p,p`-DDT/m2) were determined using IQK and HPLC (n = 1964 field samples). Analysis of 161 Bostik samples (pooled sample pairs) by IQK and HPLC produced excellent correlation (R2 = 0.96; Bland-Altman bias = −0.0038). IQK analysis of the remaining field samples matched HPLC data in identifying households that had been under sprayed, in range or over sprayed. Interpretation A simple dipstick assay has been developed for monitoring DDT spraying that gives comparable results to HPLC. By making laboratory-based analysis of DDT dosing accessible to field operatives, routine monitoring of DDT levels can be promoted in low- and middle- income countries to maximise the effectiveness of IRS. PMID:26760773

Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice.

PubMed

La Merrill, Michele A; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

2016-11-01

Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. We hypothesized that perinatal DDT exposure causes hypertension in adult mice. DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722-1727; http://dx.doi.org/10.1289/EHP164.

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system.

PubMed

Ali, Imran; Alharbi, Omar M L; Alothman, Zeid A; Alwarthan, Abdulrahman

2018-01-01

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0μgL -1 concentration of o,p-DDT, 60min contact time, 5.0pH, 6.0gL -1 amount of reverine sediment and 25°C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4μgL -1 concentration of o,p-DDT, pH 7 and 35°C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem. Copyright © 2017. Published by Elsevier Inc.

Factors affecting HCH and DDT in soils around watersheds of Beijing reservoirs, China.

PubMed

Hu, Wenyou; Lu, Yonglong; Wang, Tieyu; Luo, Wei; Zhang, Xiang; Geng, Jing; Wang, Guang; Shi, Yajuan; Jiao, Wentao; Chen, Chunli

2010-04-01

The factors that influence the dynamics of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in soils around the watersheds of Beijing reservoirs were examined. Compared with other studies on HCH and DDT in soils and established reference values, the concentrations of HCH and DDT in soils around our study area were relatively low. The relationships between HCH and DDT concentrations and land use, soil texture, and soil properties were discussed. HCH and DDT concentrations were higher in arable soils than those in uncultivated fallow soils. Although land use was the most important factor affecting HCH and DDT residues, additional factors such as soil texture and soil total organic carbon were also involved in pesticide retention in soils. The results indicated that the historical agricultural applications of HCH and DDT were the major source of their residues. Atmospheric deposition, as well as long-distance transportation and inputs from surrounding weathered agricultural soils may also serve as important sources of HCH and DDT residues in the watersheds.

In Vitro Effects of the Endocrine Disruptor p,p’-DDT on Human Follitropin Receptor

PubMed Central

Munier, Mathilde; Grouleff, Julie; Gourdin, Louis; Fauchard, Mathilde; Chantreau, Vanessa; Henrion, Daniel; Coutant, Régis; Schiøtt, Birgit; Chabbert, Marie; Rodien, Patrice

2016-01-01

Background: 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p′-DDT) is a persistent environmental endocrine disruptor (ED). Several studies have shown an association between p,p′-DDT exposure and reproductive abnormalities. Objectives: To investigate the putative effects of p,p′-DDT on the human follitropin receptor (FSHR) function. Methods and Results: We used Chinese hamster ovary (CHO) cells stably expressing human FSHR to investigate the impact of p,p′-DDT on FSHR activity and its interaction with the receptor. At a concentration of 5 μM p,p′-DDT increased the maximum response of the FSHR to follitropin by 32 ± 7.45%. However, 5 μM p,p′-DDT decreased the basal activity and did not influence the maximal response of the closely related LH/hCG receptor to human chorionic gonadotropin (hCG). The potentiating effect of p,p′-DDT was specific for the FSHR. Moreover, in cells that did not express FSHR, p,p′-DDT had no effect on cAMP response. Thus, the potentiating effect of p,p′-DDT was dependent on the FSHR. In addition, p,p′-DDT increased the sensitivity of FSHR to hCG and to a low molecular weight agonist of the FSHR, 3-((5methyl)-2-(4-benzyloxy-phenyl)-5-{[2-[3-ethoxy-4-methoxy-phenyl)-ethylcarbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-benzamide (16a). Basal activity in response to p,p′-DDT and potentiation of the FSHR response to FSH by p,p′-DDT varied among FSHR mutants with altered transmembrane domains (TMDs), consistent with an effect of p,p′-DDT via TMD binding. This finding was corroborated by the results of simultaneously docking p,p′-DDT and 16a into the FSHR transmembrane bundle. Conclusion: p,p′-DDT acted as a positive allosteric modulator of the FSHR in our experimental model. These findings suggest that G protein–coupled receptors are additional targets of endocrine disruptors. Citation: Munier M, Grouleff J, Gourdin L, Fauchard M, Chantreau V, Henrion D, Coutant R, Schiøtt B, Chabbert M, Rodien P. 2016. In vitro effects of the endocrine disruptor p,p′-DDT on human follitropin receptor. Environ Health Perspect 124:991–999; http://dx.doi.org/10.1289/ehp.1510006 PMID:26895433

In Vitro Effects of the Endocrine Disruptor p,p'-DDT on Human Follitropin Receptor.

PubMed

Munier, Mathilde; Grouleff, Julie; Gourdin, Louis; Fauchard, Mathilde; Chantreau, Vanessa; Henrion, Daniel; Coutant, Régis; Schiøtt, Birgit; Chabbert, Marie; Rodien, Patrice

2016-07-01

1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p'-DDT) is a persistent environmental endocrine disruptor (ED). Several studies have shown an association between p,p'-DDT exposure and reproductive abnormalities. To investigate the putative effects of p,p'-DDT on the human follitropin receptor (FSHR) function. We used Chinese hamster ovary (CHO) cells stably expressing human FSHR to investigate the impact of p,p'-DDT on FSHR activity and its interaction with the receptor. At a concentration of 5 μM p,p'-DDT increased the maximum response of the FSHR to follitropin by 32 ± 7.45%. However, 5 μM p,p'-DDT decreased the basal activity and did not influence the maximal response of the closely related LH/hCG receptor to human chorionic gonadotropin (hCG). The potentiating effect of p,p'-DDT was specific for the FSHR. Moreover, in cells that did not express FSHR, p,p'-DDT had no effect on cAMP response. Thus, the potentiating effect of p,p'-DDT was dependent on the FSHR. In addition, p,p'-DDT increased the sensitivity of FSHR to hCG and to a low molecular weight agonist of the FSHR, 3-((5methyl)-2-(4-benzyloxy-phenyl)-5-{[2-[3-ethoxy-4-methoxy-phenyl)-ethylcarbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-benzamide (16a). Basal activity in response to p,p'-DDT and potentiation of the FSHR response to FSH by p,p'-DDT varied among FSHR mutants with altered transmembrane domains (TMDs), consistent with an effect of p,p'-DDT via TMD binding. This finding was corroborated by the results of simultaneously docking p,p'-DDT and 16a into the FSHR transmembrane bundle. p,p'-DDT acted as a positive allosteric modulator of the FSHR in our experimental model. These findings suggest that G protein-coupled receptors are additional targets of endocrine disruptors. Munier M, Grouleff J, Gourdin L, Fauchard M, Chantreau V, Henrion D, Coutant R, Schiøtt B, Chabbert M, Rodien P. 2016. In vitro effects of the endocrine disruptor p,p'-DDT on human follitropin receptor. Environ Health Perspect 124:991-999; http://dx.doi.org/10.1289/ehp.1510006.

Metabolic and Target-Site Mechanisms Combine to Confer Strong DDT Resistance in Anopheles gambiae

PubMed Central

Mitchell, Sara N.; Rigden, Daniel J.; Dowd, Andrew J.; Lu, Fang; Wilding, Craig S.; Weetman, David; Dadzie, Samuel; Jenkins, Adam M.; Regna, Kimberly; Boko, Pelagie; Djogbenou, Luc; Muskavitch, Marc A. T.; Ranson, Hilary; Paine, Mark J. I.; Mayans, Olga; Donnelly, Martin J.

2014-01-01

The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible strains of An. gambiae, revealed a non-synonymous polymorphism (I114T), proximal to the DDT binding domain, which segregated with strain phenotype. Recombinant protein expression and DDT metabolism analysis revealed that the proteins from the susceptible strain lost activity at higher DDT concentrations, characteristic of substrate inhibition. The effect of I114T on GSTE2 protein structure was explored through X-ray crystallography. The amino acid exchange in the DDT-resistant strain introduced a hydroxyl group nearby the hydrophobic DDT-binding region. The exchange does not result in structural alterations but is predicted to facilitate local dynamics and enzyme activity. Expression of both wild-type and 114T alleles the allele in Drosophila conferred an increase in DDT tolerance. The 114T mutation was significantly associated with DDT resistance in wild caught M-form populations and acts in concert with target-site mutations in the voltage gated sodium channel (Vgsc-1575Y and Vgsc-1014F) to confer extreme levels of DDT resistance in wild caught An. gambiae. PMID:24675797

4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) inhibit myogenesis in C2C12 myoblasts.

PubMed

Kim, Jonggun; Park, Min Young; Kim, Yoo; Yoon, Kyong Sup; Clark, John Marshall; Park, Yeonhwa; Whang, Kwang-Youn

2017-12-01

Most countries have banned the use of 4,4'-dichlorodiphenyltrichloroethane (DDT). However, owing to its extremely high lipophilic characteristics, DDT and its metabolite 4,4'-dichlorodiphenyldichloroethylene (DDE) are ubiquitous in the environment and in many types of food. The positive correlation between exposure to insecticides, including DDT and DDE, and weight gain, resulting in impaired energy metabolism in offspring following perinatal DDT and DDE exposure, was previously reported. Therefore the influence of DDT and DDE on myogenesis using C2C12 myoblasts was investigated in this study. DDT and DDE decreased myotube formation dose- and time-dependently. Among myogenic regulatory factors, DDT and DDE mainly decreased MyoD1 and Myf5 expression. DDT and DDE treatment also altered Myostatin expression, phosphorylation of protein kinase B, p70 ribosomal protein S6 kinase, forkhead box O protein 3 and mammalian target of rapamycin, resulting in attenuation of myotube formation. These results may have significant implications for understanding the effects of developmental exposure of DDT and DDE on myogenesis and development of obesity and type 2 diabetes later in life. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Global Status of DDT and Its Alternatives for Use in Vector Control to Prevent Disease

PubMed Central

van den Berg, Henk

2009-01-01

Objective I review the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, along with current evidence on its benefits and risks in relation to the available alternatives. Data sources and extraction Contemporary data on DDT use were largely obtained from questionnaires and reports. I also conducted a Scopus search to retrieve published articles. Data synthesis DDT has been recommended as part of the arsenal of insecticides available for indoor residual spraying until suitable alternatives are available. Approximately 14 countries use DDT for disease control, and several countries are preparing to reintroduce DDT. The effectiveness of DDT depends on local settings and merits close consideration in relation to the alternatives. Concerns about the continued use of DDT are fueled by recent reports of high levels of human exposure associated with indoor spraying amid accumulating evidence on chronic health effects. There are signs that more malaria vectors are becoming resistant to the toxic action of DDT, and that resistance is spreading to new countries. A comprehensive cost assessment of DDT versus its alternatives that takes side effects into account is missing. Effective chemical methods are available as immediate alternatives to DDT, but the choice of insecticide class is limited, and in certain areas the development of resistance is undermining the efficacy of insecticidal tools. New insecticides are not expected in the short term. Nonchemical methods are potentially important, but their effectiveness at program level needs urgent study. Conclusions To reduce reliance on DDT, support is needed for integrated and multipartner strategies of vector control and for the continued development of new technologies. Integrated vector management provides a framework for developing and implementing effective technologies and strategies as sustainable alternatives to reliance on DDT. PMID:20049114

Evidence for Dual Binding Sites for 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in Insect Sodium Channels*

PubMed Central

Du, Yuzhe; Nomura, Yoshiko; Zhorov, Boris S.; Dong, Ke

2016-01-01

1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), the first organochlorine insecticide, and pyrethroid insecticides are sodium channel agonists. Although the use of DDT is banned in most of the world due to its detrimental impact on the ecosystem, indoor residual spraying of DDT is still recommended for malaria control in Africa. Development of resistance to DDT and pyrethroids is a serious global obstacle for managing disease vectors. Mapping DDT binding sites is necessary for understanding mechanisms of resistance and modulation of sodium channels by structurally different ligands. The pioneering model of the housefly sodium channel visualized the first receptor for pyrethroids, PyR1, in the II/III domain interface and suggested that DDT binds within PyR1. Previously, we proposed the second pyrethroid receptor, PyR2, at the I/II domain interface. However, whether DDT binds to both pyrethroid receptor sites remains unknown. Here, using computational docking of DDT into the Kv1.2-based mosquito sodium channel model, we predict that two DDT molecules can bind simultaneously within PyR1 and PyR2. The bulky trichloromethyl group of each DDT molecule fits snugly between four helices in the bent domain interface, whereas two p-chlorophenyl rings extend into two wings of the interface. Model-driven mutagenesis and electrophysiological analysis confirmed these propositions and revealed 10 previously unknown DDT-sensing residues within PyR1 and PyR2. Our study proposes a dual DDT-receptor model and provides a structural background for rational development of new insecticides. PMID:26637352

Evidence for Dual Binding Sites for 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in Insect Sodium Channels.

PubMed

Du, Yuzhe; Nomura, Yoshiko; Zhorov, Boris S; Dong, Ke

2016-02-26

1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), the first organochlorine insecticide, and pyrethroid insecticides are sodium channel agonists. Although the use of DDT is banned in most of the world due to its detrimental impact on the ecosystem, indoor residual spraying of DDT is still recommended for malaria control in Africa. Development of resistance to DDT and pyrethroids is a serious global obstacle for managing disease vectors. Mapping DDT binding sites is necessary for understanding mechanisms of resistance and modulation of sodium channels by structurally different ligands. The pioneering model of the housefly sodium channel visualized the first receptor for pyrethroids, PyR1, in the II/III domain interface and suggested that DDT binds within PyR1. Previously, we proposed the second pyrethroid receptor, PyR2, at the I/II domain interface. However, whether DDT binds to both pyrethroid receptor sites remains unknown. Here, using computational docking of DDT into the Kv1.2-based mosquito sodium channel model, we predict that two DDT molecules can bind simultaneously within PyR1 and PyR2. The bulky trichloromethyl group of each DDT molecule fits snugly between four helices in the bent domain interface, whereas two p-chlorophenyl rings extend into two wings of the interface. Model-driven mutagenesis and electrophysiological analysis confirmed these propositions and revealed 10 previously unknown DDT-sensing residues within PyR1 and PyR2. Our study proposes a dual DDT-receptor model and provides a structural background for rational development of new insecticides. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The evaluation of p,p'-DDT exposure on cell adhesion of hepatocellular carcinoma.

PubMed

Jin, Xiaoting; Chen, Meilan; Song, Li; Li, Hanqing; Li, Zhuoyu

2014-08-01

Many studies have found a positive association between the progression of hepatocellular carcinoma and DDT exposure. These studies mainly focus on the effect of DDT exposure on cell proliferation and epithelial to mesenchymal transition (EMT) promotion. However, the influence of DDT on cell adhesion of hepatocellular carcinoma remains to be unclear. The aim of our study was to determine the effect of p,p'-DDT on cell adhesion of hepatocellular carcinoma in vitro and in vivo. The data showed that p,p'-DDT, exposing HepG2 cells for 6 days, decreased cell-cell adhesion and elevated cell-matrix adhesion. Strikingly, p,p'-DDT increased reactive oxygen species (ROS) content, and this was accompanied by the activation of JAK/STAT3 pathway. Moreover, ROS inhibitor supplement reversed these effects significantly. However, the addition of ER inhibitor, ICI, had no effect on the p,p'-DDT-induced effects. p,p'-DDT altered the mRNA levels of related adhesion molecules, including inhibition of E-cadherin and promotion of N-cadherin along with CD29. Interestingly, the p,p'-DDT-altered adhesion molecules could be reversed with JAK inhibitor or STAT3 inhibitor. Likewise, p,p'-DDT stimulated the JAK/STAT3 pathway in nude mice, as well as altered the mRNA levels of E-cadherin, N-cadherin, and CD29. Taken together, these results indicate that p,p'-DDT profoundly promotes the adhesion process by decreasing cell-cell adhesion and inducing cell-matrix adhesion via the ROS-mediated JAK/STAT3 pathway. All these events account for the carcinogenic potential of p,p'-DDT in liver. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis

NASA Astrophysics Data System (ADS)

Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

2016-02-01

A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment.

Matrix-enhanced degradation of p,p'-DDT during gas chromatographic analysis: A consideration

USGS Publications Warehouse

Foreman, W.T.; Gates, Paul M.

1997-01-01

Analysis of p,p‘-DDT in environmental samples requires monitoring the GC-derived breakdown of this insecticide, which produces p,p‘-DDD and/or p,p‘-DDE, both also primary environmental degradation products. A performance evaluation standard (PES) containing p,p‘-DDT but notp,p‘-DDD or p,p‘-DDE can be injected at regular intervals throughout an analytical sequence to monitor GC degradation. Some U.S. EPA methods limit GC breakdown of DDT in the PES to ≤20%. GC/MS analysis of large-volume natural water samples fortified with deuterium- and 13C-labeled p,p‘-DDT exhibited up to 65% DDT breakdown by the GC inlet. These matrix-enhanced GC degradation amounts substantially exceeded the <20% breakdown levels indicated by bracketing injections of the PES containing unlabeled and labeled DDT. Substantial matrix-enhanced GC degradation was not observed during analysis of a limited number of fractionated bed-sediment extracts containing labeled DDT. Use of isotopically labeled DDT seems to provide an effective tool for monitoring sample-specific DDT breakdown during GC/MS analysis. However, analyte co-elutions render impractical their use in GC/ECD analysis. The oc currence of matrix-enhanced GC degradation might have important implications on data quality and the resultant interpretations of the environmental degradation of DDT and other thermolabile contaminants.

4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) promote adipogenesis in 3T3-L1 adipocyte cell culture.

PubMed

Kim, Jonggun; Sun, Quancai; Yue, Yiren; Yoon, Kyong Sup; Whang, Kwang-Youn; Marshall Clark, J; Park, Yeonhwa

2016-07-01

4,4'-Dichlorodiphenyltrichloroethane (DDT), a chlorinated hydrocarbon insecticide, was extensively used in the 1940s and 1950s. DDT is mainly metabolically converted into 4,4'-dichlorodiphenyldichloroethylene (DDE). Even though most countries banned DDT in the 1970s, due to the highly lipophilic nature and very stable characteristics, DDT and its metabolites are present ubiquitously in the environment, including food. Recently, there are publications on relationships between exposure to insecticides, including DDT and DDE, and weight gain and altered glucose homeostasis. However, there are limited reports regarding DDT or DDE and adipogenesis, thus we investigated effects of DDT and DDE on adipogenesis using 3T3-L1 adipocytes. Treatment of DDT or DDE resulted in increased lipid accumulation accompanied by increased expression of CCAAT/enhancer-binding protein α (C/EBPα), peroxisome-proliferator activated receptor-γ (PPARγ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipose triglyceride lipase, and leptin. Moreover, treatment of DDT or DDE increased protein levels of C/EBPα, PPARγ, AMP-activated protein kinase-α (AMPKα), and ACC, while significant decrease of phosphorylated forms of AMPKα and ACC were observed. These finding suggest that increased lipid accumulation caused by DDT and DDE may mediate AMPKα pathway in 3T3-L1 adipocytes. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis.

PubMed

Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

2016-02-18

A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment.

Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

PubMed

Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

2017-07-24

Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

Dechlorination of DDT, DDD and DDE in soil (slurry) phase using magnesium/palladium system.

PubMed

Gautam, Sumit Kumar; Suresh, Sumathi

2006-12-01

Mg0/Pd4+ was able to dechlorinate >99% of extractable DDT (initial concentration of 10 mg DDT kg(-1) of soil) and >90% of extractable DDT (initial concentration of 50 mg DDT kg(-1) of soil) in soil slurry. Mg0/Pd4+ was also found to be effective in dechlorinating of 50 mg kg(-1) DDD and DDE, in soil aged for varying time periods. GC-MS analyses revealed the formation of 1,1-diphenylethane as an end product from DDT, DDE and DDD. To the best of our knowledge this is the first report describing the application Mg0/Pd4+ system for remediation of DDT, DDD and DDE contaminated soil. We conclude that reductive dechlorination reaction catalyzed by Mg0/Pd4+ may be a promising system to remediate soil contaminated with DDT and its dechlorinated products such as DDD and DDE.

Levels and mass burden of DDTs in sediments from fishing harbors: the importance of DDT-containing antifouling paint to the coastal environment of China.

PubMed

Lin, Tian; Hu, Zhaohui; Zhang, Gan; Li, Xiangdong; Xu, Weihai; Tang, Jianhui; Li, Jun

2009-11-01

DDT remains an important type of persistent organic pollutant (POP) in the environment of China. One of the current applications of DDT in China has been through antifouling paint for fishing ships as an active component. It has been estimated that approximately 5000 t of DDT was released into the Chinese coastal environment during the last two decades. Therefore, sediments in coastal fishing harbors of China may be the important sinks of DDT. In this study, DDT and its metabolites in 58 sediment samples from nine typical fishing harbors along the coastal line of China were characterized to assess their accumulation levels, sediment burdens, and potential ecological risks. The concentrations of DDTs ranged from 9 to 7350 ng/g dry weight, which were generally 1-2 orders of magnitude higher than those of the adjacent estuarine/marine sediments. The high concentrations of DDT coupled with the lower concentrations of HCH and TOC clearly indicated a strong local DDT input, i.e., DDT-containing antifouling paint, within the fishing harbors. A significant correlation between the total DDT concentrations and p,p'-DDT concentrations further confirmed the existence of fresh DDT input. The overall burden of DDTs within the upper 10 cm sediment layer in the fishing harbors of the Pearl River Delta, southern China, was estimated to be 1.0-5.7 t, which was several times higher than the DDT accumulation in the surface sediment of the Pearl River estuary. The concentrations of DDTs in the fishing harbor sediments significantly exceeded the sediment quality guidelines on the basis of adverse biological effects. The absence or low concentrations of p,p'-DDD in aquatic organisms and human may imply that either p,p'-DDD may be less bioaccumulated by fish and human, or is biotransformed to other metabolites. A national ban of DDT as an additive to antifouling paint was implemented in 2009 in China; however, the legacy high DDT burden in the coastal fishing harbors needs further monitoring and proper management.

40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false DDT (Dichlorodiphenyltrichloroethane... Substances § 721.2287 DDT (Dichlorodiphenyltrichloroethane). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance DDT (dichlorodiphenyltrichloroethane) (CAS No. 50-29-3...

Wildlife effects of DDT dust used for tick control on a Texas prairie

USGS Publications Warehouse

George, J.L.; Stickel, W.H.

1949-01-01

SUMMARY The effect of DDT dust on wildlife was studied at Camp Bullis, Bexar County, Texas, in the summer of 1947. Studies were made on a 206.6 acre plot that was treated with DDT for experimental control of the Lone Star tick (Amblyomrna americanum). A dust consisting of one part of DDT to nine parts of pyrophyllite was applied at an average rate of 4.4 pounds of DDT per acre. The limits of DDT concentration that affected wildlife cannot be stated exactly because of a heavy rain that fell near the end of the dusting, and because of irregularity in DDT deposition. Since absolute uniformity of dusting could not be expected in any large scale DDT application, the effects observed in these trials were probably fairly representative. However, continued dry weather would have permitted longer exposure to DDT, possibly with more severe effects than those found in this study. The vegetation of the experimental area was roughly 70 percent ungrazed tall-grass prairie and 30 percent trees and shrubs. Ground and bush feeding birds were severely affected. Cardinals, lark sparrows, field sparrows, Bewick's wrens, Carolina wrens, Kentucky warblers, yellow-breasted chats, blue grosbeaks, and painted buntings were nearly or entirely eliminated from the treated area. Birds affected, but less drastically reduced in numbers, were yellow-billed cuckoo, black and white warbler, yellow-throated vireo, and white-eyed vireo. Birds found dead in the DDT area were 9 cardinals, 2 painted buntings, 2 lark sparrows, 1 yellow-breasted chat, and 1 white-eyed vireo. Bird mortality had begun by the day after dusting and was largely over by the end of the fifth day. Census of deer in DDT and check areas before and after treatment showed no reduction in deer numbers and no diminution in use of the DDT area. No deer or fawns were found dead or affected. Box-trapping of raccoons in DDT and check areas before and after treatment showed no effects that could be attributed to DDT. Limited observations on armadillos, striped skunks, and rabbits gave no indication of pronounced damage to these forms. No mammals of any kind were found dead or affected in or near the DDT area. Four rough green snakes and one Texan spiny lizard were found dead in the DDT area. Mortality was probably high among insectivorous reptiles.

Is DDT use a public health problem in Mexico?

PubMed Central

López-Carrillo, L; Torres-Arreola, L; Torres-Sánchez, L; Espinosa-Torres, F; Jiménez, C; Cebrián, M; Waliszewski, S; Saldate, O

1996-01-01

We review the potential impact of DDT on public health in Mexico. DDT production and consumption patterns in Mexico during the last 20 years are described and compared with those in the United States. In spite of the restrictions on DDT use in antimalaria campaigns in Mexico, use of DDT is still higher than in other Latin American countries. We analyzed information from published studies to determine accumulated levels of this insecticide in blood, adipose tissue, and breast milk samples from Mexican women. Current lipid-adjusted DDE levels from women living in Mexico City are 6.66 ppb in mammary adipose tissue and 0.594 ppm in total breast milk. Finally, the methodological limitations of existing epidemiological studies on DDT exposure and breast cancer are discussed. We conclude that DDT use in Mexico is a public health problem, and suggest two solutions: identification of alternatives for the control of malaria and educational intervention to reduce DDT exposure. We also recommend strengthening epidemiological studies to evaluate the association between accumulated DDT levels in adipose tissue and breast cancer incidence among Mexican women. Images Figure 1. Figure 2. Figure 3. PMID:8793339

Predictors of Plasma DDT and DDE Concentrations among Women Exposed to Indoor Residual Spraying for Malaria Control in the South African Study of Women and Babies (SOWB)

PubMed Central

Bornman, Riana M.S.; Archer, Janet I.; Kudumu, Mwenda O.; Travlos, Gregory S.; Wilson, Ralph E.; Longnecker, Matthew P.

2014-01-01

Background: Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. Methods: The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. Results: Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. Conclusion: The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target. Citation: Whitworth KW, Bornman RM, Archer JI, Kudumu MO, Travlos GS, Wilson RE, Longnecker MP. 2014. Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB). Environ Health Perspect 122:545–552; http://dx.doi.org/10.1289/ehp.1307025 PMID:24577839

Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis

PubMed Central

Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

2016-01-01

A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment. PMID:26888254

Influence of PCBs in water on uptake and elimination of DDT and DDE by lake trout

USGS Publications Warehouse

Hesselberg, Robert J.; Nicholson, Lawrence W.

1981-01-01

Researchers predicted that several hundred years would be required before DDT (1,1,1 trichloro-2,2-bis [P-chlorophyl] ethane) and its metabolites were likely to decrease to nondetectable levels in Lake Michigan. But following the ban on DDT in 1970, residues of total DDT in Lake Michigan lake trout (Salvelinus namaycush) declined rapidly from 10.5µg/g in 1970 to 5.7 µg/g in 1976. During this period, polychlorinated biphenyls (PCBs) were being detected in lake trout tissues at about 20 µg/g. It was hypothesized that the high level of PCBs being accumulated by fish may have influenced uptake and elimination of DDT and DDE (1,1-dichloro-2,2-bis [p-chlorophenyl] ethylene) by fish. To test this hyphophesis, fingeriing lake trout were exposed to various combinations of DDT, DDE (100 ng/liter), and PCBs (100 and 500 ng/liter) in water for 12 weeks. After DDT and DDe exposures were completed, exposure to PCBs was continued for an additional 16 weeks to measure any effect PCBs may have on the elimination of DDT and DDE by fish. Accumulation and elimination rates of DDT and DDE were compared. It was found that PCBs did not influence the accumulation or elimination rates of DDT or DDE in lake trout and therefore should not have had a major influence on the decline of DDT in lake trout.

Prenatal and postnatal exposure to DDT by breast milk analysis in Canary Islands.

PubMed

Vall, Oriol; Gomez-Culebras, Mario; Puig, Carme; Rodriguez-Carrasco, Ernesto; Gomez Baltazar, Arelis; Canchucaja, Lizzeth; Joya, Xavier; Garcia-Algar, Oscar

2014-01-01

The use of p,p'-dichlorodiphenyltrichloroethane (DDT) has been banned since the late 1970s due to its toxicity. However, its long half-life makes it persistent in the environment and, consequently, almost everyone has DDT residues in the body. Human milk constitutes an ideal non-conventional matrix to investigate environmental chronic exposure to organochlorine compounds (OCs) residues. The study aimed to identify potential population risk factors of exposure to DDT due to the proximity to countries where it is still used. Seventy-two consecutive lactating women were prospectively included in Tenerife, Canary Islands (Spain). A validated questionnaire was used to obtain socioeconomic, demographics data, and daily habits during pregnancy. DDT levels in breast milk were measured by gas chromatography with-electron capture detector (GC-ECD). Anthropometrics measurements in newborns were obtained. Thirty-four out of 72 (47.2%) of the analysed milk samples presented detectable levels of DDT (mean: 0.92 ng/g), ranging between 0.08 to 16.96 ng/g. The socio-demographic variables did not significantly differ between detectable DDT and non-detectable DDT groups. We found positive association between DDT levels and vegetables (OR (95%CI): 1.23 (1.01-1.50)) and poultry meat (OR (95%CI): 2.05 (1.16-3.60)) consumption, and also between the presence of DDT in breast milk and gestational age (OR (95%CI): 0.59 (0.40-0.90)). DDT is present in breast milk of women at the time of delivery. Residual levels and the spread from countries still using DDT explain DDT detection from vegetables and from animal origin food. The presence of this compound in breast milk represents a pre- and postnatal exposure hazard for foetuses and infants due to chronic bioaccumulation and poor elimination, with possible deleterious effects on health. This data should be used to raise awareness of the risks of OCs exposure and to help establish health policies in order to avoid its use worldwide and thus, to prevent its propagation.

Short-tailed shrews: Toxicity and residue relationships of DDT, dieldrin, and endrin

USGS Publications Warehouse

Blus, L.J.

1978-01-01

Experiments involving dietary toxicity and residue relationships of DDT, dieldrin, and endrin were conducted with short-tailed shrews. Dietary concentrations of DDT dissolved in vegetable oils were usually more toxic than diets containing comparable amounts of powdered DDT. Younger shrews, particularly females, were more tolerant of powdered DDT than older animals; yet, there were no conspicuous age differences in toxicity of DDT dissolved in oils. In comparison to other mammals, short-tailed shrews are not unusually sensitive to DDT, dieldrin, or endrin on the basis of two-week feeding tests. The influence of age and sex on toxicity of DDT, endrin, and dieldrin was sometimes more important than body weight. Of those shrews of the same age and sex that were fed the same dietary dosage, heavier shrews were more tolerant than lighter individuals; and, heavier shrews tended to lose a greater percentage of body weight before death. There was a range of 15 to 105 DDT equivalents in brains of shrews dying on dietary dosages of DDT. Six shrews fed a high level of DDT seemed to have unusual metabolite capabilities and died with apparent lethal levels of DDD in their brains. Levels of dieldrin in brains of shrews that died on a dietary dosage of dieldrin ranged from 3.7 to 12.6 ppm. In the rates of gain and loss experiments where shrews were given diets containing 400 ppm DDT or 50 ppm dieldrin up to 17 days, high residues were noted in tissues of shrews after two weeks on a contaminated diet and a few died at that time. After shrews were placed on clean food, it was determined that >50% of the dieldrin residues in carcass and brain were lost in 50% of residues of DDT and metabolites in brains after 2 weeks on clean food; males lost nearly 50% of residues in carcasses after two weeks on clean food compared with a loss of only 11% in females.

Interaction between duck hepatitis virus and DDT in ducks

USGS Publications Warehouse

Ragland, W.L.; Friend, Milton; Trainer, D.O.; Sladek, N.E.

1971-01-01

Injections of duck hepatitis virus (DVH) decreased, and exposure to DDT increased, hepatic microsomal mixed-function oxidase activity. Injection of DFV prior to exposure to DDT did not prevent stimulation of hepatic microsomal mixed-function oxidase activity by DDT and may have enhanced it.

Pleiotropic Effects of DDT Resistance on Male Size and Behaviour.

PubMed

Rostant, Wayne G; Bowyer, Jemima; Coupland, Jack; Facey, James; Hosken, David J; Wedell, Nina

2017-07-01

Understanding the evolution and spread of insecticide resistance requires knowing the relative fitness of resistant organisms. In the absence of insecticides, resistance is predicted to be costly. The Drosophila melanogaster DDT resistance allele (DDT-R) is associated with a male mating cost. This could be because resistant males are generally smaller, but DDT-R may also alter courtship behaviours. Here we tested for body size and courtship effects of DDT-R on mating success in competitive and non-competitive mating trials respectively. We also assessed relative aggression in resistant and susceptible males because aggression can also influence mating success. While the effect of DDT-R on male size partly contributed to reduced mating success, resistant males also had lower rates of courtship and were less aggressive than susceptible males. These differences contribute to the observed DDT-R mating costs. Additionally, these pleiotropic effects of DDT-R are consistent with the history and spread of resistance alleles in nature.

PARACHUTING CATS AND CRUSHED EGGS The Controversy Over the Use of DDT to Control Malaria

PubMed Central

2008-01-01

The use of DDT to control malaria has been a contentious practice for decades. This controversy centers on concerns over the ecological harm caused by DDT relative to the gains in public health from its use to prevent malaria. Given the World Health Organization's recent policy decisions concerning the use of DDT to control malaria, it is worth reviewing the historical context of DDT use. Ecological concerns focused on evidence that DDT ingestion by predatory birds resulted in eggs with shells so thin they were crushed by adult birds. In addition, DDT spraying to control malaria allegedly resulted in cats being poisoned in some areas, which led to increased rodent populations and, in turn, the parachuting of cats into the highlands of the island of Borneo to kill the rodents, a story that influenced the decision to ban DDT spraying. I focus on this story with the intention of grounding the current debate on lessons from the past. PMID:18799776

Organochlorine insecticide residues in soil and earthworms in the Delhi area, India, August-October 1974

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, D.V.; Mittal, P.K.; Agarwal, H.C.

1981-09-01

DDT residues in soil and earthworms from 50 sites in Delhi were monitored. DDT was detected in all but two samples each of soil and earthworms. Among DDT residues, p,p'-DDE was most common and was found in 48 samples each of soil and earthworms; p,p'-DDT was detected in only 43 soil samples and 46 earthworm samples. p,p'-TDE and o,p'-DDT were also present in smaller concentrations in 29 and 15 soil samples and in 43 and 25 earthworm samples, respectively. Maximum total DDT concentration of 2.6 ppm was detected in the soil from Durga Nagar in the vicinity of a DDTmore » factory. The highest concentration of 37.7 ppm total DDT in earthworms was also obtained from the same site. The maximum concentration factor found in the earthworms was 551. The total DDT concentration in the earthworms and soil showed significant correlation.« less

Effects of the Endocrine-Disrupting Chemical DDT on Self-Renewal and Differentiation of Human Mesenchymal Stem Cells

PubMed Central

Strong, Amy L.; Shi, Zhenzhen; Strong, Michael J.; Miller, David F.B.; Rusch, Douglas B.; Buechlein, Aaron M.; Flemington, Erik K.; McLachlan, John A.; Nephew, Kenneth P.

2014-01-01

Background: Although the global use of the endocrine-disrupting chemical DDT has decreased, its persistence in the environment has resulted in continued human exposure. Accumulating evidence suggests that DDT exposure has long-term adverse effects on development, yet the impact on growth and differentiation of adult stem cells remains unclear. Objectives: Human mesenchymal stem cells (MSCs) exposed to DDT were used to evaluate the impact on stem cell biology. Methods: We assessed DDT-treated MSCs for self-renewal, proliferation, and differentiation potential. Whole genome RNA sequencing was performed to assess gene expression in DDT-treated MSCs. Results: MSCs exposed to DDT formed fewer colonies, suggesting a reduction in self-renewal potential. DDT enhanced both adipogenic and osteogenic differentiation, which was confirmed by increased mRNA expression of glucose transporter type 4 (GLUT4), lipoprotein lipase (LpL), peroxisome proliferator-activated receptor gamma (PPARγ), leptin, osteonectin, core binding factor 1 (CBFA1), and FBJ murine osteosarcoma viral oncogene homolog (c-Fos). Expression of factors in DDT-treated cells was similar to that in estrogen-treated MSCs, suggesting that DDT may function via the estrogen receptor (ER)-mediated pathway. The coadministration of ICI 182,780 blocked the effects of DDT. RNA sequencing revealed 121 genes and noncoding RNAs to be differentially expressed in DDT-treated MSCs compared with controls cells. Conclusion: Human MSCs provide a powerful biological system to investigate and identify the molecular mechanisms underlying the effects of environmental agents on stem cells and human health. MSCs exposed to DDT demonstrated profound alterations in self-renewal, proliferation, differentiation, and gene expression, which may partially explain the homeostatic imbalance and increased cancer incidence among those exposed to long-term EDCs. Citation: Strong AL, Shi Z, Strong MJ, Miller DF, Rusch DB, Buechlein AM, Flemington EK, McLachlan JA, Nephew KP, Burow ME, Bunnell BA. 2015. Effects of the endocrine-disrupting chemical DDT on self-renewal and differentiation of human mesenchymal stem cells. Environ Health Perspect 123:42–48; http://dx.doi.org/10.1289/ehp.1408188 PMID:25014179

The insecticide 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) alters the membrane raft location of the TSH receptor stably expressed in Chinese hamster ovary cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Gregorio, Francesca; Pellegrino, Mario; Picchietti, Simona

2011-06-01

DDT is a highly lipophilic molecule known to deplete membrane rafts of their phosphoglycolipid and cholesterol contents. However, we have recently shown that DDT can also alter the thyroid homeostasis by inhibiting TSH receptor (TSHr) internalization. The present study was undertaken to verify whether DDT goitrogenic effects are due to the insecticide acting directly on TSHr or via alteration of the membrane rafts hosting the receptor itself. Our results demonstrate that, in CHO-TSHr transfected cells, TSHr is activated in the presence of TSH, while it is inhibited following DDT exposure. DDT can also reduce the endocytic vesicular traffic, alter themore » extension of multi-branched microvilli along their plasma membranes and induce TSHr shedding in vesicular forms. To verify whether TSHr displacement might depend on DDT altering the raft constitution of CHO-TSHr cell membranes the extent of TSHr and lipid raft co-localization was examined by confocal microscopy. Evidence shows that receptor/raft co-localization increased significantly upon exposure to TSH, while receptors and lipid rafts become dislodged on opposite cell poles in DDT-exposed CHO-TSHr cells. As a control, under similar culturing conditions, diphenylethylene, which is known to be a lipophilic substance that is structurally related to DDT, did not affect the extent of TSHr and lipid raft co-localization in CHO-TSHr cells treated with TSH. These findings corroborate and extend our view that, in CHO cells, the DDT disrupting action on TSHr is primarily due to the insecticide acting on membranes to deplete their raft cholesterol content, and that the resulting inhibition on TSHr internalization is due to receptor dislodgement from altered raft microdomains of the plasma membrane. - Highlights: >DDT is a pesticide with a severe environmental impact >Epidemiologic correlation exists between exposition to DDT and thyroid dysfunction >DDT is a lipophilic molecule that has been shown to inhibit TSH receptor function >DDT depletes membrane raft cholesterol content and by this way inhibits TSH receptor« less

Chronic oral DDT toxicity in juvenile coho and chinook salmon

USGS Publications Warehouse

Buhler, Donald R.; Rasmusson, Mary E.; Shanks, W.E.

1969-01-01

Technical and p,p′-DDT was incorporated into test diets and fed to juvenile chinook and coho salmon for periods as long as 95 days. Pure p,p′-DDT was slightly more toxic to young salmon than was the technical DDT mixture. Chinook salmon appeared to be 2–3 times more sensitive to a given concentration of DDT in the diet than were coho salmon. The size of the fish greatly influenced toxicity, smaller younger fish being more susceptible to a given diet than larger older fish. The dose of DDT accumulated within the median survival time ranged from 27–73 mg/kg for chinook salmon and from 56–72 mg/kg for coho salmon. The extrapolated 90-dose LD50 (Hayes, 1967) for young chinook and coho salmon were 0.0275 and 0.064 mg/kg/day, respectively. Liver size decreased on prolonged feeding with DDT, and carcass lipid content was increased. A severe surface ulceration of the nose region appeared in coho salmon fed DDT over long periods. In addition, an interesting localized degeneration of the distal convoluted tubule was observed in the kidney of coho salmon receiving DDT.

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O., E-mail: pustylnyak@ngs.ru

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CARmore » and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell cycle and apoptosis target genes. • DDT produced increases in cell cycle and anti-apoptosis proteins and decrease in p53. • DDT mixture was unable to stimulate the β-catenin signalling pathway in mouse livers.« less

Lake Erie walleyes--again on the upswing?

USGS Publications Warehouse

Seldon, Charles P.; Van Meter, Harry D.

1960-01-01

SUMMARY The effect of DDT dust on wildlife was studied at Camp Bullis, Bexar County, Texas, in the summer of 1947. Studies were made on a 206.6 acre plot that was treated with DDT for experimental control of the Lone Star tick (Amblyomrna americanum). A dust consisting of one part of DDT to nine parts of pyrophyllite was applied at an average rate of 4.4 pounds of DDT per acre. The limits of DDT concentration that affected wildlife cannot be stated exactly because of a heavy rain that fell near the end of the dusting, and because of irregularity in DDT deposition. Since absolute uniformity of dusting could not be expected in any large scale DDT application, the effects observed in these trials were probably fairly representative. However, continued dry weather would have permitted longer exposure to DDT, possibly with more severe effects than those found in this study. The vegetation of the experimental area was roughly 70 percent ungrazed tall-grass prairie and 30 percent trees and shrubs. Ground and bush feeding birds were severely affected. Cardinals, lark sparrows, field sparrows, Bewick's wrens, Carolina wrens, Kentucky warblers, yellow-breasted chats, blue grosbeaks, and painted buntings were nearly or entirely eliminated from the treated area. Birds affected, but less drastically reduced in numbers, were yellow-billed cuckoo, black and white warbler, yellow-throated vireo, and white-eyed vireo. Birds found dead in the DDT area were 9 cardinals, 2 painted buntings, 2 lark sparrows, 1 yellow-breasted chat, and 1 white-eyed vireo. Bird mortality had begun by the day after dusting and was largely over by the end of the fifth day. Census of deer in DDT and check areas before and after treatment showed no reduction in deer numbers and no diminution in use of the DDT area. No deer or fawns were found dead or affected. Box-trapping of raccoons in DDT and check areas before and after treatment showed no effects that could be attributed to DDT. Limited observations on armadillos, striped skunks, and rabbits gave no indication of pronounced damage to these forms. No mammals of any kind were found dead or affected in or near the DDT area. Four rough green snakes and one Texan spiny lizard were found dead in the DDT area. Mortality was probably high among insectivorous reptiles.

Lethal mobilization of DDT by cowbirds

USGS Publications Warehouse

Van Velzen, A.C.; Stiles, W.B.; Stickel, L.F.

1972-01-01

This study is an experimental demonstration of lethal mobilization of DDT by brown-headed cowbirds (Molothrus ater) and the effects of food deprivation on the distribution and loss of DDT, DDD, and DDE. The principal experimental group consisted of 20 birds fed a dietary dosage of 100 ppm of DDT for 13 days. After 2 days of full rations of untreated food, they were subjected to food restriction. Food was reduced to 43 percent of normal. Seven of the 20 birds died within 4 days. No birds died in the three control groups, treated as follows: ( 1 ) 20 birds fed 100 ppm DDT for 13 days and full rations of untreated food thereafter, (2) 20 birds fed only untreated food but subjected to food restriction, and (3) 20 birds fed full rations of untreated food throughout. In a pilot study, birds were fed 100, 200, or 300 ppm of DDT and subjected to two periods of food restriction, the first of these immediately after dosage ceased and the second 4 months later. DDT-dosed birds from all dosage levels died in each period of food restriction. Before the weight loss that accompanied food restriction, the brains of DDT-dosed birds had concentrations of DDT and DDD that were far below the lethal range. Concentrations increased rapidly to lethal levels. In these birds, DDT in carcasses decreased while DDD increased. DDT-dosed birds that died during food restriction lost 16 percent of their total body burden of DDT + DDD + DDE, 21 percent of their weight, and 81 percent of their fat. The DDT-dosed birds that were subjected to food restriction but survived lost a significantly greater proportion of their body burden of residues than similarly dosed birds not subjected to weight loss. Brain levels of DDT and DDD in birds that died during food restriction soon after dosage did not differ significantly from brain levels of birds that died in a period of food restriction 4 months after dosage. Concentrations of DDE were significantly higher in the latter group, although they were lower than concentrations considered to be lethal. In contrast, carcass levels of DDT and DDD were significantly lower, and DDE was only slightly higher, in the birds that died in the second period of food restriction. It is concluded that stored DDT residues present a hazard to birds, which utilize stored fat during periods of stress due to reproduction, cold weather, disease, injury, limited food supply, or migration.

Enantioselective Effects of o,p'-DDT on Cell Invasion and Adhesion of Breast Cancer Cells: Chirality in Cancer Development.

PubMed

He, Xiangming; Dong, Xiaowu; Zou, Dehong; Yu, Yang; Fang, Qunying; Zhang, Quan; Zhao, Meirong

2015-08-18

The o,p'-dichlorodiphenyltrichloroethane (DDT) with a chiral center possesses enantioselective estrogenic activity, in which R-(-)-o,p'-DDT exerts a more potent estrogenic effect than S-(+)-o,p'-DDT. Although concern regarding DDT exposure and breast cancer has increased in recent decades, the mode of enantioselective action of o,p'-DDT in breast cancer development is still unknown. Herein, we conducted a systematic study of the effect of o,p'-DDT on stereoselective breast tumor cell progression in a widely used in vitro breast tumor cell model, MCF-7 cells. We demonstrated that R-(-)-o,p'-DDT promoted more cancer cell invasion mediated by the human estrogen receptor (ER) by inducing invasion-promoted genes (matrix metalloproteinase-2 and -9 and human telomerase reverse transcriptase) and inhibiting invasion-inhibited genes (tissue inhibitor of metalloproteinase-1 and -4). Molecular docking verified that the binding affinity between R-(-)-o,p'-DDT and human ER was stronger than that of S-(+)-o,p'-DDT. The enantioselective-induced decrease in cell-to-cell adhesion may involve the downregulation of adhesion-promoted genes (E-cadherin and β-catenin). For the first time, these results reveal that estrogenic-like chiral compounds are of significant concern in the progression of human cancers and that human health risk assessment of chiral chemicals should consider enantioselectivity.

DDT exposure of frogs: A case study from Limpopo Province, South Africa.

PubMed

Viljoen, Ignatius M; Bornman, Riana; Bouwman, Hindrik

2016-09-01

Amphibians are globally under pressure with environmental contaminants contributing to this. Despite caution aired more than 80 years ago of threats posed to amphibians by DDT spraying for disease vector control, no data have been published on concentrations or effects of DDT contamination in frogs from areas where DDT is actively sprayed to control the insect vectors of malaria. In this study, we sampled fat bodies of Xenopus laevis and Xenopus muelleri naturally occurring in an area where indoor residual spraying of DDT is employed and from adjacent, non-sprayed, areas. ΣDDT concentrations ranged between 

First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area.

PubMed

Bouwman, Hindrik; Bornman, Riana; van Dyk, Cobus; Barnhoorn, Irene

2015-10-01

In malaria-endemic areas, where DDT is still used for vector control by indoor residual spraying (IRS), the concentrations of DDT in human blood and breast milk are high, and there are indications of human health impacts. To identify the possible avenues of exposure reduction, we created the concept of a Total Homestead Environment Approach (THEA). THEA characterizes the interactions between DDT, humans, and the biota within and around homesteads. One dietary route of human exposure and uptake of DDT, namely, chicken egg consumption, has to our knowledge never been studied. The ΣDDT in eggs from a DDT-sprayed village ranged between 5200 and 48,000 ng/g wm (wet mass), with a median of 11,000 ng/g wm. On a lipid mass-basis (lm), the mean ΣDDT for eggs from the sprayed village was 100,000 ng/g lm. The maximum egg concentration observed was three orders of magnitude higher than the median. The acceptable daily intake (ADI) was not exceeded based on the consumption of three eggs per week for a 60 kg person. This equates to an intake of 0.089 g DDT per person per year. Chicken egg consumption is therefore a possible target for exposure reduction, probably best achieved by reducing the DDT concentrations in soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cycling and effects of 36Cl labeled DDT on soil invertebrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dindal, Daniel L.

1978-08-01

DDT, radiolabeled with /sup 36/Cl (total activity of 10.2 mc) and applied in the field at the rate of 1.12 kg/ha, cannot be detected within decomposer microarthropods using liquid scintillation spectrometry. Soil microarthropods exhibit both positive and negative responses to direct and indirect effects of DDT. Faunal simplification (decreased diversity) resulting from pesticide application as reported by many others does not apply to the oribatid and prostigmatid mites of the old field. New colonization is possible by some species of Acari as a result of DDT application. Soil microbial respiration is enhanced by a single DDT application of 1 kg/ha.more » No apparent relationships exist between the increased microbial respiration and soil microarthropod population dynamics in this DDT treated old field. No apparent relationships exist between soil pH, moisture levels, texture and soil microarthropod population dynamics. Microarthropod community structure (species diversity and richness, interspecific relationships and similarity) are definitely affected by a single application of DDT. The Prostigmata are the most numerous mites in the soil of an old field in central Ohio. Vertebrate predators feeding on terrestrial snails may be subjected to magnified concentrations of DDT residues. Coprophagic decomposer organisms feeding on snail feces will be subject to much larger DDT concentrations. Terrestrial snails represented by Cepaea and Otala are not killed by acute oral doses of DDT. Within a three year period after a single application of DDT no effects on the soil faunal populations were seen below 3 cm of soil.« less

Determination of DDT and metabolites in surface water and sediment using LLE, SPE, ACE and SE.

PubMed

Sibali, Linda L; Okonkwo, Jonathan O; Zvinowanda, Caliphs

2009-12-01

Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,4'DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 μg/L, nd-0.80 μg/L, nd-1.21 μg/L and 1.92 μg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,4' and 4,4'-DDT) in water and sediment samples ranged from 1.20-3.25 μg/L and 1.82-5.24 μg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

Efficient transformation of DDT by peroxymonosulfate activated with cobalt in aqueous systems: Kinetics, products, and reactive species identification.

PubMed

Qin, Wenxiu; Fang, Guodong; Wang, Yujun; Wu, Tongliang; Zhu, Changyin; Zhou, Dongmei

2016-04-01

Recently, sulfate radical ( [Formula: see text] ) based-advanced oxidation technologies (AOTs) have been attracted great attention in the remediation of contaminated soil and groundwater. In the present study, Co(2+) ions activated peroxymonosulfate (PMS) system was used to degrade 1, 1, 1-trichloro-2, 2'bis(p-chlorophenyl) ethane (DDT) in aqueous solutions. It was found that DDT was efficiently degraded in the PMS/Co(II) solutions within several hours, and the degradation efficiency of DDT was dependent on the concentrations of PMS and Co(II), and the optimum molar ratio of PMS and Co(II) was 50:1. The degradation kinetics of DDT were well described with pseudo-first-order equations over a range of temperature (10-40 °C), and the activation energy that was calculated with Arrhenius equation was 72.3 ± 2.6 kJ/mol. Electron paramagnetic resonance (EPR) and GC-MS techniques were applied to identify the intermediates and reactive species for DDT degradation. The results indicated that [Formula: see text] and OH were the main reactive species accounting for DDT degradation. Dichlorobenzophenone, 4-chlorobenzoic acid and benzylalcohol were the dominant intermediates for DDT degradation, and the likely degradation pathway of DDT was proposed on the basis of these identified products. Increasing pH inhibited the formation of [Formula: see text] and OH, and thus decreased the catalytic degradation of DDT. Cl(-) ion was found to significantly inhibit, while [Formula: see text] and dissolved oxygen had limited effects on DDT degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nanoscale zerovalent iron-mediated degradation of DDT in soil.

PubMed

Han, Yuling; Shi, Nan; Wang, Huifang; Pan, Xiong; Fang, Hua; Yu, Yunlong

2016-04-01

Nanoscale zerovalent iron (nZVI)-mediated degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was investigated in a spiked soil under different conditions (iron sources, iron dosage, soil moisture, temperature, and soil types) and DDT-contaminated field. The degradation efficiency of p,p'-DDT by nZVI and nZVI coated with sodium oleate (SO-nZVI) was much higher than that by nZVI coated with polyimide (PI-nZVI). The rapid degradation of p,p'-DDT by nZVI only occurred in flooded soil. The degradation half-life of p,p'-DDT decreased significantly from 58.3 to 27.6 h with nZVI dosage from 0.5 to 2.0% and from 46.5 to 32.0 h with temperature from 15 to 35 °C. The degradation efficiency of p,p'-DDT by nZVI differed in Jinhua (JH), Jiaxing (JX), Xiaoshan (XS), Huajiachi (HJC), and Heilongjiang (HLJ) soils. A good correlation was found between the degradation half-life of p,p'-DDT and multiple soil properties. The probable nZVI-mediated degradation pathway of p,p'-DDT in soil was proposed as DDT → DDD/DDE → DDNS → DDOH based on the metabolites identified by GC-MS. The in situ degradation efficiency of residual DDTs in a contaminated field was profoundly enhanced by the addition of nZVI as compared to the control. It is concluded that nZVI might be an efficient agent for the remediation of DDT-contaminated soil under anaerobic environment.

Insecticides: effects on cutthroat trout of repeated exposure to DDT

USGS Publications Warehouse

Allison, Don; Kallman, Burton J.; Cope, Oliver B.; Van Valin, Charles C.

1963-01-01

Cutthroat trout were periodically exposed to p, pp-DDT, in acetone solution or in the food. Excessive mortality occurred only in lots treated with high concentrations of DDT, probably as a result of decreased resistance to nonspecific stressors. Surviving fish in these lots were significantly larger than those in the control lot, or in the lots treated with low concentrations of DDT. The number and volume of eggs produced was not reduced by DDT, but mortality among sac fry appeared to be highest in the lots treated with high concentrations. The data suggest that the sublethal concentrations of DDT ordinarily encountered in the environment are unlikely to damage a fishery.

Residues, Sources and Potential Biological Risk of Organochlorine Pesticides in Surface Sediments of Qiandao Lake, China.

PubMed

Yang, Huayun; Zhou, Shanshan; Li, Weidong; Liu, Qi; Tu, Yunjie

2015-10-01

Sediment samples were analyzed to comprehensively characterize the concentrations, distribution, possible sources and potential biological risk of organochlorine pesticides in Qiandao Lake, China. Concentrations of sumHCH and sumDDT in sediments ranged from 0.03 to 5.75 ng/g dry weight and not detected to 14.39 ng/g dry weight. The predominant β-HCH and the α-HCH/γ-HCH ratios indicated that the residues of HCHs were derived not only from historical technical HCH use but also from additional usage of lindane. Ratios of o,p'-DDT/p,p'-DDT and DDD/DDE suggested that both dicofol-type DDT and technical DDT applications may be present in most study areas. Additionally, based on two sediment quality guidelines, γ-HCH, o,p'-DDT and p,p'-DDT could be the main organochlorine pesticides species of ecotoxicological concern in Qiandao Lake.

DISTRIBUTION OF RESIDENTIAL ORGANOCHLORINE PESTICIDE RESIDUALS ALONG THE ARIZONA/MEXICO BORDER

EPA Science Inventory

The use of DDT has been banned for many years in the United States. Mexico began a 10-year phase out of DDT in 1997. DDT was banned in the U.S. primarily because of its environmental persistence. Thus, DDT is still found in the outdoor and indoor environment. We report the ...

Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility

USGS Publications Warehouse

Hinck, J.E.; Norstrom, R.J.; Orazio, C.E.; Schmitt, C.J.; Tillitt, D.E.

2009-01-01

Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations were measured in largemouth bass from the Tombigbee River near a former DDT manufacturing facility at McIntosh, Alabama. Evaluation of mean p,p???- and o,p???-DDT isomer concentrations and o,p???- versus p,p???-isomer proportions in McIntosh bass indicated that DDT is moving off site from the facility and into the Tombigbee River. Concentrations of p,p???-DDT isomers in McIntosh bass remained unchanged from 1974 to 2004 and were four times greater than contemporary concentrations from a national program. Total DDT in McIntosh bass exceeded dietary effect concentrations developed for bald eagle and osprey. Hexachlorobenzene, PCBs, and toxaphene concentrations in bass from McIntosh also exceeded thresholds to protect fish and piscivorous wildlife. Whereas concentrations of DDT and most other organochlorine chemicals in fish have generally declined in the U.S. since their ban, concentrations of DDT in fish from McIntosh remain elevated and represent a threat to wildlife.

Dust Devil Tracks and Wind Streaks in the North Polar Region of Mars: A Study of the 2007 Phoenix Mars Lander Sites

NASA Technical Reports Server (NTRS)

Drake, Nathan B.; Tamppari, Leslie K.; Baker, R. David; Cantor, Bruce A.; Hale, Amy S.

2006-01-01

The 65-72 latitude band of the North Polar Region of Mars, where the 2007 Phoenix Mars Lander will land, was studied using satellite images from the Mars Global Surveyor (MGS) Mars Orbiter Camera Narrow-Angle (MOC-NA) camera. Dust devil tracks (DDT) and wind streaks (WS) were observed and recorded as surface evidence for winds. No active dust devils (DDs) were observed. 162 MOC-NA images, 10.3% of total images, contained DDT/WS. Phoenix landing Region C (295-315W) had the highest concentration of images containing DDT/WS per number of available images (20.9%); Region D (130-150W) had the lowest (3.5%). DDT and WS direction were recorded for Phoenix landing regions A (110-130W), B (240-260W), and C to infer local wind direction. Region A showed dominant northwest-southeast DDT/WS, Region B showed dominant north-south, east-west and northeast-southwest DDT/WS, and region C showed dominant west/northwest - east/southeast DDT/ WS. Results indicate the 2007 Phoenix Lander has the highest probability of landing near DDT/WS in landing Region C. Based on DDT/WS linearity, we infer Phoenix would likely encounter directionally consistent background wind in any of the three regions.

Enantioselective Cytotoxicity Profile of o,p’-DDT in PC 12 Cells

PubMed Central

Zhang, Chunlong; Wen, Yuezhong; Liu, Weiping

2012-01-01

Background The continued uses of dichlordiphenyltrichloroethane (DDT) for indoor vector control in some developing countries have recently fueled intensive debates toward the global ban of this persistent legacy contaminant. Current approaches for ecological and health risk assessment has ignored the chiral nature of DDT. In this study by employing an array of cytotoxicity related endpoints, we investigated the enantioselective cytotoxicity of o,p’-DDT. Principal Findings we demonstrated for the first time that R-(−)-o,p’-DDT caused more neuron cell death by inducing more severe oxidative stress, which selectively imbalanced the transcription of stress-related genes (SOD1, SOD2, HSP70) and enzyme (superoxide dismutase and lactate dehydrogenase) activities, and greater cellular apoptosis compared to its enantiomer S-(+)-o,p’-DDT at the level comparable to malaria area exposure (parts per million). We further elucidated enantioselective modes of action using microarray combined with enzyme-linked immunosorbent assay. The enantioselective apoptosis might involve three signaling pathways via caspase 3, tumor protein 53 (p53) and NFkB. Conclusions Based on DDT stereochemistry and results reported for other chiral pesticides, our results pointed to the same directional enantioselectivity of chiral DDT toward mammalian cells. We proposed that risk assessment on DDT should consider the enantiomer ratio and enantioselectivities. PMID:22937105

Assessment of DDT levels in selected environmental media and biological samples from Mexico and Central America.

PubMed

Pérez-Maldonado, Iván N; Trejo, Antonio; Ruepert, Clemens; Jovel, Reyna del Carmen; Méndez, Mónica Patricia; Ferrari, Mirtha; Saballos-Sobalvarro, Emilio; Alexander, Carlos; Yáñez-Estrada, Leticia; Lopez, Dania; Henao, Samuel; Pinto, Emilio R; Díaz-Barriga, Fernando

2010-03-01

Taking into account the environmental persistence and the toxicity of DDT, the Pan American Health Organization (PAHO) organized a surveillance program in Mesoamerica which included the detection of residual DDT in environmental (soil) and biological samples (fish tissue and children's blood). This program was carried out in communities from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. This paper presents the first report of that program. As expected, the results show that the levels for [summation operator] DDT in soil (outdoor or indoor) and fish samples in the majority of the locations studied are below guidelines. However, in some locations, we found children with high concentrations of DDT as in Mexico (mean level 50.2 ng/mL). Furthermore, in some communities and for some matrices, the DDT/DDE quotient is higher than one and this may reflect a recent DDT exposure. Therefore, more efforts are needed to avoid exposure and to prevent the reintroduction of DDT into the region. In this regard it is important to know that under the surveillance of PAHO and with the support of UNEP, a regional program in Mesoamerica for the collection and disposal of DDT and other POPs stockpiles is in progress. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

The Environmental Issues of DDT Pollution and Bioremediation: a Multidisciplinary Review.

PubMed

Mansouri, Ahlem; Cregut, Mickael; Abbes, Chiraz; Durand, Marie-Jose; Landoulsi, Ahmed; Thouand, Gerald

2017-01-01

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is probably the best known and most useful organochlorine insecticide in the world which was used since 1945 for agricultural purposes and also for vector-borne disease control such as malaria since 1955, until its banishment in most countries by the Stockholm convention for ecologic considerations. However, the World Health Organization allowed its reintroduction only for control of vector-borne diseases in some tropical countries in 2006. Due to its physicochemical properties and specially its persistence related with a half-life up to 30 years, DDT linked to several health and social problems which are due to its accumulation in the environment and its biomagnification properties in living organisms. This manuscript compiles a multidisciplinary review to evaluate primarily (i) the worldwide contamination of DDT and (ii) its (eco) toxicological impact onto living organisms. Secondly, several ways for DDT bioremediation from contaminated environment are discussed. For this, reports on DDT biodegradation capabilities by microorganisms and ways to enhance bioremediation strategies to remove DDT are presented. The different existing strategies for DDT bioremediation are evaluated with their efficiencies and limitations to struggle efficiently this contaminant. Finally, rising new approaches and technological bottlenecks to promote DDT bioremediation are discussed.

p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.

PubMed

Sun, Jianxian; Wang, Chen; Peng, Hui; Zheng, Guomao; Zhang, Shiyi; Hu, Jianying

2016-01-05

Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.

Survival, growth, detoxifying and antioxidative responses of earthworms (Eisenia fetida) exposed to soils with industrial DDT contamination.

PubMed

Shi, Yajuan; Zhang, Qiangbin; Huang, Dunqi; Zheng, Xiaoqi; Shi, Yajing

2016-03-01

The survival, growth, activity of the biotransformation system phase II enzyme glutathione-S-transferase (GST) and the oxidative defense enzyme catalase (CAT) of earthworms exposed to the contaminated soils from a former DDT plant and reference soils were investigated, and compared with the corresponding indicators in simulated soil-earthworm system, unpolluted natural soils with spiked-in DDT series, to identify the toxic effects of DDT on earthworms and their cellular defense system in complex soil system. The results indicated that DDT level in the contaminated soils was significantly higher than that in the reference soils with similar level of other pollutants and soil characters. The mortality, growth inhibition rates, GST and CST activities of earthworms exposed to the contaminated soils were significantly higher than that in reference soils. The contribution of historical DDT in contaminated soils to earthworms was confirmed by the DDT spiked tests. DDT spiked in soils at rates of higher than 200 mg·kg(-1) was significantly toxic to both the survival and the growth of earthworms. DDT significantly stimulated GST and CAT activity in earthworms after 14 days. The CAT and GST activities were also stimulated by DDT exposure at rates of 100 mg·kg(-1) after chronic exposure (42 days). The results provide implications for validating the extrapolation from laboratory simulated soils criteria to contaminated soils and for making site risk assessments. Copyright © 2015 Elsevier B.V. All rights reserved.

Bird mortality following DDT spray for Dutch elm disease

USGS Publications Warehouse

Wurster, D.H.; Wurster, C.F.; Strickland, W.N.

1965-01-01

Avian populations in Hanover, N. H., a town that has sprayed its elms with DDT for many years in an attempt to control Dutch elm disease, were compared with those in Norwich, Vt., a town 1 mile (1.6 km) west of Hanover that has never sprayed. Hanover applied 109 lb DDT/acre (2.1 kg/hectare) in April 1963, then used Methoxychlor in April 1964. Population surveys were taken regularly during spring and early summer of these years, dead birds were collected in both towns, and 106 birds were analyzed for DDT, DDE, and DDD. Severe mortality of both resident and migrant birds occurred in Hanover during spring 1963, and the evidence implicates DDT as its cause. Robin loss was estimated at 70% of the resident population, or 350 to 400 individuals, but mortality among other species of widely varied feeding habits was also substantial. Feeding habits suggest that some birds acquired the toxicant by eating living insects carrying DDT, presenting the paradox of survival of the intended DDT victims, and death, instead, of insectivorous birds. Organ and whole bird analyses are presented and criteria for establishing cause of death are discussed. Most of the DDT had been converted to DDE and DDD, and residues were found in all organs analyzed. Robin mortality was reduced, but not eliminated following Methoxychlor application in 1964; these losses were believed caused by residual DDT in the soil. There was no evidence DDT poisoning among other species in 1964, though the dead birds collected were not analyzed.

Modeling the fate of p,p'-DDT in water and sediment of two typical estuarine bays in South China: Importance of fishing vessels' inputs.

PubMed

Fang, Shu-Ming; Zhang, Xianming; Bao, Lian-Jun; Zeng, Eddy Y

2016-05-01

Antifouling paint applied to fishing vessels is the primary source of dichloro-diphenyl-trichloroethane (DDT) to the coastal marine environments of China. With the aim to provide science-based support of potential regulations on DDT use in antifouling paint, we utilized a fugacity-based model to evaluate the fate and impact of p,p'-DDT, the dominant component of DDT mixture, in Daya Bay and Hailing Bay, two typical estuarine bays in South China. The emissions of p,p'-DDT from fishing vessels to the aquatic environments of Hailing Bay and Daya Bay were estimated as 9.3 and 7.7 kg yr(-1), respectively. Uncertainty analysis indicated that the temporal variability of p,p'-DDT was well described by the model if fishing vessels were considered as the only direct source, i.e., fishing vessels should be the dominant source of p,p'-DDT in coastal bay areas of China. Estimated hazard quotients indicated that sediment in Hailing Bay posed high risk to the aquatic system, and it would take at least 21 years to reduce the hazards to a safe level. Moreover, p,p'-DDT tends to migrate from water to sediment in the entire Hailing Bay and Daya Bay. On the other hand, our previous research indicated that p,p'-DDT was more likely to migrate from sediment to water in the maricultured zones located in shallow waters of these two bays, where fishing vessels frequently remain. These findings suggest that relocating mariculture zones to deeper waters would reduce the likelihood of farmed fish contamination by p,p'-DDT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Male fertility following occupational exposure to dichlorodiphenyltrichloroethane (DDT).

PubMed

Campagna, Marcello; Satta, Giannina; Fadda, Domenica; Pili, Sergio; Cocco, Pierluigi

2015-04-01

The inconsistent epidemiological results of the endocrine disrupting effects of DDT fuel a harsh debate on its global ban. We tested the hypothesis that occupational exposure to dichloro-diphenyl-trichloroethane (DDT) causes impairment in male fertility in a cohort of DDT exposed workers, in Sardinia, Italy. We accessed official records on date of marriage and date of birth of the first child to estimate time to pregnancy (TTP) in the spouses of 1223 workers employed in a 1946-1950 anti-malarial campaign. The TTP calculation was censored at the 13th month after date of marriage. We used a modified Cox's proportional hazard model to calculate the fecundability ratio (FR) by job, by cumulative exposure to DDT, and by time window in relation to the anti-malarial operations, adjusting by paternal age at marriage. Among the spouses of DDT applicators, fecundability did not vary during DDT use (FR=1.22, 95% CI 0.84-1.77) nor in the following decade (FR=1.01, 95% CI 0.67-1.50) with reference to the prior years. A significant increase occurred among the unexposed and the less exposed sub-cohorts, which generated a non-significantly reduced FR among the DDT applicator sub-cohort with reference to the unexposed following exposure. We did not find evidence of an impairment in male fertility following heavy occupational exposure to DDT. However, although fecundability was highest among the spouses of the DDT applicators in the years prior to the anti-malarial campaign, we cannot exclude that DDT exposure prevented an increase parallel to that observed among the unexposed and the less exposed sub-cohorts. Copyright © 2015. Published by Elsevier Ltd.

Prenatal and Postnatal Exposure to DDT by Breast Milk Analysis in Canary Islands

PubMed Central

Vall, Oriol; Gomez-Culebras, Mario; Puig, Carme; Rodriguez-Carrasco, Ernesto; Gomez Baltazar, Arelis; Canchucaja, Lizzeth; Joya, Xavier; Garcia-Algar, Oscar

2014-01-01

Introduction The use of p,p′-dichlorodiphenyltrichloroethane (DDT) has been banned since the late 1970s due to its toxicity. However, its long half-life makes it persistent in the environment and, consequently, almost everyone has DDT residues in the body. Human milk constitutes an ideal non-conventional matrix to investigate environmental chronic exposure to organochlorine compounds (OCs) residues. The study aimed to identify potential population risk factors of exposure to DDT due to the proximity to countries where it is still used. Methods Seventy-two consecutive lactating women were prospectively included in Tenerife, Canary Islands (Spain). A validated questionnaire was used to obtain socioeconomic, demographics data, and daily habits during pregnancy. DDT levels in breast milk were measured by gas chromatography with-electron capture detector (GC-ECD). Anthropometrics measurements in newborns were obtained. Results Thirty-four out of 72 (47.2%) of the analysed milk samples presented detectable levels of DDT (mean: 0.92 ng/g), ranging between 0.08 to 16.96 ng/g. The socio-demographic variables did not significantly differ between detectable DDT and non-detectable DDT groups. We found positive association between DDT levels and vegetables (OR (95%CI): 1.23 (1.01–1.50)) and poultry meat (OR (95%CI): 2.05 (1.16–3.60)) consumption, and also between the presence of DDT in breast milk and gestational age (OR (95%CI): 0.59 (0.40–0.90)). Conclusions DDT is present in breast milk of women at the time of delivery. Residual levels and the spread from countries still using DDT explain DDT detection from vegetables and from animal origin food. The presence of this compound in breast milk represents a pre- and postnatal exposure hazard for foetuses and infants due to chronic bioaccumulation and poor elimination, with possible deleterious effects on health. This data should be used to raise awareness of the risks of OCs exposure and to help establish health policies in order to avoid its use worldwide and thus, to prevent its propagation. PMID:24416174

GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES) EXPOSED TO O,P'-DDT IN WATER OR THROUGH MATERNAL TRANSFER

EPA Science Inventory

Various isomers and metabolites of DDT disrupt endocrine systems and gonadal development in fish andxwildlife and o,p'-DDT has been shown to be a relatively potent estrogen agonist. In this study, we exposed Japanese medaka (Oryzias latipes) to o,p'-DDT using two exposure protoco...

Bird mortality after spraying for Dutch elm disease with DDT

USGS Publications Warehouse

Wurster, C.F.; Wurster, D.H.; Strickland, W.N.

1965-01-01

In Hanover, New Hampshire, where elms were sprayed with DDT, 151 dead birds were found; 10 dead birds were found in Norwich, Vermont, where no DDT was used. Chemical analyses of dead birds, observation of symptoms of DDT poisoning, and a population decline after spraying all indicate severe mortality among certain species in Hanover.

Association between lung function in adults and plasma DDT and DDE levels: results from the Canadian Health Measures Survey.

PubMed

Ye, Ming; Beach, Jeremy; Martin, Jonathan W; Senthilselvan, Ambikaipakan

2015-05-01

Although DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane] has been banned in many countries since the 1970s, it may still pose a risk to human respiratory health. In agriculture, DDT exposures have been associated with asthma and chronic bronchitis. However, little is known about the effect of DDT on lung function. We used data on 1,696 participants 20-79 years of age from the Canadian Health Measures Survey (CHMS) and conducted multiple regression analysis to estimate associations between plasma p,p´-DDT/DDE and lung function. Almost all participants (> 99.0%) had detectable concentrations of plasma p,p´-DDE, but only 10.0% had detectable p,p´-DDT. Participants with detectable p,p´-DDT had significantly lower mean FVC (difference = 311 mL; 95% CI: -492, -130; p = 0.003) and FEV1 (difference = 232 mL; 95% CI: -408, -55; p = 0.015) than those without. A 100-ng/g lipid increase in plasma p,p´-DDE was associated with an 18.8-mL decrease in mean FVC (95% CI: -29, -9) and an 11.8-mL decrease in mean FEV1 (95% CI: -21, -3). Neither exposure was associated with FEV1/FVC ratio or FEF25%-75%. DDT exposures, which may have occurred decades ago, were still detectable among Canadians. Plasma DDT and DDE were negatively associated with lung function parameters. Additional research on the potential effects of DDT use on lung function is warranted.

Combined Knockdown of D-dopachrome Tautomerase and Migration Inhibitory Factor Inhibits the Proliferation, Migration, and Invasion in Human Cervical Cancer.

PubMed

Wang, Qingying; Wei, Yingze; Zhang, Jiawen

2017-05-01

D-dopachrome tautomerase (D-DT) is a homologue of macrophage migration inhibitory factor (MIF) with similar functions. However, the possible biological roles of D-DT in cervical cancer remain unknown so far. D-dopachrome tautomerase was assessed by immunohistochemistry in 83 cervical cancer and 31 normal cervix tissues. The stable knockdown of D-DT and MIF by lentivirus-delivered short hairpin RNA was established, and tumor growth was examined in vitro and in vivo. The effects of D-DT and MIF on the migration and invasion were further detected by wound healing assay and transwell assay. Western blot was used to explore the mechanism of D-DT and MIF in cervical cancer pathogenesis. We found that D-DT was significantly high in cervical cancer, which correlated with lymph node metastasis. The knockdown of D-DT and MIF, individually and additively, inhibited the proliferation, migration, and invasion in HeLa and SiHa cells and restrained the growth of xenograft tumor. The ablation of D-DT and MIF rescued the expression of E-cadherin and inhibited the expression of PCNA, cyclin D1, gankyrin, Sam68, and vimentin, as well as phospho-Akt and phospho-glycogen synthase kinase 3-β. The inhibition of D-DT and MIF in combination may represent a potential therapeutic strategy for cervical cancer.

Interactions of polymeric drug carriers with DDT reduce their combined cytotoxicity.

PubMed

Zhang, Xuejiao; Lei, Lei; Zhang, Haiyan; Zhang, Siyu; Xing, Weiwei; Wang, Jin; Li, Haibo; Zhao, Qing; Xing, Baoshan

2018-06-07

Attention has been paid to the environmental distribution and fate of nanomedicines. However, their effects on the toxicity of environmental pollutants are lack of knowledge. In this study, the negatively charged poly (ethylene glycol)-b-poly (L-lactide-co-glycolide) (mPEG-PLA) and positively charged polyethyleneimine-palmitate (PEI-PA) nanomicelles were synthesized and served as model drug carriers to study the interaction and combined toxicity with dichlorodiphenyltrichloroethane (DDT). DDT exerted limited effect on the biointerfacial behavior of mPEG-PLA nanomicelles, whereas it significantly mitigated the attachment of PEI-PA nanomicelles on the model cell membrane as monitored by quartz crystal microbalance with dissipation (QCM-D). The cytotoxicity of DDT towards NIH 3T3 cells was greatly decreased by either co-treatment or pre-treatment with the nanomicelles according to the results of real-time cell analysis (RTCA). The cell viability of NIH 3T3 exposed to DDT was increased up to 90% by the co-treatment with mPEG-PLA nanomicelles. Three possible reasons were proposed: (1) decreased amount of free DDT in the cell culture medium due to the partitioning of DDT into nanomicelles; (2) mitigated cellular uptake of nanomicelle-DDT complexes due to the complex agglomeration or electrostatic repulsion between complexes and cell membrane; (3) detoxification effect in the lysosome upon endocytosis of nanomicelle-DDT complexes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enantiomer signature and carbon isotope evidence for the migration and transformation of DDTs in arable soils across China

NASA Astrophysics Data System (ADS)

Niu, Lili; Xu, Chao; Zhu, Siyu; Bao, Huiming; Xu, Yang; Li, Hongyi; Zhang, Zhijian; Zhang, Xichang; Qiu, Jiguo; Liu, Weiping

2016-12-01

Due to the adverse impact of DDTs on ecosystems and humans, a full fate assessment deems a comprehensive study on their occurrence in soils over a large region. Through a sampling campaign across China, we measured the concentrations, enantiomeric fractions (EFs), compound-specific carbon isotope composition of DDT and its metabolites, and the microbial community in related arable soils. The geographically total DDT concentrations are higher in eastern than western China. The EFs and δ13C of o,p’-DDT in soils from western China show smaller deviations from those of racemic/standard compound, indicating the DDT residues there mainly result from atmospheric transport. However, the sources of DDT in eastern China are mainly from historic application of technical DDTs and dicofol. The inverse dependence of o,p’-DDT and p,p’-DDE on temperature evidences the transformation of parent DDT to its metabolites. Initial usage, abiotic parameters and microbial communities are found to be the main factors influencing the migration and transformation of DDT isomers and their metabolites in soils. In addition, a prediction equation of DDT concentrations in soils based on stepwise multiple regression analysis is developed. Results from this study offer insights into the migration and transformation pathways of DDTs in Chinese arable soils, which will allow data-based risk assessment on their use.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology

NASA Astrophysics Data System (ADS)

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium.

Biodegradation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) by using Serratia marcescens NCIM 2919.

PubMed

Grewal, Jasneet; Bhattacharya, Amrik; Kumar, Sumit; Singh, Dileep K; Khare, Sunil K

2016-12-01

A solvent tolerant bacterium Serratia marcescens NCIM 2919 has been evaluated for degradation of DDT (1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane). The bacterium was able to degrade up to 42% of initial 50 mg L -1 of DDT within 10 days of incubation. The highlight of the work was the elucidation of DDT degradation pathway in S. marcescens. A total of four intermediates metabolites viz. 2,2-bis (chlorophenyl)-1,1-dichloroethane (DDD), 2,2-bis (chlorophenyl)-1,1-dichloroethylene (DDE), 2,2-bis (chlorophenyl)-1-chloroethylene (DDMU), and 4-chlorobenzoic acid (4-CBA) were identified by GC-Mass and FTIR. 4-CBA was found to be the stable product of DDT degradation. Metabolites preceding 4-CBA were not toxic to strain as reveled through luxuriant growth in presence of varying concentrations of exogenous DDD and DDE. However, 4-CBA was observed to inhibit the growth of bacterium. The DDT degrading efficiency of S. marcescens NCIM 2919 hence could be used in combination with 4-CBA utilizing strains either as binary culture or consortia for mineralization of DDT. Application of S. marcescens NCIM 2919 to DDT contaminated soil, showed 74.7% reduction of initial 12.0 mg kg -1 of DDT after 18-days of treatment.

Occurrences and fate of DDT principal isomers/metabolites, DDA, and o,p'-DDD enantiomers in fish, sediment and water at a DDT-impacted Superfund site.

PubMed

Garrison, A W; Cyterski, M; Roberts, K D; Burdette, D; Williamson, J; Avants, J K

2014-11-01

In the 1950s and 60s, discharges from a DDT manufacturing plant contaminated a tributary system of the Tennessee River near Huntsville, Alabama, USA. Regulatory action resulted in declaring the area a Superfund site which required remediation and extensive monitoring. Monitoring data collected from 1988, after remediation, through 2011 showed annual decreases approximating first-order decay in concentrations of total DDT and its six principal congeners (p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE and o,p'-DDE) in filets from three species of fish. As of 2013, these concentrations met the regulatory requirements of 5 mg/kg or less total DDT for each fish tested. The enantiomer fractions (EF) of chiral o,p'-DDD in smallmouth buffalo and channel catfish were always below 0.5, indicating preferential decay of the (+)-enantiomer of this congener; this EF did not change significantly over 15 years. The often-neglected DDT metabolite p,p'-DDA was found at a concentration of about 20 μg/l in the ecosystem water. Published by Elsevier Ltd.

Comparison of DDT and its metabolites concentrations in cow milk from agricultural and industrial areas.

PubMed

Kuba, Jarosław; Tomza-Marciniak, Agnieszka; Pilarczyk, Bogumiła; Tarasewicz, Natalia; Pilarczyk, Renata; Ligocki, Marek

2015-01-01

The risk of pesticidal intoxication in humans is severe, especially because of the strongly negative impact on human health. The consequences of the exposure to these substances may include cancerogenesis or endocrine abnormalities resulting for example in decreased fertility. Therefore, the aim of our study was to evaluate the content of dichlorodiphenyltrichloroethane (DDT) and its metabolites in cow milk from two regions of Poland, varying by level of industrialization. Samples were collected from agricultural (n = 25) and industrial (n = 25) areas, and the concentrations of DDT and its metabolites were evaluated by gas chromatography. Residues of DDT were detected in all the milk samples tested, mostly in the samples from the agricultural area, where a total DDT median concentration reached 0.336 μg L(-1). In the milk samples from the industrial area, the median concentration was lower, at 0.131 μg L(-1). 4,4'-DDT was the main metabolite, constituting 83% of total DDT metabolites. Although none of the samples exceeded the level above which they should be considered dangerous, the results showed that the problem of DDT had not diminished and so should be constantly monitored.

Passive air sampling of organochlorine pesticides in Mexico.

PubMed

Wong, Fiona; Alegria, Henry A; Bidleman, Terry F; Alvarado, Víctor; Angeles, Felipe; Galarza, Alfredo Avila; Bandala, Erick R; Hinojosa, Idolina de la Cerda; Estrada, Ignacio Galindo; Reyes, Guillermo Galindo; Gold-Bouchot, Gerardo; Zamora, Jose Vinicio Macías; Murguía-González, Joaquín; Espinoza, Elias Ramirez

2009-02-01

The spatial and temporal variation of organochlorine pesticides (OCs) in air across Mexico was investigated by deploying passive samplers at eleven stations across the country during 2005-2006. Integrated samples were taken over three-month periods and quantified for DDT compounds, endosulfans, toxaphenes, components of technical chlordane, hexachlorocyclohexanes (HCHs), and dieldrin. Enantiomers of chiral chlordanes and o,p'-DDT were determined on chiral stationary phase columns as an indicator of source and age. Results are discussed in combination with pumped air samples taken at four other stations in southern Mexico during 2002-2004. DDT and its metabolites, endosulfan and toxaphene were the most abundant OCs detected in all sampling sites. Atmospheric concentrations of SigmaDDT (p,p'-DDT + o,p'-DDT + p,p'-DDE + o,p'-DDE + p,p'-DDD + o,p'-DDD) ranged from 15 to 2360 pg m(-3) with the highest concentrations found in southern Mexico and the lowest found in northern and central Mexico. A fresher DDT residue was observed at sites with greater DDT use and in the southern part of the country, as shown from the higher FDDTe = p,p'-DDT/(p,p'-DDT + p,p'-DDE) and nearly racemic o,p'-DDT. This agrees with the former heavy use of DDT in the endemic malarious area of the country. A local hotspot of endosulfan was identified at an agricultural area in Mazatlan, Sinaloa, with a annual mean concentration of SigmaENDO (endosulfans I + II + endosulfan sulfate) = 26,800 pg m(-3). At this site, higher concentrations of SigmaENDO were recorded during the winter (November to February) and spring (February to May) periods. From back trajectory analysis, this coincides with a shift in the air mass coming from the Pacific Ocean (May to November) to the inland agricultural area (November to May). The elevated SigmaENDO observed is likely due to the local agricultural usage. HCHs, chlordanes, transnonachlors, and dieldrin were more evenly distributed across the country likely due to them being aged residues and more diffuse in the environment. In contrast, hotspots of endosulfans, DDTs, and toxaphenes were observed as they were heavily used in localized agricultural or malarious regions of Mexico.

Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring.

PubMed

Crago, Jordan; Xu, Elvis Genbo; Kupsco, Allison; Jia, Fang; Mehinto, Alvine C; Lao, Wenjian; Maruya, Keith A; Gan, Jay; Schlenk, Daniel

2016-06-01

High concentrations of DDT and metabolites (ΣDDT) have been detected in sediment and the demersal flatfish hornyhead turbot (Pleuronichtys verticalis) collected from Palos Verdes (PV), California, USA, a site contaminated with over 100 metric tons of DDT throughout 1960s-70s. This study was conducted to assess the transfer of ΣDDT from PV-sediment into polychaetes (Neanthes arenaceodentata) and hornyhead turbot, and to investigate if the responses in turbots from two different laboratory exposures mimic those in turbots caught in PV (PV-turbot). Turbot fed PV-sediment-contaminated polychaete for 7 days had liver concentrations of ΣDDT similar to PV-turbot. After 28 days, ΣDDT also accumulated in livers of turbot gavaged with a ΣDDT mixture. In vitro cell bioassays indicated significant increases of 17β-estradiol equivalents (EEQ) in turbot bile extracts as compared to the control in the 7-day study. These responses corresponded to those measured in PV-fish. Glucocorticoid receptor (GR), anti-androgen receptor (anti-AR), estrogen receptor (ER) or aryl hydrocarbon receptor (AhR) activities were also observed in extracts of PV-sediment, and PV-sediment-exposed worm. Anti-AR, AhR and GR activities were significantly higher in PV-sediment than reference sediment (San Diego, SD). Higher transcripts of hepatic VTG, ERα and ERβ were found in PV-turbot than SD-turbot, but were unaltered in fish exposed to sediment-contaminated worms for the 7-day study. In contrast, liver extracts from the 28-day treatment of ΣDDT showed lower EEQ but similar hepatic VTG and ERβ transcripts relative to those of PV-turbot. These data indicated that trophic transfer of sediment-associated DDT in 7-day exposures corresponded to field measurements of DDT residues and in vitro ER bioactivities, but failed to mimic in vivo biological effects observed in field fish. In contrast, treatment with ΣDDT alone for 28 days mimicked in vivo biological effects of DDTs in PV fish, but did not correspond to liver concentrations or in vitro bioactivities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photocatalytic degradation of p,p'-DDT under UV and visible light using interstitial N-doped TiO₂.

PubMed

Ananpattarachai, Jirapat; Kajitvichyanukul, Puangrat

2015-01-01

1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (or p,p'-DDT) is one of the most persistent pesticides. It is resistant to breakdown in nature and cause the water contamination problem. In this work, a major objective was to demonstrate the application of N-doped TiO2 in degradation and mineralization of the p,p'-DDT under UV and visible light in aqueous solution. The N-doped TiO2 nanopowders were prepared by a simple modified sol-gel procedure using diethanolamine (DEA) as a nitrogen source. The catalyst characteristics were investigated using XRD, SEM, TEM, and XPS. The adsorption and photocatalytic oxidation of p,p'-DDT using the synthesized N-doped TiO2 under UV and visible light were conducted in a batch photocatalytic experiment. The kinetics and p,p'-DDT degradation performance of the N-doped TiO2 were evaluated. Results show that the N-doped TiO2 can degrade p,p'-DDT effectively under both UV and visible lights. The rate constant of the p,p'-DDT degradation under UV light was only 0.0121 min(-1), whereas the rate constant of the p,p'-DDT degradation under visible light was 0.1282 min(-1). Under visible light, the 100% degradation of p,p'-DDT were obtained from N-doped TiO2 catalyst. The reaction rate of p,p'-DDT degradation using N-doped TiO2 under visible light was sixfold higher than that under UV light. According to Langmuir-Hinshelwood model, the adsorption equilibrium constant (K) for the N-doped TiO2 under visible light was 0.03078 L mg(-1), and the apparent reaction rate constant (k) was 1.3941 mg L(-1)-min. Major intermediates detected during the p,p'-DDT degradation were p,p'-DDE, o,p'-DDE, p,p'-DDD and p,p'-DDD. Results from this work can be applied further for the breakdown of p,p'-DDT molecule in the real contaminated water using this technology.

Spatial and seasonal variations of pesticide contamination in agricultural soils and crops sample from an intensive horticulture area of Hohhot, North-West China.

PubMed

Zhang, Fujin; He, Jiang; Yao, Yiping; Hou, Dekun; Jiang, Cai; Zhang, Xinxin; Di, Caixia; Otgonbayar, Khureldavaa

2013-08-01

The spatial variability and temporal trend in concentrations of the organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in soils and agricultural corps were investigated on an intensive horticulture area in Hohhot, North-West China, from 2008 to 2011. The most frequently found and abundant pesticides were the metabolites of DDT (p,p'-DDE, p,p'-DDT, o,p'-DDT and p,p'-DDD). Total DDT concentrations ranged from ND (not detectable) to 507.41 ng/g and were higher than the concentration of total HCHs measured for the range of 4.84-281.44 ng/g. There were significantly positive correlations between the ∑DDT and ∑HCH concentrations (r (2)>0.74) in soils, but no significant correlation was found between the concentrations of OCPs in soils and clay content while a relatively strong correlation was found between total OCP concentrations and total organic carbon (TOC). β-HCH was the main isomer of HCHs, and was detected in all samples; the maximum proportion of β-HCH compared to ∑HCHs (mean value 54%) was found, suggesting its persistence. The α/γ-HCH ratio was between 0.89 and 5.39, which signified the combined influence of technical HCHs and lindane. Low p,p'-DDE/p,p'-DDT in N1, N3 and N9 were found, reflecting the fresh input of DDTs, while the relatively high o,p'-DDT/p,p'-DDT ratios indicated the agricultural application of dicofol. Ratios of DDT/(DDE+DDD) in soils do not indicate recent inputs of DDT into Hohhot farmland soil environment. Seasonal variations of OCPs featured higher concentrations in autumn and lower concentrations in spring. This was likely associated with their temperature-driven re-volatilization and application of dicofol in late spring.

Levels and Determinants of DDT and DDE Exposure in the VHEMBE Cohort.

PubMed

Gaspar, Fraser W; Chevrier, Jonathan; Quirós-Alcalá, Lesliam; Lipsitt, Jonah M; Barr, Dana Boyd; Holland, Nina; Bornman, Riana; Eskenazi, Brenda

2017-07-07

Although indoor residual spraying (IRS) is an effective tool for malaria control, its use contributes to high insecticide exposure in sprayed communities and raises concerns about possible unintended health effects. The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort study initiated in 2012 to characterize prenatal exposure to IRS insecticides and exposures' impacts on child health and development in rural South Africa. In this report, we describe the VHEMBE cohort and dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) serum concentrations measured in VHEMBE mothers when they presented for delivery. In addition, we applied a causal inference framework to estimate the potential reduction in population-level p , p' -DDT and p , p' -DDE serum concentrations under five hypothetical interventions. A total of 751 mothers were enrolled. Serum concentrations of p , p' isomers of DDT and DDE were above the limit of detection (LOD) in ≥98% of the samples, whereas the o , p' isomers were above the LOD in at least 80% of the samples. Median (interquartile range) p , p' -DDT and p , p' -DDE serum concentrations for VHEMBE cohort participants were 55.3 (19.0-259.3) and 242.2 (91.8-878.7) ng/g-lipid, respectively. Mothers reporting to have lived in a home sprayed with DDT for malaria control had ~5-7 times higher p , p' -DDT and p , p' -DDE serum concentrations than those who never lived in a home sprayed with DDT. Of the five potential interventions tested, we found increasing access to water significantly reduced p , p' -DDT exposure and increasing the frequency of household wet mopping significantly reduced p , p' -DDT and p , p' -DDE exposure. Our findings suggest that several intervention approaches may reduce DDT/DDE exposure in pregnant women living in IRS communities. https://doi.org/10.1289/EHP353.

Association between Lung Function in Adults and Plasma DDT and DDE Levels: Results from the Canadian Health Measures Survey

PubMed Central

Ye, Ming; Beach, Jeremy; Martin, Jonathan W.

2014-01-01

Background Although DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane] has been banned in many countries since the 1970s, it may still pose a risk to human respiratory health. In agriculture, DDT exposures have been associated with asthma and chronic bronchitis. However, little is known about the effect of DDT on lung function. Methods We used data on 1,696 participants 20–79 years of age from the Canadian Health Measures Survey (CHMS) and conducted multiple regression analysis to estimate associations between plasma p,p´-DDT/DDE and lung function. Results Almost all participants (> 99.0%) had detectable concentrations of plasma p,p´-DDE, but only 10.0% had detectable p,p´-DDT. Participants with detectable p,p´-DDT had significantly lower mean FVC (difference = 311 mL; 95% CI: –492, –130; p = 0.003) and FEV1 (difference = 232 mL; 95% CI: –408, –55; p = 0.015) than those without. A 100-ng/g lipid increase in plasma p,p´-DDE was associated with an 18.8-mL decrease in mean FVC (95% CI: –29, –9) and an 11.8-mL decrease in mean FEV1 (95% CI: –21, –3). Neither exposure was associated with FEV1/FVC ratio or FEF25%–75%. Conclusions DDT exposures, which may have occurred decades ago, were still detectable among Canadians. Plasma DDT and DDE were negatively associated with lung function parameters. Additional research on the potential effects of DDT use on lung function is warranted. Citation Ye M, Beach J, Martin JW, Senthilselvan A. 2015. Association between lung function in adults and plasma DDT and DDE levels: results from the Canadian Health Measures Survey. Environ Health Perspect 123:422–427; http://dx.doi.org/10.1289/ehp.1408217 PMID:25536373

Levels and Determinants of DDT and DDE Exposure in the VHEMBE Cohort

PubMed Central

Gaspar, Fraser W.; Chevrier, Jonathan; Quirós-Alcalá, Lesliam; Lipsitt, Jonah M.; Barr, Dana Boyd; Holland, Nina; Bornman, Riana

2017-01-01

Background: Although indoor residual spraying (IRS) is an effective tool for malaria control, its use contributes to high insecticide exposure in sprayed communities and raises concerns about possible unintended health effects. Objective: The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort study initiated in 2012 to characterize prenatal exposure to IRS insecticides and exposures’ impacts on child health and development in rural South Africa. Methods: In this report, we describe the VHEMBE cohort and dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) serum concentrations measured in VHEMBE mothers when they presented for delivery. In addition, we applied a causal inference framework to estimate the potential reduction in population-level p,p′-DDT and p,p′-DDE serum concentrations under five hypothetical interventions. A total of 751 mothers were enrolled. Results: Serum concentrations of p,p′ isomers of DDT and DDE were above the limit of detection (LOD) in ≥98% of the samples, whereas the o,p′ isomers were above the LOD in at least 80% of the samples. Median (interquartile range) p,p′-DDT and p,p′-DDE serum concentrations for VHEMBE cohort participants were 55.3 (19.0–259.3) and 242.2 (91.8–878.7) ng/g-lipid, respectively. Mothers reporting to have lived in a home sprayed with DDT for malaria control had ∼5–7 times higher p,p′-DDT and p,p′-DDE serum concentrations than those who never lived in a home sprayed with DDT. Of the five potential interventions tested, we found increasing access to water significantly reduced p,p′-DDT exposure and increasing the frequency of household wet mopping significantly reduced p,p′-DDT and p,p′-DDE exposure. Conclusion: Our findings suggest that several intervention approaches may reduce DDT/DDE exposure in pregnant women living in IRS communities. https://doi.org/10.1289/EHP353 PMID:28696207

In Utero DDT and DDE Exposure and Obesity Status of 7-Year-Old Mexican-American Children in the CHAMACOS Cohort

PubMed Central

Schall, Raul Aguilar; Harley, Kim G.; Bradman, Asa; Barr, Dana; Eskenazi, Brenda

2013-01-01

Background: In utero exposure to endocrine disrupting compounds including dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) has been hypothesized to increase risk of obesity later in life. Objectives: The 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. Methods: We 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. Results: At 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. Conclusion: We 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. PMID:23512307

Depressive-like effect of prenatal exposure to DDT involves global DNA hypomethylation and impairment of GPER1/ESR1 protein levels but not ESR2 and AHR/ARNT signaling.

PubMed

Kajta, Malgorzata; Wnuk, Agnieszka; Rzemieniec, Joanna; Litwa, Ewa; Lason, Wladyslaw; Zelek-Molik, Agnieszka; Nalepa, Irena; Rogóż, Zofia; Grochowalski, Adam; Wojtowicz, Anna K

2017-07-01

Several lines of evidence suggest that exposures to Endocrine Disrupting Chemicals (EDCs) such as pesticides increase the risks of neuropsychiatric disorders. Despite extended residual persistence of dichlorodiphenyltrichloroethane (DDT) in the environment, the mechanisms of perinatal actions of DDT that could account for adult-onset of depression are largely unknown. This study demonstrated the isomer-specific induction of depressive-like behavior and impairment of Htr1a/serotonin signaling in one-month-old mice that were prenatally exposed to DDT. The effects were reversed by the antidepressant citalopram as evidenced in the forced swimming (FST) and tail suspension (TST) tests in the male and female mice. Prenatally administered DDT accumulated in mouse brain as determined with gas chromatography and tandem mass spectrometry, led to global DNA hypomethylation, and altered the levels of methylated DNA in specific genes. The induction of depressive-like behavior and impairment of Htr1a/serotonin signaling were accompanied by p,p'-DDT-specific decrease in the levels of estrogen receptors i.e. ESR1 and/or GPER1 depending on sex. In contrast, o,p'-DDT did not induce depressive-like effects and exhibited quite distinct pattern of biochemical alterations that was related to aryl hydrocarbon receptor (AHR), its nuclear translocator ARNT, and ESR2. Exposure to o,p'-DDT increased AHR expression in male and female brains, and reduced expression levels of ARNT and ESR2 in the female brains. The evolution of p,p'-DDT-induced depressive-like behavior was preceded by attenuation of Htr1a and Gper1/GPER1 expression as observed in the 7-day-old mouse pups. Because p,p'-DDT caused sex- and age-independent attenuation of GPER1, we suggest that impairment of GPER1 signaling plays a key role in the propagation of DDT-induced depressive-like symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparing water, bovine milk, and indoor residual spraying as possible sources of DDT and pyrethroid residues in breast milk.

PubMed

Sereda, Barbara; Bouwman, Henk; Kylin, Henrik

2009-01-01

The presence of pollutants in human breast milk is of major concern, especially in malaria control areas where 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) is currently used as indoor residual spray (IRS). The levels of DDT and pyrethroids (PYR) were determined in breast milk, bovine milk, and drinking water from northern KwaZulu-Natal, South Africa. Both reference and exposed mothers used the same market food, but the DDT levels in the exposed mothers (mean SigmaDDT 10 microg/g milk fat [mf]) were much higher than for the reference mothers (mean SigmaDDT 1.3 microg/g milk fat). This difference in residue levels indicates uptake from IRS-applied DDT, most likely via air and skin contact, and excludes food as the main source of pollutants. DDT levels in bovine milk (mean SigmaDDT 0.15 microg/g mf) from the exposed area were less than levels in breast milk from the reference area, and lower than the 20 microg/L maximum residue limit (MRL) set by the Food and Agriculture Organization (FAO). Mean SigmaDDT in water was 0.0065 microg/L, much lower then the WHO limit of the sum of all metabolites in drinking water of 1 microg/L, and therefore highly unlikely to have contributed to any extent toward levels in breast milk. Permethrin in breast milk (mean 1.1-1.6 microg/g milk fat) was probably derived from home garden and indoor use, while the other PYR (cypermethrin and cyfluthrin) at lower concentrations were probably derived from food and agricultural exposure. It is postulated that a better understanding of the indoor dynamics of DDT and other insecticides, through a concept of Total Homestead Environment Approach (THEA), is crucial for investigating options of reducing human exposure and uptake under malaria control conditions.

DDT Analysis of Wetland Sediments in Upper Escambia Bay, Florida

NASA Astrophysics Data System (ADS)

Hopko, M. N.; Wright, J.; Liebens, J.; Vaughan, P.

2017-12-01

Dichlorodiphenyltrichloroethane (DDT) was a commonly used pesticide from World War II through the 1960's. DDT is generally used to control mosquito populations and as an agricultural insecticide. The pesticide and its degradation products (DDD and DDE) can bioaccumulate within ecosystems having negative implications for animal and human health. Consequently, DDT usage was banned in the United States in 1973. In a contaminant study performed in Escambia Bay, Florida, in 2009, DDT was present in 25% of study sites, most of which were located in the upper bay wetlands. Concentrations were well above the Florida Department of Environmental Protection's (FDEP) Probable Effect Level (PEL) and ratios of DDT and its metabolites indicated a recent introduction to the system. A follow-up study performed in 2016 found no DDT, but did show DDE at several sites. The current study repeated sampling in May 2017 at sites from the 2009 and 2016 studies. Sediment samples were collected in triplicate using a ponar sampler and DDT, DDD and DDE were extracted using EPA methods 3540c and 3620c. Extracts were analyzed using a gas chromatograph with electron capture detection (GC-ECD) as per EPA method 8081c. Sediment was also analyzed for organic carbon and particle size using an elemental NC analyzer and a laser diffraction particle sizer. Results show the presence of breakdown products DDE and DDD at multiple sites, but no detectable levels of DDT at any site. Sampling sites with high levels of DDT contamination in 2009 show only breakdown products in both 2016 and 2017. Particle size has little influence on DDD or DDE concentrations but OC is a controlling factor as indicated for contaminated sites by Pearson correlations between OC and DDE and DDD of 0.82 and 0.92, respectively. The presence of only DDD and/or DDE in the 2016 and 2017 studies indicates that the parent, DDT, has not been re-introduced into the watershed since 2009 but is degrading in the environment.

Effects of nano-sized zero-valent iron (nZVI) on DDT degradation in soil and its toxicity to collembola and ostracods.

PubMed

El-Temsah, Yehia S; Joner, Erik J

2013-06-01

Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg(-1)) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg(-1)). These were incubated with 1 or 10 g nZVI kg(-1), and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg(-1) was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation. Copyright © 2013 Elsevier Ltd. All rights reserved.

DDT-based indoor residual spraying suboptimal for visceral leishmaniasis elimination in India

PubMed Central

Coleman, Michael; Foster, Geraldine M.; Deb, Rinki; Pratap Singh, Rudra; Ismail, Hanafy M.; Shivam, Pushkar; Ghosh, Ayan Kumar; Dunkley, Sophie; Kumar, Vijay; Coleman, Marlize; Hemingway, Janet; Paine, Mark J. I.; Das, Pradeep

2015-01-01

Indoor residual spraying (IRS) is used to control visceral leishmaniasis (VL) in India, but it is poorly quality assured. Quality assurance was performed in eight VL endemic districts in Bihar State, India, in 2014. Residual dichlorodiphenyltrichloroethane (DDT) was sampled from walls using Bostik tape discs, and DDT concentrations [grams of active ingredient per square meter (g ai/m2)] were determined using HPLC. Pre-IRS surveys were performed in three districts, and post-IRS surveys were performed in eight districts. A 20% threshold above and below the target spray of 1.0 g ai/m2 was defined as “in range.” The entomological assessments were made in four districts in IRS and non-IRS villages. Vector densities were measured: pre-IRS and 1 and 3 mo post-IRS. Insecticide susceptibility to 4% DDT and 0.05% deltamethrin WHO-impregnated papers was determined with wild-caught sand flies. The majority (329 of 360, 91.3%) of pre-IRS samples had residual DDT concentrations of <0.1 g ai/m2. The mean residual concentration of DDT post-IRS was 0.37 g ai/m2; 84.9% of walls were undersprayed, 7.4% were sprayed in range, and 7.6% were oversprayed. The abundance of sand flies in IRS and non-IRS villages was significantly different at 1 mo post-IRS only. Sand flies were highly resistant to DDT but susceptible to deltamethrin. The Stockholm Convention, ratified by India in 2006, calls for the complete phasing out of DDT as soon as practical, with limited use in the interim where no viable IRS alternatives exist. Given the poor quality of the DDT-based IRS, ready availability of pyrethroids, and susceptibility profile of Indian sand flies, the continued use of DDT in this IRS program is questionable. PMID:26124110

Exposure assessment for workers applying DDT to control malaria in Veracruz, Mexico.

PubMed Central

Rivero-Rodriguez, L; Borja-Aburto, V H; Santos-Burgoa, C; Waliszewskiy, S; Rios, C; Cruz, V

1997-01-01

DDT has systematically been used in sanitation campaigns against malaria in Mexico. To assess chronic occupational exposure, we studied a group of workers dedicated to spraying houses to control malaria vectors in the state of Veracruz. Exposure was directly estimated for a subgroup of 40 workers by measuring DDT metabolites in adipose tissue samples and indirectly estimated for 331 workers by using a questionnaire to determine their occupational history. Participants ranged in age from 20 to 70 years, and 80% of the workers had been employed in the sanitation campaign for at least 20 years. The mean concentrations of extractable lipids found in adipose tissue samples were as follows: total DDT, 104.48 micrograms/g; p,p'-DDE, 60.98 micrograms/g; p,p'-DDT, 31.0 micrograms/g; o,p'-DDT, 2.10 micrograms/g; and p,p'-DDD, 0.95 microgram/g. The DDT metabolite p,p'-DDE was selected as the indicator of chronic exposure. An index of chronic occupational exposure was constructed according to worker position and based on the historical duration and intensity of DDT application. A linear model including this index, the use of protective gear, and recent weight loss explained 55% of the variation of p,p'-DDE concentrations in adipose tissue. By this model, the predicted values of p,p'-DDE concentration in adipose tissue for the 331 workers are between 9.56 micrograms/g and 298.4 micrograms/g of fat, with a geometric mean of 67.41 micrograms/g. These high levels of DDT in adipose tissue call for exposure prevention programs and the promotion of more secure application measures and hygiene. We also discuss the use of indirect measures of DDT exposure in epidemiological studies of health effects. PMID:9074888

Biotransformation of dichlorodiphenyltrichloroethane in the benthic polychaete, Nereis succinea: quantitative estimation by analyzing the partitioning of chemicals between gut fluid and lipid.

PubMed

Wang, Fei; Pei, Yuan-yuan; You, Jing

2015-02-01

Biotransformation plays an important role in the bioaccumulation and toxicity of a chemical in biota. Dichlorodiphenyltrichloroethane (DDT) commonly co-occurs with its metabolites (dichlorodiphenyldichloroethane [DDD] and dichlorodiphenyldichloroethylene [DDE]), in the environment; thus it is a challenge to accurately quantify the biotransformation rates of DDT and distinguish the sources of the accumulated metabolites in an organism. The present study describes a method developed to quantitatively analyze the biotransformation of p,p'-DDT in the benthic polychaete, Nereis succinea. The lugworms were exposed to sediments spiked with DDT at various concentrations for 28 d. Degradation of DDT to DDD and DDE occurred in sediments during the aging period, and approximately two-thirds of the DDT remained in the sediment. To calculate the biotransformation rates, residues of individual compounds measured in the bioaccumulation testing (after biotransformation) were compared with residues predicted by analyzing the partitioning of the parent and metabolite compounds between gut fluid and tissue lipid (before biotransformation). The results suggest that sediment ingestion rates decreased when DDT concentrations in sediment increased. Extensive biotransformation of DDT occurred in N. succinea, with 86% of DDT being metabolized to DDD and <2% being transformed to DDE. Of the DDD that accumulated in the lugworms, approximately 70% was the result of DDT biotransformation, and the remaining 30% was from direct uptake of sediment-associated DDD. In addition, the biotransformation was not dependent on bulk sediment concentrations, but rather on bioaccessible concentrations of the chemicals in sediment, which were quantified by gut fluid extraction. The newly established method improved the accuracy of prediction of the bioaccumulation and toxicity of DDTs. © 2014 SETAC.

Low Concentrations of o,p’-DDT Inhibit Gene Expression and Prostaglandin Synthesis by Estrogen Receptor-Independent Mechanism in Rat Ovarian Cells

PubMed Central

Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

2012-01-01

o,p’-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p’-DDT at range of 0.3–500 ng/g (8.46×10−10 M−1.41×10−6 M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p’-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p’-DDT (10−12−10−8 M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p’-DDT at 0.5–1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p’-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p’-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p’-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p’-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

Protective Efficacy of Vitamins C and E on p,p′-DDT-Induced Cytotoxicity via the ROS-Mediated Mitochondrial Pathway and NF-κB/FasL Pathway

PubMed Central

Jin, Xiaoting; Song, Li; Liu, Xiangyuan; Chen, Meilan; Li, Zhuoyu; Cheng, Long; Ren, Hua

2014-01-01

Dichlorodiphenoxytrichloroethane (DDT) is a known persistent organic pollutant and liver damage toxicant. However, there has been little emphasis on the mechanism underlying liver damage toxicity of DDT and the relevant effective inhibitors. Hence, the present study was conducted to explore the protective effects of vitamin C (VC) and vitamin E (VE) on the cytotoxicity of DDT in HL-7702 cells and elaborate the specific molecular mechanisms. The results demonstrated that p,p′-DDT exposure at over 10 µM depleted cell viability of HL-7702 cells and led to cell apoptotic. p,p′-DDT treatment elevated the level of reactive oxygen species (ROS) generation, induced mitochondrial membrane potential, and released cytochrome c into the cytosol, with subsequent elevations of Bax and p53, along with suppression of Bcl-2. In addition, the activations of caspase-3 and -8 were triggered. Furthermore, p,p′-DDT promoted the expressions of NF-κB and FasL. When the cells were exposed to the NF-κB inhibitor (PDTC), the up-regulated expression of FasL was attenuated. Strikingly, these alterations caused by DDT treatment were prevented or reversed by the addition of VC or VE, and the protective effects of co-treatment with VC and VE were higher than the single supplement with p,p′-DDT. Taken together, these findings provide novel experimental evidences supporting that VC or/and VE could reduce p,p′-DDT-induced cytotoxicity of HL-7702 cells via the ROS-mediated mitochondrial pathway and NF-κB/FasL pathway. PMID:25464339

DDT-based indoor residual spraying suboptimal for visceral leishmaniasis elimination in India.

PubMed

Coleman, Michael; Foster, Geraldine M; Deb, Rinki; Pratap Singh, Rudra; Ismail, Hanafy M; Shivam, Pushkar; Ghosh, Ayan Kumar; Dunkley, Sophie; Kumar, Vijay; Coleman, Marlize; Hemingway, Janet; Paine, Mark J I; Das, Pradeep

2015-07-14

Indoor residual spraying (IRS) is used to control visceral leishmaniasis (VL) in India, but it is poorly quality assured. Quality assurance was performed in eight VL endemic districts in Bihar State, India, in 2014. Residual dichlorodiphenyltrichloroethane (DDT) was sampled from walls using Bostik tape discs, and DDT concentrations [grams of active ingredient per square meter (g ai/m(2))] were determined using HPLC. Pre-IRS surveys were performed in three districts, and post-IRS surveys were performed in eight districts. A 20% threshold above and below the target spray of 1.0 g ai/m(2) was defined as "in range." The entomological assessments were made in four districts in IRS and non-IRS villages. Vector densities were measured: pre-IRS and 1 and 3 mo post-IRS. Insecticide susceptibility to 4% DDT and 0.05% deltamethrin WHO-impregnated papers was determined with wild-caught sand flies. The majority (329 of 360, 91.3%) of pre-IRS samples had residual DDT concentrations of <0.1 g ai/m(2). The mean residual concentration of DDT post-IRS was 0.37 g ai/m(2); 84.9% of walls were undersprayed, 7.4% were sprayed in range, and 7.6% were oversprayed. The abundance of sand flies in IRS and non-IRS villages was significantly different at 1 mo post-IRS only. Sand flies were highly resistant to DDT but susceptible to deltamethrin. The Stockholm Convention, ratified by India in 2006, calls for the complete phasing out of DDT as soon as practical, with limited use in the interim where no viable IRS alternatives exist. Given the poor quality of the DDT-based IRS, ready availability of pyrethroids, and susceptibility profile of Indian sand flies, the continued use of DDT in this IRS program is questionable.

Exposure to DDT and its metabolites from khat (Catha edulis) chewing: Consumers risk assessment from southwestern Ethiopia.

PubMed

Mekonen, Seblework; Ambelu, Argaw; Negassa, Belay; Spanoghe, Pieter

2017-07-01

Khat (Catha edulis) is one of the most consumed plant in the horn of African countries. However, it is a stimulant plant that has several side effects on the health of consumers. On top of that, the khat leaves used for human consumption are often contain contaminants such as pesticide residues. The present study aims to investigate the level of DDT residue and its metabolites (p'p-DDE, p'p-DDD, o'p-DDT and p'p-DDT) in khat samples and to undertake exposure assessment to consumers. The khat samples were collected from local markets in southwestern Ethiopia. Consumption survey was undertaken using 24 h recall method for both male and female khat consumers. The finding showed that 80% of the khat samples contained DDT and its metabolites. Some of the residues were above the maximum residue limit (MRL) set by Food and Agricultural Organization (FAO). The concentration of p'p-DDE and p'p-DDT in khat were in the range of 0.033-0.113 and 0.010-0.026 mg/kg, respectively. High concentration of the metabolite (p'p-DDE) compared to the parent compound (p'p-DDT) revealed the historical use of DDT in the study area. Probabilistic exposure analysis indicated that the mean and 97.5 percentile (P97.5), of the estimated daily intake of total DDT were 0.002 and 0.006 mg/kg bw/day, respectively. The study concluded that khat consumers are exposed to the stimulant effect of the plant as well as DDT and its metabolites in Jimma zone. Copyright © 2017 Elsevier Inc. All rights reserved.

DDT and DDE concentrations in the blood of Mexican children residing in the southeastern region of Mexico.

PubMed

Pérez-Maldonado, Iván N; Trejo-Acevedo, Antonio; Orta-García, Sandra Teresa; Ochoa-Martinez, Angeles C; Varela-Silva, José Antonio; Pérez-Vázquez, Francisco Javier

2014-01-01

The aim of this study was to assess the levels of dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) in the blood of children living in the southeastern region of Mexico. In this study, we found high levels of DDT and its principal metabolite (DDE) in the blood of children residing in the communities studied. The levels of total DDT found in our study ranged from 4,676.4 ng/g lipid to 64,245.2 ng/g lipid. All of the children in the study had detectable levels of DDT and/or DDE. In conclusion, our data indicate that children living within the study areas are exposed to high levels of DDT and DDE. Moreover, these results can be used as a trigger to revisit local policies on environmental exposures.

Prenatal DDT exposure and child adiposity at age 12: The CHAMACOS study.

PubMed

Warner, Marcella; Ye, Morgan; Harley, Kim; Kogut, Katherine; Bradman, Asa; Eskenazi, Brenda

2017-11-01

Using 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. We 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. At 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. These results support the chemical obesogen hypothesis, that in utero exposure to DDT and DDE may increase risk of obesity in males later in life. Copyright © 2017. Published by Elsevier Inc.

Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring

PubMed Central

La Merrill, Michele; Karey, Emma; Moshier, Erin; Lindtner, Claudia; La Frano, Michael R.; Newman, John W.; Buettner, Christoph

2014-01-01

Dichlorodiphenyltrichloroethane (DDT) has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring. PMID:25076055

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology.

PubMed

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium. Copyright © 2017 Elsevier B.V. All rights reserved.

RNAi validation of resistance genes and their interactions in the highly DDT-resistant 91-R strain of Drosophila melanogaster.

PubMed

Gellatly, Kyle J; Yoon, Kyong Sup; Doherty, Jeffery J; Sun, Weilin; Pittendrigh, Barry R; Clark, J Marshall

2015-06-01

4,4'-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control. Previous DDT use has resulted in resistance, and with continued use resistance will increase in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, numerous studies done on insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold), however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has validated the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (Mdr50, Mdr65, and Mrp1) involved in DDT resistance. Further, increased sensitivity to DDT in the 91-R strain after intra-abdominal dsRNA injection for Mdr50, Mdr65, and Mrp1 was determined by a DDT contact bioassay, directly implicating these genes in DDT efflux and resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Variation effect on the insecticide activity of DDT analogues. A chemometric approach

NASA Astrophysics Data System (ADS)

Itoh, S.; Nagashima, U.

2002-08-01

We investigated a variation effect on the insecticide activity of DDT analogues by using the first principles electronic structure calculations and the neural network analysis. It has been found that the charge distribution at the specific atomic sites in the DDT molecule is related to their toxicity. This approach can contribute to designing a new insecticide and a new harmlessness process of the DDT analogues.

Bioturbation delays attenuation of DDT by clean sediment cap but promotes sequestration by thin-layered activated carbon.

PubMed

Lin, Diana; Cho, Yeo-Myoung; Werner, David; Luthy, Richard G

2014-01-21

The effects of bioturbation on the performance of attenuation by sediment deposition and activated carbon to reduce risks from DDT-contaminated sediment were assessed for DDT sediment-water flux, biouptake, and passive sampler (PE) uptake in microcosm experiments with a freshwater worm, Lumbriculus variegatus. A thin-layer of clean sediment (0.5 cm) did not reduce the DDT flux when bioturbation was present, while a thin (0.3 cm) AC cap was still capable of reducing the DDT flux by 94%. Bioturbation promoted AC sequestration by reducing the 28-day DDT biouptake (66%) and DDT uptake into PE (>99%) compared to controls. Bioturbation further promoted AC-sediment contact by mixing AC particles into underlying sediment layers, reducing PE uptake (55%) in sediment compared to the AC cap without bioturbation. To account for the observed effects from bioturbation, a mass transfer model together with a biodynamic model were developed to simulate DDT flux and biouptake, respectively, and models confirmed experimental results. Both experimental measurements and modeling predictions imply that thin-layer activated carbon placement on sediment is effective in reducing the risks from contaminated sediments in the presence of bioturbation, while natural attenuation process by clean sediment deposition may be delayed by bioturbation.

Newly Identified DDT-Related Compounds Accumulating in Southern California Bottlenose Dolphins.

PubMed

Mackintosh, Susan A; Dodder, Nathan G; Shaul, Nellie J; Aluwihare, Lihini I; Maruya, Keith A; Chivers, Susan J; Danil, Kerri; Weller, David W; Hoh, Eunha

2016-11-15

Nontargeted GC×GC-TOF/MS analysis of blubber from 8 common bottlenose dolphins (Tursiops truncatus) inhabiting the Southern California Bight was performed to identify novel, bioaccumulative DDT-related compounds and to determine their abundance relative to the commonly studied DDT-related compounds. We identified 45 bioaccumulative DDT-related compounds of which the majority (80%) is not typically monitored in environmental media. Identified compounds include transformation products, technical mixture impurities such as tris(chlorophenyl)methane (TCPM), the presumed TCPM metabolite tris(chlorophenyl)methanol (TCPMOH), and structurally related compounds with unknown sources, such as hexa- to octachlorinated diphenylethene. To investigate impurities in pesticide mixtures as possible sources of these compounds, we analyzed technical DDT, the primary source of historical contamination in the region, and technical Dicofol, a current use pesticide that contains DDT-related compounds. The technical mixtures contained only 33% of the compounds identified in the blubber, suggesting that transformation products contribute to the majority of the load of DDT-related contaminants in these sentinels of ocean health. Quantitative analysis revealed that TCPM was the second most abundant compound class detected in the blubber, following DDE, and TCPMOH loads were greater than DDT. QSPR estimates verified 4,4',4″-TCPM and 4,4'4,″-TCPMOH are persistent and bioaccumulative.

Assessment of DDT and Metabolites in Soil and Sediment of Potentially Contaminated Areas of Belém, Amazon Region, Brazil.

PubMed

Rodrigues, Andreia Oliveira; de Souza, Larissa Costa; da Silva Rocha, Cássia Christina; da Costa, Amilton Cesar Gomes; de Alcântara Mendes, Rosivaldo

2017-07-01

The aim of this study was to evaluate the distribution of DDT and metabolites in surface soils and soil profiles from two areas containing deposits of obsolete pesticides in Belém, Amazon Region, Brazil. DDT and metabolites were extracted by microwave assisted extraction and analyzed by gas chromatography with electron capture detection. Concentrations of total DDT in surface soil samples ranged from 64.22 mg kg -1 in area 1 (A1) to 447.84 mg kg -1 in area 2 (A2). Lower levels were found in soil profiles than at the surface (6.21-21.17 mg kg -1 in A1 and 36.13-113.66 mg kg -1 in A2). pp'-DDT, pp'-DDE and pp'-DDD were detected in sediments at levels of 2.01, 0.96 and 0.35 mg kg -1 , respectively. The ratio (DDE + DDD)/ΣDDT was low indicating the recent introduction of DDT to the environment in the two study areas, through the volatilization and atmospheric deposition of the obsolete pesticides.

Application of sewage sludge and intermittent aeration strategy to the bioremediation of DDT- and HCH-contaminated soil.

PubMed

Liang, Qi; Lei, Mei; Chen, Tongbin; Yang, Jun; Wan, Xiaoming; Yang, Sucai

2014-08-01

Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) contaminated soil was investigated in bench scale experiments, and intermittent aeration strategy was also used in this study to form an anaerobic-aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%-80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to 218 g/kg, and it could also introduce efficient degradation microbes to soil, including Pseudomonas sp., Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH, and anaerobic removal rates of β-HCH, o,p'-DDT and p,p'-DDT accounted for more than 50% of the total removal rates, but the content of α-HCH declined more in the aerobic phase. Copyright © 2014. Published by Elsevier B.V.

Development of a Thermal Desorption Gas Chromatography-Mass Spectrometry Analysis Method for Airborne Dichlorodiphenyltrichloroethane

DTIC Science & Technology

2013-05-28

span of 1-250 ng DDT. Furthermore, laboratory and field experiments utilizing this method confirmed that significant DDT concentration differences ... different between the two sample introduction methods when comparing the same DDT mass which may be due to differences in the precision of split...degradation of DDT was significantly different between the liquid and TD methods (t-test; p < 0.001). For TD analyses the relative percent

Degradation of chlorinated pesticide DDT by litter-decomposing basidiomycetes.

PubMed

Suhara, Hiroto; Adachi, Ai; Kamei, Ichiro; Maekawa, Nitaro

2011-11-01

One hundred and two basidiomycete strains (93 species in 41 genera) that prefer a soil environment were examined for screening of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) biodegradation. Three strains within two litter-decomposing genera, Agrocybe and Marasmiellus, were selected for their DDT biotransformation capacity. Eight metabolites; 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD), two monohydroxy-DDTs, monohydroxy-DDD, 2,2-dichloro-1,1-bis(4-chlorophenyl)ethanol, putative 2,2-bis(4-chlorophenyl)ethanol and two unidentified compounds were detected from the culture with Marasmiellus sp. TUFC10101. A P450 inhibitor, 1-ABT, inhibited the formation of monohydroxy-DDTs and monohydroxy-DDD from DDT and DDD, respectively. These results indicated that oxidative pathway which was catalyzed by P450 monooxygenase exist beside reductive dechlorination of DDT. Monohydroxylation of the aromatic rings of DDT (and DDD) by fungal P450 is reported here for the first time.

The toxicity of p,p'-DDT to the clapper rail

USGS Publications Warehouse

Van Velzen, A.; Kreitzer, J.F.

1975-01-01

The LC50 (concentration of toxicant in the diet expected to kill half of the test birds in 5 days) for p,p' -DDT in clapper rails (Rallus longirostris) was found to be 1,612 ppm for males and 1,896 ppm for females. Amounts of DDT + DDD in the brains of birds that died were significantly greater (P < 0.01) than those in the brains of survivors. Thirty ppm DDT + DDD approximated the lower limit of these compounds in the brains of rails diagnostic of death from DDT poisoning. Residues in livers and carcasses are reported. Considering the relatively high resistance of the clapper rail to DDT poisoning, we concluded that exposure to this pesticide in marshes is not likely to be a significant factor in mortality of adult rails. Effects other than direct mortality were not evaluated in this study.

Accelerated anaerobic dechlorination of DDT in slurry with Hydragric Acrisols using citric acid and anthraquinone-2,6-disulfonate (AQDS).

PubMed

Liu, Cuiying; Xu, Xianghua; Fan, Jianling

2015-12-01

The application of electron donor and electron shuttle substances has a vital influence on electron transfer, thus may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in anaerobic reaction systems. To evaluate the roles of citric acid and anthraquinone-2,6-disulfonate (AQDS) in accelerating the reductive dechlorination of DDT in Hydragric Acrisols that contain abundant iron oxide, a batch anaerobic incubation experiment was conducted in a slurry system with four treatments of (1) control, (2) citric acid, (3) AQDS, and (4) citric acid+AQDS. Results showed that DDT residues decreased by 78.93%-92.11% of the initial quantities after 20days of incubation, and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane (DDD) was the dominant metabolite. The application of citric acid accelerated DDT dechlorination slightly in the first 8days, while the methanogenesis rate increased quickly, and then the acceleration effect improved after the 8th day while the methanogenesis rate decreased. The amendment by AQDS decreased the Eh value of the reaction system and accelerated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus enhancing the reductive dechlorination rate of DDT. The addition of citric acid+AQDS was most efficient in stimulating DDT dechlorination, but no significant interaction between citric acid and AQDS on DDT dechlorination was observed. The results will be of great significance for developing an efficient in situ remediation strategy for DDT-contaminated sites. Copyright © 2015. Published by Elsevier B.V.

Elucidating Turnover Pathways of Bioactive Small Molecules by Isotopomer Analysis: The Persistent Organic Pollutant DDT

PubMed Central

Ehlers, Ina; Betson, Tatiana R.; Vetter, Walter; Schleucher, Jürgen

2014-01-01

The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment. To differentiate between DDD formation pathways, we applied deuterium NMR spectroscopy to measure intramolecular deuterium distributions (2H isotopomer abundances) of DDT and DDD. DDD formed in the technical DDT synthesis was strongly deuterium-enriched at one intramolecular position, which we traced back to 2H/1H fractionation of a chlorination step in the technical synthesis. In contrast, DDD formed by reductive degradation was strongly depleted at the same position, which was due to the incorporation of 2H-depleted hydride equivalents during reductive degradation. Thus, intramolecular isotope distributions give mechanistic information on reaction pathways, and explain a puzzling difference in the whole-molecule 2H/1H ratio between DDT and DDD. In general, our results highlight that intramolecular isotope distributions are essential to interpret whole-molecule isotope ratios. Intramolecular isotope information allows distinguishing pathways of DDD formation, which is important to identify polluters or to assess DDT turnover in the environment. Because intramolecular isotope data directly reflect isotope fractionation of individual chemical reactions, they are broadly applicable to elucidate transformation pathways of small bioactive molecules in chemistry, physiology and environmental science. PMID:25350380

Bioavailability assessments following biochar and activated carbon amendment in DDT-contaminated soil.

PubMed

Denyes, Mackenzie J; Rutter, Allison; Zeeb, Barbara A

2016-02-01

The effects of 2.8% w/w granulated activated carbon (GAC) and two types of biochar (Burt's and BlueLeaf) on DDT bioavailability in soil (39 μg/g) were investigated using invertebrates (Eisenia fetida), plants (Cucurbita pepo spp. pepo) and a polyoxymethylene (POM) passive sampler method. Biochar significantly reduced DDT accumulation in E. fetida (49%) and showed no detrimental effects to invertebrate health. In contrast, addition of GAC caused significant toxic effects (invertebrate avoidance and decreased weight) and did not significantly reduce the accumulation of DDT into invertebrate tissue. None of the carbon amendments reduced plant uptake of DDT. Bioaccumulation of 4,4'DDT and 4,4'-DDE in plants (C. pepo spp. pepo) and invertebrates (E. fetida) was assessed using bioaccumulation factors (BAFs) and compared to predicted bioavailability using the freely-dissolved porewater obtained from a polyoxymethylene (POM) equilibrium biomimetic method. The bioavailable fraction predicted by the POM samplers correlated well with measured invertebrate uptake (<50% variability), but was different from plant root uptake by 134%. A literature review of C. pepo BAFs across DDT soil contamination levels and the inclusion of field data from a 2.5 μg/g DDT-contaminated site found that these plants exhibit a concentration threshold effect at [DDT](soil) > 10 μg/g. The results of these studies illustrate the importance of including plants in bioavailability studies as the use of carbon materials for in situ contaminant sorption moves from predominantly sediment to soil remediation technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

DDT Exposure in Utero and Breast Cancer.

PubMed

Cohn, Barbara A; La Merrill, Michele; Krigbaum, Nickilou Y; Yeh, Gregory; Park, June-Soo; Zimmermann, Lauren; Cirillo, Piera M

2015-08-01

Currently no direct evidence links in utero dichlorodiphenyltrichloroethane (DDT) exposure to human breast cancer. However, in utero exposure to another xenoestrogen, diethylstilbestrol, predicts an increased breast cancer risk. If this finding extends to DDT, it could have far-reaching consequences. Many women were heavily exposed in utero during widespread DDT use in the 1960s. They are now reaching the age of heightened breast cancer risk. DDT exposure persists and use continues in Africa and Asia without clear knowledge of the consequences for the next generation. In utero exposure to DDT is associated with an increased risk of breast cancer. This was a case-control study nested in a prospective 54-year follow-up of 9300 daughters in the Child Health and Development Studies pregnancy cohort (n = 118 breast cancer cases, diagnosed by age 52 y and 354 controls matched on birth year). Kaiser Foundation Health Plan members who received obstetric care in Alameda County, California, from 1959 to 1967, and their adult daughters participated in the study. Daughters' breast cancer diagnosed by age 52 years as of 2012 was measured. Maternal o,p'-DDT predicted daughters' breast cancer (odds ratio fourth quartile vs first = 3.7, 95% confidence interval 1.5-9.0). Mothers' lipids, weight, race, age, and breast cancer history did not explain the findings. This prospective human study links measured DDT exposure in utero to risk of breast cancer. Experimental studies are essential to confirm results and discover causal mechanisms. Findings support classification of DDT as an endocrine disruptor, a predictor of breast cancer, and a marker of high risk.

In-utero exposure to DDT and cognitive development among infants and school-aged children

PubMed Central

Jusko, Todd A.; Klebanoff, Mark A.; Brock, John W.; Longnecker, Matthew P.

2012-01-01

Background Dichlorodiphenyltrichloroethane (DDT) continues to be used for control of infectious diseases in several countries. In-utero exposure to DDT and dichlorodiphenyldichloroethylene (DDE) has been associated with developmental and cognitive impairment among children. We examined this association in an historical cohort in which the level of exposure was greater than in previous studies. Methods The association of in-utero DDT and DDE exposure with infant and child neurodevelopment was examined in approximately 1100 subjects in the Collaborative Perinatal Project, a prospective birth cohort enrolling pregnant women from 12 study centers in the U.S. from 1959 to 1965. Maternal DDT and DDE concentrations were measured in archived serum specimens. Infant mental and motor development was assessed at age 8 months using the Bayley Scales of Infant Development, and child cognitive development was assessed at age 7 years using the Wechsler Intelligence Scale for Children. Results Although levels of both DDT and DDE were relatively high in this population (median DDT concentration, 8.9 µg/L; DDE, 24.5 µg/L), neither was related to Mental or Psychomotor Development scores on the Bayley Scales or to Full-Scale IQ at 7 years of age. Categorical analyses showed no evidence of dose-response for either maternal DDT or DDE, and estimates of the association between continuous measures of exposure and neurodevelopment were indistinguishable from 0. Conclusions Adverse associations were not observed between maternal serum DDT and DDE concentrations and offspring neurodevelopment at 8 months or 7 years of age in this cohort. PMID:22766752

Current implications of past DDT indoor spraying in Oman.

PubMed

Booij, Petra; Holoubek, Ivan; Klánová, Jana; Kohoutek, Jiří; Dvorská, Alice; Magulová, Katarína; Al-Zadjali, Said; Čupr, Pavel

2016-04-15

In Oman, DDT was sprayed indoors during an intensive malaria eradication program between 1976 and 1992. DDT can remain for years after spraying and is associated with potential health risk. This raises the concern for human exposure in areas where DDT was used for indoor spraying. Twelve houses in three regions with a different history of DDT indoor spraying were chosen for a sampling campaign in 2005 to determine p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) levels in indoor air, dust, and outdoor soil. Although DDT was only sprayed indoor, p,p'-DDT, p,p'-DDE and p,p'-DDD were also found in outdoor soil. The results indicate that release and exposure continue for years after cessation of spraying. The predicted cancer risk based on concentrations determined in 2005, indicate that there was still a significant cancer risk up to 13 to 16years after indoor DDT spraying. A novel approach, based on region-specific half-lives, was used to predict concentrations in 2015 and showed that more than 21years after spraying, cancer risk for exposure to indoor air, dust, and outdoor soil are acceptable in Oman for adults and young children. The model can be used for other locations and countries to predict prospective exposure of contaminants based on indoor experimental measurements and knowledge about the spraying time-schedule to extrapolate region-specific half-lives and predict effects on the human population years after spraying. Copyright © 2015 Elsevier B.V. All rights reserved.

DDT: A Renaissance?

ERIC Educational Resources Information Center

Devlin, Robert M.

1974-01-01

A critical review is made of the literature linking DDT to harmful effects on animal life. Implications of a ban on the use of DDT are discussed and studies which have found relatively no harmful effect on non-insect life are cited. (JP)

Selective and conventional house-spraying of DDT and bendiocarb against Anopheles pseudopunctipennis in southern Mexico.

PubMed

Casas, M; Torres, J L; Bown, D N; Rodríguez, M H; Arredondo-Jiménez, J I

1998-12-01

Indoor feeding behaviors and mortalities of Anopheles pseudopunctipennis females were evaluated following contact with selective (bands covering mosquitoes' preferred resting areas) and full applications of DDT and bendiocarb on indoor sprayable surfaces. The DDT residues provoked strong avoidance behavior. To a lesser degree, mosquitoes were also repelled by bendiocarb-sprayed surfaces. Because of strong irritancy/repellency, unfed mosquitoes were driven outdoors in proportionally higher numbers. The resting time on selectively or fully DDT-sprayed huts was greatly reduced in comparison to bendiocarb-sprayed huts. Although unfed mosquitoes tended to rest on non-DDT-sprayed surfaces in the selectively treated hut, the man-biting rate was similar with both types of treatments. Unfed mosquitoes were repelled less from selectively bendiocarb-treated surfaces. Similar reductions in postfed resting times were observed on all surfaces suggesting that once fed, mosquitoes rested on sprayed surfaces for shorter intervals of time. Engorged mosquitoes had normal resting behavior (pre- and postspray) within the range of preferred resting heights in both DDT- and bendiocarb-sprayed huts, but the proportion of mosquitoes fed in the DDT-treated huts was lower. Selective spraying of walls was as effective as spraying the complete walls with both insecticides, but DDT was more effective in reducing mosquito-human contact. These studies show that by more effectively targeting vector behavior, a cost-effective alternative to traditional control techniques can be achieved.

Linking Environmental Exposure with Public Health: Dichlorodiphenyltrichloroethane Extracted from Soils and Water of Recently Exposed Communities of Selected Locations in Zambia

PubMed Central

Sipilanyambe Munyinda, Nosiku; Michelo, Charles; Sichilongo, Kwenga

2015-01-01

Background. In 2000, a Zambian private mining company reintroduced the use of dichlorodiphenyltrichloroethane (DDT) to control malaria in two districts. From 2000 to 2010, DDT had been applied in homes without any studies conducted to ascertain its fate in the environment. We aimed to quantify the presence of DDT and its metabolites in the soil and water around communities where it was recently used. Methods. We collected superficial soil and water samples from drinking sources of three study areas. DDT was extracted by QuEChERS method and solid phase extraction for soils and water, respectively. Analysis was by gas chromatography-mass spectrometry. A revalidated method with limits of detection ranging from 0.034 to 0.04 ppb was used. Results. Median levels of total DDT were found at 100.4 (IQR 90.9–110) and 725.4 ng/L (IQR 540–774.5) for soils and water, respectively. No DDT above detection limits was detected in the reference area. These results are clinically significant given the persistent characteristics of DDT. Conclusion. DDT presence in these media suggests possible limitations in the environmental safeguards during IRS. Such occurrence could have potential effects on humans, especially children; hence, there is a need to further examine possible associations between this exposure and humans. PMID:26579199

Enhanced degradation performances of plate-like micro/nanostructured zero valent iron to DDT.

PubMed

Kang, Shenghong; Liu, Shengwen; Wang, Huimin; Cai, Weiping

2016-04-15

Micro/nanostructured zero valent iron (MNZVI) is successfully mass-synthesized by ball-milling the industrially-reduced iron powders. The as-prepared MNZVI is plate-like in morphology with about 2-5μm in planar size and 35-55nm in thickness, and ∼16m(2)/g in specific surface area. Such plate-like MNZVI has demonstrated much higher degradation performances to DDT [or 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane] in the aqueous solution than the commercial ZVI powders under acidic conditions. The MNZVI-induced DDT degradation is also much faster than the previously reported results. The time-dependent DDT removal amount can be described by the pseudo first-order kinetic model. Further experiments have shown that more than 50% of DDT can be mineralized in 20min and the rest is dechlorinated to DDX (the products with less chlorine). It has been revealed that the DDT degradation could be attributed to the acid assisted ZVI-induced mineralization and dechlorination. The mineralization process is dominant during the initial stage within 20min, and the dechlorination is the main reaction in the anaphase of the degradation. This work not only deepens understanding of DDT degradation but also could provide a highly efficient material for the practical treatment of the DDT in a real environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Splice form variant and amino acid changes in MDR49 confers DDT resistance in transgenic Drosophila

PubMed Central

Seong, Keon Mook; Sun, Weilin; Clark, John M.; Pittendrigh, Barry R.

2016-01-01

The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R. PMID:27003579

Splice form variant and amino acid changes in MDR49 confers DDT resistance in transgenic Drosophila.

PubMed

Seong, Keon Mook; Sun, Weilin; Clark, John M; Pittendrigh, Barry R

2016-03-22

The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R.

Preconception serum 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane and B-vitamin status: independent and joint effects on women's reproductive outcomes1234

PubMed Central

Ouyang, Fengxiu; Longnecker, Matthew P; Venners, Scott A; Johnson, Sara; Korrick, Susan; Zhang, Jun; Xu, Xiping; Christian, Parul; Wang, Mei-Cheng

2014-01-01

Background: Although preconception 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane (DDT) exposure and B-vitamin deficiencies have each been shown to negatively affect human reproductive outcomes, little is known about their joint effect. Objective: We sought to examine whether B-vitamin sufficiency protects against adverse effects of DDT on clinical pregnancy (CP) and subclinical early pregnancy loss (EPL). Design: We measured preconception concentrations of plasma B vitamins (vitamin B-6, vitamin B-12, and folate) and serum total DDT [sum of p,p’ and o,p’ isomers of DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] in 291 nulligravid women from Anhui, China, who were studied in 1996–1998. The women were followed prospectively from the time they stopped contraception until CP (gestational age ≥42 d) or 12 mo (whichever occurred first). EPL was identified by using daily urinary human chorionic gonadotropin. The women were categorized according to B-vitamin status (deficiency compared with sufficiency) and DDT concentration (high compared with low). Results: Of 291 study women, a total of 385 conceptions (31% of which ended in EPL) and 265 CPs occurred. Compared with women with adequate B-vitamins and low DDT, incidence rates of CP were reduced in women with B-vitamin deficiency and a high DDT concentration (P < 0.05 for all). Most notably, in women with sufficient vitamin B-12, DDT was not associated with the incidence of CP; in contrast, in women with vitamin B-12 deficiency, high DDT was associated with a lower incidence of CP (HR: 0.44; 95% CI: 0.23, 0.84); and the test for interaction was significant (P < 0.05). The odds of EPL decreased by 45% (95% CI: 21%, 62%) for each interquartile distance increase in folate in women with high DDT concentrations, and the test for interaction was significant (P = 0.006). Conclusions: Our results provide suggestive evidence that vitamin B-12 and folate sufficiency may help protect against adverse reproductive effects of DDT exposure. Additional studies are needed to confirm our findings. PMID:25411282

Systems Studies of DDT Transport

ERIC Educational Resources Information Center

Harrison, H. L.; And Others

1970-01-01

Major consequences of present and additional environmental quantities of DDT pesticide are predictable by mathematical models of transport, accumulation and concentration mechanisms in the Wisconsin regional ecosystem. High solubility and stability produce increased DDT concentrations at high organism trophic levels within world biosphere…

Plasma Levels of Macrophage Migration Inhibitory Factor and d-Dopachrome Tautomerase Show a Highly Specific Profile in Early Life

PubMed Central

Roger, Thierry; Schlapbach, Luregn J.; Schneider, Anina; Weier, Manuela; Wellmann, Sven; Marquis, Patrick; Vermijlen, David; Sweep, Fred C. G. J.; Leng, Lin; Bucala, Richard; Calandra, Thierry; Giannoni, Eric

2017-01-01

Macrophage migration inhibitory factor (MIF) is a pleiotropic, constitutively expressed, pro-inflammatory cytokine and an important regulator of immune responses. d-dopachrome tautomerase (DDT), a newly described member of the MIF protein superfamily, shares sequence homology and biological activities with MIF. We recently reported that high expression levels of MIF sustain innate immune responses in newborns. Here, we elected to further characterize age-dependent MIF expression and to define whether DDT shares a similar expression profile with MIF. Therefore, we delineated the circulating concentrations of MIF and DDT throughout life using a large cohort of 307 subjects including fetuses, newborns, infants, children, and adults. Compared to levels measured in healthy adults (median: 5.7 ng/ml for MIF and 16.8 ng/ml for DDT), MIF and DDT plasma concentrations were higher in fetuses (median: 48.9 and 29.6 ng/ml), increased further at birth (median: 82.6 and 52.0 ng/ml), reached strikingly elevated levels on postnatal day 4 (median: 109.5 and 121.6 ng/ml), and decreased to adult levels during the first months of life. A strong correlation was observed between MIF and DDT concentrations in all age groups (R = 0.91, P < 0.0001). MIF and DDT levels correlated with concentrations of vascular endothelial growth factor, a protein upregulated under low oxygen tension and implicated in vascular and lung development (R = 0.70, P < 0.0001 for MIF and R = 0.65, P < 0.0001 for DDT). In very preterm infants, lower levels of MIF and DDT on postnatal day 6 were associated with an increased risk of developing bronchopulmonary dysplasia and late-onset neonatal sepsis. Thus, MIF and DDT plasma levels show a highly specific developmental profile in early life, supporting an important role for these cytokines during the neonatal period. PMID:28179905

Macrophage migration inhibitory factor (MIF) family in arthropods: Cloning and expression analysis of two MIF and one D-dopachrome tautomerase (DDT) homologues in mud crabs, Scylla paramamosain.

PubMed

Huang, Wen-Shu; Duan, Li-Peng; Huang, Bei; Wang, Ke-Jian; Zhang, Cai-Liang; Jia, Qin-Qin; Nie, Pin; Wang, Tiehui

2016-03-01

The macrophage migration inhibitory factor (MIF) family, consisting of MIF and D-dopachrome tautomerase (DDT) in vertebrates, is evolutionarily ancient and has been found across Kingdoms including vertebrates, invertebrates, plants and bacteria. The mammalian MIF family are chemokines at the top of the inflammatory cascade in combating infections. They also possess enzymatic activities, e.g. DDT catalysis results in the production of 5,6-dihydroxyindole (DHI), a precursor of eumelanin. MIF-like genes are widely distributed, but DDT-like genes have only been described in vertebrates and a nematode. In this report, we cloned a DDT-like gene, for the first time in arthropods, and a second MIF in mud crab. The mud crab MIF family have a three exon/two intron structure as seen in vertebrates. The identification of a DDT-like gene in mud crab and other arthropods suggests that the separation of MIF and DDT preceded the divergence of protostomes and deuterostomes. The MIF family is differentially expressed in tissues of adults and during embryonic development and early life. The high level expression of the MIF family in immune tissues, such as intestine and hepatopancreas, suggests an important role in mud crab innate immunity. Mud crab DDT is highly expressed in early embryos, in megalops and crablets and this coincides with the requirement for melanisation in egg chorion tanning and cuticular hardening in arthropods, suggesting a potential novel role of DDT in melanogenesis via its tautomerase activity to produce DHI in mud crab. The clarification of the presence of both MIF and DDT in this report paves the way for further investigation of their functional roles in immunity and in melanogenesis in mud crab and other arthropods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organochlorine pesticides in residential soils and sediments within two main agricultural areas of northwest Mexico: Concentrations, enantiomer compositions and potential sources.

PubMed

Sánchez-Osorio, José Luis; Macías-Zamora, José Vinicio; Ramírez-Álvarez, Nancy; Bidleman, Terry F

2017-04-01

The agricultural Mexicali and Yaqui valleys (MV, YV) in northwest Mexico were heavily treated with organochlorine pesticides in the past. Residential soils and agricultural drain sediments were sampled in 2008-2009 and analyzed for DDTs (o,p'- and p,p'- isomers of DDE, DDD and DDT); hexachlorocyclohexanes (α-, β-, γ- and δ-HCH) and chlordanes (trans-chlordane, cis-chlordane, heptachlor and heptachlor exo-epoxide). Geometric means (GMs) (ng g -1 dry weight) were: MV soils (n = 27) ΣDDT 22, ΣHCH 0.80, ΣCHL 0.88; YV soils (n = 25) ΣDDT 5.0, ΣHCH 0.23, ΣCHL 0.67; MV sediments (n = 3) ΣDDT 5.0, ΣHCH 0.23, ΣCHL 0.53; YV sediments (n = 8) ΣDDT 2.6, ΣHCH 0.12, ΣCHL 0.090. GMs were significantly higher (p < 0.05) in MV than YV soils for ΣDDT and ΣHCH, but not for ΣCHL. Comparison to worldwide regulatory guideline values (RGVs) for residential soils showed all compounds below mean or GM RGVs, but above the lowest RGV in some cases. Low p,p'-DDT/(p,p'-DDT + p,p'-DDE) in most soils indicated aged residues. Lack of p,p'-DDT metabolism might account for its dominance in a few soils. HCH isomer profiles suggested aged technical HCH in the YV, and technical HCH + lindane in the MV. Heptachlor dominated the ΣCHL, probably from application of technical heptachlor as well as chlordane. Chiral compounds were nonracemic in soils and sediments and indicated enantioselective microbial degradation of (+)α-HCH, (-)trans-chlordane, (-)cis-chlordane and (+)o,p'-DDT. Depletion of (+)o,p'-DDT in soils may account for similar enantiomer signatures previously reported in air of northwest Mexico. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of the malaria management model to the analysis of costs and benefits of DDT versus non-DDT malaria control.

PubMed

Pedercini, Matteo; Movilla Blanco, Santiago; Kopainsky, Birgit

2011-01-01

DDT is considered to be the most cost-effective insecticide for combating malaria. However, it is also the most environmentally persistent and can pose risks to human health when sprayed indoors. Therefore, the use of DDT for vector control remains controversial. In this paper we develop a computer-based simulation model to assess some of the costs and benefits of the continued use of DDT for Indoor Residual Spraying (IRS) versus its rapid phase out. We apply the prototype model to the aggregated sub Saharan African region. For putting the question about the continued use of DDT for IRS versus its rapid phase out into perspective we calculate the same costs and benefits for alternative combinations of integrated vector management interventions. Our simulation results confirm that the current mix of integrated vector management interventions with DDT as the main insecticide is cheaper than the same mix with alternative insecticides when only direct costs are considered. However, combinations with a stronger focus on insecticide-treated bed nets and environmental management show higher levels of cost-effectiveness than interventions with a focus on IRS. Thus, this focus would also allow phasing out DDT in a cost-effective manner. Although a rapid phase out of DDT for IRS is the most expensive of the tested intervention combinations it can have important economic benefits in addition to health and environmental impacts that are difficult to assess in monetary terms. Those economic benefits captured by the model include the avoided risk of losses in agricultural exports. The prototype simulation model illustrates how a computer-based scenario analysis tool can inform debates on malaria control policies in general and on the continued use of DDT for IRS versus its rapid phase out in specific. Simulation models create systematic mechanisms for analyzing alternative interventions and making informed trade offs.

Application of the Malaria Management Model to the Analysis of Costs and Benefits of DDT versus Non-DDT Malaria Control

PubMed Central

Pedercini, Matteo; Movilla Blanco, Santiago; Kopainsky, Birgit

2011-01-01

Introduction DDT is considered to be the most cost-effective insecticide for combating malaria. However, it is also the most environmentally persistent and can pose risks to human health when sprayed indoors. Therefore, the use of DDT for vector control remains controversial. Methods In this paper we develop a computer-based simulation model to assess some of the costs and benefits of the continued use of DDT for Indoor Residual Spraying (IRS) versus its rapid phase out. We apply the prototype model to the aggregated sub Saharan African region. For putting the question about the continued use of DDT for IRS versus its rapid phase out into perspective we calculate the same costs and benefits for alternative combinations of integrated vector management interventions. Results Our simulation results confirm that the current mix of integrated vector management interventions with DDT as the main insecticide is cheaper than the same mix with alternative insecticides when only direct costs are considered. However, combinations with a stronger focus on insecticide-treated bed nets and environmental management show higher levels of cost-effectiveness than interventions with a focus on IRS. Thus, this focus would also allow phasing out DDT in a cost-effective manner. Although a rapid phase out of DDT for IRS is the most expensive of the tested intervention combinations it can have important economic benefits in addition to health and environmental impacts that are difficult to assess in monetary terms. Those economic benefits captured by the model include the avoided risk of losses in agricultural exports. Conclusions The prototype simulation model illustrates how a computer-based scenario analysis tool can inform debates on malaria control policies in general and on the continued use of DDT for IRS versus its rapid phase out in specific. Simulation models create systematic mechanisms for analyzing alternative interventions and making informed trade offs. PMID:22140467

Prenatal DDT and DDE Exposure and Child IQ in the CHAMACOS Cohort

PubMed Central

Gaspar, Fraser W.; Harley, Kim G.; Kogut, Katherine; Chevrier, Jonathan; Mora, Ana Maria; Sjödin, Andreas; Eskenazi, Brenda

2016-01-01

Although banned in most countries, dichlorodiphenyl-trichloroethane (DDT) continues to be used for vector control in some malaria endemic areas. Previous findings from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort study found increased prenatal levels of DDT and its breakdown product dichlorodiphenyl-dichloroethylene (DDE) to be associated with altered neurodevelopment in children at 1 and 2 years of age. In this study, we combined the measured maternal DDT/E concentrations during pregnancy obtained for the prospective birth cohort with predicted prenatal DDT and DDE levels estimated for a retrospective birth cohort. Using generalized estimating equation (GEE) and linear regression models, we evaluated the relationship of prenatal maternal DDT and DDE serum concentrations with children’s cognition at ages 7 and 10.5 years as assessed using the Full Scale Intelligence Quotient (IQ) and 4 subtest scores (Working Memory, Perceptual Reasoning, Verbal Comprehension, and Processing Speed) of the Wechsler Intelligence Scale for Children (WISC). In GEE analyses incorporating both age 7 and 10.5 scores (n = 619), we found prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales (p-value >0.05). In linear regression analyses assessing each time point separately, prenatal DDT levels were inversely associated with Processing Speed at age 7 years (n = 316), but prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales at age 10.5 years (n = 595). We found evidence for effect modification by sex. In girls, but not boys, prenatal DDE levels were inversely associated with Full Scale IQ and Processing Speed at age 7 years. We conclude that prenatal DDT levels may be associated with delayed Processing Speed in children at age 7 years and the relationship between prenatal DDE levels and children’s cognitive development may be modified by sex, with girls being more adversely affected. PMID:26414943

Prenatal DDT and DDE exposure and child IQ in the CHAMACOS cohort.

PubMed

Gaspar, Fraser W; Harley, Kim G; Kogut, Katherine; Chevrier, Jonathan; Mora, Ana Maria; Sjödin, Andreas; Eskenazi, Brenda

2015-12-01

Although banned in most countries, dichlorodiphenyl-trichloroethane (DDT) continues to be used for vector control in some malaria endemic areas. Previous findings from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort study found increased prenatal levels of DDT and its breakdown product dichlorodiphenyl-dichloroethylene (DDE) to be associated with altered neurodevelopment in children at 1 and 2years of age. In this study, we combined the measured maternal DDT/E concentrations during pregnancy obtained for the prospective birth cohort with predicted prenatal DDT and DDE levels estimated for a retrospective birth cohort. Using generalized estimating equation (GEE) and linear regression models, we evaluated the relationship of prenatal maternal DDT and DDE serum concentrations with children's cognition at ages 7 and 10.5years as assessed using the Full Scale Intelligence Quotient (IQ) and 4 subtest scores (Working Memory, Perceptual Reasoning, Verbal Comprehension, and Processing Speed) of the Wechsler Intelligence Scale for Children (WISC). In GEE analyses incorporating both age 7 and 10.5 scores (n=619), we found prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales (p-value>0.05). In linear regression analyses assessing each time point separately, prenatal DDT levels were inversely associated with Processing Speed at age 7years (n=316), but prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales at age 10.5years (n=595). We found evidence for effect modification by sex. In girls, but not boys, prenatal DDE levels were inversely associated with Full Scale IQ and Processing Speed at age 7years. We conclude that prenatal DDT levels may be associated with delayed Processing Speed in children at age 7years and the relationship between prenatal DDE levels and children's cognitive development may be modified by sex, with girls being more adversely affected. Copyright © 2015 Elsevier Ltd. All rights reserved.

On the deflagration-to-detonation transition (DDT) process with added energetic solid particles for pulse detonation engines (PDE)

NASA Astrophysics Data System (ADS)

Nguyen, V. B.; Li, J.; Chang, P.-H.; Phan, Q. T.; Teo, C. J.; Khoo, B. C.

2018-01-01

In this paper, numerical simulations are performed to study the dynamics of the deflagration-to-detonation transition (DDT) in pulse detonation engines (PDE) using energetic aluminum particles. The DDT process and detonation wave propagation toward the unburnt hydrogen/air mixture containing solid aluminum particles is numerically studied using the Eulerian-Lagrangian approach. A hybrid numerical methodology combined with appropriate sub-models is used to capture the gas dynamic characteristics, particle behavior, combustion characteristics, and two-way solid-particle-gas flow interactions. In our approach, the gas mixture is expressed in the Eulerian frame of reference, while the solid aluminum particles are tracked in the Lagrangian frame of reference. The implemented computer code is validated using published benchmark problems. The obtained results show that the aluminum particles not only shorten the DDT length but also reduce the DDT time. The improvement of DDT is primarily attributed to the heat released from surface chemical reactions on the aluminum particles. The temperatures associated with the DDT process are greater than the case of non-reacting particles added, with an accompanying rise in the pressure. For an appropriate range of particle volume fraction, particularly in this study, the higher volume fraction of the micro-aluminum particles added in the detonation chamber can lead to more heat energy released and more local instabilities in the combustion process (caused by the local high temperature), thereby resulting in a faster DDT process. In essence, the aluminum particles contribute to the DDT process of successfully transitioning to detonation waves for (failure) cases in which the fuel gas mixture can be either too lean or too rich. With a better understanding of the influence of added aluminum particles on the dynamics of the DDT and detonation process, we can apply it to modify the geometry of the detonation chamber (e.g., the length of the detonation tube) accordingly to improve the operational performance of the PDE.

Biodegradation of ddt (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) by the white rot fungus phanerochaete chrysosporium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bumpus, J.A.; Aust, S.D.

1987-01-01

Extensive biodegradation of 1,1,1-trichloro-2,2bis(4-chlorophenyl)ethane (DDT) by the white rot fungus Phanerochaete chrysosporium was demonstrated by disappearance and mineralization of (14C) DDT in nutrient nitrogen-deficient cultures. Mass balance studies demonstrated the formation of polar and water-soluble metabolites during degradation. Hexane-extractable metabolites identified by gas chromatography-mass spectrometry included 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane(DDD), 2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol (dicofol), 2,2-dichloro-1,1-bis(4-chlorophenyl) ethanol (FW-152), and 4,4'-dichlorobenzophenone (DBP). DDD was the first metabolite observed; it appeared after 3 days of incubation and disappeared from culture upon continued incubation. This, as well as the fact that ((14)C) dicofol was mineralized, demonstrates that intermediates formed during DDT degradation are also metabolized. These results demonstrate thatmore » the pathway for DDT degradation in P. chrysosporium is clearly different from the major pathway proposed for microbial or environmental degradation of DDT. Like P. chrysosporium ME-446 and BKM-F-1767, the white rot fungi Pleurotus ostreatus, Phellinus weirii, and Polyporus versicolor also mineralized DDT.« less

DDT, DDD, and DDE in soil of Xiangfen County, China: Residues, sources, spatial distribution, and health risks.

PubMed

Ma, Jin; Pan, Li-Bo; Yang, Xiao-Yang; Liu, Xiao-Ling; Tao, Shi-Yang; Zhao, Long; Qin, Xiao-Peng; Sun, Zai-Jin; Hou, Hong; Zhou, Yong-Zhang

2016-11-01

We collected and analyzed 128 surface soil samples from Xiangfen County for dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE). Total DDT concentrations (DDTs; sum of p,p'-DDD, p,p'-DDE, and p,p'-DDT) ranged from ND to 427.81 ng g(-1) (dry weight, dw), with a mean of 40.26 ng g(-1) (dw). Among the three compounds, p,p'-DDD was the most dominant. The DDTs in Xiangfen County soils mainly originated from historical DDT use, but there were also new inputs likely related to dicofol use. The DDTs in Xiangfen County soils were mainly degraded under anaerobic conditions, and direct degradation to DDD was the main degradation route. Regions with relatively high concentrations of DDTs were mainly located in North and South Xiangfen County. In these regions, many soil samples contained p,p'-DDT as the predominant pollutant, suggestive of extensive new inputs of DDT. A health risk assessment revealed that there are no serious long-term health impacts of exposure to DDTs in soil, for adults or children. Copyright © 2016 Elsevier Ltd. All rights reserved.

DDT: participation in ultraviolet-detectable, charge-transfer complexation.

PubMed

Wilson, W E; Fishbein, L; Clements, S T

1971-01-15

The chlorophenyl groups of DDT and several of its metabolites are capable of participating in a charge-transfer interaction with tetracyanoethylene detectable in the ultraviolet region of the spectrum. In addition, during a change of state DDT undergoes ultraviolet spectral alterations that closely resemble those previously claimed to support the hypothesis suggesting charge-transfer interaction between this pesticide and a component of insect nerve tissue. The pesticide DDT possesses structural characteristics that would permit it to participate in several types of molecular association.

Toxic effects of male Perna viridis gonad exposed to BaP, DDT and their mixture: A metabolomic and proteomic study of the underlying mechanism.

PubMed

Song, Qinqin; Zheng, Pengfei; Qiu, Liguo; Jiang, Xiu; Zhao, Hongwei; Zhou, Hailong; Han, Qian; Diao, Xiaoping

2016-01-05

Benzo(a)pyrene and dichlorodiphenyltrichloroethane are typical persistent organic pollutants, and also the widespread environmental estrogens with known toxicity towards green mussels Perna viridis. In this study, the toxicological effects of BaP and DDT and their mixture were assessed in green mussel gonads using proteomic and metabolomic approaches. Metabolomics by NMR spectroscopy revealed that BaP did not show obvious metabolite changes in the gonad of male green mussel. DDT mainly caused some disturbance of osmotic regulation and energy metabolism by changing BCAAs, alanine, threonine, arginine, etc., unknown metabolite (3.53 ppm), glycine, homarine and ATP at different levels. However, the mixture of BaP and DDT mainly caused some disturbance in osmotic regulation and energy metabolism by differentially altering branched chain amino acids, glutamate, alanine, arginine, unknown metabolite (3.53 ppm), glycine, 4-aminobutyrate, dimethylglycine, homarine and ATP. The results suggest that DDT alone may cause most of metabolites changes in the mixture exposed male mussel gonad, and the results also show that the male P. viridis gonad was more sensitive to DDT than BaP exposures. Proteomic study showed that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced signal transduction, oxidative stress, spermatogenesis, etc. in the male green mussel gonad; whereas DDT exposure altered proteins that were associated with signal transduction, oxidative stress, cytoskeleton and cell structure, cellular organization, energy metabolism, etc. However, the mixture of BaP and DDT affected proteins related to cytoskeleton and cell structure, oxidative stress, cellular organization, etc. This research demonstrated that metabolomic and proteomic approaches could better elucidate the underlying mechanism of environmental pollutants gonad toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

DDT Exposure in Utero and Breast Cancer

PubMed Central

La Merrill, Michele; Krigbaum, Nickilou Y.; Yeh, Gregory; Park, June-Soo; Zimmermann, Lauren; Cirillo, Piera M.

2015-01-01

Context: Currently no direct evidence links in utero dichlorodiphenyltrichloroethane (DDT) exposure to human breast cancer. However, in utero exposure to another xenoestrogen, diethylstilbestrol, predicts an increased breast cancer risk. If this finding extends to DDT, it could have far-reaching consequences. Many women were heavily exposed in utero during widespread DDT use in the 1960s. They are now reaching the age of heightened breast cancer risk. DDT exposure persists and use continues in Africa and Asia without clear knowledge of the consequences for the next generation. Hypothesis: In utero exposure to DDT is associated with an increased risk of breast cancer. Design: This was a case-control study nested in a prospective 54-year follow-up of 9300 daughters in the Child Health and Development Studies pregnancy cohort (n = 118 breast cancer cases, diagnosed by age 52 y and 354 controls matched on birth year). Setting and Participants: Kaiser Foundation Health Plan members who received obstetric care in Alameda County, California, from 1959 to 1967, and their adult daughters participated in the study. Main Outcome Measure: Daughters' breast cancer diagnosed by age 52 years as of 2012 was measured. Results: Maternal o,p′-DDT predicted daughters' breast cancer (odds ratio fourth quartile vs first = 3.7, 95% confidence interval 1.5–9.0). Mothers' lipids, weight, race, age, and breast cancer history did not explain the findings. Conclusions: This prospective human study links measured DDT exposure in utero to risk of breast cancer. Experimental studies are essential to confirm results and discover causal mechanisms. Findings support classification of DDT as an endocrine disruptor, a predictor of breast cancer, and a marker of high risk. PMID:26079774

Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort.

PubMed

Gaspar, Fraser W; Chevrier, Jonathan; Bornman, Riana; Crause, Madelein; Obida, Muvhulawa; Barr, Dana Boyd; Bradman, Asa; Bouwman, Henk; Eskenazi, Brenda

2015-12-01

Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (98% and 100% detection, respectively). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dichlorodiphenyltrichloroethane (DDT) and risk of hepatocellular carcinoma

PubMed Central

Persson, E. Christina; Graubard, Barry I.; Evans, Alison A.; London, W. Thomas; Weber, Jean-Philippe; LeBlanc, Alain; Chen, Gang; Lin, Wenyao; McGlynn, Katherine A.

2014-01-01

Dichlorodiphenyltrichloroethane (p,p’-DDT), an organochlorine pesticide known to have deleterious health effects in humans, has been linked to hepatocellular carcinoma (HCC) in rodents. A recent study has reported that p,p’-DDT and its most persistent metabolite, dichlorodiphenyldichloroethylene (p,p’-DDE), may also be associated with HCC in humans. To examine whether there is an association between p,p’-DDT and/or p,p’-DDE in a population at high-risk of developing HCC. A nested case-control study was conducted within the 83,794 person Haimen City Cohort in China. Sera and questionnaire data were collected from all participants between 1992 and 1993. The current study included 473 persons who developed HCC and 492 who did not, frequency matched on sex, age and area of residence. p,p’-DDT and p,p’-DDE levels were determined by mass spectrometry. Hepatitis B viral infection status (based on hepatitis B virus surface antigen; HBsAg) was also determined. Adjusting for age, sex, area of residence, HBsAg, family history of HCC, history of acute hepatitis, smoking, alcohol, occupation (farmers) and levels of p,p’-DDT or p,p’-DDE, odds ratios (OR) and 95% confidence intervals (CI) were calculated via unconditional logistic regression, p,p’-DDT and/or p,p’-DDE serum levels were significantly associated with sex, area of residence, occupation, alcohol consumption and cigarette smoking. Overall, the highest quintile of p,p’-DDT was associated with an increased risk of HCC, OR= 2.96 95% CI; 1.19–7.40. There were no statistically significant associations with p,p’-DDE. Overall, these results suggest that recent exposure to p,p’-DDT may increase risk of HCC. PMID:22290210

Prenatal Exposure to the Pesticide DDT and Hypertension Diagnosed in Women before Age 50: A Longitudinal Birth Cohort Study

PubMed Central

Cirillo, Piera M.; Terry, Mary Beth; Krigbaum, Nickilou Y.; Flom, Julie D.; Cohn, Barbara A.

2013-01-01

Background: Elevated levels of the pesticide DDT (dichlorodiphenyltrichloroethane) have been positively associated with blood pressure and hypertension in studies among adults. Accumulating epidemiologic and toxicologic evidence suggests that hypertension during adulthood may also be affected by earlier life and possibly the prenatal environment. Objectives: We assessed whether prenatal exposure to the pesticide DDT increases risk of adult hypertension. Methods: We examined concentrations of DDT (p,p´- and o,p´-) and its metabolite p,p´-DDE (dichlorodiphenyldichloroethylene) in prenatal serum samples from a subset of women (n = 527) who had participated in the prospective Child Health and Development Studies birth cohort in the San Francisco Bay area while they were pregnant between 1959 and 1967. We surveyed daughters 39–47 years of age by telephone interview from 2005 to 2008 to obtain information on self-reported physician-diagnosed hypertension and use of hypertensive medication. We used multivariable regression analysis of time to hypertension based on the Cox proportional hazards model to estimate relative rates for the association between prenatal DDT exposures and hypertension treated with medication in adulthood, with adjustment for potential confounding by maternal, early-life, and adult exposures. Results: Prenatal p,p´-DDT exposure was associated with hypertension [adjusted hazard ratio (aHR) = 3.6; 95% CI: 1.8, 7.2 and aHR = 2.5; 95% CI: 1.2, 5.3 for middle and high tertiles of p,p´-DDT relative to the lowest tertile, respectively]. These associations between p,p´-DDT and hypertension were robust to adjustment for independent hypertension risk factors as well as sensitivity analyses. Conclusions: These findings suggest that the association between DDT exposure and hypertension may have its origins early in development. PMID:23591545

[Accumulation and degradation of organochorine pesticides in shellfish culture environment in Xiamen sea area].

PubMed

Zhong, Shuo-liang; Dong, Li-ming

2011-09-01

By using GC-ECD, the concentrations of organochlorine pesticides hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in the shellfish culture environment (sea water, sediments, and culture-shellfishes) in Xiamen sea area were analyzed, and the accumulation and degradation patterns of the HCH and DDT were preliminarily approached. In the sea area, there existed remarkable differences in the accumulation and degradation of HCH and DDT among different shellfish culture environments, being mostly associated with the habitation environment and physiological life habits of shellfish. The accumulated HCH isomers (Rx > 1) were mainly beta-HCH, delta-HCH, and gamma-HCH, whereas the degraded HCH isomers (Rx < 1) were mainly alpha-HCH. The ratio of alpha-HCH to gamma-HCH was less than or equal to 1.0, suggesting that the HCH was come from industrial HCH and lindane, most of the HCH had remained in the culture environment for a longer time, and a small amount of lindane was imported. The DDT in the sea water was aerobically degraded, its main degradation product was DDE, and the ratios of (DDD+DDE) to DDTs (p,p-DDE+p,p-DDD+o,p-DDT+p,p-DDT) was less than 0.5, whereas the DDT in sediments and shellfishes was anaerobically degraded, its main degradation product was DDD, and the ratios of (DDD+DDE) to DDTs was greater than 0.5, suggesting that there was a small amount of DDT newly imported in the sea water, and most DDT in sediments and shellfishes were already degraded and transformed into DDD and DDE. There were definite differences in the degradation rates of HCH isomers in the culture environment, suggesting the conformational change of HCH in its transformation processes in the shellfish culture ecosystem.

o,p'-DDT induces cyclooxygenase-2 gene expression in murine macrophages: Role of AP-1 and CRE promoter elements and PI3-kinase/Akt/MAPK signaling pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Eun Hee; Kim, Ji Young; Kim, Hyung-Kyun

Dichlorodiphenyltrichloroethane (DDT) has been used as an insecticide to prevent the devastation of malaria in tropical zones. However, many reports suggest that DDT may act as an endocrine disruptor and may have possible carcinogenic effects. Cyclooxygenase-2 (COX-2) acts as a link between inflammation and carcinogenesis through its involvement in tumor promotion. In the present study, we examined the effect of o,p'-DDT on COX-2 gene expression and analyzed the molecular mechanism of its activity in murine RAW 264.7 macrophages. Exposure to o,p'-DDT markedly enhanced the production of prostaglandin E{sub 2} (PGE{sub 2}), a major COX-2 metabolite, in murine macrophages. Furthermore, o,p'-DDTmore » dose-dependently increased the levels of COX-2 protein and mRNA. Transfection with human COX-2 promoter construct, electrophoretic mobility shift assays and DNA-affinity protein-binding assay experiments revealed that o,p'-DDT activated the activator protein 1 (AP-1) and cyclic AMP response element (CRE) sites, but not the NF-{kappa}B site. Phosphatidylinositol 3 (PI3)-kinase, its downstream signaling molecule, Akt, and mitogen-activated protein kinases (MAPK) were also significantly activated by the o,p'-DDT-induced AP-1 and CRE activation. These results demonstrate that o,p'-DDT induced COX-2 expression via AP-1 and CRE activation through the PI3-K/Akt/ERK, JNK, and p38 MAP kinase pathways. These findings provide further insight into the signal transduction pathways involved in the carcinogenic effects of o,p'-DDT.« less

Trophic transfer efficiency of DDT to lake trout (Salvelinus namaycush) from their prey

USGS Publications Warehouse

Madenjian, C.P.; O'Connor, D.V.

2004-01-01

The objective of our study was to determine the efficiency with which lake trout retain DDT from their natural food. Our estimate of DDT assimilation efficiency would represent the most realistic estimate, to date, for use in risk assessment models.

DDT, DDD, AND DDE DECHLORINATION BY ZERO-VALENT IRON

EPA Science Inventory

Traditionally, destruction of DDT [1,1,1-trichIoro-2,2-bis(p-chlorophenyl)ethane] for environmental remediation required high-energy processes such as incineration. Here, the capability of powdered zero-valent iron to dechlorinate DDT and related compounds at room tempera...

Contaminants still high in top-level carnivores in the Southern California Bight: levels of DDT and PCBs in resident and transient pinnipeds.

PubMed

Blasius, Mary Ellen; Goodmanlowe, Gwen D

2008-12-01

Highly industrialized areas, such as the Southern California Bight, often have high levels of contaminants in marine sediments, which can cause chronic exposure to organisms long after their use has ceased. tDDT and tPCB were analyzed in the blubber of 145 stranded pinnipeds that died at local marine mammal centers between 1994 and 2006. Resident species (California sea lion and Pacific harbor seal) had significantly higher concentrations of tDDT and tPCB than the transient species (northern elephant seal). Adult female California sea lions had significantly lower concentrations of tDDT and tPCB than pups, yearlings, and adult males. Concentrations of both tDDT and tPCB in California sea lions significantly declined over time, but did not change in northern elephant seals. Current concentrations of tDDT and tPCB in California sea lions and harbor seals are among the highest values reported worldwide for marine mammals and exceed those reported to cause adverse health effects.

THE DEVELOPMENT AND TREND OF INSECTICIDE-RESISTANCE IN ANOPHELES ACONITUS DOENITZ AND ANOPHELES SUNDAICUS RODENWALDT.

PubMed

SOERONO, M; DAVIDSON, G; MUIR, D A

1965-01-01

The spread of insecticide-resistance in the two main vectors of malaria in Java, Anopheles aconitus Dönitz and A. sundaicus Rodenwaldt, has been of concern to workers in the Indonesian malaria eradication programme since DDT-resistance was first detected, in A. sundaicus, in 1954. The history of development of resistance in these two vectors has been summarized in this paper by assembling the available records in chronological order, thus facilitating reference.The picture which emerges is that of somewhat erratic occurrence of DDT-resistance in A. sundaicus and more stable, expanding areas of DDT-resistant A. aconitus. Dieldrin-resistance is more widespread than DDT-resistance in both species and preceded the onset of DDT-resistance in A. aconitus but not in A. sundaicus. These features should not be regarded as species characteristics, however, since selection pressures on the two species have been far from uniform.Malathion appears to be a promising alternative to DDT and dieldrin for the control of the two vectors in the circumstances described.

Determination of co-metabolism for 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) degradation with enzymes from Trametes versicolor U97.

PubMed

Sari, Ajeng Arum; Tachibana, Sanro; Itoh, Kazutaka

2012-08-01

Trametes versicolor U97 isolated from nature degraded 73% of the 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) in a malt extract liquid medium after a 40-d incubation period. This paper presents a kinetic study of microbial growth using the Monod equation. T. versicolor U97 degraded DDT during an exponential growth phase, using glucose as a carbon source for growth. The growth of T. versicolor U97 was not affected by DDT. DDT was degraded by T. versicolor U97 only when the secondary metabolism coincided with the production of several enzymes. Furthermore, modeling of several inhibitors using the partial least squares function in Minitab 15, revealed lignin peroxidase (98.7 U/l) plays a role in the degradation of DDT. T. versicolor U97 produced several metabolites included a single-ring aromatic compound, 4-chlorobenzoic acid. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Situation report: Heavy DDT contamination at Wheeler National Wildlife Refuge

USGS Publications Warehouse

Fleming, W.J.; Atkeson, T.Z.

1980-01-01

A DDT manufacturing plant that operated on the Redstone Arsenal near Huntsville, Alabama discharged DDT-Iaden effluent from 1947 to 1970 into a creek on Wheeler National Wildlife Refuge. Seven to 9 years after the plant closed, high DDT, DDE, and DDD levels were reported in soils, river sediments, and fish in the area. Eleven of 27 mallards (Anas platyrhynchos) collected on the Refuge during February 1979 had carcass DDE residues that exceeded levels associated with eggshell thinning. DDE residues in a smaller number of mallards exceeded levels associated with egg breakage, poor hatchability, and abnormal hehavior and poor survival of offspring. Several avian species have disappeared from the Refuge since 1950, probably due to both industrial discharges of DDT from the plant and insecticidal use of DDT in the area. The contamination still presents a threat to herons, waterfowl, and raptors including occasional wintering or migrant eagles (Haliaeetus leucocephalus), and probably many other avian species. A maternity colony of endangered gray bats (Myotis grisescens) is also threatened by this contamination.

Organochlorine insecticide residues in ducklings and their dilution by growth.

PubMed

Charnetski, W A

1976-08-01

Residues of DDT, DDD, DDE, and dieldrin in 7 species of ducklings from Alberta, Canada, were measured. Levels of DDT and metabolites ranged from 0 to 36.48 ppm in fat of 96% of the birds and from 0 to 0.97 ppm im muscle from 67% of the birds. Residue levels of dieldrin ranged from 0 to 2.62 ppm in fat and from 0 to 0.11 ppm in muscle of 43 and 19% of the birds, respectively. Growth dilution was considered to be the most significant factor in reducing the insecticide residue levels in the ducklings. DDT (total DDT, DDE, and DDD) residue levels were decreased with increased weight of pintail (A. acuta), baldpate (Mareca americana), and gadwall (A. strepera) ducklings. Dieldrin used in grasshopper control did not contribute to residue levels in the ducklings. Contamination by DDT was considered to have originated from outside the habitat. No dieldrin or DDT residues were found in ducklings' food sources analysed.

From coal to DDT: the history of the development of the pesticide DDT from synthetic dyes till Silent Spring.

PubMed

Jarman, Walter M; Ballschmiter, Karlheinz

2012-12-01

The controversial pesticide DDT arose out of a number of practical and conceptual developments in science and industry during the nineteenth and twentieth centuries. Here we trace its story back to experiments involving the industrial by-product coal tar, proceed to the development of modern organic chemistry and the establishment of an advanced dye industry, and go on to chart the attempt to identify and synthesize chemicals capable of killing the insects involved in human and crop diseases. This paper argues that work on the chemistry of coal tar played a significant role in the history of DDT because it helped bring about the scientific ideas and the practical objectives that led chemists to embark on the search for pesticides. It concludes by examining the Swiss-German DDT production industry in the early 1940s and the subsequent condemnation of DDT by an environmental movement epitomized by Rachel Carson's Silent Spring. Copyright © 2012 Elsevier Ltd. All rights reserved.

Simple procedures for enrichment of chlorinated aromatic pollutants from fat, water and milk for subsequent analysis by high-resolution methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Egestad, B.; Curstedt, T.; Sjoevall, J.

1982-01-01

Procedures for enrichment of non-volatile chlorinated aromatic pollutants from fat, water and milk are described. /sup 14/C-DDT was used as a model compound in recovery experiments. A several thousand-fold enrichment of DDT added to butter was achieved by two consecutive straight-phase chromatographies on Lipidex 5000. Trace amounts of DDT in liter volumes of water could be quantitatively extracted by rapid filtration through 2 ml beds of Lipidex 1000. A batch extraction procedure permitted enrichment of DDT from milk after addition of n-pentylamine, methanol and water. DDT could then be eluted from the gel with retention of more than 90% ofmore » the lipids. A reversed-phase system with Lipidex 5000 could be used for separation of TCDD from DDT and PCBs. The liquid-gel chromatographic procedures are simple and suitable for clean-up of samples prior to application of high-resolution methods. 5 tables.« less

Mixtures of benzo(a)pyrene, dichlorodiphenyltrichloroethane and tributyltin are more toxic to neotropical fish Rhamdia quelen than isolated exposures.

PubMed

Oliveira, Heloísa H P; Liebel, Samuel; Rossi, Stéfani C; Azevedo, Ana C B; Barrera, Ellie A L; Garcia, Juan Ramon Esquivel; Grötzner, Sônia Regina; Neto, Francisco Filipak; Randi, Marco A F; Ribeiro, Ciro A O

2015-12-01

The effects of benzo(a)pyrene (BaP), dichlorodiphenyltrichloroethane (DDT) and tributyltin (TBT) association were investigated through a multi-biomarker approach. Ten Rhamdia quelen fish per group were exposed through intraperitoneal injections either to BaP (0.3; 3 or 30 mg kg(-1)), DDT or TBT (0.03; 0.3 or 3 mg kg(-1)) or BaP/DDT, BaP/TBT, DDT/TBT or BaP/DDT/TBT on their lowest doses. The experiments were divided in acute (one dose, 5-day) and sub-chronic (3 doses, 15-day). Control groups received an equal volume of PBS or canola oil (1 ml kg(-1)). The three tested contaminants altered AChE activity in brain and muscle in similar ways; the mixtures antagonized the increase evoked by the contaminants alone. BaP and TBT increased GSH content and mixtures reduced it. GPx activity was increased by DDT and TBT in the 15-day experiment and reduced by the mixtures. BaP increased GST activity in sub-chronic experiment while TBT reduced it in the acute experiment. BaP/TBT increased GST activity compared to all groups; the other mixtures reduced it compared to BaP or DDT in the 5-day experiment. BaP, DDT and TBT increased δ-ALAd activity mainly in acute exposure; the mixtures also increased δ-ALAd compared to DDT or TBT in 5 and 15-day. BaP, TBT and BaP/DDT decreased LPO in the acute experiment. In the sub-chronic experiment DDT/TBT increased LPO when compared to TBT. None of the contaminants alone altered PCO, but all mixtures increased it compared to one or another contaminant. Contaminants isolated had a more acute effect in ALT plasma level; their lowest dose, which had no effect alone, in combination has led to an increase of this enzyme, especially after 15 days. DDT increased AST in the acute and sub-chronic experiments, while TBT did the same in the latter. DDT/TBT decreased AST opposing the effect of the contaminants alone in the 5-day experiment. Hepatic lesions index could be explained by a more acute effect of the contaminants alone or combined and by activation of cell defenses after the sub-chronic exposure. TBT increased melanomacrophages counting in the 5-day experiment and the mixtures increased it in the 5 and 15-day experiments. Overall, the majority of the biomarkers pointed to a more toxic effect when these contaminants were combined, leading to unexpected toxicities compared to individual exposure scenarios. These findings are relevant considering environmental exposure conditions, since organisms are often exposed to different combinations of contaminants. Copyright © 2015 Elsevier Inc. All rights reserved.

Differential effects of the organochlorine pesticide DDT and its metabolite p,p'-DDE on p-glycoprotein activity and expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shabbir, Arsalan; DiStasio, Susan; Zhao, Jingbo

1,1-Bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) is an organochlorine pesticide. Its metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethene (p,p'-DDE) is a persistent environmental contaminant and both compounds accumulate in animals. Because multidrug resistance transporters, such as p-glycoprotein, function as a defense against xenobiotic exposure, we analyzed the ability of DDT and p,p'-DDE to act as efflux modulators. Using a competitive intact cell assay based on the efflux of the fluorescent dye rhodamine 123, we found that DDT, but not p,p'-DDE, stimulated dye retention. Subsequent studies using verapamil as competitor suggested that DDT is a weak p-glycoprotein inhibitor. Further studies addressed the ability of DDT and p,p'-DDE to induce MDR1,more » the gene encoding p-glycoprotein. In HepG2 cells, we found that both compounds induced MDR1 by twofold to threefold. Similar results were observed in mouse liver after a single dose of p,p'-DDE, although some gender-specific induction differences were noted. By contrast, p,p'-DDE failed to induce MDR1 in HeLa cells, indicating some cell-specific effects for induction. Further expression studies demonstrated increased levels of the endoplasmic reticulum molecular chaperone, Bip, in response to DDT, but not p,p'-DDE. These results suggest that DDT, but not p,p'-DDE, induces an endoplasmic reticulum stress response.« less

Disruption of dopamine transport by DDT and its metabolites

PubMed Central

Hatcher, Jaime M.; Delea, Kristin C.; Richardson, Jason R.; Pennell, Kurt D.; Miller, Gary W.

2016-01-01

Epidemiological studies suggest a link between pesticide exposure and an increased risk of developing Parkinson’s disease (PD). Although studies have been unable to clearly identify specific pesticides that contribute to PD, a few human studies have reported higher levels of the organochlorine pesticides dieldrin and DDE (a metabolite of DDT) in post-mortem PD brains. Previously, we found that exposure of mice to dieldrin caused perturbations in the nigrostriatal dopamine system consistent with those seen in PD. Given the concern over the environmental persistence and reintroduction of DDT for the control of malaria-carrying mosquitoes and other pests, we sought to determine whether DDT and its two major metabolites, DDD and DDE, could damage the dopamine system. In vitro analyses in mouse synaptosomes and vesicles demonstrated that DDT and its metabolites inhibit the plasma membrane dopamine transporter (DAT) and the vesicular monoamine transporter (VMAT2). However, exposure of mice to either DDT or DDE failed to show evidence of nigrostriatal damage or behavioral abnormalities in any of the measures examined. Thus, we report that in vitro effects of DDT and its metabolites on components of the dopamine system do not translate into neurotoxicological outcomes in orally exposed mice and DDT appears to have less dopamine toxicity when compared to dieldrin. These data suggest elevated DDE levels in PD patients may represent a measure of general pesticide exposure and that other pesticides may be responsible for the association between pesticide exposure and PD. PMID:18533268

Toxicological effects of benzo(a)pyrene, DDT and their mixture on the green mussel Perna viridis revealed by proteomic and metabolomic approaches.

PubMed

Song, Qinqin; Chen, Hao; Li, Yuhu; Zhou, Hailong; Han, Qian; Diao, Xiaoping

2016-02-01

Benzo(a)pyrene (BaP) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants and environmental estrogens (EEs) with known toxicity towards the green mussel, Perna viridis. In this study, the toxic effects of BaP (10 µg/L) and DDT (10 µg/L) and their mixture were assessed in green mussel gills with proteomic and metabolomic approaches. Metabolic responses indicated that BaP mainly caused disturbance in osmotic regulation by significantly decrease in branched chain amino acids, dimethylamine and dimethylglycine in gills of male green mussels after exposure for 7 days. DDT mainly caused disturbance in osmotic regulation and energy metabolism by differential alteration of betaine, dimethylamine, dimethylglycine, amino acids, and succinate in gills of male green mussels. However, the mixture of BaP and DDT didn't show obvious metabolite changes. Proteomic analysis showed different protein expression profiles between different treatment groups, which demonstrated that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced cell apoptosis, disturbance in protein digestion and energy metabolism in gills of green mussels, whereas DDT exposure altered proteins that were associated with oxidative stress, cytoskeleton and cell structure, protein digestion and energy metabolism. However, the mixture of BaP and DDT affected proteins related to the oxidative stress, cytoskeleton and cell structure, protein biosynthesis and modification, energy metabolism, growth and apoptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

The interactive biotic and abiotic processes of DDT transformation under dissimilatory iron-reducing conditions.

PubMed

Jin, Xin; Wang, Fang; Gu, Chenggang; Yang, Xinglun; Kengara, Fredrick O; Bian, Yongrong; Song, Yang; Jiang, Xin

2015-11-01

The objective of the study was to elucidate the biotic and abiotic processes under dissimilatory iron reducing conditions involved in reductive dechlorination and iron reduction. DDT transformation was investigated in cultures of Shewanella putrefaciens 200 with/without α-FeOOH. A modified first-order kinetics model was developed and described DDT transformation well. Both the α-FeOOH reduction rate and the dechlorination rate of DDT were positively correlated to the biomass. Addition of α-FeOOH enhanced reductive dechlorination of DDT by favoring the cell survival and generating Fe(II) which was absorbed on the surface of bacteria and iron oxide. 92% of the absorbed Fe(II) was Na-acetate (1M) extractable. However, α-FeOOH also played a negative role of competing for electrons as reflected by the dechlorination rate of DDT was inhibited when increasing the α-FeOOH from 1 g L(-1) to 5 g L(-1). DDT was measured to be toxic to S. putrefaciens 200. The metabolites DDD, DDE and DDMU were recalcitrant to S. putrefaciens 200. The results suggested that iron oxide was not the key factor to promote the dissipation of DDX (DDT and the metabolites), whereas the one-electron reduction potential (E1) of certain organochlorines is the main factor and that the E1 higher than the threshold of the reductive driving forces of DIRB probably ensures the occur of reductive dechlorination. Copyright © 2015 Elsevier Ltd. All rights reserved.

ANAEROBIC DDT BIOTRANSFORMATION: ENHANCEMENT BY APPLICATION OF SURFACTANTS AND LOW OXIDATION REDUCTION POTENTIAL

EPA Science Inventory

Enhancement of anaerobic DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane) biotransformation by mixed cultures was studied with application of surfactants and oxidation reduction potential reducing agents. Without amendments, DDT transformation resulted mainly in the pr...

40 CFR 129.101 - DDT, DDD and DDE.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 22 2011-07-01 2011-07-01 false DDT, DDD and DDE. 129.101 Section 129.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE...

Perinatal exposure to the pesticide DDT impairs energy expenditure and metabolism in adult female mice

USDA-ARS?s Scientific Manuscript database

Dichlorodiphenyltrichloroethane (DDT) has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene have an increa...

40 CFR 129.101 - DDT, DDD and DDE.

Code of Federal Regulations, 2010 CFR

2010-07-01

... stormwater runoff or other discharges from areas subject to contamination solely by fallout from air... other discharges from areas subject to contamination solely by fallout from air emissions of DDT; or to... subject to direct contamination by DDT as a result of the manufacturing process, including but not limited...

Features and News. DDT Stands Trial Again

ERIC Educational Resources Information Center

Jukes, Thomas H.

1972-01-01

Presents an informative account for the layman of the use of DDT as viewed by the government, scientists and courtroom. Considering the allegations and counter-allegations for its use, the article suggests that DDT is not as harmful as projected by agencies. The outcome of the hearings are not included. (PS)

Reductive dechlorination of DDT to DDD by yeast

USGS Publications Warehouse

Kallman, Burton J.; Andrews, Austin K.

1963-01-01

Labeled DDD [ 1,1-dichlor-o-2,2-bis(p-chlorophenyl)-ethane] was formed from C14-labeled DDT in the presence of yeast. The formation of DDD from DDE [1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene] was not observed, indicating that a reductive dechlorination of DDT occurs.

Abilities of Co-cultures of Brown-Rot Fungus Fomitopsis pinicola and Bacillus subtilis on Biodegradation of DDT.

PubMed

Sariwati, Atmira; Purnomo, Adi Setyo; Kamei, Ichiro

2017-09-01

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is one of the pesticides that are hazardous for the environment and human health. Effective environmental-friendly treatment using co-cultures of fungi and bacteria is needed. In this study, the bacteria Bacillus subtilis at various volumes of 1, 3, 5, 7, and 10 mL (1 mL ≈ 6.7 × 10 8  CFU) were mixed into 10 mL of the brown-rot fungus Fomitopsis pinicola culture for degrading DDT during a 7-days incubation period. DDT was degraded by approximately 42% by F. pinicola during the 7-days incubation period. The addition of 10 mL of B. subtilis into F. pinicola culture showed the highest DDT degradation of approximately 86% during the 7-days incubation period. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl)ethylene) were detected as metabolic products from DDT degradation by co-cultures of F. pinicola and B. subtilis. Transformation pathway was proposed in which DDT was transformed into three pathways as follows: (1) dechlorination to DDD, (2) dehydrochlorination to DDE, and (3) formation of DDMU.

Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling

2010-06-14

GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model ofmore » the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. We also show that the ancestral GSTD1 is likely to have possessed DDT dehydrochlorinase activity because both GSTD1 from D. melanogaster and its sibling species, Drosophila simulans, have this activity.« less

Sequelae in male rabbits following developmental exposure to p,p'-DDT or a mixture of p,p'-DDT and vinclozolin: cryptorchidism, germ cell atypia, and sexual dysfunction.

PubMed

Veeramachaneni, D N R; Palmer, J S; Amann, R P; Pau, K-Y F

2007-01-01

Rabbit does (7-9 per group) were treated daily per orum from gestation day 15 through post-natal week 4 to provide per kg body wt 25 micaromol (low) or 250 micromol (high) p,p'-DDT or a mixture of DDT and vinclozolin (12.5 and 125 micromol each). Developmental as well as post-pubertal reproductive sequelae of male progeny were studied. Testicular descent in some pups was impaired by DDT. Serum LH or testosterone was not affected. FSH was lower in mixture- but not in DDT-exposed rabbits. Lack of sexual interest, penile erection and ejaculation were observed in some mixture rabbits. Sperm counts were unaffected, but morphologically normal spermatozoa were fewer; nuclear and acrosomal morphogenesis was disrupted. Atypical germ cells resembling carcinoma in situ were found. Also considering data for vinclozolin [Veeramachaneni DNR, Palmer JS, Amann RP, Kane CM, Higuchi TT, Pau K-YF. Disruption of sexual function, FSH secretion, and spermiogenesis in rabbits following developmental exposure to vinclozolin, a fungicide. Reproduction 2006;131:805-16], we concluded that DDT causes cryptorchidism and germ cell atypia, vinclozolin permanently disrupts FSH secretion and sexual function, and the mixture causes the full spectrum of dysgenesis.

DDT contamination in selected estuarine and coastal marine finfish and shellfish of New Jersey.

PubMed

Kennish, M J; Ruppel, B E

1996-08-01

Analysis of DDT contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey (USA) reveals consistently highest organochlorine pesticide levels in samples from the north and northeast regions of the state. The mean concentrations of DDT and its metabolites, DDE and DDD, in bluefish, striped bass, weakfish, and blue crabs collected at 27 stations throughout the state between 1988 and 1991 ranged from <25 to >300 microg/kg wet weight (wet wt). Gas chromatographic analysis of 175 tissue samples from these four species showed that the highest levels of DDTs (DDT plus DDE and DDD), exceeding 300 microg/kg wet wt, occurred in blue crabs (hepatopancreas) from the Hudson-Newark-Raritan Bay complex in the northeast region. Lower mean concentrations of DDTs (<200 microg/kg wet wt) were recorded in tissue samples of these species from all other regions of the state. The lowest levels of DDT contamination (mean <110 microg/kg wet wt) were found in samples from the south coast region. The greatest impact of DDT contamination is nearby metropolitan areas of the state, although the total concentrations of DDT in tissue samples from these areas are far less than the U.S. Food and Drug Administration action level of 5,000 microg/kg wet wt for this contaminant.

DDT residue contamination in sediments from Lake Sibaya in northern KwaZulu-Natal, South Africa: implications for conservation in a World Heritage Site.

PubMed

Humphries, Marc S

2013-11-01

Maputaland in northern KwaZulu-Natal is a biodiversity hotspot and host to a number of ecologically important systems, including Lake Sibaya, southern Africa's largest natural freshwater lake. The region is malaria endemic and this study reports the presence of DDT and its metabolites in the sediments of Lake Sibaya that have resulted from the widespread and continued use of DDT in the region. DDT residues (p,p'-DDT, p,p'-DDD, and p,p'-DDE) were detected at all 11 sites sampled, with total concentrations ranging from 0.8 to 123 ng g(-1). Total DDT concentrations at Lake Sibaya represent some of the highest levels reported in South Africa, with most samples exceeding sediment quality guideline values. The findings from this study raise concerns and indicate that urgent further work is needed to investigate the potential for bioaccumulation, which could adversely affect breeding fish, bird, and crocodile populations in the region. While this study represents the first report on DDT contamination in Lake Sibaya, results have important implications for a number of other aquatic ecosystems within the Maputaland ecoregion, as well as the many local people who depend on them. Copyright © 2013 Elsevier Ltd. All rights reserved.

Organochlorine pesticides in soils and air of southern Mexico: Chemical profiles and potential for soil emissions

NASA Astrophysics Data System (ADS)

Wong, Fiona; Alegria, Henry A.; Jantunen, Liisa M.; Bidleman, Terry F.; Salvador-Figueroa, Miguel; Gold-Bouchot, Gerardo; Ceja-Moreno, Victor; Waliszewski, Stefan M.; Infanzon, Raul

The extent of organochlorine pesticides (OCs) contamination in southern Mexico was investigated in this study. Biweekly air samplings were carried out in two sites in the state of Chiapas (during 2002-2003), and one in each state of Veracruz and Tabasco (during 2003-2004). Corresponding to the air sampling locations, soil samples were also collected to gauge the soil-air exchange of OCs in the region. ∑DDTs in soils ranged from 0.057 to 360 ng g -1 whereas those in air ranged from 240 to 2400 pg m -3. DDT and metabolite DDE were expressed as fractional values, FDDTe = p, p'-DDT/( p, p'-DDT + p, p'-DDE) and FDDTo = p,p'-DDT/( p,p'-DDT + o,p'-DDT). FDDTe in soils ranged from 0.30 to 0.69 while those in air ranged from 0.45 to 0.84. FDDTe in air at a farm in Chiapas (0.84) was closer to that of technical DDT (0.95) which is suggestive of fresh DDT input. Enantiomer fractions (EF) of o,p'-DDT in air were racemic at all locations (0.500-0.504). However, nonracemic o,p'-DDT was seen in the soils (EFs = 0.456-0.647). Fugacities of OCs in soil ( fs) and air ( fa) were calculated, and the fugacity fraction, ff = fs/( fs + fa) of DDTs ranged from 0.013 to 0.97 which indicated a mix of net deposition ( ff < 0.5) and volatilization ( ff > 0.5) from soil among the sites. It is suggested that DDTs in Mexico air are due to a combination of ongoing regional usage and re-emission of old DDT residues from soils. Total toxaphene in soils ranged from 0.066 to 69 ng g -1 while levels in air ranged from 6.2 to 230 pg m -3. Chromatographic profiles of toxaphenes in both air and soil showed depletion of Parlar congeners 39 and 42. Fugacity fractions of toxaphene were within the equilibrium range or above the upper equilibrium threshold boundary. These findings suggested that soil emission of old residues is the main source of toxaphenes to the atmosphere. Results from this study provide baseline data for establishing a long-term OC monitoring program in Mexico.

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz; Smetana, Pavel; Halada, Petr

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cellmore » line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin, cytokeratin 8 and 18 was reduced in NES2Y/DDT. • Expression of HNRH1 and cytokeratin 18 was reduced in NES2Y/DDE.« less

Modeling the dynamics of DDT in a remote tropical floodplain: indications of post-ban use?

PubMed

Mendez, Annelle; Ng, Carla A; Torres, João Paulo Machado; Bastos, Wanderley; Bogdal, Christian; Dos Reis, George Alexandre; Hungerbuehler, Konrad

2016-06-01

Significant knowledge gaps exist regarding the fate and transport of persistent organic pollutants like dichlorodiphenyltrichloroethane (DDT) in tropical environments. In Brazil, indoor residual spraying with DDT to combat malaria and leishmaniasis began in the 1950s and was banned in 1998. Nonetheless, high concentrations of DDT and its metabolites were recently detected in human breast milk in the community of Lake Puruzinho in the Brazilian Amazon. In this work, we couple analysis of soils and sediments from 2005 to 2014 at Puruzinho with a novel dynamic floodplain model to investigate the movement and distribution of DDT and its transformation products (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)) and implications for human exposure. The model results are in good agreement with the accumulation pattern observed in the measurements, in which DDT, DDE, and DDD (collectively, DDX) accumulate primarily in upland soils and sediments. However, a significant increase was observed in DDX concentrations in soil samples from 2005 to 2014, coupled with a decrease of DDT/DDE ratios, which do not agree with model results assuming a post-ban regime. These observations strongly suggest recent use. We used the model to investigate possible re-emissions after the ban through two scenarios: one assuming DDT use for IRS and the other assuming use against termites and leishmaniasis. Median DDX concentrations and p,p'-DDT/p,p'-DDE ratios from both of these scenarios agreed with measurements in soils, suggesting that the soil parameterization in our model was appropriate. Measured DDX concentrations in sediments were between the two re-emission scenarios. Therefore, both soil and sediment comparisons suggest re-emissions indeed occurred between 2005 and 2014, but additional measurements would be needed to better understand the actual re-emission patterns. Monte Carlo analysis revealed model predictions for sediments were very sensitive to highly uncertain parameters associated with DDT degradation and partitioning. With this model as a tool for understanding inter-media cycling, additional research to refine these parameters would improve our understanding of DDX fate and transport in tropical sediments.

Bisphenol A, Dichlorodiphenyltrichloroethane (DDT) and Vinclozolin Affect ex-vivo Uterine Contraction in Rats via Uterotonin (Prostaglandin F2α, Acetylcholine and Oxytocin) Related Pathways.

PubMed

Salleh, Naguib; Giribabu, Nelli; Feng, Angeline Oh Mei; Myint, Kyaimon

2015-01-01

Bisphenol-A (BPA), dichrolodiphenyltrichloroethane (DDT) and vinclozolin were found able to induce abnormal uterine contraction. The mechanisms involved remains unclear. We hypothesized that the effect of these compounds were mediated via the uterotonin pathways. Therefore, in this study, effects of BPA, vinclozolin and DDT-only and in combination with uterotonins (PGF-2α, acetylcholine and oxytocin) on the force and pattern of uterine contraction were observed. Uteri were harvested from intact adult female rats 24 hours after a single injection (1 mg/kg/b.w) of estrogen to synchronize their oestrous cycle. The uterine horns were subjected for ex-vivo contraction studies in an organ bath connected to Powerlab data acquisition system. Different doses of BPA, vinclozolin and DDT were added into the bathing solution and changes in the pattern and strength of uterine contraction were recorded. Further, increasing doses of uterotonins were concomitantly administered with these compounds and changes in the force and pattern of contraction were observed. In the absence of uterotonins, uterine contractile force decreased with increasing doses of BPA and DDT. However, vinclozolin induced sharp increase in the contractile forces which then gradually decrease. Administration of BPA, DDT and vinclozolin alone reduced the force of uterine contraction following stimulation of contraction by uterotonins. However, BPA, vinclozolin or DDT effects were relieved upon co-administration with uterotonins at increasing doses. The antagonizing effect of uterotonins on BPA, vinclozolin and DDT actions could explain the mechanism underlying the adverse effect of these compounds on uterine contraction.

o-p′-DDT-mediated uterotrophy and gene expression in immature C57BL/6 mice and Sprague–Dawley rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwekel, Joshua C.; Forgacs, Agnes L.; Center for Integrative Toxicology, Michigan State University, East Lansing, MI

1,1,1-Trichloro-2,2-bis(2-chlorophenyl-4-chlorophenyl)ethane (o,p′-DDT) is an organochlorine pesticide and endocrine disruptor known to activate the estrogen receptor. Comprehensive ligand- and species-comparative dose- and time-dependent studies were conducted to systematically assess the uterine physiological, morphological and gene expression responses elicited by o,p′-DDT and ethynyl estradiol (EE) in immature ovariectomized C57BL/6 mice and Sprague–Dawley rats. Custom cDNA microarrays were used to identify conserved and divergent differential gene expression responses. A total of 1256 genes were differentially expressed by both ligands in both species, 559 of which exhibited similar temporal expression profiles suggesting that o,p′-DDT elicits estrogenic effects at high doses when compared to EE.more » However, 51 genes exhibited species-specific uterine expression elicited by o,p′-DDT. For example, carbonic anhydrase 2 exhibited species- and ligand-divergent expression as confirmed by quantitative real-time PCR. The identification of comparable temporal phenotypic responses linked to gene expression demonstrates that systematic comparative gene expression assessments are valuable for elucidating conserved and divergent estrogen signaling mechanisms in rodent uterotrophy. - Highlights: • o,p′-DDT and enthynyl estradiol (EE) both elicit uterotrophy in mice and rats. • o,p′-DDT and EE have different kinetics in uterine wet weight induction. • o,p′-DDT elicited stromal hypertrophy in rats but myometrial hypertrophy in mice. • 1256 genes were differentially expressed by both ligands in both species. • Only 51 genes had species-specific uterine expression.« less

Serum sex hormones in men occupationally exposed to dichloro-diphenyl-trichloro ethane (DDT) as young adults.

PubMed

Cocco, Pierluigi; Loviselli, Andrea; Fadda, Domenica; Ibba, Antonio; Melis, Massimo; Oppo, Alessandro; Serra, Stefano; Taberlet, Alessandro; Tocco, Maria Giuseppina; Flore, Costantino

2004-09-01

To explore endocrine effects in relation to para,para'-dichloro-diphenyl-dichloro ethylene (p,p'-DDE) body burden and past occupational exposure to its precursor dichloro-diphenyl-trichloro ethane (DDT), we assayed serum sex hormones, including serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17beta-estradiol (E2), testosterone and sex hormone binding globulin (SHBG), and p,p'-DDE levels in 107 male participants in a 1946-1950 anti-malarial campaign in Sardinia, Italy. Cumulative DDT exposure during the anti-malarial operations was retrospectively estimated from detailed reports of the anti-malarial agency. Ortho,para-DDE, and its precursor ortho,para-DDT were always below the detection limit. p,p'-DDT was detected in 14/107 subjects, and p,p'-DDE in 106/107 subjects. The median lipid-adjusted p,p'-DDE serum concentration over the total study population was 396 parts per billion (interquartile range 157-1045), and it did not vary according to the job at the time of anti-malarial operations, nor was it affected by cumulative DDT exposure. LH, FSH, and SHBG, but not testosterone or E2, showed a significant positive correlation with age. Neither current serum p,p'-DDE nor past cumulative DDT exposure affected sex hormone concentrations. Our results suggest that (1) the low current p,p'-DDE serum concentration does not affect serum hormone levels, and (2) past cumulative DDT exposure is not correlated with the current p,p'-DDE serum level, nor does it show persistent effects on serum hormone levels.

Bisphenol A, Dichlorodiphenyltrichloroethane (DDT) and Vinclozolin Affect ex-vivo Uterine Contraction in Rats via Uterotonin (Prostaglandin F2α, Acetylcholine and Oxytocin) Related Pathways

PubMed Central

Salleh, Naguib; Giribabu, Nelli; Feng, Angeline Oh Mei; Myint, Kyaimon

2015-01-01

Bisphenol-A (BPA), dichrolodiphenyltrichloroethane (DDT) and vinclozolin were found able to induce abnormal uterine contraction. The mechanisms involved remains unclear. We hypothesized that the effect of these compounds were mediated via the uterotonin pathways. Therefore, in this study, effects of BPA, vinclozolin and DDT-only and in combination with uterotonins (PGF-2α, acetylcholine and oxytocin) on the force and pattern of uterine contraction were observed. Methods: Uteri were harvested from intact adult female rats 24 hours after a single injection (1 mg/kg/b.w) of estrogen to synchronize their oestrous cycle. The uterine horns were subjected for ex-vivo contraction studies in an organ bath connected to Powerlab data acquisition system. Different doses of BPA, vinclozolin and DDT were added into the bathing solution and changes in the pattern and strength of uterine contraction were recorded. Further, increasing doses of uterotonins were concomitantly administered with these compounds and changes in the force and pattern of contraction were observed. Results: In the absence of uterotonins, uterine contractile force decreased with increasing doses of BPA and DDT. However, vinclozolin induced sharp increase in the contractile forces which then gradually decrease. Administration of BPA, DDT and vinclozolin alone reduced the force of uterine contraction following stimulation of contraction by uterotonins. However, BPA, vinclozolin or DDT effects were relieved upon co-administration with uterotonins at increasing doses. Conclusions: The antagonizing effect of uterotonins on BPA, vinclozolin and DDT actions could explain the mechanism underlying the adverse effect of these compounds on uterine contraction. PMID:26640411

Evaluation of organochlorine pesticides in serum from students in Coimbra, Portugal: 1997-2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lino, Celeste Matos; Silveira, M. Irene Noronha da

2006-11-15

In 1997, 1999, 2000, and 2001, in an attempt to evaluate the contamination level of a Portuguese population, organochlorine pesticide residues were evaluated in human serum from students of the University of Coimbra. Concentrations of selected organochlorine pollutants ({alpha}-, {beta}-, and {gamma}-HCH, aldrin, dieldrin, HE, HCB, p,p'-DDT, o,p'-DDT, p,p'-DDE, p,p'-DDD) and endosulfan sulfate was measured with gas chromatography-electron capture detector. Our objective is to point out the general levels of pesticide contamination and the differences between the four populations; and together with this, if a connection could be established with gender or the residence area of the subjects. Endosulfan sulfate,more » p,p'-DDE, o,p'-DDT, and p,p'-DDD were the most frequently identified residues. Endosulfan sulfate present the highest concentrations for all subjects, 42.6 {mu}g/l, with concentrations ranging from undetected to 1295.5 {mu}g/l. Between DDT, isomers, and analogues, o,p'-DDT, and p,p'-DDT presented the highest levels, 24.8 and 21.9 {mu}g/l, respectively. Mean total DDT levels were higher than mean total HCH levels. For {sigma}-DDT, the highest levels were found among female gender and urban samples. An opposite situation was found in {sigma}-HCH: males presented higher levels than females. The mean concentration of organochlorine pesticide residues, present in the student populations, showed that it is among the highest levels of contamination, when compared with others from Europe, Asia, and America.« less

BIODEGRADATION OF DDT [1,1,1-TRICHLORO-2,2-BIS(4- CHLOROPHENYL) ETHANE] BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOSPORIUM

EPA Science Inventory

Extensive biodegradation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) by the white rot fungus Phanerochaete chrysosporium was demonstrated by disappearance and mineralization of [14C]DDT in nutrient nitrogen-deficient cultures. Mass balance studies demonstrated the form...

Psychoacoustic Assessment of Speech Communication Systems. The Diagnostic Discrimination Test.

ERIC Educational Resources Information Center

Grether, Craig Blaine

The present report traces the rationale, development and experimental evaluation of the Diagnostic Discrimination Test (DDT). The DDT is a three-choice test of consonant discriminability of the perceptual/acoustic dimensions of consonant phonemes within specific vowel contexts. The DDT was created and developed in an attempt to provide a…

An evaluation of the success of dredging as remediation at a DDT-contaminated site in San Francisco Bay, California, USA.

PubMed

Weston, Donald P; Jarman, Walter M; Cabana, Gilbert; Bacon, Corinne E; Jacobson, Lisa A

2002-10-01

Lauritzen Canal, a portion of San Francisco Bay near Richmond, California, USA, was heavily contaminated with dichlorodiphenyltrichloroethane (DDT) and dieldrin as a result of releases from a pesticide-formulating firm. In 1996 and 1997, 82,000 m3 of contaminated sediment was removed from the canal by dredging. This study evaluated the success of the dredging based largely on body burdens of DDT and its metabolites (sigmaDDT) in resident biota, with some data on sediment- and water-contaminant levels and sediment toxicity testing. Sediment disturbance during dredging introduced a pulse of sigmaDDT into the Lauritzen Canal ecosystem, and body burdens of fish and invertebrates increased 2- to 76-fold, depending on the species. Approximately 1 1/2 years after remediation, 11 of 14 indicators showed contamination comparable with or worse than the contamination that existed prior to dredging. Monitoring of mussels up to four years postdredging suggests some modest improvement, although the sigmaDDT body burden of canal mussels remained far above the norm for San Francisco Bay. The elevated sigmaDDT body burdens in biota that persisted for years after remediation reflect recent exposure and are not merely a result of slow metabolic elimination of the sigmaDDT pulse associated with dredging. Sediment sigmaDDT concentrations were low immediately after dredging, but within months, the canal bottom became covered with a veneer of fine sediment as contaminated as that that had been removed. The source of this material has not been conclusively established, but we suspect it came from slumping and erosion from the flanks of the canal beneath docks and around pilings where dredging was not done. In retrospect, either capping in place or more thorough dredging may have been more successful in reducing pesticide exposure of the biota, although there were difficulties associated with both alternatives.

Birds and Dutch elm disease control

USGS Publications Warehouse

DeWitt, J.B.

1958-01-01

Brief, factual review of information on effect of DDT and other insecticides on birds. One program for control of elm disease caused 22% decrease in number of adult birds and 56% mortality of nestlings. Quail fed 3 oz. of DDT per ton of food had 16% reduction in young hatched and 500% increase in defective chicks. Quail fed same dosage during winter and breeding seasons had 30% decrease in fertile eggs and 800% increase in defective chicks. More than 90% of their chicks died in first 6 weeks although fed no insecticide. Almost equally bad results came from feeding Pheasants diets with about 1 oz. DDT per ton. Other common insecticides (chlorinated hydrocarbons) also caused lowered chick survival and higher percentages of crippled chicks. From field data we know that 2 lbs. DDT/acre can affect birds and has even worse effects on cold-blooded animals. Efforts to control elm disease have left as much as 196 lbs. DDT/acre in top 3 inches of soil. Earthworms concentrate DDT in their tissues. Thus the treated areas can be traps for birds and other animals. What can be done? 1) In control of elm disease, use minimum effective amount of insecticide; mist blowers use less than sprayers. 2) Avoid applications during migration and nesting seasons. It has been reported that adequate control can be obtained with dormant sprays and that foliar applications may not be required. Tables of this paper show effects of DDT on reproduction of Quail, relative toxicity to quail of 8 insecticides, and amounts of 7 insecticides required to cause 40% or more decrease in Quail reproduction. These comparisons demonstrate that Aldrin, Endrin, and Dieldrin are 20 to 200 times as toxic as DDT and that Heptachlor and Chlordane are only slightly less toxic than Dieldrin. Methoxychlor and Strobane are less toxic to Quail than is DDT.

Re-Tooling the Agency's Engineering Predictive Practices for Durability and Damage Tolerance

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Knight, Norman F., Jr.

2017-01-01

Over the past decade, the Agency has placed less emphasis on testing and has increasingly relied on computational methods to assess durability and damage tolerance (D&DT) behavior when evaluating design margins for fracture-critical components. With increased emphasis on computational D&DT methods as the standard practice, it is paramount that capabilities of these methods are understood, the methods are used within their technical limits, and validation by well-designed tests confirms understanding. The D&DT performance of a component is highly dependent on parameters in the neighborhood of the damage. This report discusses D&DT method vulnerabilities.

Adverse effects of pesticides on central auditory functions in tobacco growers.

PubMed

França, Denise Maria Vaz Romano; Bender Moreira Lacerda, Adriana; Lobato, Diolen; Ribas, Angela; Ziliotto Dias, Karin; Leroux, Tony; Fuente, Adrian

2017-04-01

To investigate the effects of exposure to pesticides on the central auditory functions (CAF) of Brazilian tobacco growers. This was a cross-sectional study carried out between 2010 and 2012. Participants were evaluated with two behavioural procedures to investigate CAF, the random gap detection test (RGDT) and the dichotic digit test in Portuguese (DDT). A total of 22 growers exposed to pesticides (study group) and 21 subjects who were not exposed to pesticides (control group) were selected. No significant differences between groups were observed for pure-tone thresholds. A significant association between pesticide exposure and the results for RGDT and DDT was found. Significant differences between pesticide-exposed and nonexposed subjects were found for RGDT frequency average and DDT binaural average, when including age and hearing level as covariates. Age was significantly associated with RGDT frequency average, DDT left ear score, DDT binaural average and DDT right ear advantage. Hearing levels were not significantly associated with any of the test scores. The relative risk of failing the DDT and RGDT for the study group was 1.88 (95% CI: 1.10-3.20) and 1.74 (95% CI: 1.06-2.86), respectively, as compared with the control group. The results showed that tobacco growers exposed to pesticides exhibited signs of central auditory dysfunction characterised by decrements in temporal processing and binaural integration processes/abilities.

Synthesis of the DDT metabolite 2,4-dichloro-1-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene (o-Cl-DDMU) and its detection in abiotic and biotic samples.

PubMed

Gallistl, Christoph; Proctor, Katie; Bader, Korinna; Vetter, Walter

2017-07-01

Technical dichlorodiphenyltrichloroethane (DDT) has been used worldwide as a pesticide since the beginning of the 1940s. Due to its persistence, DDT residues are still ubiquitously distributed in the environment. Photochemical UV degradation has been shown to be a potent degradation path for DDT and most of the resulting photoproducts have been identified up to now. Nevertheless, in 2012, a new DDT metabolite, most likely formed photochemically from DDE, was detected in ray liver samples from Brazil, an area which is highly contaminated with DDT. This study includes photochemical generation, chemical synthesis and isolation of this compound which was verified to consist of both cis- and trans-2,4-dichloro-1-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene. Both stereoisomers were resolved by gas chromatography on a polar capillary column and detected in more than 60 biotic (e.g. marine mammals, birds, human milk) and abiotic samples (fat deposits in kitchen hoods) from different areas all over the world. The stereoisomer distribution and concentrations (0.3-3.9% relative to corresponding 1,1-dichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDE) levels) were determined by means of the synthesized analytical standard, indicating the widespread occurrence of this compound as an additional minor metabolite of DDT.

Toxic responses of Perna viridis hepatopancreas exposed to DDT, benzo(a)pyrene and their mixture uncovered by iTRAQ-based proteomics and NMR-based metabolomics.

PubMed

Song, Qinqin; Zhou, Hailong; Han, Qian; Diao, Xiaoping

2017-11-01

Dichlorodiphenyltrichloroethane (DDT) and benzo(a)pyrene (BaP) are environmental estrogens (EEs) that are ubiquitous in the marine environment. In the present study, we integrated isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic and nuclear magnetic resonance (NMR)-based metabolomic approaches to explore the toxic responses of green mussel hepatopancreas exposed to DDT (10μg/L), BaP (10μg/L) and their mixture. The metabolic responses indicated that BaP primarily disturbed energy metabolism and osmotic regulation in the hepatopancreas of the male green mussel P. viridis. Both DDT and the mixture of DDT and BaP perturbed the energy metabolism and osmotic regulation in P. viridis. The proteomic responses revealed that BaP affected the proteins involved in energy metabolism, material transformation, cytoskeleton, stress responses, reproduction and development in green mussels. DDT exposure could change the proteins involved in primary metabolism, stress responses, cytoskeleton and signal transduction. However, the mixture of DDT and BaP altered proteins associated with material and energy metabolism, stress responses, signal transduction, reproduction and development, cytoskeleton and apoptosis. This study showed that iTRAQ-based proteomic and NMR-based metabolomic approaches could effectively elucidate the essential molecular mechanism of disturbances in hepatopancreas function of green mussels exposed to environmental estrogens. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of sensitive methods for detection of DNA damage on human lymphocytes exposed to p,p'-DDT: Comet assay and new criteria for scoring micronucleus test.

PubMed

Gajski, Goran; Ravlic, Sanda; Capuder, Zeljka; Garaj-Vrhovac, Vera

2007-08-01

Wide distribution, stability and long persistence in the environment of dichlorodiphenyltrichloroethane (DDT), probably the best-known and most useful insecticide in the world, imposes the need for further examination of the effect of this chemical on human health and especially on the human genome. In this study, peripheral blood human lymphocytes from a healthy donor were exposed to 0.025 mg/L concentration of p,p'-DDT at different time periods (1, 2, 24 and 48 h). For the assessment of genotoxic effect, the new criteria for scoring micronucleus test and alkaline comet assay were used. Both methods showed that p,p'-DDT induces DNA damage in low concentration used in this research. Results of micronucleus test showed a statistically significant (p < 0.05) genotoxic effect of p,p'-DDT on human lymphocytes compared with corresponding control and a different exposure time. A comet assay also showed increased DNA damage caused in p,p'-DDT-exposed human lymphocytes than in corresponding control cells for the tail length. Results obtained by measuring the level of DNA migration and incidence of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) indicate the sensitivity of these tests and their application in detection of primary genome damage after long-term exposure to establish the effect of p,p'-DDT on human genome.

Occurences and Fate of DDT Principal Isomers/Metabolites, DDA, and o,p'-DDD Enantiomers in Fish, Sediment and Water at a DDT-Impacted Superfund Site

EPA Science Inventory

In the 1950s and 60s, discharges from a DDT manufacturing plant contaminated a tributary system of the Tennessee River near Huntsville, Alabama, USA. Regulatory action resulted in declaring the area a Superfund site which required remediation and extensive monitoring. Monitoring ...

Organochlorine pesticides in the Johnson Creek Basin, Oregon, 1988-2002

USGS Publications Warehouse

Tanner, Dwight Q.; Lee, Karl K.

2004-01-01

Organochlorine pesticides were detected in unfiltered samples from Johnson Creek that were collected during a storm in March, 2002. Total DDT (the sum of DDT and its metabolites), as well as dieldrin, potentially exceeded Oregon chronic, freshwater criteria at all four Johnson Creek stream-sampling sites. The total DDT criterion was also potentially exceeded at a storm drain at SE 45th Avenue and Umatilla Street. The concentration of total DDT in water samples has decreased by an order of magnitude since previous sampling was done on Johnson Creek in 1989?1990. This decrease was probably due to the movement of these compounds out of the basin and to degradation processes. Concentrations and loads of the organochlorine pesticides were largest at the most upstream sampling site, Johnson Creek at Palmblad Road, which has historically been primarily affected by agricultural land cover. Concentrations and loads were smaller at downstream locations, and there were only a few detections from storm drains. For the purposes of assessing trends in total DDT concentration in Johnson Creek, data for total suspended solids (TSS) were examined, because TSS is often correlated with DDT concentrations, and TSS data are collected routinely by regulatory agencies. As an intermediate step, linear regression was used to relate TSS (measured in the recent study) and turbidity (measured both in the earlier and in the recent studies). For 77 samples, TSS (in mg/L [milligrams per liter]) = 0.88 x Turbidity (in nephleometric turbidity units). The r2 value was 0.82. The TSS concentration (measured, or estimated by the regression) was compared to the concentration of total DDT using linear regression. The TSS concentration associated with meeting the Oregon water-quality criterion for total DDT was 15 to 18 mg/L in the lower and middle part of the basin and 8 mg/L in the upper reaches of the basin. This TSS/DDT relationship is based on only one storm and may not be valid for other conditions of streamflow and runoff. Dieldrin concentration was not well correlated with TSS. Organochlorine compounds also were detected in significant concentrations in Kelley Creek, an important tributary to Johnson Creek, but quality-control considerations made it difficult to interpret some of the data. It does appear, however, that some of the metabolites of DDT were positively associated with TSS. The high concentrations of the DDT metabolites and dieldrin were correlated with agricultural areas.

Precision cancer therapy: profiting from tumor specific defects in the DNA damage tolerance system.

PubMed

Buoninfante, Olimpia Alessandra; Pilzecker, Bas; Aslam, Muhammad Assad; Zavrakidis, Ioannis; van der Wiel, Rianne; van de Ven, Marieke; van den Berk, Paul C M; Jacobs, Heinz

2018-04-10

DNA damage tolerance (DDT) enables replication to continue in the presence of a damaged template and constitutes a key step in DNA interstrand crosslink repair. In this way DDT minimizes replication stress inflicted by a wide range of endogenous and exogenous agents, and provides a critical first line defense against alkylating and platinating chemotherapeutics. Effective DDT strongly depends on damage-induced, site-specific PCNA-ubiquitination at Lysine (K) 164 by the E2/E3 complex (RAD6/18). A survey of The Cancer Genome Atlas (TCGA) revealed a high frequency of tumors presents RAD6/RAD18 bi-allelic inactivating deletions. For instance, 11% of renal cell carcinoma and 5% of pancreatic tumors have inactivating RAD18 -deletions and 7% of malignant peripheral nerve sheath tumors lack RAD6B . To determine the potential benefit for tumor-specific DDT defects, we followed a genetic approach by establishing unique sets of DDT-proficient Pcna K164 and -defective Pcna K164R lymphoma and breast cancer cell lines. In the absence of exogenous DNA damage, Pcna K164R tumors grew comparably to their Pcna K164 controls in vitro and in vivo . However, DDT-defective lymphomas and breast cancers were compared to their DDT-proficient controls hypersensitive to the chemotherapeutic drug cisplatin (CsPt), both in vitro and in vivo. CsPt strongly inhibited tumor growth and the overall survival of tumor bearing mice greatly improved in the DDT-defective condition. These insights open new therapeutic possibilities for precision cancer medicine with DNA damaging chemotherapeutics and optimize Next-Generation-Sequencing (NGS)-based cancer-diagnostics, -therapeutics, and -prognosis.

Precision cancer therapy: profiting from tumor specific defects in the DNA damage tolerance system

PubMed Central

Buoninfante, Olimpia Alessandra; Pilzecker, Bas; Aslam, Muhammad Assad; Zavrakidis, Ioannis; van der Wiel, Rianne; van de Ven, Marieke; van den Berk, Paul C.M.; Jacobs, Heinz

2018-01-01

DNA damage tolerance (DDT) enables replication to continue in the presence of a damaged template and constitutes a key step in DNA interstrand crosslink repair. In this way DDT minimizes replication stress inflicted by a wide range of endogenous and exogenous agents, and provides a critical first line defense against alkylating and platinating chemotherapeutics. Effective DDT strongly depends on damage-induced, site-specific PCNA-ubiquitination at Lysine (K) 164 by the E2/E3 complex (RAD6/18). A survey of The Cancer Genome Atlas (TCGA) revealed a high frequency of tumors presents RAD6/RAD18 bi-allelic inactivating deletions. For instance, 11% of renal cell carcinoma and 5% of pancreatic tumors have inactivating RAD18-deletions and 7% of malignant peripheral nerve sheath tumors lack RAD6B. To determine the potential benefit for tumor-specific DDT defects, we followed a genetic approach by establishing unique sets of DDT-proficient PcnaK164 and -defective PcnaK164R lymphoma and breast cancer cell lines. In the absence of exogenous DNA damage, PcnaK164R tumors grew comparably to their PcnaK164 controls in vitro and in vivo. However, DDT-defective lymphomas and breast cancers were compared to their DDT-proficient controls hypersensitive to the chemotherapeutic drug cisplatin (CsPt), both in vitro and in vivo. CsPt strongly inhibited tumor growth and the overall survival of tumor bearing mice greatly improved in the DDT-defective condition. These insights open new therapeutic possibilities for precision cancer medicine with DNA damaging chemotherapeutics and optimize Next-Generation-Sequencing (NGS)-based cancer-diagnostics, -therapeutics, and -prognosis. PMID:29721165

Risk of DDT residue in maize consumed by infants as complementary diet in southwest Ethiopia.

PubMed

Mekonen, Seblework; Lachat, Carl; Ambelu, Argaw; Steurbaut, Walter; Kolsteren, Patrick; Jacxsens, Liesbeth; Wondafrash, Mekitie; Houbraken, Michael; Spanoghe, Pieter

2015-04-01

Infants in Ethiopia are consuming food items such as maize as a complementary diet. However, this may expose infants to toxic contaminants like DDT. Maize samples were collected from the households visited during a consumption survey and from markets in Jimma zone, southwestern Ethiopia. The residues of total DDT and its metabolites were analyzed using the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method combined with dispersive solid phase extraction cleanup (d-SPE). Deterministic and probabilistic methods of analysis were applied to determine the consumer exposure of infants to total DDT. The results from the exposure assessment were compared with the health based guidance value in this case the provisional tolerable daily intake (PTDI). All maize samples (n=127) were contaminated by DDT, with a mean concentration of 1.770 mg/kg, which was far above the maximum residue limit (MRL). The mean and 97.5 percentile (P 97.5) estimated daily intake of total DDT for consumers were respectively 0.011 and 0.309 mg/kg bw/day for deterministic and 0.011 and 0.083 mg/kg bw/day for probabilistic exposure assessment. For total infant population (consumers and non-consumers), the 97.5 percentile estimated daily intake were 0.265 and 0.032 mg/kg bw/day from the deterministic and probabilistic exposure assessments, respectively. Health risk estimation revealed that, the mean and 97.5 percentile for consumers, and 97.5 percentile estimated daily intake of total DDT for total population were above the PTDI. Therefore, in Ethiopia, the use of maize as complementary food for infants may pose a health risk due to DDT residue. Copyright © 2014 Elsevier B.V. All rights reserved.

A single mutation in the GSTe2 gene allows tracking of metabolically based insecticide resistance in a major malaria vector

PubMed Central

2014-01-01

Background Metabolic resistance to insecticides is the biggest threat to the continued effectiveness of malaria vector control. However, its underlying molecular basis, crucial for successful resistance management, remains poorly characterized. Results Here, we demonstrate that the single amino acid change L119F in an upregulated glutathione S-transferase gene, GSTe2, confers high levels of metabolic resistance to DDT in the malaria vector Anopheles funestus. Genome-wide transcription analysis revealed that GSTe2 was the most over-expressed detoxification gene in DDT and permethrin-resistant mosquitoes from Benin. Transgenic expression of GSTe2 in Drosophila melanogaster demonstrated that over-transcription of this gene alone confers DDT resistance and cross-resistance to pyrethroids. Analysis of GSTe2 polymorphism established that the point mutation is tightly associated with metabolic resistance to DDT and its geographical distribution strongly correlates with DDT resistance patterns across Africa. Functional characterization of recombinant GSTe2 further supports the role of the L119F mutation, with the resistant allele being more efficient at metabolizing DDT than the susceptible one. Importantly, we also show that GSTe2 directly metabolizes the pyrethroid permethrin. Structural analysis reveals that the mutation confers resistance by enlarging the GSTe2 DDT-binding cavity, leading to increased DDT access and metabolism. Furthermore, we show that GSTe2 is under strong directional selection in resistant populations, and a restriction of gene flow is observed between African regions, enabling the prediction of the future spread of this resistance. Conclusions This first DNA-based metabolic resistance marker in mosquitoes provides an essential tool to track the evolution of resistance and to design suitable resistance management strategies. PMID:24565444

Assessing the underlying breast cancer risk of Chinese females contributed by dietary intake of residual DDT from agricultural soils.

PubMed

Tang, Mengling; Zhao, Meirong; Zhou, Shanshan; Chen, Kun; Zhang, Chunlong; Liu, Weiping

2014-12-01

The greatest concern over DDT exposure in China arose since the early 1990s for the rising breast cancer incidence, and the cause still remains to be elucidated. An extensive survey of DDT background in agricultural soils, covered the entire region of China, was conducted. DDT at concentrations greater than 100 ng/g (the China's Farmland Environmental Quality Evaluation Standards for Edible Agricultural Products) was found to impact 42.3 million Chinese population. Considering the geographical differences with diverse DDT contributions and different diet products and habits, the average daily dietary intake was modeled and estimated to be 0.34 μg/kg p,p'-DDE (the main bioactive constituent in DDT). Population attributable fraction derived from a case-control study from 78 women with breast cancer and 72 controls was used to assess the DDT exposure risk to breast cancer. Based on the estimated population attributable fraction with a median value of 0.6% (IQR 0.23-2.11%), the excess annual breast cancer incidence rate attributable to p,p'-DDE exposure averaged 0.06×10(-5) with significant spatial variations varying from 0.00021×10(-5) to 11.05×10(-5) in Chinese females. Exposure to DDT is a contributor to breast cancer, but the overall limited relative risk and population attributable fraction imply confounding factors for breast cancer in Chinese females. Exposure risk in a regional scale helps understand the cause and prevention of breast cancer. Our mapping and modeling method could be used to assess other environmental carcinogens and related cancer diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

The primary evaluation and characterization of obsolete DDT pesticide from a precalciner of a cement kiln.

PubMed

Li, Yang; Wang, Qi; Huang, Qifei; He, Jie

2014-01-01

1,1,1-Trichloro-2,2-bi(4-chlorophenyl)ethane (DDT) pesticide that has been extensively used in agriculture in China in the last century, and even now, has been banned from all purposes. The disposal of obsolete DDT pesticide has been an urgent task for the Chinese government. In order to evaluate the feasibility of co-processing DDT in the current new style dry-process rotary kiln with a precalciner as the feeding point, the destruction efficiency (DE) of DDTs (including p,p(')-DDT, o,p(')-DDT, p,p(')-DDE and p,p(')-DDD), proportion of DDTs in the combustion residue and exhaust gas, and the release of chlorine were studied under different operating conditions of temperature, oxygen content and gas retention time in the laboratory. The DE of DDTs exceeded 99% when the temperature was over 800 °C with enough oxygen. As the temperature increased from 600 °C to 1200 °C, the proportion of p,p(')-DDD increased and p,p(')-DDT decreased but still the main effective component remained in the combustion residue. In the exhaust gas, the most dominant phenomenon was the rapid increase in p,p(')-DDE concentration as the temperature increased. The release of chlorine reached a peak between 800 °C and 900 °C. It was found that the oxygen content had a positive correlation with the process of dechlorination. The proportion of p,p(')-DDE increased as the oxygen content was increased in the exhaust gas. The gas retention time had almost no influenced on the DE of DDTs, but affected the degradation extent of DDTs in the gas phase. These experiments showed that co-processing of obsolete DDT pesticide in cement kiln precalciners is feasible.

Selective Sweep Analysis in the Genomes of the 91-R and 91-C Drosophila melanogaster Strains Reveals Few of the ‘Usual Suspects’ in Dichlorodiphenyltrichloroethane (DDT) Resistance

PubMed Central

Steele, Laura D.; Coates, Brad; Valero, M. Carmen; Sun, Weilin; Seong, Keon Mook; Muir, William M.; Clark, John M.; Pittendrigh, Barry R.

2015-01-01

Adaptation of insect phenotypes for survival after exposure to xenobiotics can result from selection at multiple loci with additive genetic effects. To the authors’ knowledge, no selective sweep analysis has been performed to identify such loci in highly dichlorodiphenyltrichloroethane (DDT) resistant insects. Here we compared a highly DDT resistant phenotype in the Drosophila melanogaster (Drosophila) 91-R strain to the DDT susceptible 91-C strain, both of common origin. Whole genome re-sequencing data from pools of individuals was generated separately for 91-R and 91-C, and mapped to the reference Drosophila genome assembly (v. 5.72). Thirteen major and three minor effect chromosome intervals with reduced nucleotide diversity (π) were identified only in the 91-R population. Estimates of Tajima's D (D) showed corresponding evidence of directional selection in these same genome regions of 91-R, however, no similar reductions in π or D estimates were detected in 91-C. An overabundance of non-synonymous proteins coding to synonymous changes were identified in putative open reading frames associated with 91-R. Except for NinaC and Cyp4g1, none of the identified genes were the ‘usual suspects’ previously observed to be associated with DDT resistance. Additionally, up-regulated ATP-binding cassette transporters have been previously associated with DDT resistance; however, here we identified a structurally altered MDR49 candidate resistance gene. The remaining fourteen genes have not previously been shown to be associated with DDT resistance. These results suggest hitherto unknown mechanisms of DDT resistance, most of which have been overlooked in previous transcriptional studies, with some genes having orthologs in mammals. PMID:25826265

Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

PubMed Central

2013-01-01

Background Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease. Methods Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm. Results The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity. Conclusions Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance. PMID:24228800

Susceptibility of malaria vectors to DDT in Greece

PubMed Central

Livadas, Gregory A.; Thymakis, Kyriacos

1956-01-01

The authors describe an investigation, started in Greece in the autumn of 1953 and continued during the 1954 malaria-transmission season, to determine the variations in the susceptibility to DDT of the anophelines in different localities, with a view to establishing a point of departure which would make it possible to follow any future changes in susceptibility to this insecticide. The degree of susceptibility of the mosquitos to DDT was assessed numerically by both the technique of topical application of microdoses of the insecticide and the technique devised by Busvine & Nash. The villages of Elos and Asterion (Skála area), the Agoulinitsa area, and the Georgioupolis (Crete) area were chosen for the investigation. The findings disclosed considerable differences in the susceptibility to DDT in the above areas, but showed that, on the whole, the tendency for anophelines to acquire resistance to DDT seemed to be continuing in Greece. PMID:13404428

Insights into DDT Resistance from the Drosophila melanogaster Genetic Reference Panel

PubMed Central

Schmidt, Joshua M.; Battlay, Paul; Gledhill-Smith, Rebecca S.; Good, Robert T.; Lumb, Chris; Fournier-Level, Alexandre; Robin, Charles

2017-01-01

Insecticide resistance is considered a classic model of microevolution, where a strong selective agent is applied to a large natural population, resulting in a change in frequency of alleles that confer resistance. While many insecticide resistance variants have been characterized at the gene level, they are typically single genes of large effect identified in highly resistant pest species. In contrast, multiple variants have been implicated in DDT resistance in Drosophila melanogaster; however, only the Cyp6g1 locus has previously been shown to be relevant to field populations. Here we use genome-wide association studies (GWAS) to identify DDT-associated polygenes and use selective sweep analyses to assess their adaptive significance. We identify and verify two candidate DDT resistance loci. A largely uncharacterized gene, CG10737, has a function in muscles that ameliorates the effects of DDT, while a putative detoxifying P450, Cyp6w1, shows compelling evidence of positive selection. PMID:28935691

Differential transcription of cytochrome P450s and glutathione S transferases in DDT-susceptible and resistant Drosophila melanogaster strains in response to DDT and oxidative stress

USDA-ARS?s Scientific Manuscript database

Metabolic DDT resistance in Drosophila melanogaster has previously been associated with constitutive over-transcription of cytochrome P450s. Increased P450 activity has also been associated with increased oxidative stress. In contrast, over-transcription of glutathione S transferases (GSTs) has been...

Problem Definition Studies on Potential Environmental Pollutants. VII. Physical, Chemical, Toxicological, and Biological Properties of DDT and Its Derivatives

DTIC Science & Technology

1979-06-01

WORDS (C-enlnuo on reverse side If n*co*or and Identlif by block numbe) Amphibians Birds DDT Man Analytical Methods Carcinogenesis Fish Metabolism ...18 Bioaccumulation and the Food Chain .. .. .. .. .. . .19 Effects on Terrestrial Animals. .. ........ .. .... 21 Effects on...Aquatic Organisms .. . . .. .. .. .. .. . .25 Effects on Microorganisms .. ........... .. .... 41 VI. STANDARDS AND CRITERIA FOR DDT

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

USDA-ARS?s Scientific Manuscript database

While DDT and dieldrin have been banned in most countries, contaminated agricultural sites exist in many areas and wildlife exposure is still of concern. Soil was obtained from a historical orchard that received routine pesticide applications more than 40 years ago. Bioavailability of DDT and diel...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Juberg, D.R.; Loch-Caruso, R.

Elevated levels of DDT and other organochlorine pesticides have been associated with spontaneous abortion and preterm birth in several species, including humans. Despite the prevalence of organochlorine pesticides in the environment, a mechanistic basis for this association has not been explored. Furthermore, while DDT has been associated with inhibition of calcium ATPases, altered gap junctional communication and electrophysiological changes, all of which could affect the excitation-contraction process characteristic of smooth muscle, direct effects of DDT on uterine smooth muscle have not been reported. This study was initiated to assess the direct effects of o,p{prime}-DDT (an estrogenic isomer present in themore » technical grade preparation) on pregnant rat uterine tissue.« less

Adsorption of DDT and PCB by Nanomaterials from Residual Soil.

PubMed

Taha, Mohd Raihan; Mobasser, Shariat

2015-01-01

This paper presents the findings of a study on adsorption of dichlorodiphenythreechloroethen (DDT) and polychlorinated biphenyls (PCBs) on three nanomaterials including Multi walled Carbon Nanotube (MWNT), nano-clay and nano-alumina. DDT and PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different DDT and PCBs concentrations, from 10 to 60 mg/L. The amounts of MWNT, nano-clay and Nano-alumina used were 0.25%, 0.50%, 0.75%, 1%, 2% and 10%. The adsorption of PCBs solution onto the MWNT, nano-clay and nano-alumina was characterized by an initial rapid adsorption which eventually became constant within 22, 20, and 17 hours, respectively. The adsorption of DDT solution onto the MWNT, nano-clay and nano-alumina was also characterized by an initial rapid adsorption which gradually became constant within 22, 22 and 16 hours, respectively. Results of this study indicated that MWNT was a better adsorbent material compared to nano-clay and nano-alumina for both contaminants in this study. While at 10% of MWNT 88.9% and 77% of DDT and PCB were removed by MWNT, respectively. The effect of pH and temperature were also investigated.

Adsorption of DDT and PCB by Nanomaterials from Residual Soil

PubMed Central

Taha, Mohd Raihan; Mobasser, Shariat

2015-01-01

This paper presents the findings of a study on adsorption of dichlorodiphenythreechloroethen (DDT) and polychlorinated biphenyls (PCBs) on three nanomaterials including Multi walled Carbon Nanotube (MWNT), nano-clay and nano-alumina. DDT and PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different DDT and PCBs concentrations, from 10 to 60 mg/L. The amounts of MWNT, nano-clay and Nano-alumina used were 0.25%, 0.50%, 0.75%, 1%, 2% and 10%. The adsorption of PCBs solution onto the MWNT, nano-clay and nano-alumina was characterized by an initial rapid adsorption which eventually became constant within 22, 20, and 17 hours, respectively. The adsorption of DDT solution onto the MWNT, nano-clay and nano-alumina was also characterized by an initial rapid adsorption which gradually became constant within 22, 22 and 16 hours, respectively. Results of this study indicated that MWNT was a better adsorbent material compared to nano-clay and nano-alumina for both contaminants in this study. While at 10% of MWNT 88.9% and 77% of DDT and PCB were removed by MWNT, respectively. The effect of pH and temperature were also investigated. PMID:26659225

Malaria control and longitudinal changes in levels of DDT and its metabolites in human serum from KwaZulu.

PubMed Central

Bouwman, H.; Becker, P. J.; Schutte, C. H.

1994-01-01

Blood samples were obtained on four occasions over a 12-month period from individuals living in KwaZulu, South Africa, who had been exposed to DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) as a consequence of its use in their homes to control transmission of malaria. The longitudinal changes in serum DDT and its major metabolities, DDE and DDD, were determined. No additional risk was considered to have been presented by the increases that occurred following application of the pesticide. There were significant increases in DDT, DDE and sigma DDT (DDT + its metabolites) for the age group > or = 21 years, but for the age group 3-20 years a reduction in serum levels occurred over 12 months. Two concurrent processes probably govern the increase and decrease in serum levels, and the relative contributions of each interchange as the individual becomes older. The results suggest that children in KwaZulu experience conditions that differ from those of their parents, as well as from those that affect children in developed countries. In consequence, it is desirable that risk assessments of vector control chemicals consider all sectors of a population. PMID:7867138

Gene 1.7 of bacteriophage T7 confers sensitivity of phage growth to dideoxythymidine.

PubMed

Tran, Ngoc Q; Rezende, Lisa F; Qimron, Udi; Richardson, Charles C; Tabor, Stanley

2008-07-08

Bacteriophage T7 DNA polymerase efficiently incorporates dideoxynucleotides into DNA, resulting in chain termination. Dideoxythymidine (ddT) present in the medium at levels not toxic to Escherichia coli inhibits phage T7. We isolated 95 T7 phage mutants that were resistant to ddT. All contained a mutation in T7 gene 1.7, a nonessential gene of unknown function. When gene 1.7 was expressed from a plasmid, T7 phage resistant to ddT still arose; analysis of 36 of these mutants revealed that all had a single mutation in gene 5, which encodes T7 DNA polymerase. This mutation changes tyrosine-526 to phenylalanine, which is known to increase dramatically the ability of T7 DNA polymerase to discriminate against dideoxynucleotides. DNA synthesis in cells infected with wild-type T7 phage was inhibited by ddT, suggesting that it resulted in chain termination of DNA synthesis in the presence of gene 1.7 protein. Overexpression of gene 1.7 from a plasmid rendered E. coli cells sensitive to ddT, indicating that no other T7 proteins are required to confer sensitivity to ddT.

Evaluation of the Synergistic Effect of Mixed Cultures of White-Rot Fungus Pleurotus ostreatus and Biosurfactant-Producing Bacteria on DDT Biodegradation.

PubMed

Purnomo, Adi Setyo; Ashari, Khoirul; Hermansyah, Farizha Triyogi

2017-07-28

DDT (1,1,1-trichloro-2,2- bis (4-chlorophenyl) ethane) is one of the organic synthetic pesticides that has many negative effects for human health and the environment. The purpose of this study was to investigate the synergistic effect of mixed cutures of white-rot fungus, Pleurotus ostreatus , and biosurfactant-producing bacteria, Pseudomonas aeruginosa and Bacillus subtilis , on DDT biodegradation. Bacteria were added into the P. ostreatus culture (mycelial wet weight on average by 8.53 g) in concentrations of 1, 3, 5, and 10 ml (1 ml ≈ 1.25 × 10 9 bacteria cells/ml culture). DDT was degraded to approximately 19% by P. ostreatus during the 7-day incubation period. The principal result of this study was that the addition of 3 ml of P. aeruginosa into P. ostreatus culture gave the highest DDT degradation rate (approximately 86%) during the 7-day incubation period. This mixed culture combination of the fungus and bacteria also gave the best ratio of optimization of 1.91. DDD (1,1-dichloro-2,2- bis (4-chlorophenyl) ethane), DDE (1,1-dichloro-2,2- bis (4-chlorophenyl) ethylene), and DDMU (1-chloro-2,2- bis (4-chlorophenyl) ethylene) were detected as metabolic products from the DDT degradation by P. ostreatus and P. aeruginosa . The results of this study indicate that P. aeruginosa has a synergistic relationship with P. ostreatus and can be used to optimize the degradation of DDT by P. ostreatus .

Prenatal DDT Exposure in Relation to Anthropometric and Pubertal Measures in Adolescent Males

PubMed Central

Gladen, Beth C.; Klebanoff, Mark A.; Hediger, Mary L.; Katz, Solomon H.; Barr, Dana B.; Davis, Mark D.; Longnecker, Matthew P.

2004-01-01

DDT (dichlorodiphenyltrichloroethane), a pesticide once used widely in agriculture and now limited to public health use, remains a controversial chemical because of a combination of benefits and risks. DDT or its breakdown products are ubiquitous in the environment and in humans. Compounds in the DDT family have endocrine actions and have been associated with reproductive toxicity. A previous study reported associations between prenatal exposure to p,p′-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene] and increased height and weight in adolescent boys. We examined a group with higher exposures to see whether similar associations would occur. Our study group was 304 males born in Philadelphia in the early 1960s who had participated in a previous study. Anthropometric and pubertal measures from one to six visits during their adolescent years were available, as were stored maternal serum samples from pregnancy. We measured p,p′-DDE, p,p′-DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)-ethane], and o,p′-DDT [1,1,1-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)-ethane] in the maternal serum. Outcomes examined in the boys were height, ratio of sitting height to height, body mass index, triceps skinfold thickness, ratio of subscapular to the sum of triceps and subscapular skinfold thicknesses, skeletal age, serum testosterone, and serum dehydroepiandrosterone sulfate. No associations between prenatal exposure to any of the DDT compounds and any outcome measure were seen. PMID:15579424

DDT, global strategies, and a malaria control crisis in South America.

PubMed

Roberts, D R; Laughlin, L L; Hsheih, P; Legters, L J

1997-01-01

Malaria is reemerging in endemic-disease countries of South America. We examined the rate of real growth in annual parasite indexes (API) by adjusting APIs for all years to the annual blood examination rate of 1965 for each country. The standardized APIs calculated for Brazil, Peru, Guyana, and for 18 other malaria-endemic countries of the Americas presented a consistent pattern of low rates up through the late 1970s, followed by geometric growth in malaria incidence in subsequent years. True growth in malaria incidence corresponds temporally with changes in global strategies for malaria control. Underlying the concordance of these events is a causal link between decreased spraying of homes with DDT and increased malaria; two regression models defining this link showed statistically significant negative relationships between APIs and house-spray rates. Separate analyses of data from 1993 to 1995 showed that countries that have recently discontinued their spray programs are reporting large increases in malaria incidence. Ecuador, which has increased use of DDT since 1993, is the only country reporting a large reduction (61%) in malaria rates since 1993. DDT use for malaria control and application of the Global Malaria Control Strategy to the Americas should be subjects of urgent national and international debate. We discuss the recent actions to ban DDT, the health costs of such a ban, perspectives on DDT use in agriculture versus malaria control, and costs versus benefits of DDT and alternative insecticides.

DDT, global strategies, and a malaria control crisis in South America.

PubMed Central

Roberts, D. R.; Laughlin, L. L.; Hsheih, P.; Legters, L. J.

1997-01-01

Malaria is reemerging in endemic-disease countries of South America. We examined the rate of real growth in annual parasite indexes (API) by adjusting APIs for all years to the annual blood examination rate of 1965 for each country. The standardized APIs calculated for Brazil, Peru, Guyana, and for 18 other malaria-endemic countries of the Americas presented a consistent pattern of low rates up through the late 1970s, followed by geometric growth in malaria incidence in subsequent years. True growth in malaria incidence corresponds temporally with changes in global strategies for malaria control. Underlying the concordance of these events is a causal link between decreased spraying of homes with DDT and increased malaria; two regression models defining this link showed statistically significant negative relationships between APIs and house-spray rates. Separate analyses of data from 1993 to 1995 showed that countries that have recently discontinued their spray programs are reporting large increases in malaria incidence. Ecuador, which has increased use of DDT since 1993, is the only country reporting a large reduction (61%) in malaria rates since 1993. DDT use for malaria control and application of the Global Malaria Control Strategy to the Americas should be subjects of urgent national and international debate. We discuss the recent actions to ban DDT, the health costs of such a ban, perspectives on DDT use in agriculture versus malaria control, and costs versus benefits of DDT and alternative insecticides. PMID:9284373

Genetic requirements for sensitivity of bacteriophage t7 to dideoxythymidine.

PubMed

Tran, Ngoc Q; Tabor, Stanley; Richardson, Charles C

2014-08-01

We previously reported that the presence of dideoxythymidine (ddT) in the growth medium selectively inhibits the ability of bacteriophage T7 to infect Escherichia coli by inhibiting phage DNA synthese (N. Q. Tran, L. F. Rezende, U. Qimron, C. C. Richardson, and S. Tabor, Proc. Natl. Acad. Sci. U. S. A. 105:9373-9378, 2008, doi:10.1073/pnas.0804164105). In the presence of T7 gene 1.7 protein, ddT is taken up into the E. coli cell and converted to ddTTP. ddTTP is incorporated into DNA as ddTMP by the T7 DNA polymerase, resulting in chain termination. We have identified the pathway by which exogenous ddT is converted to ddTTP. The pathway consists of ddT transport by host nucleoside permeases and phosphorylation to ddTMP by the host thymidine kinase. T7 gene 1.7 protein phosphorylates ddTMP and ddTDP, resulting in ddTTP. A 74-residue peptide of the gene 1.7 protein confers ddT sensitivity to the same extent as the 196-residue wild-type gene 1.7 protein. We also show that cleavage of thymidine to thymine and deoxyribose-1-phosphate by the host thymidine phosphorylase greatly increases the sensitivity of phage T7 to ddT. Finally, a mutation in T7 DNA polymerase that leads to discrimination against the incorporation of ddTMP eliminates ddT sensitivity. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The Clinical Significance of the MIF Homolog D-Dopachrome Tautomerase (MIF-2) and its Circulating Receptor (sCD74) in Burn Injury

PubMed Central

Kim, Bong-Sung; Stoppe, Christian; Grieb, Gerrit; Leng, Lin; Sauler, Maor; Assis, David; Simons, David; Boecker, Arne Hendrick; Schulte, Wibke; Piecychna, Marta; Hager, Stephan; Bernhagen, Jürgen; Pallua, Norbert; Bucala, Richard

2016-01-01

Background We reported earlier that the cytokine macrophage migration inhibitory factor (MIF) is a potential biomarker in burn injury. In the present study, we investigated the clinical significance in severely burned patients of expression levels the newly discovered MIF family member D-dopachrome tautomerase (DDT or MIF-2) and their common soluble receptor CD74 (sCD74). Methods DDT and sCD74 serum levels were measured 20 severely burned patients and 20 controls. Serum levels were correlated to the abbreviated burn severity index (ABSI) and TBSA followed by receiver operating characteristic (ROC) analysis. Data were supported by gene expression dataset analysis of 31 burn patients and 28 healthy controls. Results CD74 and DDT were increased in burn patients. Furthermore, CD74 and DDT also were elevated in septic non-survivors when compared to survivors. Serum levels of DDT showed a positive correlation with the ABSI and TBSA in the early stage after burn injury, and the predictive character of DDT was strongest at 24 hrs. Serum levels of CD74 only correlated with the ABSI five days post-injury. Conclusions DDT may assist in the monitoring of clinical outcome and prediction of sepsis during the early post-burn period. sCD74 and MIF, by contrast, have limited value as an early predictor of death due to their delayed response to burn injury. PMID:27209369

Genetic Requirements for Sensitivity of Bacteriophage T7 to Dideoxythymidine

PubMed Central

Tran, Ngoc Q.; Tabor, Stanley

2014-01-01

We previously reported that the presence of dideoxythymidine (ddT) in the growth medium selectively inhibits the ability of bacteriophage T7 to infect Escherichia coli by inhibiting phage DNA synthese (N. Q. Tran, L. F. Rezende, U. Qimron, C. C. Richardson, and S. Tabor, Proc. Natl. Acad. Sci. U. S. A. 105:9373–9378, 2008, doi:10.1073/pnas.0804164105). In the presence of T7 gene 1.7 protein, ddT is taken up into the E. coli cell and converted to ddTTP. ddTTP is incorporated into DNA as ddTMP by the T7 DNA polymerase, resulting in chain termination. We have identified the pathway by which exogenous ddT is converted to ddTTP. The pathway consists of ddT transport by host nucleoside permeases and phosphorylation to ddTMP by the host thymidine kinase. T7 gene 1.7 protein phosphorylates ddTMP and ddTDP, resulting in ddTTP. A 74-residue peptide of the gene 1.7 protein confers ddT sensitivity to the same extent as the 196-residue wild-type gene 1.7 protein. We also show that cleavage of thymidine to thymine and deoxyribose-1-phosphate by the host thymidine phosphorylase greatly increases the sensitivity of phage T7 to ddT. Finally, a mutation in T7 DNA polymerase that leads to discrimination against the incorporation of ddTMP eliminates ddT sensitivity. PMID:24858186

Effects of selected food phytochemicals in reducing the toxic actions of TCDD and p,p′-DDT in U937 macrophages

PubMed Central

Sciullo, Eric M.; Vogel, Christoph F.; Wu, Dalei; Murakami, Akira; Ohigashi, Hajime

2010-01-01

To assess the effectiveness of selected food phytochemicals in reducing the toxic effects of the environmental toxicants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and p,p′-DDT (DDT), we tested the potencies of auraptene, nobiletin, zerumbone, and (±)-13-hydroxy-10-oxo-trans-11-octadecenoic acid (13-HOA) in reversing the inflammatory action of these toxicants in U937 human macrophages. Using quantitative RT–PCR as the initial screening assay, we identified antagonistic actions of zerumbone and auraptene against the action of TCDD and DDT in up-regulating the mRNA expressions of COX-2 and VEGF. The functional significance of the inhibitory action of zerumbone on COX-2 expression was confirmed by demonstrating its suppression of TCDD-induced activation of COX-2 gene expression in mouse MMDD1 cells. We tested auraptene on DDT-induced reactive oxygen species (ROS) formation in U937 macrophages and found that auraptene is a powerful agent antagonizing this action of DDT. To confirm the significance of these actions of zerumbone and auraptene at the cellular level, we assessed their influence on TCDD-induced apoptosis resistance in intact U937 macrophages and found that they are capable of reversing this action of TCDD. In conclusion, zerumbone and auraptene were identified to be the most effective agents in protecting U937 macrophages from developing these cell toxic effects of TCDD and DDT. PMID:20865247

The effect of larval nutritional deprivation on the life history and DDT resistance phenotype in laboratory strains of the malaria vector Anopheles arabiensis

PubMed Central

2013-01-01

Background Anopheles arabiensis is a major malaria vector in Africa. It thrives in agricultural areas and has been associated with increased malaria incidence in areas under rice and maize cultivation. This effect may be due to increased adult size and abundance as a consequence of optimal larval nutrition. The aim of this study was to examine the effect of larval nutrition on the life history and expression of insecticide resistance in adults of laboratory reared An. arabiensis. Methods Larvae drawn from an insecticide susceptible An. arabiensis strain (SENN) as well as a DDT-resistant strain (SENN-DDT) were subjected to three fasting regimes: 1 mg of food per larva offered once per day, once every second day and once every third day. Control cohorts included larvae offered 1 mg food thrice per day. The rate of larval development was compared between matched cohorts from each strain as well as between fasted larvae and their respective controls. The expression of DDT resistance/tolerance in adults was compared between the starved cohorts and their controls by strain. Factors potentially affecting variation in DDT resistance/tolerance were examined including: adult body size (wing length), knock-down resistance (kdr) status and levels of detoxification enzyme activity. Results and conclusion Anopheles arabiensis larval development is prolonged by nutrient deprivation and adults that eclose from starved larvae are smaller and less tolerant to DDT intoxication. This effect on DDT tolerance in adults is also associated with reduced detoxification enzyme activity. Conversely, well fed larvae develop comparatively quickly into large, more DDT tolerant (SENN) or resistant (SENN-DDT) adults. This is important in those instances where cereal farming is associated with increased An. arabiensis transmitted malaria incidence, because large adult females with high teneral reserves and decreased susceptibility to insecticide intoxication may also prove to be more efficient malaria vectors. In general, larval nutrient deprivation in An. arabiensis has important implications for subsequent adults in terms of their size and relative insecticide susceptibility, which may in turn impact on their malaria vector capacity in areas where insecticide based control measures are in place. PMID:23368928

DDT-related compounds as non-extractable residues in submarine sediments of the Palos Verdes Shelf, California, USA.

PubMed

Kucher, S; Schwarzbauer, J

2017-10-01

The Palos Verdes Shelf (PVS) and the continental slope off the Palos Verdes Peninsula are highly contaminated by degradation products of the pesticide DDT (1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene). Sediment samples from two box cores were analyzed to obtain further information about the fate of DDT and its degradation products within the environment. After solvent extraction, an alkaline hydrolysis procedure was applied. A comprehensive screening for 26 DDT compounds revealed that DDT and its degradates contaminate not only the extractable fraction but also the fraction released by alkaline hydrolysis. A comparison of the quantitative distribution of DDT degradation products in the extractable fraction and released by alkaline hydrolysis showed a distinct difference. DDE (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene), DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene), DDMS (1-chloro-4-[2-chloro-1-(4-chlorophenyl)ethyl]benzene), and DDMU (1-chloro-4-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene) were predominant in the sediment extracts but minor components of the hydrolyzable fraction. The most abundant compounds released by the alkaline hydrolysis were DBP (bis(4-chlorophenyl)methanone), DDNU (1-chloro-4-[1-(4-chlorophenyl)ethenyl]benzene), DDM (1-chloro-4-[(4-chlorophenyl)methyl]benzene) and the water-soluble DDA (2,2-bis(4-chlorophenyl)acetic acid). The release of DDA may point to the presence of an important degradation pathway in marine environments. Concentration levels of DDT-related compounds showed corresponding vertical profiles in both fractions, but were significantly lower in the fraction released by alkaline hydrolysis. In contrast to fluvial sediments contaminated by DDT and its degradates the alkaline hydrolysis products represented a minor portion of the total sedimentary burden in the analyzed marine sediments. These findings show the necessity of a comprehensive screening for all DDT isomers and breakdown products in the extractable and non-extractable fraction to assess the total contamination abundance and potential environmental risks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of dressing and cooking on DDT concentrations in certain fish from Lake Michigan

USGS Publications Warehouse

Reinert, Robert E.; Stewart, Donald; Seagran, Harry L.

1972-01-01

Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.

Discovery and Biogeochemical Investigation of Chlorinated Industrial Waste in the Deep Ocean

NASA Astrophysics Data System (ADS)

Lemkau, K. L.; Kivenson, V. B.; Carmichael, C. A.; Aeppli, C.; Bagby, S. C.; Wentz, K.; Baxter, A.; Paul, B. G.; Pizarro, O.; Yoerger, D.; Reddy, C. M.; Valentine, D. L.

2014-12-01

Prior to the 1972 US ban on DDT use, dumping of solid waste from DDT manufacturing was permitted at two locations off the coast of Southern California. Between 1947 and 1961, 37-53 million liters of DDT waste (containing an estimated 350-700 metric tons of DDT) were disposed of at these deep-ocean dumpsites. In 2011 and 2013 we explored these sites with ROV Jason and AUV Sentry, discovering the remains of ~60 barrels scattered across dumpsite 2. Strikingly, many of these barrels were surrounded by distinctive white rings suggestive of microbial activity. We describe our identification and exploration of these sites and present results from chemical analysis of sediment cores collected around waste barrels. DDT and its degradation products (DDE, DDD and DDMU) were detectable at ng to μg per gram concentrations and showed spatial trends with both distance and depth around barrels. Analysis of microbial community DNA provides a first look at the role of microbiological processes in shaping these trends.

Residues of organochlorine pesticides in intertidal flat surface sediments from coastal zone of Jiangsu Province, China

NASA Astrophysics Data System (ADS)

Han, Xiumei; Zheng, Rong; Zhao, Jiale; Ma, Chao; Gao, Xiaojiang

2014-09-01

Sixteen surface sediment samples were collected and analysed to evaluate the residues of organochlorine pesticides (OCPs) from intertidal flat in Jiangsu Province. Overall, 22 OCPs were detected with total concentrations of OCPs ranging widely from 0.96 to 12.14 ng/g (dry wt). Total hexachlorocyclohexane (HCH) and total dichlorodiphenyltrichloroethane (DDT) levels varied from <0.01 to 0.67 ng/g and from 0.23 to 4.85 ng/g, respectively. DDTs were the predominant compounds. The dominance of β-HCH indicated a history of HCH pollution. According to the ratios of ( p, p'-DDD+ p, p'-DDE)/ p, p'-DDT and o,p'-DDT/ p, p'-DDT, new input of DDTs did not occur in most sites, and the main sources were historical usage of technical DDTs. OCPs such as dieldrin, endrin, p, p'-DDD, and p, p'-DDT exceeded the effects range low, showing adverse biological effects that would occasionally occur at some sites of the study area.

Insights into DDT Resistance from the Drosophila melanogaster Genetic Reference Panel.

PubMed

Schmidt, Joshua M; Battlay, Paul; Gledhill-Smith, Rebecca S; Good, Robert T; Lumb, Chris; Fournier-Level, Alexandre; Robin, Charles

2017-11-01

Insecticide resistance is considered a classic model of microevolution, where a strong selective agent is applied to a large natural population, resulting in a change in frequency of alleles that confer resistance. While many insecticide resistance variants have been characterized at the gene level, they are typically single genes of large effect identified in highly resistant pest species. In contrast, multiple variants have been implicated in DDT resistance in Drosophila melanogaster ; however, only the Cyp6g1 locus has previously been shown to be relevant to field populations. Here we use genome-wide association studies (GWAS) to identify DDT-associated polygenes and use selective sweep analyses to assess their adaptive significance. We identify and verify two candidate DDT resistance loci. A largely uncharacterized gene, CG10737 , has a function in muscles that ameliorates the effects of DDT, while a putative detoxifying P450, Cyp6w1 , shows compelling evidence of positive selection. Copyright © 2017 by the Genetics Society of America.

Residues of DDT in brains and bodies of birds that died on dosage and in survivors

USGS Publications Warehouse

Stickel, L.F.; Stickel, W.H.; Christensen, R.

1966-01-01

Residues of 1,1 ,l-trichloro-2,2-bis(p-chlorophenyl)-ethane (DDT) and 1,1 -dichloro-2.2-bis(p-chlorophenyl)-ethane (DDD) in brains of cowbirds (Molothrus ater) killed hy dietary dosage of DDT were similar in birds that died after various lengths of time on dosage and in birds that died of delayed effects after as much as 40 days on clean food, Residues of DDT and DDD, but not of 1,1 -dichloro-2.2-bis-(p-chlorophenyl)-ethylene (DDE), were much lower in survivors 112 days after dosage. The relative importance of DDT and DDD in brains could nlot he determined, but DDE appeared not to be critical. Residues in brains of cowbirds were similar to those reported for robins, sparrows, eagles, and white rats. Residues in livers and carcass remainders (with the possible exception of DDD in the liver) appeared unsuitable for diagnosing the cause of death.

Bioremediation of soil contaminated by dichlorodiphenyltrichloroethane with the use of aerobic strain Rhodococcus wratislaviensis Ch628

NASA Astrophysics Data System (ADS)

Egorova, D. O.; Farafonova, V. V.; Shestakova, E. A.; Andreyev, D. N.; Maksimov, A. S.; Vasyanin, A. N.; Buzmakov, S. A.; Plotnikova, E. G.

2017-10-01

The concentration of dichlorodiphenyltrichloroethane (DDT) was determined in a sandy soil of specially Protected Natural Area Osinskaya Lesnaya Dacha (Perm region) 45 years after the last application of the insecticide in this area. The concentration of DDT in the soil exceeded the maximum permissible concentration by 250 times and reached 25.05 mg/kg of soil. Under the conditions of model experiment, efficient decontamination of the soil was recorded in the system with the introduced strain Rhodococcus wratislaviensis Ch628; the DDT concentration decreased by 99.7% and equaled 0.07 mg/kg. The process of DDT degradation proceeded slower in the model soil system with autochthonous microbial complex. In this case, 58.2% DDT degraded in 70 days, and the final concentration was 10.47 mg/kg. The soil lost its toxicity for animal and plant test objects by the end of the experiment only in the model system containing the R. wratislaviensis Ch628 strain.

Bioassay for Volatile Low Molecular Weight Insecticides and Methods of Use

DTIC Science & Technology

2007-07-05

2003; Festucci-Buselli eta!., 2005). Hikone-R is resistant to a number of insecticides, including malathion, DDT and neonicotinoids (Sundseth et a...Hikone-R strain (LeGoff eta!. 2003; Festucci-Buselli et a!., 2005) confers resistance to malathion (Sundseth et a!., 1989), DDT, neonicotinoids (Daborn...eventually contribute to NCR with DDT, neonicotinoids and organo- phosphates such as malathion and DDVP. Regarding target site insensitivity, by the same

Comparison of semipermeable membrane device (SPMD) and large-volume solid-phase extraction techniques to measure water concentrations of 4,4'-DDT, 4,4'-DDE, and 4,4'-DDD in Lake Chelan, Washington.

PubMed

Ellis, Steven G; Booij, Kees; Kaputa, Mike

2008-07-01

Semipermeable membrane devices (SPMDs) spiked with the performance reference compound PCB29 were deployed 6.1 m above the sediments of Lake Chelan, Washington, for a period of 27 d, to estimate the dissolved concentrations of 4,4'-DDT, 4,4'-DDE, and 4,4'-DDD. Water concentrations were estimated using methods proposed in 2002 and newer equations published in 2006 to determine how the application of the newer equations affects historical SPMD data that used the older method. The estimated concentrations of DDD, DDE, and DDD calculated using the older method were 1.5-2.9 times higher than the newer method. SPMD estimates from both methods were also compared to dissolved and particulate DDT concentrations measured directly by processing large volumes of water through a large-volume solid-phase extraction device (Infiltrex 300). SPMD estimates of DDD+DDE+DDT (SigmaDDT) using the older and newer methods were lower than Infiltrex concentrations by factors of 1.1 and 2.3, respectively. All measurements of DDT were below the Washington State water quality standards for the protection of human health (0.59 ng l(-1)) and aquatic life (1.0 ng l(-1)).

DDT degradation efficiency and ecotoxicological effects of two types of nano-sized zero-valent iron (nZVI) in water and soil.

PubMed

El-Temsah, Yehia S; Sevcu, Alena; Bobcikova, Katerina; Cernik, Miroslav; Joner, Erik J

2016-02-01

Nano-scale zero-valent iron (nZVI) has been conceived for cost-efficient degradation of chlorinated pollutants in soil as an alternative to e.g permeable reactive barriers or excavation. Little is however known about its efficiency in degradation of the ubiquitous environmental pollutant DDT and its secondary effects on organisms. Here, two types of nZVI (type B made using precipitation with borohydride, and type T produced by gas phase reduction of iron oxides under H2) were compared for efficiency in degradation of DDT in water and in a historically (>45 years) contaminated soil (24 mg kg(-1) DDT). Further, the ecotoxicity of soil and water was tested on plants (barley and flax), earthworms (Eisenia fetida), ostracods (Heterocypris incongruens), and bacteria (Escherichia coli). Both types of nZVI effectively degraded DDT in water, but showed lower degradation of aged DDT in soil. Both types of nZVI had negative impact on the tested organisms, with nZVI-T giving least adverse effects. Negative effects were mostly due to oxidation of nZVI, resulting in O2 consumption and excess Fe(II) in water and soil. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

DNA damage tolerance in hematopoietic stem and progenitor cells in mice

PubMed Central

Pilzecker, Bas; Buoninfante, Olimpia Alessandra; van den Berk, Paul; Lancini, Cesare; Song, Ji-Ying; Citterio, Elisabetta

2017-01-01

DNA damage tolerance (DDT) enables bypassing of DNA lesions during replication, thereby preventing fork stalling, replication stress, and secondary DNA damage related to fork stalling. Three modes of DDT have been documented: translesion synthesis (TLS), template switching (TS), and repriming. TLS and TS depend on site-specific PCNA K164 monoubiquitination and polyubiquitination, respectively. To investigate the role of DDT in maintaining hematopoietic stem cells (HSCs) and progenitors, we used PcnaK164R/K164R mice as a unique DDT-defective mouse model. Analysis of the composition of HSCs and HSC-derived multipotent progenitors (MPPs) revealed a significantly reduced number of HSCs, likely owing to increased differentiation of HSCs toward myeloid/erythroid-associated MPP2s. This skewing came at the expense of the number of lymphoid-primed MPP4s, which appeared to be compensated for by increased MPP4 proliferation. Furthermore, defective DDT decreased the numbers of MPP-derived common lymphoid progenitor (CLP), common myeloid progenitor (CMP), megakaryocyte-erythroid progenitor (MEP), and granulocyte-macrophage progenitor (GMP) cells, accompanied by increased cell cycle arrest in CMPs. The HSC and MPP phenotypes are reminiscent of premature aging and stressed hematopoiesis, and indeed progressed with age and were exacerbated on cisplatin exposure. Bone marrow transplantations revealed a strong cell intrinsic defect of DDT-deficient HSCs in reconstituting lethally irradiated mice and a strong competitive disadvantage when cotransplanted with wild-type HSCs. These findings indicate a critical role of DDT in maintaining HSCs and progenitor cells, and in preventing premature aging. PMID:28761001

Monitoring of organochlorine pesticide residue levels in adipose tissue of Veracruz, Mexico inhabitants.

PubMed

Waliszewski, Stefan M; Caba, M; Herrero-Mercado, M; Saldariaga-Noreña, H; Meza, E; Zepeda, R; Martínez-Valenzuela, C; Infanzon, R; Hernández-Chalate, F

2011-11-01

The objective of the present study was to monitor the levels of organochlorine pesticides HCB, α-β-γ-HCH, pp'DDE, op'DDT and pp'DDT in 150 adipose tissue samples of Veracruz, Mexico inhabitants. In analyzed samples, the following pesticides were detected: p,p'-DDE in 100% of the samples at mean 1.643 mg/kg; p,p'-DDT in 99.3.% of the samples at mean 0.227 mg/kg; β-HCH in 97.3% of the samples at mean 0.063 mg/kg; and op'DDT in 93.3% of the samples at mean 0.022 mg/kg. Comparing mean, median and geometric mean concentrations of organochlorine pesticides shows a decrease in values from mean to median and to geometric mean which points out a prevalence of lower concentrations among the total samples and the existence of occasional cases of extreme exposure expressed in range values. The pooled samples divided according to sex, showed only significant differences of pp'DDE median concentrations between sexes. The other organochlorine pesticides indicated no statistical differences between sexes, including the pp'DDE/pp'DDT ratio. The samples grouped according to age, showed that the third tertile was more contaminated for both sexes, indicating age as a positively associated factor with organochlorine pesticide levels in adipose tissue of Veracruz inhabitants. Comparing organochlorine pesticide levels between 2008 and 2010 years, a decreased tendency for β-HCH, pp'DDE, Σ-DDT and pp'DDE/pp'DDT ratio levels was observed.

Expression of Hormonal Carcinogenesis Genes and Related Regulatory microRNAs in Uterus and Ovaries of DDT-Treated Female Rats.

PubMed

Kalinina, T S; Kononchuk, V V; Gulyaeva, L F

2017-10-01

The insecticide dichlorodiphenyltrichloroethane (DDT) is a nonmutagenic xenobiotic compound able to exert estrogen-like effects resulting in activation of estrogen receptor-α (ERα) followed by changed expression of its downstream target genes. In addition, studies performed over recent years suggest that DDT may also influence expression of microRNAs. However, an impact of DDT on expression of ER, microRNAs, and related target genes has not been fully elucidated. Here, using real-time PCR, we assessed changes in expression of key genes involved in hormonal carcinogenesis as well as potentially related regulatory oncogenic/tumor suppressor microRNAs and their target genes in the uterus and ovaries of female Wistar rats during single and chronic multiple-dose DDT exposure. We found that applying DDT results in altered expression of microRNAs-221, -222, -205, -126a, and -429, their target genes (Pten, Dicer1), as well as genes involved in hormonal carcinogenesis (Esr1, Pgr, Ccnd1, Cyp19a1). Notably, Cyp19a1 expression seems to be also regulated by microRNAs-221, -222, and -205. The data suggest that epigenetic effects induced by DDT as a potential carcinogen may be based on at least two mechanisms: (i) activation of ERα followed by altered expression of the target genes encoding receptor Pgr and Ccnd1 as well as impaired expression of Cyp19a1, affecting, thereby, cell hormone balance; and (ii) changed expression of microRNAs resulting in impaired expression of related target genes including reduced level of Cyp19a1 mRNA.

Exposures to the environmental toxicants pentachlorophenol (PCP) and dichlorodiphenyltrichloroethane (DDT) modify secretion of interleukin 1-beta (IL-1β) from human immune cells.

PubMed

Martin, Tamara J; Whalen, Margaret M

2017-04-01

Pentachlorophenol (PCP) and Dichlorodiphenyltrichloroethane (DDT) are environmental contaminants found in human blood. Previous studies have shown that PCP and DDT inhibit the lytic function of highly purified human natural killer (NK) lymphocytes and decrease the expression of several surface proteins on NK cells. Interleukin-1 βeta (IL-1β) is a cytokine produced by lymphocytes and monocytes, and anything that elevates its levels inappropriately can lead to chronic inflammation, which among other consequences can increase tumor development and invasiveness. Here, PCP and DDT were examined for their ability to alter secretion of IL-1β from immune cell preparations of various complexity: NK cells; monocyte-depleted (MD) peripheral blood mononuclear cells (PBMCS); and PBMCs. Cells were exposed to concentrations of PCP ranging from 5 to 0.05 µM and DDT concentrations of 2.5-0.025 μM for 24, 48 h, and 6 days. Results showed that both PCP and DDT increased IL-1β secretion from all of the immune cell preparations. The specific concentrations of PCP and DDT that increased IL-1β secretion varied by donor. Immune cells from all donors showed compound-induced increases in IL-1β secretion at one or more concentration at one or more length of exposure. The mechanism of PCP stimulation of IL1-β secretion was also addressed, and it appears that the MAPKs, ERK1/2 and p38, may be utilized by PCP to stimulate secretion of IL-1β.

KEY COMPARISON: CCQM-K21 Key Comparison Determination of pp’-DDT in fish oil

NASA Astrophysics Data System (ADS)

Webb, K. S.; Carter, D.; Wolff Briche, C. S. J.

2003-01-01

A key comparison on the determination of (pp'-dichlorodiphenyl) trichloroethane (pp'-DDT) in a fish oil matrix has been successfully completed. Nine NMIs participated in this key comparison and used the technique of isotope dilution gas-chromatography mass spectrometry (ID/GC/MS) for the determinations. Two samples (A and B) of fish oil were distributed to participants, each gravimetrically spiked with pp'-DDT. The KCRV for Sample A is 0.0743 +/- 0.0020 µg g-1 and that of Sample B is 0.1655 +/- 0.0014 µg g-1 of pp'-DDT in fish oil. The results for Sample A showed a RSD of 3.5%, the RSD for Sample B was within 1%. These results were an improvement over those of the corresponding pilot study (CCQM-P21), where at a mass fraction of pp'-DDT in fish oil of 0.311 µg g-1 the RSD was 2.6%. The compound pp'-DDT is a typical organochlorine pesticide and this key comparison has shown that NMIs have the ability to measure such compounds at levels typically found in the environment. The compound (pp'-dichlorodiphenyl) dichloroethylene (pp'-DDE), a metabolite of pp'-DDT, was the subject of a previous key comparison (CCQM-K5). The compound pp'-DDT is technically more challenging than that of pp'-DDE since it can decompose during the measurement procedure. Consequently the success of this key comparison, combined with that of CCQM-K5 demonstrates a broad measurement capability by NMIs for organochlorine compounds in the environment. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the Mutual Recognition Arrangement (MRA).

Associations of maternal o,p'-DDT and p,p'-DDE levels with birth outcomes in a Bolivian cohort.

PubMed

Arrebola, Juan P; Cuellar, Miriam; Bonde, Jens Peter; González-Alzaga, Beatriz; Mercado, Luis A

2016-11-01

This study examined the potential association of maternal serum levels of o,p'-DDT and p,p'-DDE with gestation time and with anthropometric measurements and thyroid-stimulating hormone (TSH) levels of newborns in a Bolivian birth cohort. Two hundred mothers were consecutively recruited between January and March 2013 at the "Hospital de la Mujer Dr. Percy Boland" in Santa Cruz de la Sierra. Potential confounders were derived from an ad hoc questionnaire. o,p'-DDT and p,p'-DDE were quantified in cord serum by high-resolution gas chromatography coupled with mass spectrometry. Multivariable linear regression analyses were performed, with POP concentrations as independent variables and log-transformed newborn birth outcomes (newborn weight, gestational age, head circumference, birth height, ponderal index, and TSH levels) as dependent variables. o,p'-DDT was detected in 82.5% of samples at median concentration of 0.22ng/mL and p,p'-DDE in 86.5% of samples at median concentration of 1.01ng/mL. Opposite associations with birth weight were found for p,p'-DDE (β=0.012, p=0.006) and o,p'-DDT (β=-0.014, p=0.039), and these associations were stronger when both chemicals were entered in the same model. p,p'-DDE was negatively associated with gestation time (β=-0.004, p=0.012), and o,p'-DDT was borderline negatively associated with newborn head circumference (β=-0.004, p=0.054). We observed no relevant changes in the magnitude of the coefficients or in statistical significance after adjustment for newborn TSH levels. This study indicates a possible impact of prenatal exposure to o,p'-DDT and p,p'-DDE on newborn anthropometric measurements in a population showing evidence of recent exposure to the pesticide DDT. Copyright © 2016 Elsevier Inc. All rights reserved.

An experimental hut study to quantify the effect of DDT and airborne pyrethroids on entomological parameters of malaria transmission

PubMed Central

2014-01-01

Background Current malaria vector control programmes rely on insecticides with rapid contact toxicity. However, spatial repellents can also be applied to reduce man-vector contact, which might ultimately impact malaria transmission. The aim of this study was to quantify effects of airborne pyrethroids from coils and DDT used an indoor residual spray (IRS) on entomological parameters that influence malaria transmission. Methods The effect of Transfluthrin and Metofluthrin coils compared to DDT on house entry, exit and indoor feeding behaviour of Anopheles gambiae sensu lato were measured in experimental huts in the field and in the semi-field. Outcomes were deterrence - reduction in house entry of mosquitoes; irritancy or excito-repellency – induced premature exit of mosquitoes; blood feeding inhibition and effect on mosquito fecundity. Results Transfluthrin coils, Metofluthrin coils and DDT reduced human vector contact through deterrence by 38%, 30% and 8%, respectively and induced half of the mosquitoes to leave huts before feeding (56%, 55% and 48%, respectively). Almost all mosquitoes inside huts with Metofluthrin and Transfluthrin coils and more than three quarters of mosquitoes in the DDT hut did not feed, almost none laid eggs and 67%, 72% and 70% of all mosquitoes collected from Transfluthrin, Metofluthrin and DDT huts, respectively had died after 24 hours. Conclusion This study highlights that airborne pyrethroids and DDT affect a range of anopheline mosquito behaviours that are important parameters in malaria transmission, namely deterrence, irritancy/excito-repellency and blood-feeding inhibition. These effects are in addition to significant toxicity and reduced mosquito fecundity that affect mosquito densities and, therefore, provide community protection against diseases for both users and non-users. Airborne insecticides and freshly applied DDT had similar effects on deterrence, irritancy and feeding inhibition. Therefore, it is suggested that airborne pyrethroids, if delivered in suitable formats, may complement existing mainstream vector control tools. PMID:24693934

Changes in the mRNA expression of structural proteins, hormone synthesis and secretion from bovine placentome sections after DDT and DDE treatment.

PubMed

Wojciechowska, A; Mlynarczuk, J; Kotwica, J

2017-01-15

Disorders in the barrier function and secretory activity of the placenta can be caused by xenobiotics (XB) present in the environment and their accumulation in tissues of living organisms. Thus, the aim of this study was to investigate the effect of 1,1,1-trichloro-2,2,-bis-4-chlorophenyl-ethane (DDT) and its metabolite 1,1-dichloro-2,2-bis-4-chlorophenyl-ethene (DDE) (for 24 or 48h) at doses of 1, 10 or 100ng/ml on the function of cow placentome sections in the second trimester of pregnancy. DDT and DDE affected neither (P>0.05) the viability nor hypoxia inducible factor 1 (HIF1α) mRNA expression of the sections. XB decreased (P<0.05) connexin (Cx) 26, 32, 43 and placenta-specific 1 (PLAC-1) mRNA expression but did not affect (P>0.05) keratin 8 (KRT8) mRNA expression. DDT and DDE also reduced (P<0.05) prostaglandin F2α (PGF2α) synthase (PGFS) mRNA expression, while DDT increased (P<0.05) prostaglandin E2 (PGE2) synthase (PGES) mRNA expression. Neither cyclooxygenase 2 (COX-2) mRNA expression nor PGF2α and PGE2 secretion were affected. Both DDT and DDE increased (P<0.05) neurophysin I/oxytocin (NP1/OT) mRNA expression and oxytocin (OT), oestradiol (E2) and progesterone (P4) secretion while DDT stimulated only 3β-hydroxysteroid dehydrogenase (3βHSD) and cholesterol side-chain cleavage enzyme (CYP11A1) mRNA expression (P<0.05). In summary, DDT and DDE impaired the barrier function and secretory activity of the placenta. Thus, these compounds can disrupt trophoblast invasion, myometrium contractility and gas/nutrient exchange throughout pregnancy in cows. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

PubMed

Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

2007-01-01

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

The effect of DDT and its metabolite (DDE) on prostaglandin secretion from epithelial cells and on contractions of the smooth muscle of the bovine oviduct in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wrobel, Michal H.; Mlynarczuk, Jaroslaw; Kotwica, Jan, E-mail: janko@pan.olsztyn.pl

2012-03-01

The insecticide DDT and its metabolite (DDE), due to their lipolytic nature and resistance to biodegradation, are accumulated in the living tissues. In cows, DDT and DDE were found to affect prostaglandin (PG) secretion from the endometrium and contractions of the myometrium. In this study, the impact of both xenobiotics (0.1, 1, 10 or 100 ng/ml) on the function of epithelial cells and muscle strips of bovine oviducts from 1 to 5 day of the oestrous cycle was examined. Therefore the concentration of PGE2 and PGFM (a metabolite of PGF2α) in culture media, mRNA expression of genes involved in PGsmore » synthesis in epithelial cells and the force and amplitude of strips contractions were measured after 2 and 24 or 48 h of incubation. Neither DDT nor DDE affected the viability of cells after 48 h (P > 0.05). Both DDT and DDE increased the concentrations of PGFM in culture medium and secretion of PGE2 after only 2 h of cell culture (P < 0.05). Similar effects were seen for the influence of DDE on amount of PGFM after 48 h, while DDT decreased secretion of PGE2 (P < 0.05). DDT after 2 h increased (P < 0.05) mRNA expression of PGF2α synthase (PGFS), while both xenobiotics decreased (P < 0.05) mRNA expression of cyclooxygenase-2 (COX-2) after 24 h. DTT also increased the force of isthmus contractions after 2 h, as did both xenobiotics after 48 h (P < 0.05). Moreover, after 2 and 48 h, DDE stimulated the amplitude of contractions of the isthmus as well as the ampulla, (P < 0.05). The effect of both compounds on oviduct contractions was diminished by indomethacin, which blocks PG synthesis. We conclude that oviductal secretion of prostaglandins is affected, by DDT and DDE. The influence of these xenobiotics on PGF2α and PGE2 secretion and ratio may be part of the mechanism by which both DDT and its metabolite disturb the contractions of oviductal muscle. -- Highlights: ► DDT and its metabolite – DDE are accumulated in the living tissues. ► The insecticides affected PGF2α and PGE2 release from epithelial cells of oviduct. ► They also stimulated markedly the contractions of oviductal strips. ► Prostaglandins were involved in the effect of insecticides on oviduct function.« less

Cometabolism of DDT analogs by a Pseudomonas sp.

PubMed Central

Francis, A J; Spanggord, R J; Ouchi, G I; Bohonos, N

1978-01-01

A Pseudomonas sp. capable of growth on several nonchlorinated and mono-p-chloro-substituted analogs of DDT as a sole carbon source degraded bis(p-chlorophenyl)methane and 1,1-bis(p-chlorophenyl)ethane only in the presence of diphenylethane. The products p-chlorophenylacetic acid and 2-(p-chlorophenyl)-propionic acid were not further metabolized by the bacterium. Other chlorinated analogs of DDT were found to be recalcitrant to cometabolic degradation with diphenylethane. PMID:637537

Space transportation system payload interface verification

NASA Technical Reports Server (NTRS)

Everline, R. T.

1977-01-01

The paper considers STS payload-interface verification requirements and the capability provided by STS to support verification. The intent is to standardize as many interfaces as possible, not only through the design, development, test and evaluation (DDT and E) phase of the major payload carriers but also into the operational phase. The verification process is discussed in terms of its various elements, such as the Space Shuttle DDT and E (including the orbital flight test program) and the major payload carriers DDT and E (including the first flights). Five tools derived from the Space Shuttle DDT and E are available to support the verification process: mathematical (structural and thermal) models, the Shuttle Avionics Integration Laboratory, the Shuttle Manipulator Development Facility, and interface-verification equipment (cargo-integration test equipment).

DDE, DDT + dieldrin: Residues in American kestrels and relations to reproduction

USGS Publications Warehouse

Wiemeyer, Stanley N.; Porter, Ron; Hensler, G.L.; Maestrelli, J.R.

1986-01-01

Captive American kestrels (Falco sparverius) given long-term dietary dosages of DDT and dieldrin in combination, at low and high rates, were compared with controls to determine the effects of the toxicants on reproductive success and eggshell thickness. Additional kestrels were dosed with DDE to determine its effect on shell thickness. Tissues of birds that died or were sacrificed, and eggs, were analyzed for DDE, DDD, DDT, and dieldrin. Eight paired birds, mostly males, given a high dosage of DDT + dieldrin died of dieldrin poisoning. Three periods of heavy mortality involving only dosed birds, which occurred in summer 1966, fall 1967, and spring 1968, followed temperature declines and other stress factors. Organochlorine concentrations in tissues of sacrificed birds and eggs in all units of the DDT + dieldrin study were significantly different among treatments. Residue concentrations in tissues of birds on high dosage of DDT + dieldrin were about 3 times higher than those on low dosage, a difference similar to the relative magnitude of the dose rates. Concentrations of some toxicants, especially DDE, were significantly higher in tissues of males than females, although these differences were difficult to interpret because males generally were sacrificed later than females. Concentrations in tissues and eggs of dosed yearlings, placed on clean food 7 to 9 weeks before pairing, were often significantly lower than in those yearlings that remained on dosage. Concentrations of each toxicant were usually highly correlated (r > 0.85) among tissues, especially for DDE and dieldrin. Organochlorine concentrations in brains and eggs could be predicted from concentrations in carcasses. DDE and dieldrin concentrations in eggs were about one-half those in carcasses, DDD about one-seventh, and DDT 1.5 to 2 times higher in eggs than carcasses. Eggshells of DDT + dieldrin-dosed kestrels were 6-23% thinner than eggshells of corresponding controls in different groups and years. Organochlorine concentrations in eggs and tissues of females were poorly correlated with shell thickness. Of the four toxicants in eggs, DDE was significantly and most closely correlated with fledging success. Interpretation of direct comparisons between our DDT + dieldrin studies and most current field situations are difficult because contaminant profiles in our birds are unlike those in most field samples.

Measurement of DDT fluxes from a historically treated agricultural soil in Canada.

PubMed

Kurt-Karakus, Perihan Binnur; Bidleman, Terry F; Staebler, Ralf M; Jones, Kevin C

2006-08-01

Organocohlorine pesticide (OCP) residues in agricultural soils are of concern due to the uptake of these compounds by crops, accumulation in the foodchain, and reemission from soils to the atmosphere. Although it has been about three decades since DDT was banned for agricultural uses in Canada, residues persist in soils of some agricultural areas. Emission of DDT compounds to the atmosphere from a historically treated field in southern Ontario was determined in fall 2004 and spring 2005. The sigmaDDTs concentration in the high organic matter (71%) soil was 19 +/- 4 microg g(-1) dry weight. Concentration gradients in the air were measured at 5, 20, 72, and 200 cm above soil using glass fiber filter-polyurethane foam cartridges. Air concentrations of sigmaDDTs averaged 5.7 +/- 5.1 ng m(-3) at 5 cm and decreased to 1.3 +/- 0.8 ng m(-3) at 200 cm and were 60-300 times higher than levels measured at a background site 30 km away. Soil-air fugacity fractions, fs/(fs + fa), of p,p'-DDE, p,p'-DDD, and p,p'-DDT ranged from 0.42 to 0.91 using air concentrations measured above the soil and > or = 0.99 using background air concentrations, indicating that the soil was a net source to the background air. Fractionation of DDT compounds during volatilization was predicted using either liquid-phase vapor pressures (PL) or octanol-air partition coefficients (KOA). Relative emissions of p,p'-DDE and p,p'-DDT were better described by PL than KOA, whereas either PL or KOA successfully accounted for the fractionation of p,p'-DDT and o,p'-DDT. Soil-to-air fluxes were calculated from air concentration gradients and turbulent exchange coefficients determined from micrometeorological measurements. Average fluxes of sigmaDDTs were 90 +/- 24 ng m(-2) h(-1) in fall and 660 +/- 370 ng m(-2) h(-1) in spring. Higher soil temperatures in spring accounted for the higher fluxes. A volatilization half-life of approximately 200 y was estimated for sigmaDDT in the upper 5 cm of the soil column, assuming the average flux rate for 12 h d-(1) over 8 months of the year. Thus, in the absence of other dissipation processes, the soil will continue to be a source of atmospheric contamination for a very long time.

Use of the p,p'-DDD: p,p'-DDE concentration ratio to trace contaminant migration from a hazardous waste site.

PubMed

Pinkney, Alfred E; McGowan, Peter C

2006-09-01

For approximately 50 years, beginning in the 1920s, hazardous wastes were disposed in an 11-hectare area of the Marine Corps Base (MCB) Quantico, Virginia, USA known as the Old Landfill. Polychlorinated biphenyls (PCBs) and DDT compounds were the primary contaminants of concern. These contaminants migrated into the sediments of a 78-hectare area of the Potomac River, the Quantico Embayment. Fish tissue contamination resulted in the MCB posting signs along the embayment shoreline warning fishermen to avoid consumption. In this paper, we interpret total PCB (t-PCBs) and total DDT (t-DDT, sum of six DDT, DDD, and DDE isomers) data from monitoring studies. We use the ratio of p,p'-DDD to p,p'-DDE concentrations as a tracer to distinguish site-related from regional contamination. The median DDD/DDE ratio in Quantico Embayment sediments (3.5) was significantly higher than the median ratio (0.71) in sediments from nearby Powells Creek, used as a reference area. In general, t-PCBs and t-DDT concentrations were significantly higher in killifish (Fundulus diaphanus) and carp (Cyprinus carpio) from the Quantico Embayment compared with Powells Creek. For both species, Quantico Embayment fish had mean or median DDD/DDE ratios greater than one. Median ratios were significantly higher in Quantico Embayment (4.6) than Powells Creek (0.28) whole body carp. In contrast, t-PCBs and t-DDT in channel catfish (Ictalurus punctatus) fillets were similar in Quantico Embayment and Powells Creek collections, with median ratios of 0.34 and 0.26, respectively. Differences between species may be attributable to movement (carp and killifish being more localized) and feeding patterns (carp ingesting sediment while feeding). We recommend that environmental scientists use this ratio when investigating sites with DDT contamination.

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

PubMed

Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

2015-10-01

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

Distinct Roles of the DmNav and DSC1 Channels in the Action of DDT and Pyrethroids

PubMed Central

Rinkevich, Frank D.; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S.; Dong, Ke

2015-01-01

Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (parats) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a parats1 allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in parats1 mutant flies was almost completely abolished in parats1;DSC1−/− double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w1118A), and the parats1;DSC1−/− double mutant flies were even more resistant to DDT compared to the DSC1 knockout or parats1 mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance. PMID:25687544

Current status and historical variations of DDT-related contaminants in the sediments of Lake Chaohu in China and their influencing factors.

PubMed

Kang, Lei; He, Qi-Shuang; He, Wei; Kong, Xiang-Zhen; Liu, Wen-Xiu; Wu, Wen-Jing; Li, Yi-Long; Lan, Xin-Yu; Xu, Fu-Liu

2016-12-01

The temporal-spatial distributions of DDT-related contaminants (DDXs), including DDT (dichlorodiphenyltrichloroethane), DDE (dichlorodiphenyldichloroethylene) and DDD (dichlorodiphenyldichloroethane), in the sediments of Lake Chaohu and their influencing factors were studied. p,p-DDE and p,p-DDD were found to be the two dominant components of DDXs in both surface and core sediments. The parent DDT compounds were still detectable in sediment cores after the late 1930s. Historical usage of technical DDT was identified as the primary source of DDXs in sediments, as indicated by DDT/(DDD + DDE) ratios of less than one. The residual levels of DDXs were higher in the surface and core sediments in the western lake area than in other lake areas, which might be due to the combined inflow effects of municipal sewage, industrial wastewater and agricultural runoff. The DDX residues in the sediment cores reached peak values in the late 1970s or early 1980s. There were significant positive relationships between DDX residues in sediment cores with annual DDT production and with fine particulate sizes (<4.5 μm). The relationship between the DDXs and TOC in sediment was complex, as indicated by the significant differences among the surface and core sediments. The algae-derived organic matter significantly influenced the amount of residue, composition and distribution of DDXs in the sediments. The DDD/DDE ratios responded well to the anaerobic conditions in the sediments that were caused by algal blooms after the late 1970s in the western lake area. This suggests that the algae-derived organic matter was an important factor and served as a biomarker of eutrophication and also affected the DDX residues and lifecycle in the lake ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

DDT Vertical Migration and Formation of Accumulation Layer in Pesticide-Producing Sites.

PubMed

Liu, Li; Bai, Liping; Man, Changgeng; Liang, Wuhong; Li, Fasheng; Meng, Xiaoguang

2015-08-04

Soil samples were collected at various depths (0.5-21.5 m) from ten boreholes that were drilled with a SH-30 Model Rig, four of which were at a dicofol production site while six were at a dichlorodiphenyltrichloroethane (DDT) production site. In industrial sites, the shallow soils at depths of 0-2 m were mostly backfill soils, which cannot represent the contamination situation of the sites. The contaminated levels in the deep original soil can represent the situation in contaminated sites. All the soil samples investigated at the DDT and dicofol production sites were found to be seriously polluted. The contents of both DDT (0.6-6071 mg/kg) and dicofol (0.5-1440 mg/kg) were much higher at the dicofol production site than at the DDT production site (DDTs, 0.01-664.6 mg/kg; dicofol, <0.1 mg/kg), even in the deep soil. DDTs had a different distribution in the soil of the pesticide production site from that in the soil outside the sites and that in agricultural soils. The results of the investigation revealed that DDTs were easily enriched in cohesive soil and in the bottom zone of aquifers, where the concentration was higher than in above the layers. DDTs were found to be hard to degrade, and their degradation speed was slower than their vertical migration, despite the fact that hydrophobic DDTs did not migrate easily in soils. In the dicofol production site, the value of DDE/DDD cannot indicate the degradation condition of DDTs, nor can the value of (DDE + DDD)/DDT identify how long DDTs have remained in the soil. It is debatable that the half-life of DDT inputted to soils is about 20-30 years, maybe longer than the generally recognized time.

Persistent organohalogen contaminants in plasma from groups of humans with different occupations in Bangladesh.

PubMed

Zamir, R; Athanasiadou, M; Nahar, N; Mamun, M I R; Mosihuzzaman, M; Bergman, A

2009-01-01

The present study is aimed to assess persistent organic halogenated pollutants in humans living in Bangladesh. The results are compared to other similar studies in the region and globally. Human blood plasma were collected from groups of men and women with different occupations, i.e. being students, garment industry workers, employees at the Power Development Board (PDB), all groups in Dhaka, fishermen and fishermen wife's from Dhaka and another group from Barisal district. The plasma was analysed for hexachlorobenzene (HCB), the hexachlorocyclohexane isomers, alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, the DDT group of chemicals, chlordane compounds, trans-chlordane, cis-chlordane, oxychlordane, trans-nonachlor, trans-heptachlorepoxide, methoxychlor and mirex. The most abundant contaminant, in all groups studied, p,p'-DDE is dominating, with p,p'-DDT/Sigma DDT ratios indicating recent and ongoing DDT exposure. Among the other pesticides analysed beta-HCH is the most abundant indicating the use of technical HCH products instead of Lindane (gamma-HCH). While the Sigma DDT is present in the low ppm range the beta-HCH is detected in up to approx. 400 ppb, lipid basis. The beta-HCH is most abundant in the groups of students. In contrast to the pesticides analysed very low concentrations of polychlorinated biphenyls (PCB) are present in all study groups, with e.g. CB-153 in the range of 5-30 ng g(-1) fat. The concentrations of the DDT group of chemical differ significantly between fishermen and fishermen's wives living and working in the Dhaka area versus those living and working in Barisal. Also, fishermen and their wives had significantly different concentrations of DDT compared to garment industry workers.

MIF and D-DT are potential disease severity modifiers in male MS subjects

PubMed Central

Benedek, Gil; Meza-Romero, Roberto; Jordan, Kelley; Zhang, Ying; Nguyen, Ha; Kent, Gail; Li, Jia; Siu, Edwin; Frazer, Jenny; Piecychna, Marta; Du, Xin; Sreih, Antoine; Leng, Lin; Wiedrick, Jack; Caillier, Stacy J.; Offner, Halina; Oksenberg, Jorge R.; Yadav, Vijayshree; Bourdette, Dennis; Bucala, Richard; Vandenbark, Arthur A.

2017-01-01

Little is known about mechanisms that drive the development of progressive multiple sclerosis (MS), although inflammatory factors, such as macrophage migration inhibitory factor (MIF), its homolog D-dopachrome tautomerase (D-DT), and their common receptor CD74 may contribute to disease worsening. Our findings demonstrate elevated MIF and D-DT levels in males with progressive disease compared with relapsing-remitting males (RRMS) and female MS subjects, with increased levels of CD74 in females vs. males with high MS disease severity. Furthermore, increased MIF and D-DT levels in males with progressive disease were significantly correlated with the presence of two high-expression promoter polymorphisms located in the MIF gene, a −794CATT5–8 microsatellite repeat and a −173 G/C SNP. Conversely, mice lacking MIF or D-DT developed less-severe signs of experimental autoimmune encephalomyelitis, a murine model of MS, thus implicating both homologs as copathogenic contributors. These findings indicate that genetically controlled high MIF expression (and D-DT) promotes MS progression in males, suggesting that these two factors are sex-specific disease modifiers and raising the possibility that aggressive anti-MIF treatment of clinically isolated syndrome or RRMS males with a high-expresser genotype might slow or prevent the onset of progressive MS. Additionally, selective targeting of MIF:CD74 signaling might provide an effective, trackable therapeutic approach for MS subjects of both sexes. PMID:28923927

Risk assessment for children exposed to DDT residues in various milk types from the Greek market.

PubMed

Tsakiris, Ioannis N; Goumenou, Marina; Tzatzarakis, Manolis N; Alegakis, Athanasios K; Tsitsimpikou, Christina; Ozcagli, Eren; Vynias, Dionysios; Tsatsakis, Aristidis M

2015-01-01

The occurrence of residues of DDT and its metabolites was monitored in 196 cow milk samples of various pasteurized commercial types collected from the Greek market. Residue levels were determined by GC-MS analysis. In 97.4% of the samples at least one DDT isomer or one of the DDT metabolites was detected, in levels not exceeding the maximum permitted residue level by the EU. Hazard Index for both carcinogenic and non-carcinogenic effects was estimated under two assumptions: a) using DDT concentrations from positive samples and b) imputing LOD/2 as an arbitrary concentration for negative samples. No statistically significant differences in detected or summed residue (p > 0.05) concentrations between different milk types were observed, with the exception of specific metabolites of DDT in some milk types. Exposure assessment scenarios were developed for children aged 1, 3, 5, 7 and 12 years old based on estimated body weights and daily milk consumption. Hazard Indices for non-carcinogenic effects were below 0.109 covering also carcinogenic effects according to WHO approach. The cancer risk values for carcinogenic effects according to the US EPA Cancer Benchmark Concentration approach, ranged from 0.4 to 18. For both effects the highest values were calculated for the 1- to 3-year-old age groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tissue distribution of HCH and DDT congeners and human health risk associated with consumption of fish collected from Kabul River, Pakistan.

PubMed

Aamir, Muhammad; Khan, Sardar; Nawab, Javed; Qamar, Zahir; Khan, Anwarzeb

2016-03-01

Distribution of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) congeners in tissues of four different fish species and their associated potential health risks to local consumers are presented in this paper. The average ∑(HCHs+DDTs) concentration in Glyptothorax punjabensis (214ngg(-1) wet weight (ww)) (carnivores) was found higher than Tor putitora (155ngg(-1) ww) (herbivores). The distribution of ∑(HCHs+DDTs) in all fish tissues was found in order of liver>muscle>stomach>gills. The profile of congeners (β-HCH/∑HCH from 0.29-0.47) indicated that all selected fish species were contaminated with HCH because of its recent usage in the study area. Furthermore, DDT profile ((DDE+DDD)/∑DDT from 0.61-0.78) showed that fish contamination with DDT originated from past usage and long-time degradation mechanism. The average estimated daily dietary intake of ∑HCHs (15.0ngkg(-1) day(-1)) was higher than ∑DDTs (12.5ngkg(-1) day(-1)) by the local consumers via fish consumption. On the basis of both 50th and 95th percentile exposure levels, the carcinogenic hazard ratios for DDT and its congeners were exceeded one (safe limit) for all fish species, indicating a great potential cancer risk for local consumers with life time consumption of contaminated fish collected from Kabul River. Copyright © 2015 Elsevier Inc. All rights reserved.

Spatial distributions and enantiomeric signatures of DDT and its metabolites in tree bark from agricultural regions across China.

PubMed

Niu, Lili; Xu, Chao; Zhang, Chunlong; Zhou, Yuting; Zhu, Siyu; Liu, Weiping

2017-10-01

Tree bark is considered as an effective passive sampler for estimating the atmospheric status of pollutants. In this study, we conducted a national scale tree bark sampling campaign across China. Concentration profiles revealed that Eastern China, especially the Jing-Jin-Ji region (including Hebei Province, Beijing and Tianjin) was a hot spot of bark DDT pollution. The enantioselective accumulation of o,p'-DDT was observed in most of the samples and 68% of them showed a preferential depletion of (+)-o,p'-DDT. These results suggest that DDTs in rural bark are likely from combined sources including historical technical DDTs and fresh dicofol usage. The tree bulk DDT levels were found to correlate with soil DDT concentrations, socioeconomy and PM 2.5 of the sampling sites. It thus becomes evident that the reemission from soils and subsequent atmospheric deposition were the major pathways leading to the accumulation of DDTs in bark. Based on a previously established bark-air partitioning model, the concentrations of DDTs in the air were estimated from measured concentrations in tree bark, and the results were comparable to those obtained by the use of passive sampling with polyurethane foam (PUF) disks. Our results demonstrate the feasibility of delineating the spatial variations in atmospheric concentration and tracing sources of DDTs by integrating the use of tree bark with enantiomeric analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Mango leaves (Manguifera indica, Anacardiacea) used as biomarker of pollution by pp'Dichlorodiphenyltrichloroethane (pp'DDT)].

PubMed

Diouf, A; Diop, Y M; Ndiaye, B; Fall, M; Sarr, D; Thiam, A; Barry, O; Thiaw, C; Ba, D; Ciss, M

2000-01-01

Dichlorodiphenyltrichloroethane (DDT), organochlorine pesticide, byanother way cumulative pesticide is banned in mostdeveloped countries. Whatever, it is still used in many countries in the Third World. This work consist to check whether this chemical compound is still used in Senegal. The biomarker of pollution by this pesticide for this research was mango leaves (mango tree is widespread in Senegal) open to accumulate halogenated hydrocarbons. Leaves sample were taken in many sites in the centerline of Dakar-Thiès (Senegal), then analysed by gas chromatography. The results allowed to note the presence of DDT and its metabolites [(dichlorodiphenyltrichloroethylen (DDE), (dichlorodiphenyltrichloroethane (DDD)] in most of samples. The comparison of DDT content in relation to those of the principal metabolite allowed to make the difference according to sample sites, an old contamination of an utilisation more or less recent of this pesticide. From those results, we can conclude that DDT, typical pesticide by its big persistence is still used in some spherical zones in this country, in particular in farming gardening zones.

Levels of organochlorine pesticides residues in human adipose tissue, data from Tabasco, Mexico.

PubMed

Waliszewski, Stefan M; Caba, M; Rodríguez Díaz, S S; Saldarriaga-Noreña, H; Meza, E; Zepeda, R; Infanzón, R

2012-11-01

The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, p,p'-DDE, o,p'-DDT and p,p'-DDT in 150 adipose tissue of inhabitants of Tabasco, Mexico. The following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.034 mg/kg; p,p'-DDT in 96.7% at mean 0.116 mg/kg; o,p'-DDT in 78.7% at mean 0.022 mg/kg and β-HCH in 58.0% at mean 0.049 mg/kg. The pooled sample was divided according to sex of donors (75 female and 75 male). Significantly higher levels of all organochlorine pesticides in females were found. The sample was divided into three age's ranges (15-28, 29-45 and 46-84 years). The mean and median levels of β-HCH, p,p'-DDE and Σ-DDT increase significantly (p < 0.05) from the first to the second and third group. The presence of organochlorine pesticide residues in Tabasco inhabitants is still observed, indicating sources of exposure to the pesticides.

Influence of Breastfeeding Time on Levels of Organochlorine Pesticides in Human Milk of a Mexican Population.

PubMed

Chávez-Almazán, Luis A; Diaz-Ortiz, Jesús; Alarcón-Romero, Mario; Davila-Vazquez, Gustavo; Saldarriaga-Noreña, Hugo; Sampedro-Rosas, Laura; López-Silva, Saúl; Santiago-Moreno, Agustín; Rosas-Acevedo, José L; Waliszewski, Stefan M

2016-02-01

This study was conducted with the objective of determining whether there is a depuration of organochlorine pesticides in breast milk according to breastfeeding time. In total, 171 samples from mothers that lived in the State of Guerrero, Mexico were analyzed. There was a weak negative relationship between pp'DDE (r = -0.216) and Σ-DDT (r = -0.222) concentrations with the days of lactation. In a comparison analysis, a statistically significant decrease of pp'DDT and pp'DDE levels was observed, as well as the Σ-DDT from the first to the fifth week of lactation. A reduction of 0.188 mg/kg lipid of pp'DDE and 0.181 mg/kg lipid of Σ-DDT per week was obtained. HCB, β-HCH and op'DDT concentrations were low and had no major fluctuations between subgroups. The low levels found and the observed reduction in time involve less exposure to the infant to these pollutants. Through this methodology changes in levels of certain organochlorine pesticides in various stages of human milk production may be shown.

[Levels of dichlorodiphenyltrichloroethane internal exposure levels in pregnant women of Xiamen and influencing factors].

PubMed

Yu, X S; He, J; Chen, J H; Lai, Z B; Su, Y H; Shi, M M; Huang, Z X; Cheng, Q J; Ke, X Y; Zhao, B H

2016-11-06

Objective: To investigate the level of and factors influencing internal exposure to dichlorodiphenyltrichloroethane (DDT) in pregnant women. Methods: In all, 1 064 pregnant women were recruited in a hospital of Xiamen. Participants were asked to complete a questionnaire to obtain data on sociodemographic characteristics and lifestyle. Peripheral venous blood and cord blood samples were collected. Of the 1 064 pregnant women, 600 were enrolled in this study after completing the questionnaire and providing peripheral venous blood and cord blood. Among those women, 150 were selected randomly using a systematic sampling method. A gas chromatography coupled electron capture detector was used to determine the concentration of six DDT homologues: p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), o,p'-dichlorodiphenyltrichloroethane (o,p'-DDT), p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), o,p'-dichlorodiphenyldichloroethane (o,p'-DDD), p,p'-dichlorodiphenylethylene (p,p'-DDE), and o,p'-dichlorodiphenylethylene (o,p'-DDE) . Pregnant women were divided into two groups according to DDT concentration: a low concentration group (detection value≤ P 50 ) and a high concentration group (detection value> P 50 ). multivariate logistic regression was used to analyze the association between the DDT levels and potential influencing factors which investigated in the questionnaire. Results: The detection rates of p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE and o,p'-DDE in the peripheral venous blood samples from the 150 pregnant women were 83.3% (125), 29.3% (44), 58.0% (87), 24.0% (36), 82.0% (123), and 34.7% (52), respectively. The median concentrations were 1.56, 0.03, 0.07, 0.03, 0.93 and 0.03 μg/ml, respectively. The detection rates of p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE and o,p'-DDE in the cord blood samples were 69.3% (104), 10.7% (16), 29.3% (44), 20.7% (31), 81.3% (122) and 45.3% (68), and the median concentrations were 0.41, 0.03, 0.03, 0.03, 0.42 and 0.03 μg/ml, respectively. The concentration ranges in the low and high DDT concentration groups which contained 75 respondents respectively were 0-3.69 and 3.74-82.09 μg/ml, respectively. In the single-factor analysis, the number (percentage) of those who consumed seafood " rarely" , "less than twice a week" , and " twice a week or more" was 15 (20.3%), 22 (29.7%), and 37 (50.0%), respectively, in the low concentration group, and 4(5.3%), 20(26.7% ), and 51(68.0% ) in the high concentration group (χ 2 =8.69, P= 0.013). The results of the multivariate logistic regression analysis indicate that pregnant women who consume seafood less than twice a week, twice a week or more have higher peripheral blood DDT concentrations compared with those who rarely consume seafood. The OR (95% CI ) values were 1.14 (1.08-1.21), 2.11 (1.55-2.85), respectively. Conclusion: The exposure level of pregnant women to DDTs in the Xiamen area is higher than that of women in other regions. High seafood intake is a risk factor for internal exposure to DDTs.

THE DEUTERIUM ISOTOPE RATE EFFECT IN FREE RADICAL REACTIONS OF t-CARBON DEUTERATED DDT AND ITS ANALOGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dachauer, A.C.

1962-01-01

DDT and several of its analogs were synthesized with deuterium in the t- carbon position so that any chemical reaction involving this site in the molecule would then be subject to the deuterium isotope rate effect. Lithium aluminum deuteride, used as the source of the deuterium, was employed to reduce trichloromethyl p-chlorophenyl ketone, trichloromethyl p-bromophenyl ketone, and trichloromethyl p-methoxyphenyl ketone to the corresponding alcohols. The alcohols were then condensed with chlorobenzene, bromobenzene, and anisole respectively to form 1,1,1-trichloro2,2-bis(p-chloro-phenyl)ethane-2-d (d-DDT), 1,1,1-trichloro-2,2-bis (p-bromophenyl)ethane-2-d (d-DBrDT), and 1,1, 1-trichloro- 2,2-bis (p-methoxyphenyl)ethane (d-methoxychlor). The deuterated and non- deuterated insecticides were identical in physical appearance andmore » melting points. Infrared spectra showed sigrificant differences; in particular, each deuterated compound had a distinctive band at ca 10.5 mu , missing in the spectra of the non-deuterated insecticides. NMR analysis confirmed the tertiary position of the deuterium and gave proof of high isotopic purity, each insecticide being 98% deuterated in the desired site. The isotope rate effect was first studied in the reaction of DDT, methoxychlor, and their deuterated analogs with alcoholic sodium- hydroxide. The base catalyzed dehydrohalogenation showed an isotope rate effect, k/sub H//k/sub D/, of the order of 5.4 for DDT and 8 for methoxychlor. The results were considered to be of a magnitude sufficient for the isotope rate effect to be manifested in the in vivo studies. The insecticides and their deuterated analogs were tested for toxicity on houseflies. The results showed that d-DDT and d-DBrDT were more toxic than their non-deuterated counterparts by a factor of ca 1.5 while d-methoxychlor showed a toxicity equal to methoxychlor. The results are explained on the basis of the detoxication process in the insects. In vitro studies showed that DDT-dehydrochlorinase, an enzyme capable of detoxifying DDT, manifested the isotope rate effect. It appeared, therefore, that in the detoxication process, the deuterated insecticide reacted more slowly, and though the initial dose given to the insect was less than that of the non- deuterated insecticide, the amount reaching the susceptible site in the insect was the same. The data support the view that at least one mode of resistance to DDT is chemical in nature and that the tertiary carbon-hydrogen group is involved. The data also indicated that susceptible houseflies contain some mechanlsm that can detoxify DDT and that this detoxication is chemical and subject to the isotope rate effect. (P.C.H.)« less

Evaluation of the efficacy of DDT indoor residual spraying and long-lasting insecticidal nets against insecticide resistant populations of Anopheles arabiensis Patton (Diptera: Culicidae) from Ethiopia using experimental huts

PubMed Central

2014-01-01

Background Indoor Residual Spraying (IRS) and Long-Lasting Insecticidal nets (LLINs) are major malaria vector control tools in Ethiopia. However, recent reports from different parts of the country showed that populations of Anopheles arabiensis, the principal malaria vector, have developed resistance to most families of insecticides recommended for public health use which may compromise the efficacy of both of these key vector control interventions. Thus, this study evaluated the efficacy of DDT IRS and LLINs against resistant populations of An. arabiensis using experimental huts in Asendabo area, southwestern Ethiopia. Methods The susceptibility status of populations of An. arabiensis was assessed using WHO test kits to DDT, deltamethrin, malathion, lambda-cyhalothrin, fenitrothion and bendiocarb. The efficacy of LLIN (PermaNet® 2.0), was evaluated using the WHO cone bioassay. Moreover, the effect of the observed resistance against malaria vector control interventions (DDT IRS and LLINs) were assessed using experimental huts. Results The findings of this study revealed that populations of An. arabiensis were resistant to DDT, deltamethrin, lambda-cyhalothrin and malathion with mortality rates of 1.3%, 18.8%, 36.3% and 72.5%, respectively but susceptible to fenitrothion and bendiocarb with mortality rates of 98.81% and 97.5%, respectively. The bio-efficacy test of LLIN (PermaNet® 2.0) against An. arabiensis revealed that the mosquito population showed moderate knockdown (64%) and mortality (78%). Moreover, mosquito mortalities in DDT sprayed huts and in huts with LLINs were not significantly different (p > 0.05) from their respective controls. Conclusion The evaluation of the efficacy of DDT IRS and LLINs using experimental huts showed that both vector control tools had only low to moderate efficacy against An. arabiensis populations from Ethiopia. Despite DDT being replaced by carbamates for IRS, the low efficacy of LLINs against the resistant population of An. arabiensis is still a problem. Thus, there is a need for alternative vector control tools and implementation of appropriate insecticide resistance management strategies as part of integrated vector management by the national malaria control program. PMID:24678605

Two multidimensional chromatographic methods for enantiomeric analysis of o,p'-DDT and o,p'-DDD in contaminated soil and air in a malaria area of South Africa.

PubMed

Naudé, Yvette; Rohwer, Egmont R

2012-06-12

In rural parts of South Africa the organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control where traditional dwellings are sprayed on the inside with small quantities of technical DDT. Since o,p'-DDT may show enantioselective oestrogenicity and biodegradability, it is important to analyse enantiomers of o,p'-DDT and its chiral degradation product, o,p'-DDD, for both health and environmental-forensic considerations. Generally, chiral analysis is performed using heart-cut multidimensional gas chromatography (MDGC) and, more recently, comprehensive two-dimensional gas chromatography (GC×GC). We developed an off-line gas chromatographic fraction collection (heart-cut) procedure for the selective capturing of the appropriate isomers from a first apolar column, followed by reinjection and separation on a second chiral column. Only the o,p'-isomers of DDT and DDD fractions from the first dimension complex chromatogram (achiral apolar GC column separation) were selectively collected onto a polydimethylsiloxane (PDMS) multichannel open tubular silicone rubber trap by simply placing the latter device on the flame tip of an inactivated flame ionisation detector (FID). The multichannel trap containing the o,p'-heart-cuts was then thermally desorbed into a GC with time-of-flight mass spectrometry detection (GC-TOFMS) for second dimension enantioselective separation on a chiral column (β-cyclodextrin-based). By selectively capturing only the o,p'-isomers from the complex sample chromatogram, (1)D separation of ultra-trace level enantiomers could be achieved on the second chiral column without matrix interference. Here, we present solventless concentration techniques for extraction of DDT from contaminated soil and air, and report enantiomeric fraction (EF) values of o,p'-DDT and o,p'-DDD obtained by a new multidimensional approach for heart-cut gas chromatographic fraction collection for off-line second dimension enantiomeric separation by (1)D GC-TOFMS of selected isomers. This multidimensional method is compared to the complementary technique of comprehensive GC×GC-TOFMS using the same enantioselective column, this time as the first dimension of separation. Copyright © 2012 Elsevier B.V. All rights reserved.

Complex metabolic interactions between benzo(a)pyrene and tributyltin in presence of dichlorodiphenyltrichloroethane in South American catfish Rhamdia quelen.

PubMed

Oliveira, Heloísa H P; Babin, Mathieu; Garcia, Juan Ramon Esquivel; Filipak Neto, Francisco; Randi, Marco A F; Oliveira Ribeiro, Ciro A; Pelletier, Émilien

2013-10-01

In an attempt to explore complex metabolic interactions between toxicants present in polluted freshwater, hepatic metabolism of benzo(a)pyrene (BaP) and tributyltin (TBT) in fish was investigated when these compounds were administrated alone, mixed together and along with dichlorodiphenyltrichloroethane (DDT). Ten Rhamdia quelen per group were treated with a single intra-peritoneal (IP) dose (5-day experiment) or three successive doses (15-day experiment) either containing BaP (0.3; 3 or 30mgkg(-1)) or TBT (0.03; 0.3 or 3mgkg(-1)) or a combination of BaP+TBT, BaP+DDT, TBT+DDT and BaP+TBT+DDT under their respective lower doses, with DDT dose kept at 0.03mgkg(-1). Tetrahydroxy-benzo(a)pyrene (BaP-tetrol-I), and dibutyltin (DBT) and monobutyltin (MBT) were analyzed to assess BaP and TBT hepatic metabolism, respectively. A significant difference in BaP-tetrol-I concentration was observed in liver and bile between the lowest and the highest doses of BaP in both 5 and 15-day experiments. In the 15-day experiment, the presence of TBT with BaP reduced the amount of BaP-tetrol-I in bile compared to the BaP alone. The time of exposure and the number of doses affected BaP-tetrol-I concentration in the bile of fish exposed to BaP 0.3mgkg(-1) and BaP+DDT. TBT and its metabolites concentrations showed a dose-dependent increase in the liver in both experiments and in the bile in the 5-day experiment. TBT at its lowest dose was completely metabolized into DBT and MBT in the liver in the 15-day experiment. No TBT metabolites were detected in the bile of fish exposed to the mixtures in the 5-day experiment, except for a small MBT amount found in BaP+TBT+DDT. This study strengthens the hypothesis of a metabolic interaction between BaP and TBT in fish and suggests DDT as an important third player when present in the mixture. Copyright © 2013 Elsevier Inc. All rights reserved.

The effects of DDT upon the survival and growth of nestling songbirds

USGS Publications Warehouse

Mitchell, R.T.; Blagbrough, H.P.; VanEtten, R.C.

1953-01-01

In an experiment conducted during the summers of 1949 and 1950 at the Patuxent Research Refuge, Laurel, Maryland, two aerial applications of DDT were made at the rate of 3 pounds per acre. Sprayings were made over an experimental area of about 20 acres of abandoned fields bordered by woods and hedgerows. T\\vo hundred and ninetythree bird boxes, with three different sizes of openings to accommodate various species of hole-nesting birds, were distributed throughout this area and in a similar check area of the same size. House wrens were the most numerous and most productive of the species restricting their activities to the areas under study, and therefore they provided the most reliable information on survival and growth-rate after spraying. A total of 149 nestling wrens were under observation in 1949 and 154 in 1950. .....There were only slight decreases in the total adult bird populations, no increase in the number of cases of desertion, no significant differences in feeding ranges through the reduction of insect food, nor any apparent avoidance of the sprayed area by nesting birds. DDT at the 3 pounds-per-acre dosage caused considerable mortality to young nestlings. The fledging success in six active first-brood wren nests in 1949 was 28 percent compared to 86 percent in the unsprayed check. In 1950, when the area was sprayed at an earlier date in respect to both the calendar and the nesting progress of the first-brood wrens, fledging success in the sprayed area was 70 percent compared to 73 percent in the check. Average weights of first-brood wren nestlings in the sprayed area in both 1949 and 1950 were significantly lower than those in the check area. The weights of second-brood nestlings in 1949 were lover than those of the checks but the differences were not significant statistically. In 1950 the weights of second-brood house wrens in the sprayed area closely approximated those of the check.....Insect-sampling showed that shortly after spraying, the check area contained 17 times as many insects as the sprayed area in 1949 and 6 times as many in 1950. Six weeks elapsed in 1949 and 8 weeks in 1950 before the invertebrate populations in the two areas became similar. Since the density of insects necessary to sustain bird life in any area is unknown, it is uncertain to what extent this reduction in food contributed to the mortality of nestlings in the sprayed area or to their being underweight in comparison with the checks. The blowfly parasite, A paulina sialia (S.&B.),did not occur in sufficient numbers in 1950 to offer evidence as to whether DDT provided any protection to nestlings as was suggested by observations in 1949. The chemical analyses of dead birds collected dwing the course of experimentation show a wide range in quantities of DDT present. For instance, quantities of DDT detected chemically in nestlings thought to have died from lethal dosages of DDT ranged from 2.6 to 77.0 micrograms per gram of body weight, and one set of wrens exhibiting symptoms of DDT poisoning contained 3.8 mcg./g. Runts from four different nests assumed to have died as a result of unsuccessful competition with their larger nestmates, however, were found to contain quantities of DDT ranging from 14.3 to 38.0 mcg./g. It is conceivable that nestlings inadequately fed or for other reasons being low in vitality could succumb to small quantities of DDT, whereas healthier individuals being nourished normally by their parents might survive for a longer period even though they consumed more DDT. Furthermore, it must be kept in mind that the amount of DDT that constitutes a minimum lethal dose for juvenile birds is still unknown. Also, there is no standard for correlating the quantity of DDT found in tissues and the quantity ingested.

Chemistry for Nonscientists

ERIC Educational Resources Information Center

Weil, Thomas A.; And Others

1974-01-01

Discusses the case of DDT which can be introduced to nonscience students in a chemistry course, including the development of DDT, problems associated with its adverse effects, and curtailment of its use in our environments. (CC)

Synthesis, photoluminescent, antibacterial activities and theoretical studies of 4-hydroxycoumarin derivatives

NASA Astrophysics Data System (ADS)

Li, Jing; Hou, Zheng; Li, Fen; Zhang, Zi-dan; Zhou, Ying; Luo, Xiao-xing; Li, Ming-kai

2014-10-01

Two new biscoumarin and epoxydicoumarin derivatives, namely, 3,3‧-(4-di-p-tolyl-amino-benzylidene)-bis-(4-hydroxycoumarin) (DBH) and 9-(4-di-p-tolyl-amino-phenyl)-1,8-dioxo-9H-dibenzo[c,h]-2,7,10-trioxanthene (DDT), were synthesized and characterized via IR, 1H NMR, HRMS, single crystal X-ray crystallography and UV-vis absorption spectra. The fluorescence behaviors of DBH and DDT in dichloromethane solutions were observed. The in vitro antibacterial activity of DBH and DDT against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC) was evaluated by observing the minimum inhibitory concentration. The results showed that compared with compound DDT, DBH exhibited better potent antibacterial activity.

Characterization of Zebrafish Abcc4 as an Efflux Transporter of Organochlorine Pesticides

PubMed Central

Lu, Xing; Long, Yong; Lin, Li; Sun, Rongze; Zhong, Shan; Cui, Zongbin

2014-01-01

DDT and lindane are highly toxic organochlorine pesticides and posing adverse effects on the environment and public health due to their frequent usage in developing countries. ABCC4/MRP4 is an organic anion transporter that mediates cellular efflux of a wide range of exogenous and endogenous compounds such as cyclic nucleotides and anti-cancer drugs; however, it remains unclear whether ABCC4 and its orthologs function in the detoxification of organochlorine pesticides. Here, we demonstrated the roles of zebrafish Abcc4 in cellular efflux of DDT and lindane. Zebrafish abcc4 was maternally expressed in the oocytes and its transcripts were detected in the lens, pancreas, gills, liver, intestine and bladder of developing embryos and in adult tissues examined. DDT and lindane were able to induce the expression of abcc4 gene and overexpression of Abcc4 significantly decreased the cytotoxicity and accumulation of DDT and lindane in LLC-PK1 cells and developing embryos. In contrast, overexpression of an Abcc4-G1188D mutant abolished its transporter function without effects on its substrate binding activity, and sensitized LLC-PK1 cells and developing embryos to toxic pesticides. Moreover, glutathione (GSH) was involved in the efflux of cellular pesticides and ATPase activity in developing embryos can be induced by DDT or lindane. Thus, zebrafish Abcc4 plays crucial roles in cellular efflux of organochlorine pesticides and can be used a potential molecular marker for the monitor of DDT and lindane contamination in the aquatic environment. PMID:25478949

Widespread Pyrethroid and DDT Resistance in the Major Malaria Vector Anopheles funestus in East Africa Is Driven by Metabolic Resistance Mechanisms

PubMed Central

Mulamba, Charles; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Barnes, Kayla G.; Mukwaya, Louis G.; Birungi, Josephine; Wondji, Charles S.

2014-01-01

Background Establishing the extent, geographical distribution and mechanisms of insecticide resistance in malaria vectors is a prerequisite for resistance management. Here, we report a widespread distribution of insecticide resistance in the major malaria vector An. funestus across Uganda and western Kenya under the control of metabolic resistance mechanisms. Methodology/Principal Findings Female An. funestus collected throughout Uganda and western Kenya exhibited a Plasmodium infection rate between 4.2 to 10.4%. Widespread resistance against both type I (permethrin) and II (deltamethrin) pyrethroids and DDT was observed across Uganda and western Kenya. All populations remain highly susceptible to carbamate, organophosphate and dieldrin insecticides. Knockdown resistance plays no role in the pyrethroid and DDT resistance as no kdr mutation associated with resistance was detected despite the presence of a F1021C replacement. Additionally, no signature of selection was observed on the sodium channel gene. Synergist assays and qRT-PCR indicated that metabolic resistance plays a major role notably through elevated expression of cytochrome P450s. DDT resistance mechanisms differ from West Africa as the L119F-GSTe2 mutation only explains a small proportion of the genetic variance to DDT resistance. Conclusion The extensive distribution of pyrethroid and DDT resistance in East African An. funestus populations represents a challenge to the control of this vector. However, the observed carbamate and organophosphate susceptibility offers alternative solutions for resistance management. PMID:25333491

Insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in an elimination area in Iran.

PubMed

Zare, Mehdi; Soleimani-Ahmadi, Moussa; Davoodi, Sayed Hossein; Sanei-Dehkordi, Alireza

2016-11-04

Iran has recently initiated a malaria elimination program with emphasis on vector control strategies which are heavily reliant on indoor residual spraying and long-lasting insecticidal nets. Insecticide resistance seriously threatens the efficacy of vector control strategies. This study was conducted to determine the insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in Jask county as an active malaria focus in southeastern Iran. In this study, the anopheline larvae were collected from different aquatic habitats in Jask county and transported to insectarium, fed with sugar and then 3-day-old adults were used for susceptibility tests. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), lambda-cyhalothrin (0.05 %), deltamethrin (0.05 %) and permethrin (0.75 %). The field strain of An. stephensi was found resistant to DDT and lambda-cyhalothrin. The LT 50 values for DDT and lambda-cyhalothrin in this species were 130.25, and 37.71 min, respectively. Moreover, An. stephensi was completely susceptible to malathion and permethrin and tolerant to deltamethrin. The present study results confirm the resistance of the major malaria vector, An. stephensi, to DDT and lambda-cyhalothrin, and tolerance to deltamethrin, which could gradually increase and spread into other malaria endemic areas. Thus, there is a need for regular monitoring of insecticide resistance in order to select suitable insecticides for vector control interventions towards malaria elimination.

Alternative treatments for indoor residual spraying for malaria control in a village with pyrethroid- and DDT-resistant vectors in the Gambia.

PubMed

Tangena, Julie-Anne A; Adiamoh, Majidah; D'Alessandro, Umberto; Jarju, Lamin; Jawara, Musa; Jeffries, David; Malik, Naiela; Nwakanma, Davis; Kaur, Harparkash; Takken, Willem; Lindsay, Steve W; Pinder, Margaret

2013-01-01

Malaria vector control is threatened by resistance to pyrethroids, the only class of insecticides used for treating bed nets. The second major vector control method is indoor residual spraying with pyrethroids or the organochloride DDT. However, resistance to pyrethroids frequently confers resistance to DDT. Therefore, alternative insecticides are urgently needed. Insecticide resistance and the efficacy of indoor residual spraying with different insecticides was determined in a Gambian village. Resistance of local vectors to pyrethroids and DDT was high (31% and 46% mortality, respectively) while resistance to bendiocarb and pirimiphos methyl was low (88% and 100% mortality, respectively). The vectors were predominantly Anopheles gambiae s.s. with 94% of them having the putative resistant genotype kdr 1014F. Four groups of eight residential compounds were each sprayed with either (1) bendiocarb, a carbamate, (2) DDT, an organochlorine, (3) microencapsulated pirimiphos methyl, an organophosphate, or (4) left unsprayed. All insecticides tested showed high residual activity up to five months after application. Mosquito house entry, estimated by light traps, was similar in all houses with metal roofs, but was significantly less in IRS houses with thatched roofs (p=0.02). Residents participating in focus group discussions indicated that IRS was considered a necessary nuisance and also may decrease the use of long-lasting insecticidal nets. Bendiocarb and microencapsulated pirimiphos methyl are viable alternatives for indoor residual spraying where resistance to pyrethroids and DDT is high and may assist in the management of pyrethroid resistance.

Concentrations and human health risk assessment of DDT and its metabolites in free-range and commercial chicken products from KwaZulu-Natal, South Africa.

PubMed

Thompson, L A; Ikenaka, Y; Yohannes, Y B; van Vuren, J J; Wepener, V; Smit, N J; Darwish, W S; Nakayama, S M M; Mizukawa, H; Ishizuka, M

2017-11-01

Organochlorine pesticides such as dichlorodiphenyltrichloroethane (DDT) have been used in agriculture and for disease control purposes over many decades. Reports suggest that DDT exposure may result in a number of adverse effects in humans. In the KwaZulu-Natal Province of South Africa, DDT is sprayed annually in homes (indoor residual spraying) to control the mosquito vector of malaria. In the northern part of the Province, samples of free-range chicken meat (n = 48) and eggs (n = 13), and commercially produced chicken meat (n = 6) and eggs (n = 11), were collected and analysed. Of the free-range chicken meat samples, 94% (45/48) contained DDTs (ΣDDTs median 6.1 ng/g wet weight [ww], maximum 79.1 ng/g ww). Chicken egg contents were also contaminated (ΣDDTs in free-range eggs median 9544 ng/g ww, maximum 96.666 ng/g ww; and in commercial eggs median 1.3 ng/g ww, maximum 4.6 ng/g ww). The predominant DDT congener detected was p,p'-DDE in both free-range meat (>63%) and eggs (>66%), followed by p,p'-DDT and then p,p'-DDD. Based on estimated daily intake values, calculated human risk ratio (carcinogenic) values were >1 for DDTs detected in both free-range chicken products. Consumption of free-range eggs poses a particularly high health risk.

Prenatal Exposure to Dichlorodiphenyltrichloroethane and Obesity at 9 Years of Age in the CHAMACOS Study Cohort

PubMed Central

Warner, Marcella; Wesselink, Amelia; Harley, Kim G.; Bradman, Asa; Kogut, Katherine; Eskenazi, Brenda

2014-01-01

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. PMID:24722999

DDT and Derivatives in Indicator Species of the Aquatic Food Web of Rangsit Agricultural Area, Central Thailand

PubMed Central

Siriwong, W.; Thirakhupt, K.; Sitticharoenchai, D.; Rohitrattana, J.; Thongkongowm, P.; Borjan, M.; Robson, M.

2009-01-01

The presence of DDT and derivatives in the food web of freshwater ecosystems of Rangsit agricultural area, Pathum Thani Province, Thailand were investigated from June 2004 to May 2007. By using gas chromatography (GC) with micro electron capture detector (μ ECD), DDT and derivatives in water, sediment, and fifteen indicator species i.e., 2 producers; Eichhornia crassipes and plankton (phyto- and zoo- plankton), an herbivore; Trichogaster microlepis (3) 3 omnivores; Trichogaster trichopterus, Oreochromis niloticus, and Puntius gonionotus, 6 carnivores; Channa striatus, Oxyeleotris marmoratus, Macrognathus siamensis, Parambassis siamensis, Anabas testudineus, and Pristolepis fasciatus, and 3 detritivores; Macrobrachium lanchesteri, Pomacea sp., and Filopaludina mertensi were measured. Results show low concentration levels (part per billion) of DDT & derivatives in each food web compartment i.e. water, sediment, aquatic plant, plankton, fish, and invertebrates. Magnification patterns, i.e. bioconcentration, bioaccumulation, and biomagnification, based on habitat and foraging behavior of selected freshwater species indicates that DDT & derivatives can accumulate and be magnified through the food chain from the lowest up to the highest trophic level. Therefore, the presence of residues and the evidence of magnification patterns can be observed as ecological indicators for evaluating ecological health risk. PMID:20161116

Water solubility enhancements of DDT and trichlorobenzene by some surfactants below and above the critical micelle concentration

USGS Publications Warehouse

Kile, D.E.; Chiou, C.T.

1989-01-01

Water solubility enhancements of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT) and 1,2,3-trichlorobenzene (TCB) by aqueous surfactants below and above their critical micelle concentrations (CMCs) have been studied at room temperature with the following surfactants: Triton X-100, Triton X-114, Triton X-405, Brij 35, sodium dodecyl sulfate, and cetyltrimethylammonium bromide. While the solubilities of DDT and TCB are greatly enhanced by all surfactants above the measured CMC, DDT also exhibits significant solubility enhancements below the CMC of the molecularly nonhomogeneous surfactants (the Triton series and Brij 35). The plot of the apparent DDT solubility against the concentration of Triton and Brij surfactants shows an uprising curve below the nominal CMC, which is attributed to the successive micellization of the heterogeneous monomer species. Above the CMC, the enhancement effect with the nonionic surfactants is closely proportional to the nonpolar chain content of the surfactant, whereas the effect with the ionic surfactants is less accountable in terms of their nonpolar chain contents. The solubilization power of a micelle relative to a bulk solvent is evaluated by a comparison of the observed micelle-water and solvent-water partition coefficients.

Organochlorine chemical residues in Northern Cardinal (Cardinalis cardinalis) eggs from Greater Washington, DC USA

USGS Publications Warehouse

Schmitt, Christopher J.; Echols, Kathy R.; Peterman, Paul; Orazio, Carl; Grimm, Christiana; Tan, Shirlee; Diggs, Nora E.; Marra, Peter P.

2018-01-01

Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination.

Resistance of Aëdes aegypti to certain chlorinated hydrocarbon and organo-phosphorus insecticides in Puerto Rico*

PubMed Central

Fox, Irving

1961-01-01

Failure to control Aëdes aegypti in Puerto Rico has suggested resistance to the insecticides, particularly DDT. A laboratory colony (named Isla Verde strain) was established from material obtained near the International Airport. This strain proved highly resistant to DDT and dieldrin as well as various other insecticides. The scientific and practical significance of this is far-reaching. Heretofore, it was thought that populations of Aëdes aegypti could be resistant to the DDT group of insecticides or to the dieldrin group but not to both, and that one type of resistance involved biochemical, toxicological and genetic characteristics different from the other. This theory must now be modified or even abandoned. From the practical point of view, it is clear that the continued use of DDT or dieldrin for Aëdes aegypti control in Puerto Rico is questionable, for it is not wise to attempt to overcome high resistance by increasing the concentration or rate of application. Further, the situation demonstrated for Puerto Rico may also obtain in other islands of the Caribbean where Aëdes aegypti is known to be DDT-resistant. PMID:13701099

Stimulation of anaerobic biodegradation of DDT and its metabolites in a muck soil: laboratory microcosm and mesocosm studies.

PubMed

Gohil, Hiral; Ogram, Andrew; Thomas, John

2014-09-01

The aim of this study was to evaluate the impact of selected electron donors and electron acceptors on the anaerobic biodegradation of DDT and its major metabolites in a muck soil with a long history of exposure to the pesticide. Loss of DDT was measured in anaerobic microcosms supplemented with H2, lactate, and acetate. The greatest loss of DDT (approximately 87 %) was observed in microcosms amended with lactate and no additional electron acceptor compared to the no additional electron donor or acceptor sets. An increase in measureable concentrations of DDx was observed in un-amended microcosms. In larger scale mesocosms, significant increases in dissolved organic carbon (DOC) corresponded with low redox potentials. Increases in DOC corresponded with sharp increases in measured concentrations of DDx, followed by a decrease in measured DDT concentrations in lactate-amended mesocosms. Our studies indicate that sorbed DDx is released upon anaerobic incubation, and that indigenous microorganisms capable of DDx degradation respond to lactate additions. Both the potential for release of sorbed DDx and the potential for biodegradation of DDx should be considered during remediation of DDx-contaminated organic soils at low redox potentials.

Elucidation of pyrethroid and DDT receptor sites in the voltage-gated sodium channel.

PubMed

Zhorov, Boris S; Dong, Ke

2017-05-01

DDT and pyrethroid insecticides were among the earliest neurotoxins identified to act on voltage-gated sodium channels. In the 1960s, equipped with, at the time, new voltage-clamp techniques, Professor Narahashi and associates provided the initial evidence that DDT and allethrin (the first commercial pyrethroid insecticide) caused prolonged flow of sodium currents in lobster and squid giant axons. Over the next several decades, continued efforts by Prof. Narahashi's group as well as other laboratories led to a comprehensive understanding of the mechanism of action of DDT and pyrethroids on sodium channels. Fast forward to the 1990s, genetic, pharmacological and toxicological data all further confirmed voltage-gated sodium channels as the primary targets of DDT and pyrethroid insecticides. Modifications of the gating kinetics of sodium channels by these insecticides result in repetitive firing and/or membrane depolarization in the nervous system. This mini-review focuses on studies from Prof. Narahashi's pioneer work and more recent mutational and computational modeling analyses which collectively elucidated the elusive pyrethroid receptor sites as well as the molecular basis of differential sensitivities of insect and mammalian sodium channels to pyrethroids. Copyright © 2016 Elsevier B.V. All rights reserved.

Specifications of the International Cooperation Administration for DDT water-dispersible powder for use in malaria control programmes

PubMed Central

Pearce, George W.; Gooden, E. L.; Johnson, Donald R.

1959-01-01

Background information is presented on the development of specifications for 75% DDT water-dispersible powder for use in malaria control programmes supported by the International Cooperation Administration (ICA) of the United States Government. Early difficulties with DDT powders used in these programmes were investigated and it was found that the most critical requirements involved packaging, suspensibility and storage stability. ICA specifications were evolved to meet these requirements. The suspensibility test developed is described, and the importance of inspection of the material procured is discussed. PMID:14431217

Estimation of p,p'-DDT degradation in soil by modeling and constraining hydrological and biogeochemical controls.

PubMed

Sanka, Ondrej; Kalina, Jiri; Lin, Yan; Deutscher, Jan; Futter, Martyn; Butterfield, Dan; Melymuk, Lisa; Brabec, Karel; Nizzetto, Luca

2018-08-01

Despite not being used for decades in most countries, DDT remains ubiquitous in soils due to its persistence and intense past usage. Because of this it is still a pollutant of high global concern. Assessing long term dissipation of DDT from this reservoir is fundamental to understand future environmental and human exposure. Despite a large research effort, key properties controlling fate in soil (in particular, the degradation half-life (τ soil )) are far from being fully quantified. This paper describes a case study in a large central European catchment where hundreds of measurements of p,p'-DDT concentrations in air, soil, river water and sediment are available for the last two decades. The goal was to deliver an integrated estimation of τ soil by constraining a state-of-the-art hydrobiogeochemical-multimedia fate model of the catchment against the full body of empirical data available for this area. The INCA-Contaminants model was used for this scope. Good predictive performance against an (external) dataset of water and sediment concentrations was achieved with partitioning properties taken from the literature and τ soil estimates obtained from forcing the model against empirical historical data of p,p'-DDT in the catchment multicompartments. This approach allowed estimation of p,p'-DDT degradation in soil after taking adequate consideration of losses due to runoff and volatilization. Estimated τ soil ranged over 3000-3800 days. Degradation was the most important loss process, accounting on a yearly basis for more than 90% of the total dissipation. The total dissipation flux from the catchment soils was one order of magnitude higher than the total current atmospheric input estimated from atmospheric concentrations, suggesting that the bulk of p,p'-DDT currently being remobilized or lost is essentially that accumulated over two decades ago. Copyright © 2018 Elsevier Ltd. All rights reserved.

A 50-years record of dichloro-diphenyl-trichloroethanes and hexachlorocyclohexanes in lake sediments and penguin droppings on King George Island, Maritime Antarctic.

PubMed

Sun, Li-guang; Yin, Xue-bin; Pan, Can-ping; Wang, Yu-hong

2005-01-01

Since the ban on the use of organochlorine pesticides (OCPs) such as dichloro-diphenyl-trichloroethane (DDT) and hexachlorocyclohexane(HCH) in agriculture, their levels have generally dropped. In a number of cases, however, the levels of these OCPs were found to be unchanging or even increasing after the ban. With the aim to unveil the possible causes of these exceptions, we collected two lake cores from King George Island, West Antarctica, and determined their accumulation flux profiles and temporal trends of these OCPs. In the lake core sediments with glacier meltwater input, the accumulation flux of DDT shows an abnormal peak around 1980s in addition to the expected one in 1960s. In the lake core sediments without glacier meltwater input, the accumulation flux of DDT shows a gradual decline trend after the peak in 1960s. This striking difference in the DDT flux profiles between the two lake cores is most likely caused by the regional climate warming and the resulted discharge of the DDT stored in the Antarctic ice cap into the lakes in the Antarctic glacier frontier. Furthermore, to investigate the change of OCPs loadings in the Antarctic coastal ecosystem, we reconstructed the HCH and DDT concentration profiles in penguin droppings and observed a gradual increase for the former and a continuous decrease for the latter during the past 50 years. The increase of HCH seems to be due to the regional warming from the early 1970s and the resulted HCH discharge to the coastal ecosystem by glaciers' meltwater and the illegal use of HCH in the Southern Hemisphere in the recent decade. Thedifferent temporal trends of HCH and DDT accumulation rate in the lake core with glacier meltwater input and the aged penguin droppings can be explained by their different water-soluble property.

Effects on forest birds of DDT used for gypsy moth control in Pennsylvania

USGS Publications Warehouse

Hotchkiss, N.; Pough, R.H.

1946-01-01

1. Systematic censuses of the birds on three 40-acre tracts of forest near Scranton, Lackawanna County, Pennsylvania, were made between May 1 and June 27, 1945, to determine the breeding populations....2. Between May 24 and June 1 a 600-acre area enclosing the first (Mile Square) was sprayed by airplane with DDT in oil solution at 5 pounds per acre. On June 9 a 350-acre area enclosing the second tract (Maple Lake) was sprayed with 1pound of DDT per acre. The third tract (Check) was not treated....3. Within 48 hours after treatment of the Mile Square tract, five sick birds were found with symptoms of DDT poisoning, and all died. Two other dead birds were found, and two nests apparently were abandoned. Species involved were red-eyed vireo (3), black-and-white warbler, black-throated blue warbler (nest abandoned), ovenbird (bird died, nest abandoned), redstart, and scarlet tanager....Within 48 hours after application of DDT to the final portion of the tract (on June 1) the population of living birds appeared to have been much reduced, and this condition continued. Before spraying the population total for all species was 1.6 pairs (3.2 birds) per acre. Three days after spraying had been completed there were only two singing males in the entire area; but on June 13 the estimated population was 0.5 bird per acre.....4. After DDT was applied to the Maple Lake tract, careful watch was kept for changes in the bird population and as to nest conditions there and on the Check tract. The apparent total reduction for all species in the Maple Lake tract was from 2.7 pairs to 2.6 pairs per acre; and in the Check tract from 2.7 pairs to 2.4 pairs per acre. Neither these changes nor the observed abandonment of nests and nestling mortality could be attributed to use of DDT.

p,p'-Dichlorodiphenyltrichloroethane (p,p'-DDT) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) repress prostate specific antigen levels in human prostate cancer cell lines.

PubMed

Wong, Lilian I L; Labrecque, Mark P; Ibuki, Naokazu; Cox, Michael E; Elliott, John E; Beischlag, Timothy V

2015-03-25

Despite stringent restrictions on their use by many countries since the 1970s, the endocrine disrupting chemicals, DDT and DDE are still ubiquitous in the environment. However, little attention has been directed to p,p'-DDT and the anti-androgen, p,p'-DDE on androgen receptor (AR) target gene transcription in human cells. Inhibitors of androgenic activity may have a deleterious clinical outcome in prostate cancer screens and progression, therefore we determined whether environmentally relevant concentrations of p,p'-DDT and p,p'-DDE negatively impact AR-regulated expression of prostate-specific antigen (PSA), and other AR target genes in human LNCaP and VCaP prostate cancer cells. Quantitative real-time PCR and immuno-blotting techniques were used to measure intracellular PSA, PSMA and AR mRNA and protein levels. We have shown for the first time that p,p'-DDT and p,p'-DDE repressed R1881-inducible PSA mRNA and protein levels in a dose-dependent manner. Additionally, we used the fully automated COBAS PSA detection system to determine that extracellular PSA levels were also significantly repressed. These chemicals achieve this by blocking the recruitment of AR to the PSA promoter region at 10 μM, as demonstrated by the chromatin immunoprecipitation (ChIP) in LNCaP cells. Both p,p'-DDT and p,p'-DDE repressed R1881-inducible AR protein accumulation at 10 μM. Thus, we conclude that men who have been exposed to either DDT or DDE may produce a false-negative PSA test when screening for prostate cancer, resulting in an inaccurate clinical diagnosis. More importantly, prolonged exposure to these anti-androgens may mimic androgen ablation therapy in individuals with prostate cancer, thus exacerbating the condition by inadvertently forcing adaptation to this stress early in the disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Distinct roles of the DmNav and DSC1 channels in the action of DDT and pyrethroids.

PubMed

Rinkevich, Frank D; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S; Dong, Ke

2015-03-01

Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (para(ts)) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a para(ts1) allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in para(ts1) mutant flies was almost completely abolished in para(ts1);DSC1(-/-) double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w(1118A)), and the para(ts1);DSC1(-/-) double mutant flies were even more resistant to DDT compared to the DSC1 knockout or para(ts1) mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Organochlorine pesticide level differences among female inhabitants from Veracruz, Puebla and Tabasco, Mexico.

PubMed

Waliszewski, Stefan M; Caba, M; Saldarriaga-Noreña, H; Martínez, A J; Meza, E; Valencia Quintana, R; Zepeda, R

2014-08-01

Organochlorine pesticides have been used in Mexico in malaria control programs and against ectoparasites. The objective of this study was to compare the levels of organochlorine pesticides: HCB, α-β-γ-HCH, pp'-DDE, op'-DDT and pp'-DDT in adipose tissue of female inhabitants from three Mexican states: Veracruz, Puebla and Tabasco. Data analyses indicated higher β-HCH levels in Puebla inhabitants. When comparing the mean values of the pp'-DDE concentrations among the three states, no statistically significant differences were noted. A trend of increasing concentrations of op'-DDT from Veracruz to Puebla and Tabasco was observed. Significantly higher pp'-DDT concentrations in Veracruz as compared to Puebla and Tabasco were determined. Using factorial analysis of three age categories (>30, 31-50, <51) organochlorine pesticide concentrations increases with age of participants, indicating time of exposure as a principal factor of organochlorine pesticides accumulation in adipose tissue.

Laboratory evaluation of the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae.

PubMed

Evans, R G

1993-09-01

In a laboratory study, the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae was evaluated at field, 1/3 field and 1/10 field rates using WHO conical exposure chambers and excito-repellency test boxes. Bendiocarb was the least irritant insecticide at all rates, inducing levels of takeoff, flight and exiting behavior similar to those of a distilled water control treatment. Of those mosquitoes introduced to the bendiocarb-treated boxes, not more than 1% exited and survived at any dose rate. Lambda-cyhalothrin and DDT were highly irritant to An. gambiae, inducing a strong stimulation to take off and fly and also a high level of exiting. Exiting-survival rates associated with lambda-cyhalothrin and DDT were between 15 and 51%. The relevance of these findings to the control of mosquito populations and the prevention of malaria transmission is discussed.

Analysis of compaction shock interactions during DDT of low density HMX

NASA Astrophysics Data System (ADS)

Rao, Pratap T.; Gonthier, Keith A.

2017-01-01

Deflagration-to-Detonation Transition (DDT) in confined, low density granular HMX occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong combustion-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting dissipative heating within the microstructure during pore collapse. Inert meso-scale simulations of successive shock loading of low density HMX are performed to examine how dissipation and hot-spot formation are affected by the initial density, and the primary and secondary shock strengths. This information is used to formulate an ignition and burn model for low density HMX that accounts for the effect of shock densensitization on burn. Preliminary DDT predictions are presented that illustrate how primary shock strength affects the transition mechanism.

Evidence of the development of resistance to DDT by Anopheles sacharovi in the Levant*

PubMed Central

Garrett-Jones, C.; Gramiccia, G.

1954-01-01

Resting A. sacharovi reappeared in the autumn of 1953 on some walls in certain localities of north Lebanon which had been treated with DDT during the preceding 18 months. Tests were made on the spot with female mosquitos having a known minimum contact of 5 to 15 minutes with DDT residues, chemically estimated at 0.1-2.0 g/m2. The resulting mortality within 48 hours (corrected to allow for deaths observed in the control runs) was 60.1% and 45.1% according to the technique used, compared with 100% to 83% within 24 hours in similar tests on the same strains some months earlier. The specimens which died had contacted a lower average residue than those which survived, and the latter included some exposed for 15 minutes to 1.8 g/m2. The theory is put forward that selection for DDT resistance (a phenomenon already known in A. sacharovi elsewhere) is probably occurring in these Lebanese strains after only two seasons of regular spraying. The prevalence of sooty surfaces, which absorb DDT, is considered to be a factor contributing to selection by reducing residues to a level within the “critical range” for the non-resistant mosquitos. Attention is drawn to work which indicates a similar response to DDT in strains of A. gambiae and A. funestus in Africa. The importance is stressed of planning antimalaria campaigns in a way that will either prevent selection for resistance or will permit counteraction of it before it can lead to large wastage of public money. PMID:13209325

Susceptibility of Culicidae Mosquitoes to Some Insecticides Recommended by WHO in a Malaria Endemic Area of Southeastern Iran

PubMed Central

Fathian, Mousa; Vatandoost, Hassan; Moosa-Kazemi, Seyed Hassan; Raeisi, Ahmad; Yaghoobi-Ershadi, Mohammad Reza; Oshaghi, Mohammad Ali; Sedaghat, Mohammad Mehdi

2015-01-01

Background: According to the national strategy plan on monitoring of insecticides resistance, this study was carried out to determine the base line susceptibility of the Culicidae mosquitoes to the WHO-recommended insecticides in an endemic focus of malaria in southeastern Iran. Methods: Larval collection was carried out by dipping method and adult collection occurred by suction tube from January to December 2010. The susceptibility test was assessed to DDT 4 %, malathion 5 %, propoxur 0.1 %, deltamethrin 0.05 %, lambda-cyhalothrin 0.05 %, and cyfluthrin 0.15 % at different interval times (discriminative dose) followed by 24 h recovery period. The LT50 and LT90 values were calculated for plotting the regression line using Microsoft office Excel software ver. 2007. Results: Anopheles stephensi was quite resistant to DDT and showed susceptible or tolerant to other insecticides. The LT50 and LT90 values to DDT in this species were 29.07, and 98.26 minutes, respectively. Anopheles culicifacies and Anopheles dthali were found susceptible or tolerant to insecticides. Culex pipiens was found resistance to DDT, propoxur, lambda-cyhalothrin and cyfluthrin whereas observed susceptible to malathion and tolerant to deltamethrin. Ochlerotatus caspius sl. was resistant to DDT, whereas found susceptible to other insecticides. Culisita longiareolata was susceptible to deltamethrin, whereas tolerant to other insecticides. The LT50 and LT90 values of Cs. longiareolata to DDT were 17.82, and 51.26 minutes. Conclusion: We suggested the same study in different parts of the country for monitoring and evaluation of control measures. PMID:26114141

Alternative Treatments for Indoor Residual Spraying for Malaria Control in a Village with Pyrethroid- and DDT-Resistant Vectors in The Gambia

PubMed Central

Tangena, Julie-Anne A.; Adiamoh, Majidah; D’Alessandro, Umberto; Jarju, Lamin; Jawara, Musa; Jeffries, David; Malik, Naiela; Nwakanma, Davis; Kaur, Harparkash; Takken, Willem; Lindsay, Steve W.; Pinder, Margaret

2013-01-01

Background Malaria vector control is threatened by resistance to pyrethroids, the only class of insecticides used for treating bed nets. The second major vector control method is indoor residual spraying with pyrethroids or the organochloride DDT. However, resistance to pyrethroids frequently confers resistance to DDT. Therefore, alternative insecticides are urgently needed. Methodology/Principal Findings Insecticide resistance and the efficacy of indoor residual spraying with different insecticides was determined in a Gambian village. Resistance of local vectors to pyrethroids and DDT was high (31% and 46% mortality, respectively) while resistance to bendiocarb and pirimiphos methyl was low (88% and 100% mortality, respectively). The vectors were predominantly Anopheles gambiae s.s. with 94% of them having the putative resistant genotype kdr 1014F. Four groups of eight residential compounds were each sprayed with either (1) bendiocarb, a carbamate, (2) DDT, an organochlorine, (3) microencapsulated pirimiphos methyl, an organophosphate, or (4) left unsprayed. All insecticides tested showed high residual activity up to five months after application. Mosquito house entry, estimated by light traps, was similar in all houses with metal roofs, but was significantly less in IRS houses with thatched roofs (p=0.02). Residents participating in focus group discussions indicated that IRS was considered a necessary nuisance and also may decrease the use of long-lasting insecticidal nets. Conclusion/Significance Bendiocarb and microencapsulated pirimiphos methyl are viable alternatives for indoor residual spraying where resistance to pyrethroids and DDT is high and may assist in the management of pyrethroid resistance. PMID:24058551

Persistence and Bioavailability of DDT in a Coastal Salt Marsh

NASA Astrophysics Data System (ADS)

Rowlett, K.; Weathers, N.; Morrison, A.; White, H. K.

2016-02-01

DDT (dichlorodiphenyltrichloroethane) was a widely-used pesticide in the United States throughout the 1900s. In 1972, the EPA banned the use of DDT due to fears of severe bioaccumulation and toxicity in animals. However, the compound persists in measurable quantities in the environment, leading to questions surrounding its current bioavailability in key ecosystems such as coastal marshes. For this study a sediment core was collected in 2015 from a salt marsh in Dover, Delaware and the sediments and plant matter were analyzed for the presence of DDT and three of its main biological metabolites: DDD, DDE, and DDMU (collectively, DDX). Samples were extracted in toluene and analyzed for DDX via gas chromatography with mass spectrometry (GC/MS) operated in selected ion monitoring (SIM) mode. The initial down-core profile revealed that the maximum concentration of DDX in both plant matter (>1mm in size) and sediments (<250µm in size) was at 22-30cm below the marsh surface, corresponding to the time of DDT application, as determined by 210Pb-dating. After initial analysis of the concentration of DDX in the sediment core, a passive sampling method using low-density polyethylene (LDPE) was employed to measure the bioavailability of the DDX compounds in the collected sediments. Bioavailability experiments with LDPE are ongoing and results will be discussed. This study will contribute to our overall understanding of the persistence of DDT in the environment by further elucidating the association of DDX compounds with plants and sedimentary material as well as their bioavailability with respect to these associations.

Distribution and ecological risk assessment of HCHs and DDTs in surface seawater and sediment of the mariculture area of Jincheng Bay, China

NASA Astrophysics Data System (ADS)

Hu, Yanbing; Sun, Shan; Song, Xiukai; Ma, Jianxin; Ru, Shaoguo

2015-04-01

The distribution of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in the surface seawater and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87 ng L-1 and were < 0.032 ng L-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-1, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column species was low. The threshold effect concentration exceeding frequency of γ-HCH, p, p'-DDD, p, p'-DDE and p, p'-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic products, e.g., sea cucumber and benthic shellfish.

p,p'-DDT induces testicular oxidative stress-induced apoptosis in adult rats.

PubMed

Marouani, Neila; Hallegue, Dorsaf; Sakly, Mohsen; Benkhalifa, Moncef; Ben Rhouma, Khémais; Tebourbi, Olfa

2017-05-26

The 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT) is a known persistent organic pollutant and male reproductive toxicant. The present study is designed to test the hypothesis that oxidative stress mediates p,p'-DDT-induced apoptosis in testis. Male Wistar rats received an intraperitoneal (ip) injection of the pesticide at doses of 50 and 100mg/kg for 10 consecutive days. The oxidative stress was evaluated by biomarkers such lipid peroxidation (LPO) and metallothioneins (MTs) levels. Antioxidant enzymes activities was assessed by determination of superoxide dismutase (SOD), catalase (CAT) and hydrogen peroxide (H 2 O 2 ) production. In addition, glutathione-dependent enzymes and reducing power in testis was evaluated by glutathione peroxidase (Gpx), glutathione reductase (GR), glutathione S-transferase (GST) activities and reduced and oxidized glutathione (GSH - GSSG) levels. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis. Germinal cells apoptosis and the apoptotic index was assessed through the TUNEL assay. After 10 days of treatment, an increase in LPO level and H 2 O 2 production occurred, while MTs level, SOD and CAT activities were decreased. Also, the Gpx, GR, GST, and GSH activities were decreased, whereas GSSG activity was increased. Testicular tissues of treated rats showed pronounced degradation of the DNA into oligonucleotides as seen in the typical electrophoretic DNA ladder pattern. Intense apoptosis was observed in germinal cells of DDT-exposed rats. In addition, the apoptotic index was significantly increased in testis of DDT-treated rats. These results clearly suggest that DDT sub-acute treatment causes oxidative stress in rat testis leading to apoptosis.

Reconstruction of historical atmospheric deposition of DDT in the Zempoala Lagoon, in the center of Mexico

USGS Publications Warehouse

van, Afferden M.; Hansen, A.M.; Fuller, C.C.

2005-01-01

Historical trend in deposition of DDT and its metabolites has been reconstructed by analyzing sediment cores of the Zempoala Lagoon, in the center of Mexico. The small watershed of this mountain lagoon is closed, and it is located between 2.800 and 3.700 masl. It ls neither affected by agriculture nor by permanent populations. The Zempoala Lagoon has an average depth of 3.9 mand a maximum depth of 8.8 m. Sediments were extracted with a eore sampler and analyzed by isotope methods (137CS and 2'OPb) for dating. Average sedimentation rate was determined in 0.129 9 cm" yr', corresponding to a maximum age of the 44 cm eore of approximately 60 years. The first presence of total-DDT oecurs in a depth between 28 and 32 cm of the sediment profile, corresponding to the 1960's, with a concentration of 5.3 I1g kg-'. The maximum eoncentration of total-DDT (13.0I1g kg-') occurs in sediment layers representing the late 1970's and beginning 1980's. More recently the concentration decreases towards the present concentration of 1.6 I1g kg-'. This concentration is below most DDT levels reported in recent sediment studies in the USA. The results indicate that the Zempoala Lagoon represents a natural reeipient for studies of the reconstruction of historical trends of atmospheric contaminant deposition in this region. The limitations of the methodology applied, due to the influenee of biodegradation on the definition of correct historical coneentrations of DDT depositions, are demonstrated.

Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the lower San Joaquin River drainage, California

USGS Publications Warehouse

Brown, Larry R.

1998-01-01

Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 16 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of total DDT (sum of o,p'- and p,p'-forms of DDD, DDE, and DDT) were statistically different among groups of sites for tissue and sediment (Kruskal-Wallis, P < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of total DDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (P < 0.05), which are indicators of the proportion of irrigation-return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total-organic- carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (P < 0.05). Regressions of the concentration of total DDT in tissue as a function of total DDT in bed sediment were significant and explained as much as 76 percent of the variance in the data. The concentration of total DDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment.

Alterations in sperm DNA methylation, non-coding RNA and histone retention associate with DDT-induced epigenetic transgenerational inheritance of disease.

PubMed

Skinner, Michael K; Ben Maamar, Millissia; Sadler-Riggleman, Ingrid; Beck, Daniel; Nilsson, Eric; McBirney, Margaux; Klukovich, Rachel; Xie, Yeming; Tang, Chong; Yan, Wei

2018-02-27

Environmental toxicants such as DDT have been shown to induce the epigenetic transgenerational inheritance of disease (e.g., obesity) through the germline. The current study was designed to investigate the DDT-induced concurrent alterations of a number of different epigenetic processes including DNA methylation, non-coding RNA (ncRNA) and histone retention in sperm. Gestating females were exposed transiently to DDT during fetal gonadal development, and then, the directly exposed F1 generation, the directly exposed germline F2 generation and the transgenerational F3 generation sperm were investigated. DNA methylation and ncRNA were altered in each generation sperm with the direct exposure F1 and F2 generations being predominantly distinct from the F3 generation epimutations. The piRNA and small tRNA were the most predominant classes of ncRNA altered. A highly conserved set of histone retention sites were found in the control lineage generations which was not significantly altered between generations, but a large number of new histone retention sites were found only in the transgenerational generation DDT lineage sperm. Therefore, all three different epigenetic processes were concurrently altered as DDT induced the epigenetic transgenerational inheritance of sperm epimutations. The direct exposure generations sperm epigenetic alterations were distinct from the transgenerational sperm epimutations. The genomic features and gene associations with the epimutations were investigated to help elucidate the integration of these different epigenetic processes. Observations demonstrate all three epigenetic processes are involved in transgenerational inheritance. The different epigenetic processes appear to be integrated in mediating the epigenetic transgenerational inheritance phenomenon.

p,p\\'-Dichlorodiphenyltrichloroethane (DDT)

Integrated Risk Information System (IRIS)

p , p ' - Dichlorodiphenyltrichloroethane ( DDT ) ; CASRN 50 - 29 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard

Degradation of insecticides used for indoor spraying in malaria control and possible solutions

PubMed Central

2011-01-01

Background The insecticide dichloro-diphenyl-trichloroethane (DDT) is widely used in indoor residual spraying (IRS) for malaria control owing to its longer residual efficacy in the field compared to other World Health Organization (WHO) alternatives. Suitable stabilization to render these alternative insecticides longer lasting could provide a less controversial and more acceptable and effective alternative insecticide formulations than DDT. Methods This study sought to investigate the reasons behind the often reported longer lasting behaviour of DDT by exposing all the WHO approved insecticides to high temperature, high humidity and ultra-violet light. Interactions between the insecticides and some mineral powders in the presence of an aqueous medium were also tested. Simple insecticidal paints were made using slurries of these mineral powders whilst some insecticides were dispersed into a conventional acrylic paint binder. These formulations were then spray painted on neat and manure coated mud plaques, representative of the material typically used in rural mud houses, at twice the upper limit of the WHO recommended dosage range. DDT was applied directly onto mud plaques at four times the WHO recommended concentration and on manure plaques at twice WHO recommended concentration. All plaques were subjected to accelerated ageing conditions of 40°C and a relative humidity of 90%. Results The pyrethroids insecticides outperformed the carbamates and DDT in the accelerated ageing tests. Thus UV exposure, high temperature oxidation and high humidity per se were ruled out as the main causes of failure of the alternative insecticides. Gas chromatography (GC) spectrograms showed that phosphogypsum stabilised the insecticides the most against alkaline degradation (i.e., hydrolysis). Bioassay testing showed that the period of efficacy of some of these formulations was comparable to that of DDT when sprayed on mud surfaces or cattle manure coated surfaces. Conclusions Bioassay experiments indicated that incorporating insecticides into a conventional paint binder or adsorbing them onto phosphogypsum can provide for extended effective life spans that compare favourably with DDT's performance under accelerated ageing conditions. Best results were obtained with propoxur in standard acrylic emulsion paint. Similarly, insecticides adsorbed on phosphogypsum and sprayed on cattle manure coated surfaces provided superior lifespans compared with DDT sprayed directly on a similar surface. PMID:22008292

Exposure to DDT and diabetic nephropathy among Mexican Americans in the 1999-2004 National Health and Nutrition Examination Survey.

PubMed

Everett, Charles J; Thompson, Olivia M; Dismuke, Clara E

2017-03-01

Concentrations of the pesticide DDT (dichlorodiphenyltrichloroethane) and its metabolite DDE (dichlorodiphenyldichloroethylene), in the blood of Mexican Americans, were evaluated to determine their relationships with diabetes and diabetic nephropathy. The data were derived from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 (unweighted N = 1,411, population estimate = 13,760,609). The sample included teens, 12-19 years old, which accounted for 19.8% of the data. The time of the study overlapped the banning of DDT in Mexico in the year 2000, and those participants born in Mexico were exposed to DDT before they immigrated to the US. We sought to better understand the relationship of DDT with diabetes in a race/ethnicity group prone to develop diabetes and exposed to DDT. In this study, nephropathy was defined as urinary albumin to creatinine ratio >30 mg/g, representing microalbuminuria and macroalbuminuria, and total diabetes was defined as diagnosed and undiagnosed diabetes (glycohemoglobin, A1c ≥ 6.5%). The proportion with the isomer p,p'-DDT >0.086 ng/g (above the maximum limit of detection) was 13.3% for Mexican Americans born in the US, and 36.9% for those born in Mexico. Levels of p,p'-DDT >0.086 ng/g were associated with total diabetes with nephropathy (odds ratio = 4.42, 95% CI 2.23-8.76), and with total diabetes without nephropathy (odds ratio = 2.02, 95% CI 1.19-3.44). The third quartile of p,p'-DDE (2.99-7.67 ng/g) and the fourth quartile of p,p'-DDE (≥7.68 ng/g) were associated with diabetic nephropathy and had odds ratios of 5.32 (95% CI 1.05-26.87) and 14.95 (95% CI 2.96-75.48) compared to less than the median, respectively, whereas p,p'-DDE was not associated with total diabetes without nephropathy. The findings of this study differ from those of a prior investigation of the general adult US population in that there were more associations found with the Mexican Americans sample. Published by Elsevier Ltd.

DDT spray for control of the ponderosa pine tip moth (Rhyacionia zozana [Kearfott])

Treesearch

Robert E. Stevens

1965-01-01

A water emulsion spray of DDT applied by hand sprayer to young trees infested with eggs and early-instar larvae of the ponderosa pine tip moth halted further larval activity and effectively prevented all damage.

DDT-treatment of rivers for eradication of Simuliidae

PubMed Central

McMahon, J. P.

1957-01-01

This article describes how to estimate the discharge of water in rivers and streams by means of weirs, current meters and floats, and how to calculate and administer doses of DDT for the treatment of simuliid-infested waters. PMID:13472410

Effects of DDT on bobwhite quail adrenal gland

USGS Publications Warehouse

Lehman, J.W.; Peterle, T.J.; Mulls, C.M.

1974-01-01

A wide range of responses to sublethal levels of DDT exist, many of which are species specific and vary within each species depending upon age, sex, and physiological state. Sublethal levels of DDT do cause an increase in the adrenal cortical tissue of bobwhite quail, which may cause increased secretion of corticosteroids, and in turn affect reproduction. A delicate homeostatic balance exists within the avian endocrine system which may be disturbed by feeding sublethal levels of chlorinated hydrocarbon pesticides. This adverse effect on the endocrine system may cause subtle reproductive failures which go unnoticed until the population is greatly reduced.

Engineering and Environmental Study of DDT Contamination of Huntsville Spring Branch, Indian Creek, and Adjacent Lands and Waters, Wheeler Reservoir, Alabama. Volume 3. Appendices IV-VI.

DTIC Science & Technology

1980-11-01

levels in fish exceed the 5 ppm limit set by the FDA for edible portions of fish. Evidence of human DDT contamination has been found in persons...Contamination of aquatic organisms, results from low levels of DDTR that now exist in water and/or sediment. 5 . Contamination of aquatic organisms also...SOIL, WATER AND OTHER SURFACES 1- 5 3.4 PERSISTENCE IN SOIL 1-7 3.5 WATER SOLUBILITY 1-7 4.0 DDT DEGRADATION IN THE ENVIRONMENT 1-7 4.1 DEGRADATION IN

Electrokinetic-Fenton remediation of organochlorine pesticides from historically polluted soil.

PubMed

Ni, Maofei; Tian, Shulei; Huang, Qifei; Yang, Yanmei

2018-04-01

Soil contamination by persistent organic pollutants (POPs) poses a great threat to historically polluted soil worldwide. In this study, soils were characterized, and organochlorine pesticides contained in the soils were identified and quantified. Individual electrokinetic (IE), EK-Fenton-coupled technologies (EF), and enhanced EK-Fenton treatment (E-1, E-2, and E-3) were applied to remediate soils contaminated with hexachloro-cyclohexane soprocide (HCH) and dichloro-diphenyl-trichloroethane (DDT). Variation of pH, electrical conductivity, and electroosmotic flow was evaluated during the EK-Fenton process. The IE treatment showed low removal efficiency for HCHs (30.5%) and DDTs (25.9%). In the EF treatment, the highest removal level (60.9%) was obtained for α-HCH, whereas P,P-DDT was the lowest (40.0%). Low solubility of pollutants impeded the HCH and DDT removal. After enhanced EK-Fenton treatment, final removal of pollutants decreased as follows: β-HCH (82.6%) > γ-HCH (81.6%) > α-HCH (81.2%) > δ-HCH (80.0%) > P,P-DDD (73.8%) > P,P-DDE (73.1%) > P,P-DDT (72.6%) > O,P-DDT (71.5%). The results demonstrate that EK-Fenton is a promising technology for POP removal in historically polluted soil.

Concurrent auditory perception difficulties in older adults with right hemisphere cerebrovascular accident.

PubMed

Talebi, Hossein; Moossavi, Abdollah; Faghihzadeh, Soghrat

2014-01-01

Older adults with cerebrovascular accident (CVA) show evidence of auditory and speech perception problems. In present study, it was examined whether these problems are due to impairments of concurrent auditory segregation procedure which is the basic level of auditory scene analysis and auditory organization in auditory scenes with competing sounds. Concurrent auditory segregation using competing sentence test (CST) and dichotic digits test (DDT) was assessed and compared in 30 male older adults (15 normal and 15 cases with right hemisphere CVA) in the same age groups (60-75 years old). For the CST, participants were presented with target message in one ear and competing message in the other one. The task was to listen to target sentence and repeat back without attention to competing sentence. For the DDT, auditory stimuli were monosyllabic digits presented dichotically and the task was to repeat those. Comparing mean score of CST and DDT between CVA patients with right hemisphere impairment and normal participants showed statistically significant difference (p=0.001 for CST and p<0.0001 for DDT). The present study revealed that abnormal CST and DDT scores of participants with right hemisphere CVA could be related to concurrent segregation difficulties. These findings suggest that low level segregation mechanisms and/or high level attention mechanisms might contribute to the problems.

Comparative study of alkylthiols and alkylamines for the phase transfer of gold nanoparticles from an aqueous phase to n-hexane.

PubMed

Li, Lingxiangyu; Leopold, Kerstin; Schuster, Michael

2013-05-01

An efficient ligand-assisted phase transfer method has been developed to transfer gold nanoparticles (Au-NPs, d: 5-25 nm) from an aqueous solution to n-hexane. Four different ligands, namely 1-dodecanethiol (DDT), 1-octadecanethiol (ODT), dodecylamine (DDA), and octadecylamine (ODA) were investigated, and DDT was found to be the most efficient ligand. It appears that the molar ratio of DDT to Au-NPs is a critical factor affecting the transfer efficiency, and 270-310 is found to be the optimum range, under which the transfer efficiency is >96%. Moreover, the DDT-assisted phase transfer can preserve the shape and size of the Au-NPs, which was confirmed by UV-vis spectra and transmission electron microscopy (TEM). Additionally, the transferred Au-NPs still can be well dispersed in the n-hexane phase and remain stable for at least 2 weeks. On the other hand, the ODT-, DDA-, and ODA-assisted phase transfer is fraught with problems either related to transfer efficiency or NPs aggregation. Overall, the DDT-assisted phase transfer of Au-NPs provides a rapid and efficient method to recover Au-NPs from an aqueous solution to n-hexane. Copyright © 2013 Elsevier Inc. All rights reserved.

DDT - A Brief History and Status

EPA Pesticide Factsheets

DDT was the first of the modern synthetic insecticides, developed in the 1940s. It helped control diseases such as typhus and malaria. Enviromental concerns led to its cancellation in the 1970s. It still has limited indoor use in Africa to prevent malaria.

Dietary Exposure of Fathead Minnows to the Explosives TNT and RDX and to the Pesticide DDT using Contaminated Invertebrates

PubMed Central

Houston, Jerre G.; Lotufo, Guilherme R.

2005-01-01

Explosive compounds have been released into the environment during manufacturing, handling, and usage procedures. These compounds have been found to persist in the environment and potentially promote detrimental biological effects. The lack of research on bioaccumulation and bioconcentration and especially dietary transfer on aquatic life has resulted in challenges in assessing ecological risks. The objective of this study was to investigate the potential trophic transfer of the explosive compounds 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) using a realistic freshwater prey/predator model and using dichlorodiphenyltrichloroethane (DDT), a highly bioaccumulative compound, to establish relative dietary uptake potential. The oligochaete worm Lumbriculus variegatus was exposed to 14C-labeled TNT, RDX or DDT for 5 hours in water, frozen in meal-size packages and subsequently fed to individual juvenile fathead minnows (Pimephales promelas). Fish were sampled for body residue determination on days 1, 2, 3, 4, 7, and 14 following an 8-hour gut purging period. Extensive metabolism of the parent compound in worms occurred for TNT but not for RDX and DDT. Fish body residue remained relatively unchanged over time for TNT and RDX, but did not approach steady-state concentration for DDT during the exposure period. The bioaccumulation factor (concentration in fish relative to concentration in worms) was 0.018, 0.010, and 0.422 g/g for TNT, RDX and DDT, respectively, confirming the expected relatively low bioaccumulative potential for TNT and RDX through the dietary route. The experimental design was deemed successful in determining the potential for trophic transfer of organic contaminants via a realistic predator/prey exposure scenario. PMID:16705829

Association between Exposure to p,p′-DDT and Its Metabolite p,p′-DDE with Obesity: Integrated Systematic Review and Meta-Analysis

PubMed Central

Cano-Sancho, German; Salmon, Andrew G.

2017-01-01

Background: The prevalence of obesity is increasing in all countries, becoming a substantial public health concern worldwide. Increasing evidence has associated obesity with persistent pollutants such as the pesticide DDT and its metabolite p,p′-DDE. Objectives: Our objective was to systematically review the literature on the association between exposure to the pesticide DDT and its metabolites and obesity to develop hazard identification conclusions. Methods: We applied a systematic review-based strategy to identify and integrate evidence from epidemiological, in vivo, and in vitro studies. The evidence from prospective epidemiological studies was quantitatively synthesized by meta-analysis. We rated the body of evidence and integrated the streams of evidence to systematically develop hazard identification conclusions. Results: We identified seven epidemiological studies reporting prospective associations between exposure to p,p′-DDE and adiposity assessed by body mass index (BMI) z-score. The results from the meta-analysis revealed positive associations between exposure to p,p′-DDE and BMI z-score (β=0.13 BMI z-score (95% CI: 0.01, 0.25) per log increase of p,p′-DDE). Two studies constituted the primary in vivo evidence. Both studies reported positive associations between exposure to p,p′-DDT and increased adiposity in rodents. We identified 19 in vivo studies and 7 in vitro studies that supported the biological plausibility of the obesogenic effects of p,p′-DDT and p,p′-DDE. Conclusions: We classified p,p′-DDT and p,p′-DDE as “presumed” to be obesogenic for humans, based on a moderate level of primary human evidence, a moderate level of primary in vivo evidence, and a moderate level of supporting evidence from in vivo and in vitro studies. https://doi.org/10.1289/EHP527 PMID:28934091

Transport of persistent organic pollutants by microplastics in estuarine conditions

NASA Astrophysics Data System (ADS)

Bakir, Adil; Rowland, Steven J.; Thompson, Richard C.

2014-03-01

Microplastics represent an increasing source of anthropogenic contamination in aquatic environments, where they may also act as scavengers and transporters of persistent organic pollutants. As estuaries are amongst the most productive aquatic systems, it is important to understand sorption behaviour and transport of persistent organic pollutants (POPs) by microplastics along estuarine gradients. The effects of salinity sorption equilibrium kinetics on the distribution coefficients (Kd) of phenanthrene (Phe) and 4,4‧-DDT, onto polyvinyl chloride (PVC) and onto polyethylene (PE) were therefore investigated. A salinity gradient representing freshwater, estuarine and marine conditions, with salinities corresponding to 0 (MilliQ water, 690 μS/cm), 8.8, 17.5, 26.3 and 35 was used. Salinity had no significant effect on the time required to reach equilibrium onto PVC or PE and neither did it affect desorption rates of contaminants from plastics. Although salinity had no effect on sorption capacity of Phe onto plastics, a slight decrease in sorption capacity was observed for DDT with salinity. Salinity had little effect on sorption behaviour and POP/plastic combination was shown to be a more important factor. Transport of Phe and DDT from riverine to brackish and marine waters by plastic is therefore likely to be much more dependent on the aqueous POP concentration than on salinity. The physical characteristics of the polymer and local environmental conditions (e.g. plastic density, particle residence time in estuaries) will affect the physical transport of contaminated plastics. A transport model of POPs by microplastics under estuarine conditions is proposed. Transport of Phe and DDT by PVC and PE from fresh and brackish water toward fully marine conditions was the most likely net direction for contaminant transport and followed the order: Phe-PE >> DDT-PVC = DDT-PE >> Phe-PVC.

Time trend tendency (1988-2014 years) of organochlorine pesticide levels in the adipose tissue of Veracruz inhabitants.

PubMed

Calderón-Garcidueñas, Ana Laura; Waliszewski, Stefan M; Ruiz-Ramos, Rubén; Del Carmen Martinez-Valenzuela, María

2018-03-10

The population that lives in areas where organochlorine pesticides were spread in the past is still exposed to them through contaminated food, particulate matter, and vapors. Due to their lipophilic properties and resistance to metabolic reactions, they accumulate in tissues and fluids rich in lipids. The aim of the study was to monitor the concentrations of organochlorine pesticides in forensic adipose tissue samples of adult inhabitants of Veracruz City, Mexico, and compare their time trend levels from 1988 to 2014. During the study, hexachlorobenzene (HCB); lindane; β-hexachorocyclohexane; p,p'-dichlorodiphenyldichloroethylene (pp'DDE); p,p'-dichlorodiphenyldichloroethane (p,p'-DDT); and o,p'-dichlorodiphenyldichloroethane (o,p'-DDT) were determined. Our survey was divided into two periods: first, from the years 1988 to 1999, during which DDT was allowed to fight malaria and dengue vectors and the second from the years 2001 to 2014, after the DDT ban. A total of 1435 samples were analyzed. There were substantial differences in the forecasted time trend values of p,p'-DDE and p,p'-DDT in human adipose tissue samples in the two different periods. During the first period, p,p'-DDE decrease time trend was 1.198 mg/kg on lipid base per year; for the second one, decrease was 0.128 mg/kg on lipid base per year. p,p'-DDT decreased 0.507 mg/kg on lipid base during the first period and 0.039 mg/kg on lipid base for the second. The different concentrations may be explained by the cessation of fresh exposure after the first period and a more equilibrated decontamination tendency during the second period. This model was useful to show the decrease in the concentration of pesticides in human adipose tissue samples.

Determination of chlorinated insecticides in bottom sediment using an electron-capture gas chromatography screening method, Austin, Texas, 1991 and 1992

USGS Publications Warehouse

Brock, Robert D.; Murtagh, Lucinda K.

1994-01-01

Twenty-two bottom-sediment samples were collected from Town Lake in Austin, Texas, in 1991 and 1992 and analyzed for chlorinated insecticides by a reconnaissance-quality, electron-capture gas chromatography screening method developed by the U.S. Geological Survey (USGS). Four different chlorinated insecticides (aldrin, chlordane, dieldrin, and p,p'-DDT) and two degradation products of p,p'-DDT (p,p'-DDD and p,p'-DDE) were detected in these samples. The most significant insecticides detected were chlordane, which was detected in 20 of the 22 samples at concentrations that ranged from 26 to 140 micrograms per kilogram, and p,p'-DDT, which was detected in all 22 samples at concen- trations that ranged from 5 to 40 micrograms per kilogram. Degradation products of p,p'-DDT were detected in all 22 samples. Concentrations of p,p'-DDD ranged from not detected to 117 micrograms per kilogram and for p,p'-DDE from 9 to 97 micrograms per kilogram. Of the 22 samples collected, 15 also were analyzed by the standard USGS laboratory analytical method for chlorinated insecticides to determine the comparability of the two methods. Correlation coefficients were calculated for chlordane (0.8662), p,p'-DDT (0.6393), p,p'-DDD (0.9401), p,p'-DDE (0.8595), and dieldrin (0.3819). A paired sign test at the 95 percent confidence level showed no significant difference between the screening method and laboratory analytical method for all detected insecticides except aldrin. P-values were calculated from the data for chlordane (l.0000), p,p'-DDT (0.1796), p,p'-DDD (l,0000), p,p'-DDE (0.1796), and dieldrin (0.2891).

Trace elements and organic chemicals in stream-bottom sediments and fish tissues, Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1992-95

USGS Publications Warehouse

Brigham, M.E.; Goldstein, R.M.; Tornes, L.H.

1998-01-01

Stream-bottom sediment and fish-tissue samples from the Red River of the North Basin, were analyzed for a large suite of chemical elements and organic chemicals. Cadmium, lead, and mercury were widespread in sediments, at concentrations not indicative of acute contamination. Mercury, the element of greatest health concern in the region, was detected at low concentrations in 38 of 43 sediment samples (<0.02-0.13 micrograms per gram) and all of eleven fish-liver samples (0.03-0.6 micrograms per gram dry weight, or 0.0066-0.13 micrograms per gram wet weight). Concentrations of many elements appeared to be controlled by mineral rather than anthropogenic sources. DDT and its metabolites were the most frequently detected synthetic organochlorines: p,p'-DDE was detected in 9 of 38 sediment samples (concentration range: <1-16 nanograms per gram) and also frequently in whole-fish samples. Total DDT (the sum of DDT and its metabolites) concentrations ranged from <5 to 217 nanograms per gram, and at least one component of total DDT was detected in 19 of 23 fish samples. Concentrations of DDT and its metabolites in stream sediments were significantly higher in the intensively cropped Red River Valley Lake Plain, compared to upland areas, probably because of greater historical DDT usage in the lake plain. Several polycyclic aromatic hydrocarbons were detected in stream-bottom sediments. Although the potentially toxic chemicals measured in this study were at low levels, relative to more contaminated areas of the Nation, maximum concentrations of some chemicals are of concern because of their possible effects on aquatic biota and human health.

Association between Exposure to p,p'-DDT and Its Metabolite p,p'-DDE with Obesity: Integrated Systematic Review and Meta-Analysis.

PubMed

Cano-Sancho, German; Salmon, Andrew G; La Merrill, Michele A

2017-09-18

The prevalence of obesity is increasing in all countries, becoming a substantial public health concern worldwide. Increasing evidence has associated obesity with persistent pollutants such as the pesticide DDT and its metabolite p,p '-DDE. Our objective was to systematically review the literature on the association between exposure to the pesticide DDT and its metabolites and obesity to develop hazard identification conclusions. We applied a systematic review-based strategy to identify and integrate evidence from epidemiological, in vivo , and in vitro studies. The evidence from prospective epidemiological studies was quantitatively synthesized by meta-analysis. We rated the body of evidence and integrated the streams of evidence to systematically develop hazard identification conclusions. We identified seven epidemiological studies reporting prospective associations between exposure to p,p' -DDE and adiposity assessed by body mass index (BMI) z -score. The results from the meta-analysis revealed positive associations between exposure to p,p' -DDE and BMI z -score (β=0.13 BMI z -score (95% CI: 0.01, 0.25) per log increase of p,p' -DDE). Two studies constituted the primary in vivo evidence. Both studies reported positive associations between exposure to p,p' -DDT and increased adiposity in rodents. We identified 19 in vivo studies and 7 in vitro studies that supported the biological plausibility of the obesogenic effects of p,p' -DDT and p,p' -DDE. We classified p,p' -DDT and p,p' -DDE as "presumed" to be obesogenic for humans, based on a moderate level of primary human evidence, a moderate level of primary in vivo evidence, and a moderate level of supporting evidence from in vivo and in vitro studies. https://doi.org/10.1289/EHP527.

Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

NASA Astrophysics Data System (ADS)

Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

2017-07-01

The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

Post World War II orcharding creates present day DDT-problems in The Sørfjord (Western Norway)--a case study.

PubMed

Ruus, Anders; Green, Norman W; Maage, Amund; Amundsen, Carl Einar; Schøyen, Merete; Skei, Jens

2010-10-01

The Sørfjord has a long history of agriculture and industry, and environmental monitoring has been conducted for decades, comprising analyses of contaminants in mussel, fish and sediments. DDT was used as an insecticide in orchards surrounding the fjord between World War II and 1970. Since the early 1990 s, elevated concentrations of DDT were found in mussels and fish. Unexpectedly, DDT-concentrations increased towards present day, despite the discontinuation of use. The highest concentrations in mussels (in 2006) corresponded to about two orders of magnitude higher than background. Analyses of sediment core sections also indicated increased input towards present day. Shifts in climatic parameters, as well as increased amounts of soil dissolved organic carbon following a decline in atmospheric sulphate deposition may have contributed to this phenomenon. We warrant the need for increased knowledge of the effects of alterations in variables acting regionally and globally on the disposition of contaminants in ecosystems. Copyright © 2010 Elsevier Ltd. All rights reserved.

Daytime distribution of DDT-resistant houseflies inside DDT-sprayed buildings*†

PubMed Central

Mer, G. G.

1953-01-01

The development of DDT resistance in houseflies makes necessary the use of an additional or substitute insecticide in fly control. For the sake of economy, and to prevent the rapid production of new resistant strains, spraying of this insecticide should be restricted as far as possible to those surfaces known to be the most frequented by flies. Between July and October 1952, an investigation into the day-time distribution and resting habits of flies inside a number of different buildings sprayed bi-monthly with 5% DDT in kerosene was carried out by the author. The results showed that walls and ceilings were the least frequented, windows and doors highly frequented, and furniture the most frequented. These data indicate the desirability of developing an insecticidal preparation adaptable to the residual treatment of furniture, and, in the absence of such a preparation, of restricting treatment to doors and windows and such night-time resting-places as are to be found inside rooms. PMID:13066986

Persistent Organic Pollutants in albacore tuna (Thunnus alalunga) from Reunion Island (Southwest Indian Ocean) and South Africa in relation to biological and trophic characteristics.

PubMed

Munschy, C; Bodin, N; Potier, M; Héas-Moisan, K; Pollono, C; Degroote, M; West, W; Hollanda, S J; Puech, A; Bourjea, J; Nikolic, N

2016-07-01

The contamination of albacore tuna (Thunnus alalunga) by Persistent Organic Pollutants (POPs), namely polychlorinated biphenyls (PCBs) and dichlorodiphenyl-trichloroethane (DDT), was investigated in individuals collected from Reunion Island (RI) and South Africa's (SA) southern coastlines in 2013, in relation to biological parameters and feeding ecology. The results showed lower PCB and DDT concentrations than those previously reported in various tuna species worldwide. A predominance of DDTs over PCBs was revealed, reflecting continuing inputs of DDT. Tuna collected from SA exhibited higher contamination levels than those from RI, related to higher dietary inputs and higher total lipid content. Greater variability in contamination levels and profiles was identified in tuna from RI, explained by a higher diversity of prey and more individualistic foraging behaviour. PCB and DDT contamination levels and profiles varied significantly in tuna from the two investigated areas, probably reflecting exposure to different sources of contamination. Copyright © 2016 Elsevier Inc. All rights reserved.

Insecticide susceptibility studies of three cryptic species of the Anopheles balabacensis complex.

PubMed

Hii, J L

1984-03-01

Susceptibilities of two colonies of the taxon An. dirus (one from Perlis and from Thailand) and one colony of An. balabacensis from Sabah to DDT, dieldrin, malathion, fenitrothion and propoxur were determined. DDT and fenitrothion tolerance was found in An. dirus species B and An. balabacensis. No resistant strain was isolated as the two colonies were not either homozygous or nearly so for resistance. Field testing of the susceptibility of the adults of An. balabacensis to DDT was carried out between 1957 to 1976. The results indicated a progressive rise in the LC50 levels greater than 1% in almost all instance. The variation in the number of sprays applied in some districts have resulted in varying sensitivities. Association between the changes in levels of DDT susceptibility and exophilic habit of An. balabacensis has been observed but needs further confirmation. The significance of these findings and the difficulties in distinguishing tolerant from truly resistant individuals are discussed in relation to accurate species identification.

Metabolomics Approach to Investigate Estrogen Receptor-Dependent and Independent Effects of o,p'-DDT in the Uterus and Brain of Immature Mice.

PubMed

Wang, Dezhen; Zhu, Wentao; Wang, Yao; Yan, Jin; Teng, Miaomiao; Miao, Jiyan; Zhou, Zhiqiang

2017-05-10

Previous studies have demonstrated the endocrine disruption of o,p'-DDT. In this study, we used a 1 H NMR based metabolomics approach to investigate the estrogenic effects of o,p'-DDT (300 mg/kg) on the uterus and brain after 3 days of oral gavage administration, and ethynylestradiol (EE, 100 μg/kg) was used as a positive control. A supervised statistical analysis (PLS-DA) indicated that o,p'-DDT exerted both estrogenic receptor-(ER)-dependent and independent effects on the uterus but mainly ER-independent effects on the brain at metabolome levels, which was verified by coexposing with the antiestrogenic ICI 182,780. Four changed metabolites-glycine, choline, fumarate, and phenylalanine-were identified as ER-independent alterations in the uterus, while more metabolites, including γ-aminobutyrate, N-acetyl aspartate, and some amino acids, were disturbed based on the ER-independent mechanism in the brain. Together with biological end points, metabolomics is a promising approach to study potential estrogenic chemicals.

Long-term trends in DDT, PCBs, and chlordane in mussels from California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephenson, M.D.; Tjeerdema, R.S.

1994-12-31

Many contaminant programs have been established to study the geographical distributions and long-term trends of potential pollutants, but unfortunately, many have been short-lived because of economic cutbacks, providing limited information on long-term trends. The California State Mussel Watch program, however, has been continuously funded for the past 15 years. Several sites have been evaluated and were sampled often enough to obtain statistical resolution. Chlordane was evaluated at 29 stations, with 48% showing significant decreases over time; DDT was evaluated at 35 sites, with 43% showing significant declines; and PCBs were evaluated at 47 sites, with 21% showing significant drops overmore » time. Both DDT and PCBs showed declines, corresponding to decreases in their concentrations in the effluent, at sites located in the vicinity of the Los Angeles County municipal sewage outfall. This long-term investigation indicates that, contrary to public opinion, the banning of DDT, chlordane, and PCBs by the USEPA has led to overall improvement in water quality.« less

Association of serum organochlorine pesticides concentrations with reproductive hormone levels and polycystic ovary syndrome in a Chinese population.

PubMed

Guo, Zhizhun; Qiu, Huiling; Wang, Lingling; Wang, Lijun; Wang, Chonggang; Chen, Meng; Zuo, Zhenghong

2017-03-01

To investigate the serum concentrations of organochlorine pesticides (OCPs) in patients with polycystic ovary syndrome (PCOS), a total of 178 women were studied. The concentrations of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in serum were determined using Gas Chromatography Mass-Mass Spectrometer. No differences with statistical significance in the mean HCH, p,p'-DDD, p,p'-DDE concentrations were observed between the patients with PCOS and the control group. Serum p,p'-DDT (P = 0.016) and o,p'-DDT (P = 0.000) levels were significantly higher in patients with PCOS compared with the control group. The results of the association between OCPs levels and hormone levels indicated that o,p'-DDT may play a role in the pathogenesis of PCOS by affecting hormones levels. Further trials should be investigated with the findings in this study to obtain new pathogenesis of PCOS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evidence of carbamate resistance in urban populations of Anopheles gambiae s.s. mosquitoes resistant to DDT and deltamethrin insecticides in Lagos, South-Western Nigeria

PubMed Central

2012-01-01

Background Resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. This study was carried out to assess the susceptibility status of urban populations of Anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to DDT and permethrin. Methods Two – three day old adult female Anopheles mosquitoes reared from larval collections in 11 study sites from Local Government Areas of Lagos were exposed to test papers impregnated with DDT 4%, deltamethrin 0.05% and propoxur 0.1% insecticides. Additional tests were carried out to determine the susceptibility status of the Anopheles gambiae population to bendiocarb insecticide. Members of the A. gambiae complex, the molecular forms, were identified by PCR assays. The involvement of metabolic enzymes in carbamate resistance was assessed using Piperonyl butoxide (PBO) synergist assays. The presence of kdr-w/e and ace-1R point mutations responsible for DDT-pyrethroid and carbamate resistance mechanisms was also investigated by PCR. Results Propoxur resistance was found in 10 out of the 11 study sites. Resistance to three classes of insecticides was observed in five urban localities. Mortality rates in mosquitoes exposed to deltamethrin and propoxur did not show any significant difference (P > 0.05) but was significantly higher (P < 0.05) in populations exposed to DDT. All mosquitoes tested were identified as A. gambiae s.s (M form). The kdr -w point mutation at allelic frequencies between 45%-77% was identified as one of the resistant mechanisms responsible for DDT and pyrethroid resistance. Ace-1R point mutation was absent in the carbamate resistant population. However, the possible involvement of metabolic resistance was confirmed by synergistic assays conducted. Conclusion Evidence of carbamate resistance in A. gambiae populations already harbouring resistance to DDT and permethrin is a clear indication that calls for the implementation of insecticide resistance management strategies to combat the multiple resistance identified. PMID:22686575

Evaluation of p,p'-DDT as a reference toxicant in bioassays

USGS Publications Warehouse

Marking, Leif L.

1966-01-01

p,p'-DDT was tested as a reference standard toxicant against 19 species of freshwater fish, including 39 lots from 10 sources. In particular, the rapidity, nonselectivity, and consistency of its toxicity to fish were evaluated in 96-hour static bioassays. The chemical was rapidly and consistently toxic to lake trout, carp, green sunfish, bluegill, and yellow perch. It lacked either rapid or consistent toxicity to rainbow trout, brook trout, goldfish, fathead minnows, and longear sunfish in 96-hour tests. Thus, p,p'-DDT is of limited usefulness as a reference standard toxicant in large bioassays with many species of fish.

Chronic lymphatic leukaemia and engine exhausts, fresh wood, and DDT: a case-referent study.

PubMed Central

Flodin, U; Fredriksson, M; Persson, B; Axelson, O

1988-01-01

The effect of potential risk factors for chronic lymphatic leukaemia was evaluated in a case-referent study encompassing 111 cases and 431 randomised referents, all alive. Information on exposure was obtained by questionnaires posted to the subjects. Crude rate ratios were increased for occupational exposure to solvents. DDT, engine exhausts, fresh wood (lumberjacks, paper pulp workers, and sawmill workers, for example) and also in farming. Further analysis of the material by means of the Miettinen confounder score technique reduced the number of rate ratios significantly exceeding unity to encompass only occupational exposure to engine exhaust, fresh wood, DDT, and contact with horses. PMID:2449239

Impact of changing over of insecticide from synthetic pyrethroids to DDT for indoor residual spray in a malaria endemic area of Orissa, India

PubMed Central

Sharma, Surya K.; Upadhyay, Ashok K.; Haque, Mohammed A.; Tyagi, Prajesh K.; Kindo, Bikrant K.

2012-01-01

Background & objectives: Development of insecticide resistance in malaria vectors has been a major problem for achieving effective vector control. Due to limited availability of insecticides, the only option is management of resistance by judiciously using the insecticides and rotating them to maintain their effectiveness. This study was carried out in a malaria endemic area of Sundergarh district in Orissa where synthetic pyrethroids (SP) were in use for the last couple of years. The change-over from SP to DDT was done in one arm of study, and the other two arms remained on SP and insecticide-treated nets (ITN). Entomological and parasitological monitoring was done to assess the impact. Methods: The study design comprised of three arms (i) two rounds of indoor residual spraying (IRS) with DDT 1g/m2 as a change-over insecticide in areas previously under synthetic pyrethroids; (ii) two rounds of IRS with synthetic pyrethroid (alphacypermethrin, ACM) @ 25 mg/m2; and (iii) an unsprayed area under ITN/long lasting insecticide nets (LNs). Indoor residual spraying was undertaken under strict supervision to maintain quality and coverage. Contact bioassays were conducted to know the persistence of insecticide on sprayed surfaces and adult vector density was monitored in fixed and randomly selected houses. Malaria incidence was measured through fortnightly domiciliary surveillance under primary health care system in all the study villages. Results: The insecticide susceptibility tests showed that An.culicifacies was resistant to DDT but susceptible to malathion and ACM. However, An. fluviatilis was susceptible to all the three insecticides. ACM was effective in killing An. culicifacies on mud and wooden sprayed surfaces and maintained effective bioefficacy ranging from 92 to 100 per cent up to five months, whereas DDT failed to achieve effective mortality in An.culicifacies. However, there was significant decline in the density of An.culicifacies in ACM and DDT areas in comparison to ITNs/LNs. There was 61 per cent reduction in the slide positivity rate in ACM area in comparison to 48 and 51 per cent in DDT and ITN/LNs areas, respectively. The adjusted incidence rate of malaria cases per 1000 population in three study areas also showed significant declines within each group. Interpretation & conclusions: The present findings show that the change-over of insecticide from synthetic pyrethroids to DDT brings about the same epidemiological impact as envisaged from continuing SP spray or distributing insecticide treated nets/long-lasting insecticidal nets provided there is a good quality spray and house coverage. PMID:22561626

Reactive and recoverable sorbents for halogenated organic compound remediation in sediments

NASA Astrophysics Data System (ADS)

Werner, David; Taggalou, Villy; Kordulis, Christos; Dolfing, Jan; Karapanagioti, Hrissi K.

2013-04-01

Activated carbon (AC) has been proposed as a sediment amendment for aquatic systems polluted with hydrophobic organic compounds. AC acts as a strong binding agent that lowers the pollutant concentration and thus, its toxicity. A draw back of this in-situ remediation method is that although the pollutant will remain non-bioavailable for many years being sorbed into AC, it actually stays in the system. A reactive sorbent, a sorbent that would, at the same time, facilitate the degradation of the pollutant, would be better accepted by the public or the regulators than AC amendment. So far, catalysts supported on AC with zero valent iron and a reactive metal have been proposed for the dechlorination of chlorinated organic compounds. These reactive metals are usually expensive or toxic and thus, their addition to the environment is not desirable. In the present study, activated carbon modified with reduced iron(AC/Fe) is tested in batch systems in the presence of sediment and DDT sorbed on polyethylene sheets. The batch systems are equilibrated for different contact times. Then, the DDT remaining in the polyethylene sheets is quantified along with DDD produced due to the dechlorination of DDT. A small percentage of DDT is degraded to DDD in the systems containing the AC/Fe material. No degradation of DDT is observed in the control systems containing the pollutant and the sediment or the pollutant, the sediment and AC. Thus, the addition of AC/Fe to the sediment with the DDT is enough to cause the dechlorination of DDT. At the end of the experiments, a magnet rod is used to recover the AC/Fe material from the batches with the sediment. An average recovery of 83% is achieved. This is a high percentage suggesting that the material can be easily recovered. Some drawbacks of the material preparation method are identified after the composite material characterization. For example, the AC/Fe surface area is decreased with the material preparation compared to the initial surface area of the AC. This fact results in decrease of the sorption ability of the AC/Fe material compared to that of the AC. At the same time, more DDT degradation might be achievable by increasing the AC/Fe dosage from the 1% weight used in this study that is lower than commonly used for sediment amendments. More research is necessary to optimize the material preparation and properties.

Organochlorine pesticides in tree bark and human hair in Yunnan Province, China: Concentrations, distributions and exposure pathway.

PubMed

Yuan, Haodong; Jin, Jun; Bai, Yao; Li, Qiuxu; Wang, Ying; Wang, Qinghua

2017-02-15

The concentrations and distributions of organochlorine pesticides (OCPs) in West China were investigated and internal and external exposure of humans to OCPs were assessed by analyzing samples of human hair and tree bark collected in Kaiyuan, in Yunnan Province, China. Dichlorodiphenyltrichloroethane and its metabolites (collectively called DDTs), hexachlorocyclohexanes (HCHs), and hexachlorobenzene (HCB) were the dominant OCPs in the human hair and tree bark samples. The mean total DDT, total HCH, and HCB concentrations in the tree bark samples were 298pg/g dry weight (dw), 100pg/g dw, and 183pg/g dw, respectively, and the mean total DDT, total HCH, and HCB concentrations in the hair samples were 2850pg/g dw, 348pg/g dw, and 1026pg/g dw, respectively. The results indicated that relatively new DDT and lindane inputs have occurred in the study area. DDT and lindane may have been released in products that are used locally. The HCB in the environment in the study area is mainly supplied by long-range atmospheric transport. External exposure was found to be the main factor controlling the p,p'-DDT, γ-HCH, and HCB concentrations in human hair, whereas p,p'-DDE and β-HCH were found to be mainly controlled by internal exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

Concurrent auditory perception difficulties in older adults with right hemisphere cerebrovascular accident

PubMed Central

Talebi, Hossein; Moossavi, Abdollah; Faghihzadeh, Soghrat

2014-01-01

Background: Older adults with cerebrovascular accident (CVA) show evidence of auditory and speech perception problems. In present study, it was examined whether these problems are due to impairments of concurrent auditory segregation procedure which is the basic level of auditory scene analysis and auditory organization in auditory scenes with competing sounds. Methods: Concurrent auditory segregation using competing sentence test (CST) and dichotic digits test (DDT) was assessed and compared in 30 male older adults (15 normal and 15 cases with right hemisphere CVA) in the same age groups (60-75 years old). For the CST, participants were presented with target message in one ear and competing message in the other one. The task was to listen to target sentence and repeat back without attention to competing sentence. For the DDT, auditory stimuli were monosyllabic digits presented dichotically and the task was to repeat those. Results: Comparing mean score of CST and DDT between CVA patients with right hemisphere impairment and normal participants showed statistically significant difference (p=0.001 for CST and p<0.0001 for DDT). Conclusion: The present study revealed that abnormal CST and DDT scores of participants with right hemisphere CVA could be related to concurrent segregation difficulties. These findings suggest that low level segregation mechanisms and/or high level attention mechanisms might contribute to the problems. PMID:25679009

Involvement of oxidative stress in the mechanism of p,p'-DDT-induced nephrotoxicity in adult rats.

PubMed

Marouani, Neila; Hallegue, Dorsaf; Sakly, Mohsen; Benkhalifa, Moncef; Ben Rhouma, Khémais; Tebourbi, Olfa

2017-07-01

The 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (p,p'-DDT) is an organochlorine pesticide that persists in the environment and has a risk to human health. We investigated whether p,p'-DDT-induces nephrotoxicity in rats and whether oxidative stress and apoptosis are involved in the pathogenesis of this process. Male rats received the pesticide at doses of 50 and 100 mg/kg for 10 days. Renal damage was evaluated by histopathological examination and serum markers. The oxidative stress was evaluated by lipid peroxidation (LPO), metallothioneins (MTs) and protein carbonyl levels. Antioxidant enzymes were assessed by determination of superoxide dismutase (SOD) and catalase (CAT) activities. Glutathione-dependent enzymes and reducing power in kidney were evaluated by glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST) activities. Renal tubular cells apoptosis was assessed through the TUNEL assay. After 10 days of treatment, an increase of serum creatinine and urea levels occurred, LPO and protein carbonyl levels were increased, while MTs level, SOD and CAT activities were decreased. Besides, the GPx, GR, GST, and GSH activities were decreased. Histological alterations in kidney tissue and intense apoptosis in renal tubular cells were observed. These results suggest that DDT sub-acute treatment causes oxidative stress and apoptosis, which may be the chief mechanisms of DDT-induced nephrotoxicity.

Progress in Global Multicompartmental Modelling of DDT

NASA Astrophysics Data System (ADS)

Stemmler, I.; Lammel, G.

2009-04-01

Dichlorophenyltrichloroethane, DDT, and its major metabolite dichlorophenyldichloroethylene, DDE, are long-lived in the environment (persistent) and circulate since the 1950s. They accumulate along food chains, cause detrimental effects in marine and terrestrial wild life, and pose a hazard for human health. DDT was widely used as an insecticide in the past and is still in use in a number of tropical countries to combat vector borne diseases like malaria and typhus. It is a multicompartmental substance with only a small mass fraction residing in air. A global multicompartment chemistry transport model (MPI-MCTM; Semeena et al., 2006) is used to study the environmental distribution and fate of dichlorodiphenyltrichloroethane (DDT). For the first time a horizontally and vertically resolved global model was used to perform a long-term simulation of DDT and DDE. The model is based on general circulation models for the ocean (MPIOM; Marsland et al., 2003) and atmosphere (ECHAM5). In addition, an oceanic biogeochemistry model (HAMOCC5.1; Maier-Reimer et al., 2005 ) and a microphysical aerosol model (HAM; Stier et al., 2005 ) are included. Multicompartmental substances are cycling in atmosphere (3 phases), ocean (3 phases), top soil (3 phases), and vegetation surfaces. The model was run for 40 years forced with historical agricultural application data of 1950-1990. The model results show that the global environmental contamination started to decrease in air, soil and vegetation after the applications peaked in 1965-70. In some regions, however, the DDT mass had not yet reached a maximum in 1990 and was still accumulating mass until the end of the simulation. Modelled DDT and DDE concentrations in atmosphere, ocean and soil are evaluated by comparison with observational data. The evaluation of the model results indicate that degradation of DDE in air was underestimated. Also for DDT, the discrepancies between model results and observations are related to uncertainties of input parameters. Furthermore, better resolution of some processes could improve model performance. References: Marsland S.J., Haak H., Jungclaus J.H., Latif M., Röske F. (2003): The Max-Planck-Institute global ocean/sea ice model with orthogonal curvilinear coordinates. Ocean Modelling 5, 91-127 Maier-Reimer E. , Kriest I., Segschneider J., Wetzel P. : The HAMburg Ocean Carbon Cycle Model HAMOCC 5.1 - Technical Description Release 1.1 (2005),Reports on Earth System Science 14 Stier P. , Feichter J. (2005), Kinne S., Kloster S., Vignati E., Wilson J.Ganzeveld L., Tegen I., Werner M., Blakanski Y., Schulz M., Boucher O., Minikin A., Petzold A.: The aerosol-climate model ECHAM5-HAM. Atmos. Chem. Phys 5, 1125-1156 Semeena V.S., Feichter J., Lammel G. (2006): Impact of the regional climate and substance properties on the fate and atmospheric long-range transport of persistent organic pollutants - examples of DDT and γ-HCH. Atmos. Chem. Phys. 6, 1231-1248

EFFECTS OF DDT SEDIMENT-CONTAMINATION ON MACROFAUNAL COMMUNITY STRUCTURE AND COMPOSITION IN SAN FRANCISCO BAY

EPA Science Inventory

The objectives of this study were to determine the effects of sediment contamination on the benthic macrofauna and to predict macrofaunal changes following remediation at a Superfund (uncontrolled hazardous waste) site in San Francisco Bay, CA, USA. DDT and its metabolites (sumDD...

EVALUATION OF A FIRST-ORDER MODEL FOR THE PREDICTION OF THE BIOACCUMULATION OF PCBS AND DDT FROM SEDIMENT INTO THE MARINE DEPOSIT-FEEDING CLAM MACOMA NASUTA

EPA Science Inventory

A first-order model for predicting contaminant bioaccumulation from sediments into benthic invertebrates was validated using a marine deposit-feeding clam, Macoma nasuta, exposed to polychlorobiphenyl (PCB)-spiked and dichlorodiphenyltrichloroethane (DDT)-contaminated sediments. ...

Dust devil track survey at Elysium Planitia, Mars: Implications for the InSight landing sites

NASA Astrophysics Data System (ADS)

Reiss, Dennis; Lorenz, Ralph D.

2016-03-01

The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) robotic lander is scheduled to land in Elysium Planitia on Mars in September 2016. InSight will perform the first comprehensive surface-based geophysical investigation including seismic measurements. Knowledge about encounter rates of dust devils with the InSight lander are important for two main reasons: (1) dust devils will affect the scientific measurements, i.e., wind-induced seismic noise, and (2) the power-supply of the InSight lander and instruments is provided by solar arrays and previous landers and rovers on Mars were affected by a steady decline in electrical power output due to atmospheric dust deposition on the solar panels. Long term science operations were only made possible by dust clearing events of the solar arrays caused by wind gusts and dust devils. In this study we analyzed dust devil tracks (DDTs) at the final InSight landing site region in Elysium Planitia. Formation of DDTs is caused by the removal of a layer of dust by passing dust devils, hence in principle the same process as clearing of dust from solar panels. We mapped the number, size (width and length), and orientation of DDTs in repeat observations using High Resolution Imaging Science Experiment (HiRISE) images covering the exact same surface area acquired within a relatively short time span (<90 martian days). In total, we analyzed 557 newly formed dust devil tracks in 8 study areas. DDTs are morphologically relatively straight with a low mean sinuosity of 1.03 and only reach maximum widths of 30 m. The mean DDT width is 4 m, indicating that the dust devil size population is dominated by small dust devils with a diameter <10 m. The size-frequency distribution of DDTs follows a -2 power law. The mean lengths of DDTs are 0.62 km and 1.23 km for complete (tracks which are visible from their start to end point) and incomplete DDTs (tracks running across the HiRISE footprint), respectively. The alignment of DDTs in combination with Mars Climate Database (MCD) predicted wind directions imply that dust devils are moving from SE to NW until early northern autumn with a reversal to NW-SE directions of movement at LS = 200° consistent with the seasonal reversal in direction of the Hadley circulation. DDT formation rates vary between 0.002 and 0.08 ddt km-2 sol-1. DDT area formation rates using the measured DDT widths, lengths, and formation rates are in the range of 0.0003-0.00006 km2 km-2 sol-1, implying that a given spot on the surface may be cleared of dust only once between ∼3000 and 16,000 sols (i.e. every ∼5-24 Mars years). Measured DDT formation rates were used to find a scaling factor to the seasonal DDA index, and then integrated over the year to estimate a mean annual DDT formation rate of 0.046 ddt km-2 sol-1. This translates into a solar panel clearing recurrence interval estimate of ∼11 Mars years using the mean annual DDT formation rate, and the mean DDT width and length from all measured DDTs. Due to several uncertainties this solar panel clearing recurrence interval for the InSight landing should be seen as an upper limit estimate.

DDE remediation and degradation.

PubMed

Thomas, John E; Ou, Li-Tse; All-Agely, Abid

2008-01-01

DDT and its metabolites, DDD and DDE, have been shown to be recalcitrant to degradation. The parent compound, DDT, was used extensively worldwide starting in 1939 and was banned in the United States in 1973. The daughter compound, DDE, may result from aerobic degradation, abiotic dehydrochlorination, or photochemical decomposition. DDE has also occurred as a contaminant in commercial-grade DDT. The p,p'-DDE isomer is more biologically active than the o,p-DDE, with a reported half-life of -5.7 years. However, when DDT was repeatedly applied to the soil, the DDE concentration may remain unchanged for more than 20 yr. Remediation of DDE-contaminated soil and water may be done by several techniques. Phytoremediation involves translocating DDT, DDD, and DDE from the soil into the plant, although some aquatic species (duckweed > elodea > parrot feather) can transform DDT into predominantly DDD with some DDE being formed. Of all the plants that can uptake DDE, Cucurbita pepo has been the most extensively studied, with translocation values approaching "hyperaccumulation" levels. Soil moisture, temperature, and plant density have all been documented as important factors in the uptake of DDE by Cucurbita pepo. Uptake may also be influenced positively by amendments such as biosurfactants, mycorrhizal inoculants, and low molecular weight organic acids (e.g., citric and oxalic acids). DDE microbial degradation by dehalogenases, dioxygenases, and hydrolases occurs under the proper conditions. Although several aerobic degradation pathways have been proposed, none has been fully verified. Very few aerobic pure cultures are capable of fully degrading DDE to CO2. Cometabolism of DDE by Pseudomonas sp., Alicaligens sp., and Terrabacter sp. grown on biphenyl has been reported; however, not all bacterial species that produce biphenyl dioxygenase degraded DDE. Arsenic and copper inhibit DDE degradation by aerobic microorganisms. Similarly, metal chelates such as EDTA inhibit the breakdown of DDE by the extracellular lignolytic enzymes produced by white rot fungi. The addition of adjutants such as sodium ion, surfactants, and cellulose increased the rate of DDT aerobic or anaerobic degradation but did little to enhance the rate of DDE disappearance under anaerobic conditions. Only in the past decade has it been demonstrated that DDE can undergo reductive dechlorination under methanogenic and sulfidogenic conditions to form the degradation product DDMU, 1-chloro-2,2'-bis-(4'-chlorophenyl)ethane. The only pure culture reported to degrade DDE under anaerobic conditions was the denitrifier Alcaligens denitrificans. The degradation of DDE by this bacterium was enhanced by glucose, whereas biphenyl fumes had no effect. Abiotic remediation by DDE volatilization was enhanced by flooding and irrigation and deepplowing inhibited the volatilization. The use of zero-valent iron and surfactants in flooded soils enhanced DDT degradation but did not significantly alter the rate of DDE removal. Other catalysts (palladized magnesium, palladium on carbon, and nickel/aluminum alloys) degraded DDT and its metabolites, including DDE. However, these systems are often biphasic or involve explosive gases or both. Safer abiotic alternatives use UV light with titanium oxide or visible light with methylene green to degrade DDT, DDD, and DDE in aqueous or mixed solvent systems. Remediation and degradation of DDE in soil and water by phytoextraction, aerobic and anaerobic microorganisms, or abiotic methods can be accomplished. However, success has been limited, and great care must be taken that the method does not transfer the contaminants to another locale (by volatilization, deep plowing, erosion, or runoff) or to another species (by ingestion of accumulating plants or contaminated water). Although the remediation of DDT-, DDD-, and DDE-contaminated soil and water is beset with myriad problems, there remain many open avenues of research.

Insecticide residues on stream sediments in Ontario, Canada.

PubMed

Miles, J R

1976-12-01

Insecticide residues on suspended and bottom sediments of streams of Ontario, Canada, have been studied in a tobacco-growing and a vegetable muck area. The proportion of TDE to DDT was less than 1 in water and greater than 1 in bottom sediments. The ratio of TDE to DDT in bottom material increased linearly from the contamination point at stream source to the mouth of Big Creek in Norfolk County, Ontario. Bed load samples contained three to six times greater concentrations of insecticides than bottom material. Adsorption of insecticides on suspended sediment decreased in order DDT greater than TDE greater than dieldrin greater than diazinon, which is consistent with the water solubility of these compounds.

Absolute configuration determination through the unique intramolecular excitonic coupling in the circular dichroisms of o,p'-DDT and o,p'-DDD. A combined experimental and theoretical study.

PubMed

Tanaka, Hiroki; Inoue, Yoshihisa; Nakano, Takeshi; Mori, Tadashi

2017-04-12

Circular dichroisms (CDs) of the o,p'-isomers of 1,1,1-trichloro- and 1,1-dichloro-2,2-bis(chlorophenyl)ethanes (DDT and DDD) were investigated experimentally and theoretically. A series of strong Cotton effect peaks in a characteristic negative-negative-positive-negative, or its mirror-imaged, pattern were observed in the CD spectra of these persistent organic pollutants. The theoretical CD spectra at the SAC-CI/B95(d) and RI-CC2/def2-TZVPP levels well reproduced the experimental ones, enabling us to unambiguously assign the absolute configuration of (+)-DDT and (-)-DDD as S.

Fluid dynamics of the unsteady two phase processes leading to DDT in granular solid propellants

NASA Technical Reports Server (NTRS)

Krier, H.; Butler, P. B.; Lembeck, M. F.

1980-01-01

Deflagration to Detonation (DDT) was predicted to occur in porous beds of high-energy solid propellants by solving the unsteady fluid mechanical convective heat transfer from hot gas products, obtained from the rapid burning at high pressures, provides the impetus to develop a narrow combustion zone and a resulting strong shock. A parametric study clearly indicates that DDT occurs only when a combination of the solids loading fraction, the burning rate constants, the propellant chemical energy, and the particle size provide for critical energy and gas release to support a detonation wave. Predictions for the run-up length to detonation as a function of these parameters are presented.

The GraVent DDT database

NASA Astrophysics Data System (ADS)

Boeck, Lorenz R.; Katzy, Peter; Hasslberger, Josef; Kink, Andreas; Sattelmayer, Thomas

2016-09-01

An open-access online platform containing data from experiments on deflagration-to-detonation transition conducted at the Institute of Thermodynamics, Technical University of Munich, has been developed and is accessible at http://www.td.mw.tum.de/ddt. The database provides researchers working on explosion dynamics with data for theoretical analyses and for the validation of numerical simulations.

Contact toxicity of 14 insecticides tested on pine butterfly larvae

Treesearch

Robert L. Lyon; Sylvia J. Brown

1971-01-01

Fourteen insecticides were evaluated for contact toxicity to 3rd and 4th stage pine butterfly larvae (Neophasia menapia F. & F.) in a laboratory spray chamber. All candidate insecticides except trichlorfon were more toxic than the standard DDT. The ranking of toxicity at LD90 and toxicity indexes (times more toxic than DDT...

To Spray or Not To Spray? A Debate Over DDT.

ERIC Educational Resources Information Center

Dinan, Frank J.; Bieron, Joseph F.

2001-01-01

Presents an activity in which students grapple with the complex issues surrounding the use of DDT to control malaria which affects millions of people in developing nations. Considers risk/benefit analysis and the pre-cautionary principle, two techniques used when making policy decisions involving the impact of science and technology on society.…

Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes

USDA-ARS?s Scientific Manuscript database

The development of an integrated strategy for the remediation of soil co-contaminated by heavy metals and persistent organic pollutants is a major research priority for the decontamination of soil slated for use in agricultural production. The objective of this study was to develop a bioremediation ...

Wavefront aberrations of x-ray dynamical diffraction beams.

PubMed

Liao, Keliang; Hong, Youli; Sheng, Weifan

2014-10-01

The effects of dynamical diffraction in x-ray diffractive optics with large numerical aperture render the wavefront aberrations difficult to describe using the aberration polynomials, yet knowledge of them plays an important role in a vast variety of scientific problems ranging from optical testing to adaptive optics. Although the diffraction theory of optical aberrations was established decades ago, its application in the area of x-ray dynamical diffraction theory (DDT) is still lacking. Here, we conduct a theoretical study on the aberration properties of x-ray dynamical diffraction beams. By treating the modulus of the complex envelope as the amplitude weight function in the orthogonalization procedure, we generalize the nonrecursive matrix method for the determination of orthonormal aberration polynomials, wherein Zernike DDT and Legendre DDT polynomials are proposed. As an example, we investigate the aberration evolution inside a tilted multilayer Laue lens. The corresponding Legendre DDT polynomials are obtained numerically, which represent balanced aberrations yielding minimum variance of the classical aberrations of an anamorphic optical system. The balancing of classical aberrations and their standard deviations are discussed. We also present the Strehl ratio of the primary and secondary balanced aberrations.

Organochlorine pesticide levels in breast milk in Guerrero, Mexico.

PubMed

Chávez-Almazán, Luis A; Diaz-Ortiz, Jesús; Alarcón-Romero, Mario; Dávila-Vazquez, Gustavo; Saldarriaga-Noreña, Hugo; Waliszewski, Stefan M

2014-09-01

In Mexico, organochlorine pesticides were used in public health and agriculture programs, causing chronic exposure to the population. Human breast milk samples were collected from 171 mothers who were residents from Guerrero, Mexico. Analysis was carried out by gas chromatography. Median concentrations (mg/kg on fat basis) for the following pesticides were: HCB, 0.009; β-HCH, 0.004; pp'DDE, 0.760; op'DDT, 0.016; pp'DDT, 0.045; and Σ-DDT, 0.833. These values are lower than in other States in Mexico, and in some countries where the use of these pesticides was banned more than 30 years ago. Differences were found in HCB, pp'DDE and pp'DDT concentrations in groups divided according to age (p < 0.05). The older age groups had higher concentrations, except for the comparison between groups 21-23/24-28 years, which were 0.913 and 0.530 mg/kg of pp'DDE, respectively. Given the restrictions on use, a greater decrease in organochlorine pesticide levels in human milk is expected in a few years.

Occurrence of persistent organic pollutants in marine fish from the Natuna Island, South China Sea.

PubMed

Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

2014-08-15

Five marine fish species were collected from the Natuna Island, South China Sea to investigate the occurrence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs in marine fish ranged from 2.85 to 7.82, 14.3 to 48.1, and 7.99 to 40.3 ng/g lipid weight, respectively. Higher concentrations of PBDEs, PCBs, and DDTs were observed in Snakefish (Trachinocephalus myops), which might be attributed to their different feeding and living habits. PCBs were the predominant POPs in all marine fish, followed by DDTs and PBDEs. BDE 47 and PCB 153 were the predominant congener of PBDEs and PCBs, respectively. Compositional distribution of DDTs indicated the possible presence of fresh input sources around the Natuna Island. The ratios of o,p'-DDT/p,p'-DDT being less than 1 in fish samples suggested that DDT contributions from dicofol seemed considerably low. New input sources of DDT in South China Sea are worth further research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Competitive sorption of persistent organic pollutants onto microplastics in the marine environment.

PubMed

Bakir, Adil; Rowland, Steven J; Thompson, Richard C

2012-12-01

Plastics are known to sorb persistent organic pollutants from seawater. However, studies to quantify sorption rates have only considered the affinity of chemicals in isolation, unlike the conditions in the environment where contaminants are present as complex mixtures. Here we examine whether phenanthrene and 4,4'-DDT, in a mixture, compete for sorption sites onto PVC with no added additives (unplasticised PVC or uPVC) and Ultra-High Molecular Weight polyethylene. Interactions were investigated by exposing particles of uPVC and UHMW PE to mixtures of 3H and 14C radiolabelled Phe and DDT. Changes in sorption capacity were modelled by applying a Freundlich binding sorption isotherms. An Extended Langmuir Model and an Interaction Factor Model were also applied to predict equilibrium concentrations of pollutants onto plastic. This study showed that in a bi-solute system, DDT exhibited no significantly different sorption behaviour than in single solute systems. However, DDT did appear to interfere with the sorption of Phe onto plastic, indicating an antagonistic effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

DDT poisoning of big brown bats, Eptesicus fuscus, in Hamilton, Montana.

PubMed

Buchweitz, John P; Carson, Keri; Rebolloso, Sarah; Lehner, Andreas

2018-06-01

Dichlorodiphenyltrichloroethane (DDT) is an insecticidal organochlorine pesticide with; known potential for neurotoxic effects in wildlife. The United States Environmental Protection Agency (US EPA) registration for this pesticide has been cancelled and there are currently no federally active products that contain this ingredient in the U.S. We present a case of a colony of big brown bats (E. Fuscus) found dead in the attic roost of an administrative building; in the city of Hamilton, Montana from unknown cause. DDT and its metabolites; dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were detected in bat tissues by gas chromatography/mass spectrometry (GC-MS) and quantified by gas chromatography tandem quadrupole mass spectrometry (GC-MS/MS). Concentrations of 4081 ppm DDT and 890 ppm DDE wet weight were found in the brain of one bat and are the highest reported concentrations in such a mortality event to date. This case emphasizes the importance of testing wildlife mortalities against a comprehensive panel of toxicologic agents including persistent organic pollutants in the absence of other more common disease threats. Copyright © 2018 Elsevier Ltd. All rights reserved.

Organochlorine insecticide residues are found in surface, irrigated water samples from several districts in Bangladesh.

PubMed

Chowdhury, Alamgir Zaman; Islam, Mohammad Nazrul; Moniruzzaman, Mohammed; Gan, Siew Hua; Alam, Md Khorshed

2013-02-01

The purpose of this study was to investigate the occurrence and distribution of organochlorines such as aldrin, dieldrin, dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyltrichloroethane (DDT), endrin, lindane and heptachlor insecticide residues in irrigated surface water samples collected from 22 districts in Bangladesh. The concentrations of the pesticides were determined using gas chromatography mass spectrophotometry. Water samples from five locations (Feni, Nawabganj, Putia, Burichang and Chatak) were contaminated with DDT; the highest DDT concentration detected was 8.29 μg/L, and its metabolite, DDE, was detected at 4.06 μg/L. Water samples from four other locations (Natore, Sikderpara, Chatak and Rajoir) were contaminated with heptachlor residues, and the highest level detected was 5.24 μg/L, which is the above the maximum contaminant level recommended by the World Health Organisation. A water sample collected from Chatak, Sunamganj, was contaminated with both DDT and heptachlor pesticide residues. None of the water samples were contaminated with aldrin, DDD, dieldrin, endrin or lindane. It is concluded that continuous, long-term monitoring and essential steps to limit the use of the pesticides in Bangladesh are needed.

Negative regulation of AMP-activated protein kinase (AMPK) activity by macrophage migration inhibitory factor (MIF) family members in non-small cell lung carcinomas.

PubMed

Brock, Stephanie E; Rendon, Beatriz E; Yaddanapudi, Kavitha; Mitchell, Robert A

2012-11-02

AMP-activated protein kinase (AMPK) is a nutrient- and metabolic stress-sensing enzyme activated by the tumor suppressor kinase, LKB1. Because macrophage migration inhibitory factor (MIF) and its functional homolog, d-dopachrome tautomerase (d-DT), have protumorigenic functions in non-small cell lung carcinomas (NSCLCs) but have AMPK-activating properties in nonmalignant cell types, we set out to investigate this apparent paradox. Our data now suggest that, in contrast to MIF and d-DTs AMPK-activating properties in nontransformed cells, MIF and d-DT act cooperatively to inhibit steady-state phosphorylation and activation of AMPK in LKB1 wild type and LKB1 mutant human NSCLC cell lines. Our data further indicate that MIF and d-DT, acting through their shared cell surface receptor, CD74, antagonize NSCLC AMPK activation by maintaining glucose uptake, ATP production, and redox balance, resulting in reduced Ca(2+)/calmodulin-dependent kinase kinase β-dependent AMPK activation. Combined, these studies indicate that MIF and d-DT cooperate to inhibit AMPK activation in an LKB1-independent manner.

Persistent organic pesticide residues in sediments of Vasai Creek near Mumbai: Assessment of sources and potential ecological risk.

PubMed

Singare, Pravin U

2015-11-15

Thirteen persistent organic pesticides were investigated in the sediments of Vasai Creek near Mumbai to evaluate their pollution levels and potential risks. It was observed that ΣOCPs level was in the range of 597-1538ng/g dw, with an average value of 1115.25ng/g dw. The level of ΣOPPs was in the range of 492-1034ng/g dw, with an average value of 798.15ng/g dw. The values o,p'-DDT/p,p'-DDT ratio gives an indication of use of technical DDT as the prime source of DDT, while the α/γ-BHC ratio indicate that BHCs in study area might have been received from fresh lindane. The results of an ecological risk assessment showed that sediment bound organic pesticides are of more ecotoxicological concern as they might create adverse ecological risk to the marine breeding habitats. These pesticides residues may get remobilize and released to overlying waters creating adverse effects on terrestrial and aquatic organisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

PCDD/F formation during thermal desorption of p,p'-DDT contaminated soil.

PubMed

Zhao, Zhonghua; Ni, Mingjiang; Li, Xiaodong; Buekens, Alfons; Yan, Jianhua

2017-05-01

Thermal treatment of polychlorinated biphenyls (PCB) contaminated soil was shown in earlier work to generate polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). In this study, the PCDD/F were studied arising during the remediation of p,p'-DDT contaminated soil by thermal desorption. Three kinds of soil (sandy, clayey and lateritic soil) were tested to investigate the effect of soil texture on PCDD/F formation. Those soils were artificially polluted with p,p'-DDT, obtaining a concentration level of 100 mg/kg. Thermal desorption experiments were conducted for 10 min at 300 °C in an air atmosphere. The total concentration of PCDD/F generated for three soils were 331, 803 and 865 ng/kg, respectively, and TeCDD and TeCDF were dominant among all PCDD/F congeners. After thermal desorption, the total amount of PCDD/F generated both in soil and in off-gas correlated positively with the amount of DDT added to soil. In addition, a possible pathway of the formation of PCDD/F was presented.

[Toxic effect of DDT, chlordane and water from the Ignacio Ramírez dam (Mexico), on Daphnia magna (Crustacea: Daphnidae)].

PubMed

Martínez-Tabche, L; Romero Solís, M; López López, E; Galar Martínez, M

1999-12-01

Chlorodiphenylnitrichloroethane (DDT) and chlordane (CLO) are currently used in Mexico to control malaria and termites. From 1990 to 1996 a total of 27 ton of DDT and 508 of CLO were imported. We establish a methodology to determine their environmental impact in a Mexican dam (Ignacio Ramírez). The toxic effect of DDT and CLO were evaluated on the o-demethylase (OD) and acethycholinesterase activities (AchA) of the cladoceran Daphnia magna exposed to different concentrations of the insecticides solved in water from three sites. Their effect on the AchA and OD activities, and so the CL50 were used as exposure bioindicators to determine the more polluted sites. The physicochemical characteristics of water and the biodiversity of the dam test sites were considered. The station near the floodgate has toxicity potential because enzymatic activities were modified. We suggest the use of AchA and OD activities measure in the cladoceran to evaluate the toxicity of a water body polluted by organochlorate insecticides.

Organochlorines and polychlorinated biphenyl environmental pollution in south coast of Rio De Janeiro state.

PubMed

da Silva, Ana Maria Ferreira; Pavesi, Thelma; Rosa, Ana Cristina Simões; Santos, Tatyane Pereira Dos; de Medeiros Tabalipa, Marianne; Lemes, Vera Regina Rossi; Alves, Sergio Rabello; de Novaes Sarcinelli, Paula

2016-07-15

The objective of this study was to evaluate the burden of environmental pollution by Polychlorinated Biphenyls (PCBs) and Organochlorine Pesticides (OCs) in two localities of Rio de Janeiro coast, through the determination of these levels in specimens of mullets and croakers collected from May to August 2008, at Guanabara Bay (GB) and from Araújo Island (AI), at Paraty Bay. Twenty three organochlorine pollutants were detected in croakers at GB and twenty in mullets and all PCBs congeners investigated in the study were present in the two species. Ratio ∑DDT/∑PCB of 1.4 shows an important contribution of agricultural residues in GB and p,p'-DDE/∑DDT of 0.1 demonstrates a reintroduction of DDT. Consumption of mullet may represent a risk to the health of fishermen families from GB, with average and maximum estimated daily intake of ∑DDT of 9.012μg/kg p.c. and 26,174μg/kg p.c., representing 45% and 131% of ADI established by WHO. Copyright © 2016 Elsevier Ltd. All rights reserved.

Insecticide susceptibility of Phlebotomus argentipes & assessment of vector control in two districts of West Bengal, India.

PubMed

Kumar, Vijay; Shankar, Lokesh; Kesari, Shreekant; Bhunia, Gouri Shankar; Dinesh, Diwakar Singh; Mandal, Rakesh; Das, Pradeep

2015-08-01

Kala-azar or visceral leishmanisis (VL) is known to be endemic in several States of India including West Bengal (WB). Only meager information is available on the vector dynamics of its vector species, Phlebotomus argentipes particularly in relation to control measure from this State. Hence, a pilot study was undertaken to assess the control strategy and its impact on vector in two endemic districts of WB, India. Two villages each from the two districts, Maldah and Burdwan, were selected for the study. Seasonal variation of sandflies was observed during pre-monsoon, post-monsoon and winter seasons. Susceptibility test of P. argentipes against DDT and bioassay on DDT sprayed wall and on long lasting insecticide nets (LN) Perma Net [®] 2.0 were conducted as per the WHO standard methods. P. argentipes density was high during March to October. Susceptibility status of P. argentipes ranged from 40 to 61.54 per cent. Bioassay test showed 57.89 per cent mortality against LN PermaNet [®] -2.0. and 50 per cent against DDT on wall within 30 min of exposure. Despite the integrated vector management approach, the sandfly population was high in the study area. The reason could be development of resistance in P. argentipes against DDT and low effectiveness of LN PermaNet [®] -2.0. The more pragmatic step will be to conduct large studies to monitor the susceptibility level in P. argentipes against DDT.

Black Carbon Facilitated Dechlorination of DDT and its Metabolites by Sulfide.

PubMed

Ding, Kai; Xu, Wenqing

2016-12-06

1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) and its metabolites 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), are often detected in soils and sediments containing high concentrations of black carbon. Sulfide (∼5 mM) from biological sulfate reduction often coexists with black carbon and serves as both a strong reductant and a nucleophile for the abiotic transformation of contaminants. In this study, we found that the abiotic transformation of DDT, DDD, and DDE (collectively referred to as DDX) require both sulfide and black carbon. 89.3 ± 1.8% of DDT, 63.2 ± 1.9% of DDD, and 50.9 ± 1.6% of DDE were degraded by sulfide (5 mM) in the presence of graphite powder (21 g/L) after 28 days at pH 7. Chloride was a product of DDX degradation. To better understand the reaction pathways, electrochemical cells and batch reactor experiments with sulfide-pretreated graphite powder were used to differentiate the involvement of black carbon materials in DDX transformation by sulfide. Our results suggest that DDT and DDD are transformed by surface intermediates formed from the reaction between sulfide and black carbon, while DDE degradation involves reductive dechlorination. This research lays the groundwork for developing an alternative in situ remediation technique for rapidly decontaminating soils and sediments to lower toxic products under environmentally relevant conditions.

Occurrence and air-soil exchange of organochlorine pesticides and polychlorinated biphenyls at a CAWNET background site in central China: Implications for influencing factors and fate.

PubMed

Zhan, Lingxi; Lin, Tian; Wang, Zuwu; Cheng, Zhineng; Zhang, Gan; Lyu, Xiaopu; Cheng, Hairong

2017-11-01

Ambient air and soil samples were collected between March 2012 and March 2013 at Jinsha, a regional background site in central China, to measure the concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The average concentrations of total OCPs and total PCBs were 191 ± 107 and 39.4 ± 27.1 pg/m 3 in air (gaseous and particulate phase) and 0.585 ± 0.437 and 0.083 ± 0.039 ng/g in soil, respectively. The higher concentrations of p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and p,p'-DDT/p,p'-DDE ratios in the soil indicated recent p,p'-DDT input to the soil. A strong positive temperature dependence and average fugacity fraction value > 0.5 were observed for p,p'-DDT, suggesting that volatilization of residual DDT in the soil was the main influencing factor on atmospheric p,p'-DDT. Highly average fugacity fractions (>0.7) of trans-chlordane (TC) and cis-chlordane (CC) and high TC/CC ratios both in the soil and atmosphere suggested fresh inputs. Higher gaseous concentrations of hexachlorobenzene (HCB) were observed in winter and negative temperature dependence was directly attributed to the surrounding ongoing source (e.g. fuel consuming activities), especially in winter. Overall, most targeted OCPs and PCBs were influenced by long-range transport, and fugacity fraction values indicated highly volatile compounds (e.g. α-hexachlorocyclohexane (α-HCH) and lower chlorinated PCBs) were volatilized and low volatility compounds (e.g. p,p'-DDE and higher chlorinated PCBs) were deposited at the air-soil interface. Knowing the source and sink of OCPs and PCBs can help to control their pollution in this area and provide a reference for other studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the San Joaquin Valley, California

USGS Publications Warehouse

Brown, L.R.

1997-01-01

Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of ??DDT (sum of o,p'- and p, p' forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal- Wallis, p < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of ??DDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (p < 0.05), which are indicators of the proportion of irrigation return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total organic carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (p < 0.05). Regressions of the concentration of ??DDT in tissue, as a function of ??DDT in bed sediment, were significant and explained up to 76% of the variance in the data. The concentration of ??DDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.

A histology-based fish health assessment of the tigerfish, Hydrocynus vittatus from a DDT-affected area

NASA Astrophysics Data System (ADS)

McHugh, K. J.; Smit, N. J.; Van Vuren, J. H. J.; Van Dyk, J. C.; Bervoets, L.; Covaci, A.; Wepener, V.

The Pongolapoort Dam (PPD) in the Phongola River, Kwa-Zulu Natal, South Africa and the surrounding area are classified as intermediate to low risk malaria areas and are continually being treated with DDT for malaria vector control. DDT is known as an endocrine disrupting chemical posing estrogenic and anti-androgenic properties and therefore might impact on the health of the 18 freshwater fish species found within this system. Of these species the tigerfish, Hydrocynus vittatus, is targeted by both recreational and local subsistence fishermen and was recently included in the South African threatened or protected species list. Their protected status and importance as a food source therefore emphasises the need for their health status elucidation. Previous research on H. vittatus in the Phongola floodplain highlighted DDT biomagnification in this species. Recent data show that the sum of the DDT levels in February 2009 (5403.9 ng/g lipid) and July 2009 (5537.4 ng/g lipid) is still comparable to the high levels found 30 years earlier. The aim of the current study was thus to determine the health status of H. vittatus in relation to DDT exposure by means of a histology-based fish health assessment protocol. Tigerfish were collected in February 2009 ( n = 30) and July 2009 ( n = 15) and gill, kidney and liver tissue were subjected to histological analyses. Mean Index values showed that the Kidney Index ( IK), Gill Index ( IG) and Fish Index ( IFISH) were higher in fish from the February survey while the Liver Index was higher in those collected during July. Liver alterations identified included intercellular oedema, granular degeneration, vacuolation, nuclear pleomorphism and lymphocyte infiltration. Kidney alterations included dilation of the glomerulus capillaries, vacuolation and hyaline droplet degeneration. Gill alterations identified included telangiectasia and hyperplasia of the secondary lamella, congestion, and rupture of pillar cells. Although histological alterations were observed, the histology based fish health assessment protocol indicated that the H. vittatus population in PPD were in a healthy state. The histological assessment did not reflect the DDT exposure induced effects that were anticipated. However, the biomagnification effects in other tertiary consumers in the PPD such as crocodiles and fish eagles cannot be ruled out.

In situ bioavailability of DDT and Hg in sediments of the Toce River (Lake Maggiore basin, Northern Italy): accumulation in benthic invertebrates and passive samplers.

PubMed

Pisanello, Francesca; Marziali, Laura; Rosignoli, Federica; Poma, Giulia; Roscioli, Claudio; Pozzoni, Fiorenzo; Guzzella, Licia

2016-06-01

DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within ±30 % of the certified values and precision was >20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was >5 % and accuracy was within ±10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary, analysis of bioaccumulation in benthic organisms provides the most realistic picture of the site-specific bioavailability of DDx and Hg, but this approach is time-consuming and not always feasible. On the other hand, the in situ deployment of passive samplers proved to be a powerful tool, providing a good surrogate measure of bioaccumulation.

Historical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs

USGS Publications Warehouse

Van Metre, P.C.; Callender, E.; Fuller, C.C.

1997-01-01

This study used chemical analyses of dated sediment cores from reservoirs to define historical trends in water quality in the influent river basins. This work applies techniques from paleolimnology to reservoirs, and in the process, highlights differences between sediment-core interpretations for reservoirs and natural lakes. Sediment cores were collected from six reservoirs in the central and southeastern United States, sectioned, and analyzed for 137Cs and organochlorine compounds. 137Cs analyses were used to demonstrate limited post-depositional mixing, to indicate sediment deposition dates, and to estimate sediment focusing factors. Relative lack of mixing, high sedimentation rates, and high focusing factors distinguish reservoir sediment cores from cores collected in natural lakes. Temporal trends in concentrations of PCBs, total DDT (DDT + DDD + DDE), and chlordane reflect historical use and regulation of these compounds and differences in land use between reservoir drainages. PCB and total DDT core burdens, normalized for sediment focusing, greatly exceed reported cumulative regional atmospheric fallout of PCBs and total DDT estimated using cores from peat hogs and natural lakes, indicating the dominance of fluvial inputs of both groups of compounds to the reservoirs.This study used chemical analyses of dated sediment cores from reservoirs to define historical trends in water quality in the influent river basins. This work applies techniques from paleolimnology to reservoirs, and in the process, highlights differences between sediment-core interpretations for reservoirs and natural lakes. Sediment cores were collected from six reservoirs in the central and southeastern United States, sectioned, and analyzed for 137Cs and organochlorine compounds. 137Cs analyses were used to demonstrate limited post-depositional mixing, to indicate sediment deposition dates, and to estimate sediment focusing factors. Relative lack of mixing, high sedimentation rates, and high focusing factors distinguish reservoir sediment cores from cores collected in natural lakes. Temporal trends in concentrations of PCBs, total DOT (DDT+DDD+DDE), and chlordane reflect historical use and regulation of these compounds and differences in land use between reservoir drainages. PCB and total DDT core burdens, normalized for sediment focusing, greatly exceed reported cumulative regional atmospheric fallout of PCBs and total DDT estimated using cores from peat bogs and natural lakes, indicating the dominance of fluvial inputs of both groups of compounds to the reservoirs.

Contact toxicity of 40 insecticides tested on pandora moth larvae

Treesearch

Robert L. Lyon

1971-01-01

Forty insecticides and an antifeeding compound were tested on pandora moth larvae (Coloradia pandora Blake) in the second and third instars. A total of 21 insecticides were more toxic at LD90 than DDT, providing a good choice of candidates for field testing. Ten exceeded DDT in toxicity tenfold or more. These were, in...

Organochlorine residues in harp seal (Phagophilus groenlandicus) tissues, Gulf of St. Lawrence, 1971, 1973.

PubMed

Rosewell, K T; Muir, D C; Baker, B E

1979-03-01

Levels of p,p'-DDT, p,p'-TDE, p,p'-DDE, dieldrin, polychlorinated biphenyls (PCBs), and HCB were determined in certain tissues of 31 harp seals (P hagophilus groenlandicus) taken from the Gulf of St. Lawrence during 1971 and 1973. The seals ranged in age from less than two weeks to 18 years. Mean concentrations of PCBs and sigma DDT in the various tissues were about the same sigma DDT levels were 1.64--9.88 ppm in adult seal blubber and 1.08--3.73 ppm in seal pup blubber. Organochlorine levels in harp seal samples taken in 1973 were similar to those reported by other workers for samples collected in the Gulf of St. Lawrence during 1967-71.

Endocrine-Disrupting Effects of Pesticides through Interference with Human Glucocorticoid Receptor.

PubMed

Zhang, Jianyun; Zhang, Jing; Liu, Rui; Gan, Jay; Liu, Jing; Liu, Weiping

2016-01-05

Many pesticides have been identified as endocrine-disrupting chemicals (EDCs) due to their ability to bind sex-steroid hormone receptors. However, little attention has been paid to the ability of pesticides to interfere with other steroid hormone receptors such as glucocorticoid receptor (GR) that plays a critical role in metabolic, endocrine, immune, and nervous systems. In this study, the glucocorticoidic and antiglucocorticoidic effects of 34 pesticides on human GR were investigated using luciferase reporter gene assay. Surprisingly, none of the test chemicals showed GR agonistic activity, but 12 chemicals exhibited apparent antagonistic effects. Bifenthrin, λ-cyhalothrin, cypermethrin, resmethrin, o,p'-DDT, p,p'-DDT, methoxychlor, ethiofencarb, and tolylfluanid showed remarkable GR antagonistic properties with RIC20 values lower than 10(-6) M. The disruption of glucocorticoid-responsive genes in H4IIE and J774A.1 cells was further evaluated on these 12 GR antagonists. In H4IIEcells, four organochlorine insecticides, bifenthrin, and 3-PBA decreased cortisol-induced PEPCK gene expression, while o,p'-DDT and methoxychlor inhibited cortisol-stimulated Arg and TAT gene expression. Cypermethrin and tolyfluanid attenuated cortisol-induced TAT expression. In J774A.1 cells, λ-cyhalothrin, resmethrin, 3-PBA, o,p'-DDT, p,p'-DDT, p,p'-DDE, methoxychlor- and tolylfluanid-reduced cortisol-stimulated GILZ expression. Furthermore, molecular docking simulation indicated that different interactions may stabilize the binding between molecules and GR. Our findings suggest that comprehensive screening and evaluation of GR antagonists and agonists should be considered to better understand the health and ecological risks of man-made chemicals such as pesticides.

Hepatoprotective activity of Rhus oxyacantha root cortex extract against DDT-induced liver injury in rats.

PubMed

Ben Miled, Hanène; Barka, Zaineb Ben; Hallègue, Dorsaf; Lahbib, Karima; Ladjimi, Mohamed; Tlili, Mounira; Sakly, Mohsen; Rhouma, Khémais Ben; Ksouri, Riadh; Tebourbi, Olfa

2017-06-01

The present investigation aimed to study the antioxidant activity and hepatoprotective effects of ethyl acetate extract of R. oxyacantha root cortex (RE) against DDT-induced liver injury in male rats. The RE exhibited high total phenolic, flavonoid and condensed tannins contents. The antioxidant activity in vitro systems showed a significant potent free radical scavenging activity of the extract. The HPLC finger print of R. oxyacantha active extract showed the presence of five phenolic compounds with higher amounts of catechol and gallic acid. The in vivo results showed that a single intraperitoneal administration of DDT enhanced levels of hepatic markers (ALT, AST and LDH) in serum of experimental animals. It also increased the oxidative stress markers resulting in increased levels of the lipid peroxidation with a significant induction of SOD and GPx, metallothioneins (MTs) and a concomitant decrease of non protein thiols (NPSH) in liver. However, pretreatment of rats with RE at a dose of 150 and 300mg/kg body weight significantly lowered serum transaminases and LDH in treated rats. A significant reduction in hepatic thiobarbituric reactive substances and a decrease in antioxidant enzymes activities and hepatic MTs levels by treatment with plant extract against DDT, were observed. These biochemical changes were consistent with histopathological observations, suggesting marked hepatoprotective effect of RE with the two doses used. These results strongly suggest that treatment with ethyl acetate extract normalizes various biochemical parameters and protects the liver against DDT-induced oxidative damage in rats and thus help in evaluation of traditional claim on this plant. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Thinning factor distributions viewed through numerical models of continental extension

NASA Astrophysics Data System (ADS)

Svartman Dias, Anna Eliza; Hayman, Nicholas W.; Lavier, Luc L.

2016-12-01

A long-standing question surrounding rifted margins concerns how the observed fault-restored extension in the upper crust is usually less than that calculated from subsidence models or from crustal thickness estimates, the so-called "extension discrepancy." Here we revisit this issue drawing on recently completed numerical results. We extract thinning profiles from four end-member geodynamic model rifts with varying width and asymmetry and propose tectonic models that best explain those results. We then relate the spatial and temporal evolution of upper to lower crustal thinning, or crustal depth-dependent thinning (DDT), and crustal thinning to mantle thinning, or lithospheric DDT, which are difficult to achieve in natural systems due to the lack of observations that constrain thinning at different stages between prerift extension and lithospheric breakup. Our results support the hypothesis that crustal DDT cannot be the main cause of the extension discrepancy, which may be overestimated because of the difficulty in recognizing distributed deformation, and polyphase and detachment faulting in seismic data. More importantly, the results support that lithospheric DDT is likely to dominate at specific stages of rift evolution because crustal and mantle thinning distributions are not always spatially coincident and at times are not even balanced by an equal magnitude of thinning in two dimensions. Moreover, either pure or simple shear models can apply at various points of time and space depending on the type of rift. Both DDT and pure/simple shear variations across space and time can result in observed complex fault geometries, uplift/subsidence, and thermal histories.

Oak leaf roller: contact toxicity of four insecticides applied to the larvae

Treesearch

Lula E. Greene; Marion Page

1974-01-01

A defoliator of oak and witch-hazel, the oak leaf roller (Archips semiferanus [Walker]) is found in large numbers in northeastern United States and in southwest Ontario, Canada. DDT was formerly used to control this insect. As a preliminary step in finding alternatives to DDT for field testing against the oak leaf roller, four insecticides were...

Origin of Bright Dust Devil Track on Mars

NASA Astrophysics Data System (ADS)

Hamada, K.; Kurita, K.; Nishizawa, S.

2017-09-01

we performed detailed in- vestigation on DDT in specific regions where BDDT are abundantly observed; in and around Schiaparelli Crater and Amazonis Planitia by using CTX images. We found 1) BDDT are confined to localized regions while DDDT are distributed broadly in these regions, 2) in 10km scale both BDDT and DDDT exhibit dom- inant orientations, 3) existence of banded DDT.

LACK OF ANTIANDROGENIC EFFECTS IN ADULT MALE RATS FOLLOWING ACUTE EXPOSURE TO 2, 2-BIS (4-CHLOROPHENYL)-1,1-DICHLOROETHYLENE (P,P'DDE)

EPA Science Inventory

Although the insecticide dichlorodiphenyltrichloroethane (DDT) was banned in the US in 1972, DDT and its major metabolite 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) are still persistent in the environment. DDE at high doses is antiandrogenic in fetal and adult rats and, t...

GW170817: Tracking the X-ray light curve to study the origin of the emission

NASA Astrophysics Data System (ADS)

Wilkes, Belinda

2016-09-01

This proposal is a merger of several DDT requests to follow-up the NS-NS merger: GW170817 as it comes out of sunblock. We will include the proposing DDT teams as co-Is on this proposal. They will all have access to the data, but this proposal does not require that they work together.

Selective sweep analysis in the genomes of the 91-R and 91-C Drosophila melanogaster strains reveals few of the ‘usual suspects’ in Dichlorodiphenyltrichloroethane (DDT) resistance

USDA-ARS?s Scientific Manuscript database

Adaptation of insect phenotypes for survival after exposure to xenobiotics can result from selection at multiple loci with additive genetic effects. A high level dichlorodiphenyltrichloroethane (DDT) resistance phenotype in the Drosophila melanogaster strain 91-R has resulted due to continuous labo...

Genome-wide sequencing and an open reading frame analysis of dichlorodiphenyltrichloroethane (DDT) susceptible (91-C) and resistant (91-R) Drosophila melanogaster laboratory populations

USDA-ARS?s Scientific Manuscript database

The Drosophila melanogaster 91-R and 91-C strains are of common origin, however, 91-R has been intensely selected for dichlorodiphenyltrichloroethane (DDT) resistance over six decades while 91-C has been maintained as the non-selected control strain. These fly strains represent a unique genetic res...

Effects of DDT and BHC on amino acid content and its varieties in Chlorella vulgaris Beij. and Cladophora sp.

NASA Astrophysics Data System (ADS)

Lin, Yixiong

1991-03-01

In Chlorella vulgaris Beij. and Cladophora sp. treated with different concentrations of r-BHC and p, p-DDT, the protein and free amino acid content in both were higher than those in the controls, and the free amino acid content was even higher than the protein amino acid content.

Green-Yellow Electroluminescence from a host-dopant blended system as the active layer in a bilayer polymer light emitting diode: Poly(n-vinyl carbazole) as the host and a new soluble thiophene based copolymer [poly(2,2‧-BT)-co-(3-DDT)] as the dopant

NASA Astrophysics Data System (ADS)

Shahalizad, Afshin; Ahmadi-Kandjani, Sohrab; Movla, Hossein; Omidi, Hafez; Massoumi, Bakhshali; Zakerhamidi, Mohammad Sadegh; Entezami, Ali Akbar

2014-11-01

A new type of bilayer Polymer Light Emitting Diode (PLED) which emits green-yellow light is reported. In this PLED, a novel thiophene-based copolymer [poly(2,2‧-BT)-co-(3-DDT)] with an excellent electron transporting property has been doped in hole transporting and electron blocking poly(n-vinylcarbazole) (PVK). Formation of type-II heterojunctions among nm-size features in PVK:poly(2,2‧-BT)-co-(3-DDT) blended system makes exciplex and electroplex emissions would be dominant in the Electroluminescence (EL) spectrum of the device. These cross recombinations between electrons in the LUMO of poly(2,2‧-BT)-co-(3-DDT) and holes in the HOMO of PVK is a reason for the low driving voltage of the PLED because there is no need for the charge carriers to hop or tunnel to the adjacent polymer. Morphological investigations demonstrate that the mixing degree between the components is high, favoring formation of exciplexes and electroplexes at the interface of the components.

DDT acceleration of mammary gland tumors induced in the male Sprague-Dawley rat by 2-acetamidophenanthrene.

PubMed

Scribner, J D; Mottet, N K

1981-01-01

2-Acetamidophenanthrene (AAP) yields adducts to rat liver DNA and RNA in amounts comparable to those found for the potent hepatocarcinogen 2-acetamidofluorene, but is not hepatocarcinogenic. This suggested that AAP might initiate liver tumors, but was incapable of causing their progression to a detectable state. To test this hypothesis, the protocol devised by Peraino was used, in which 21-day-old male Sprague-Dawley rats were fed 0.02% AAP in a grain diet for three weeks. this was followed by long-term feeding of 0.05% 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT). The mean latent period of all tumors (primarily mammary tumors) was reduced about six months by the DDT feeding. No tumors were found in rats treated with DDT only. Livers in all animals appeared normal at autopsy or on laparotomy, and showed barely detectable signs of toxicity upon histological examination. Thus, we have found that a once wide-spread environmental chemical acts as a tumor accelerator on a major target for human tumors. Because this finding is in the male rat, the significance of this result for breast cancer in women is uncertain.

DNA lesion identity drives choice of damage tolerance pathway in murine cell chromosomes.

PubMed

Cohen, Isadora S; Bar, Carmit; Paz-Elizur, Tamar; Ainbinder, Elena; Leopold, Karoline; de Wind, Niels; Geacintov, Nicholas; Livneh, Zvi

2015-02-18

DNA-damage tolerance (DDT) via translesion DNA synthesis (TLS) or homology-dependent repair (HDR) functions to bypass DNA lesions encountered during replication, and is critical for maintaining genome stability. Here, we present piggyBlock, a new chromosomal assay that, using piggyBac transposition of DNA containing a known lesion, measures the division of labor between the two DDT pathways. We show that in the absence of DNA damage response, tolerance of the most common sunlight-induced DNA lesion, TT-CPD, is achieved by TLS in mouse embryo fibroblasts. Meanwhile, BP-G, a major smoke-induced DNA lesion, is bypassed primarily by HDR, providing the first evidence for this mechanism being the main tolerance pathway for a biologically important lesion in a mammalian genome. We also show that, far from being a last-resort strategy as it is sometimes portrayed, TLS operates alongside nucleotide excision repair, handling 40% of TT-CPDs in repair-proficient cells. Finally, DDT acts in mouse embryonic stem cells, exhibiting the same pattern—mutagenic TLS included—despite the risk of propagating mutations along all cell lineages. The new method highlights the importance of HDR, and provides an effective tool for studying DDT in mammalian cells.

DNA lesion identity drives choice of damage tolerance pathway in murine cell chromosomes

PubMed Central

Cohen, Isadora S.; Bar, Carmit; Paz-Elizur, Tamar; Ainbinder, Elena; Leopold, Karoline; de Wind, Niels; Geacintov, Nicholas; Livneh, Zvi

2015-01-01

DNA-damage tolerance (DDT) via translesion DNA synthesis (TLS) or homology-dependent repair (HDR) functions to bypass DNA lesions encountered during replication, and is critical for maintaining genome stability. Here, we present piggyBlock, a new chromosomal assay that, using piggyBac transposition of DNA containing a known lesion, measures the division of labor between the two DDT pathways. We show that in the absence of DNA damage response, tolerance of the most common sunlight-induced DNA lesion, TT-CPD, is achieved by TLS in mouse embryo fibroblasts. Meanwhile, BP-G, a major smoke-induced DNA lesion, is bypassed primarily by HDR, providing the first evidence for this mechanism being the main tolerance pathway for a biologically important lesion in a mammalian genome. We also show that, far from being a last-resort strategy as it is sometimes portrayed, TLS operates alongside nucleotide excision repair, handling 40% of TT-CPDs in repair-proficient cells. Finally, DDT acts in mouse embryonic stem cells, exhibiting the same pattern—mutagenic TLS included—despite the risk of propagating mutations along all cell lineages. The new method highlights the importance of HDR, and provides an effective tool for studying DDT in mammalian cells. PMID:25589543

The effects of house spraying with DDT or lambda-cyhalothrin against Anopheles arabiensis on measures of malarial morbidity in children in Tanzania.

PubMed

Mnzava, A E; Rwegoshora, R T; Tanner, M; Msuya, F H; Curtis, C F; Irare, S G

1993-08-01

The effects of house spraying of DDT and lambda-cyhalothrin against populations of Anopheles arabiensis were assessed in children aged between 1 and 10 years with regard to fever episodes and parasite prevalences. DDT and lambda-cyhalothrin treatment did not reduce the prevalence of malaria episodes as defined by fever (temperatures > or = 37.4 degrees C and/or fever reported) combined with high parasitaemia (> or = 100 parasites/200 leucocytes). However, the prevalence of malaria parasitaemia, of the episodes of fever with any level of malaria parasitaemia and of high parasitaemia alone were significantly reduced. Furthermore, the reduction in mean parasite densities was greater in children of the 1-2 years age group for both insecticides and also for children of 3-5 years age group with lambda-cyhalothrin. Measured and/or reported fever and high parasitaemia were correlated and the data indicated that most of the fevers in these children could be attributed to malaria. Using this criterion it is concluded that the population of An. arabiensis responded to both DDT and lambda-cyhalothrin house spraying which in turn also reduced malaria-related morbidity.

Insecticides applied to a nursery colony of little brown bats (Myotis lucifugus): lethal concentrations in brain tissues

USGS Publications Warehouse

Clark, D.R.; Kunz, T.H.; Kaiser, T.E.

1978-01-01

-Forty-six Myotis lucifugus were collected in May and June 1974 at a nursery colony in Hillsborough County, New Hampshire, that had been sprayed with DDT and chlordane in August and September 1973. When collected, 27 bats were alive, two were convulsing, and 17 were dead. Brains, carcasses, and milk and masticated insects from stomachs were analyzed for organochlorine insecticides and polychlorinated biphenyls (PCB's). ...Concentrations of chemical residues in brains of surviving bats were compared with those of dead and convulsing bats. These comparisons indicated that DDT was the cause of death. Lethal brain concentrations of DDT in adult females averaged 24.52 parts per million (ppm) and suggested that adult M. lucifugus are approximately twice as sensitive to DDT as are adult laboratory rats and mice. Juvenile bats were about 1.5 times more sensitive than adult bats....Large chemical residues were present in milk. We found a statistically significant relationship between declines in carcass residues in lactating females and uterine regression for six of 10 toxicants. Among juveniles, there were corresponding, significant increases (for nine of 10 toxicants) in carcass levels of residues correlated with increasing age (growth of forearm).

Post-remediation biomonitoring of pesticides and other contaminants in marine waters and sediment near the United Heckathorn Superfund Site, Richmond, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

LD Antrim; NP Kohn

Marine sediment remediation at the United Heckathorn Superfund Site was completed in April 1997. Water and mussel tissues were sampled in February 1999 from four stations near Lauritzen Canal in Richmond, California, for Year 2 of post-remediation monitoring of marine areas near the United Heckathorn Site. Dieldrin and dichlorodiphenyl trichloroethane (DDT) were analyzed in water samples, tissue samples from resident mussels, and tissue samples from transplanted mussels deployed for 4 months. Concentrations of dieldrin and total DDT in water and total DDT in tissue were compared with Year 1 of post-remediation monitoring, and with preremediation data from the California Statemore » Mussel Watch program (tissues) and the Ecological Risk Assessment for the United Heckathorn Superfund Site (tissues and water). Mussel tissues were also analyzed for polychlorinated biphenyls (PCB), which were detected in sediment samples. Chlorinated pesticide concentrations in water samples were similar to preremediation levels and did not meet remediation goals. Mean dieidrin concentrations in water ranged from 0.62 rig/L to 12.5 ng/L and were higher than the remediation goal (0.14 ng/L) at all stations. Mean total DDT concentrations in water ranged from 14.4 ng/L to 62.3 ng/L and exceeded the remediation goal (0.59 ng/L) at all stations. The highest concentrations of both pesticides were found at the Lauritzen Canal/End station. Despite exceedence of the remediation goals, chlorinated pesticide concentrations in Lauritzen Canal water samples were notably lower in 1999 than in 1998. Tissue samples from biomonitoring organisms (mussels) provide an indication of the longer-term integrated exposure to contaminants in the water column, which overcomes the limitations of grab samples of water. Biomonitoring results indicated that the bioavailability of chlorinated pesticides has been reduced from preremediation levels both in the dredged area and throughout Richmond Harbor. Total DDT and dieldrin concentrations in mussel tissues were dramatically lower than measured levels from preremediation surveys and also lower than Year 1 levels from post-remediation biomonitoring. The lowest levels were found at the Richmond Inner Harbor Channel station (4.1 {micro}g/kg total DDT and 0.59 {micro}g/kg dieldrin, wet weight; mean of resident and transplant mussels). Mean chlorinated pesticide concentrations were highest at Lauritzen Canal/End (82 {micro}g/kg total DDT and 7.1 {micro}g/kg dieldrin, wet weight), followed by Lauritzen Canal/Mouth (22 {micro}/kg total DDT and 1.7 {micro}g/kg dieldrin, wet weight) and Santa Fe Channel/End (7.5 {micro}g/kg total DOT and 0.61 {micro}g/kg dieldrin, wet weight). These levels are 95% to 99% lower than those recorded by the California State Mussel Watch program prior to EPA's response actions. The levels of PCBs in mussel tissue were also reduced by 93% to 97% from preremediation levels. Surface sediment concentrations of dieldrin and DDT in November 1998 were highest in samples from the head or north end of Lauritzen Canal and progressively lower toward the mouth, or south end. Total DDT ranged from 130 ppm (dry weight) at the north end to 3 ppm at the south end. Dieldrin concentrations decreased from 3,270 ppb (dry weight) at the north end to 52 ppb at the south end. These results confirmed elevated pesticide concentrations in sediments collected from Lauritzen Channel by Anderson et al. (1999). The pesticide concentrations were lower than maximum concentrations found in the 1993 Remedial Investigation but comparable to the median levels measured before remediation was completed. Sediment analyses also showed the presence of elevated PCB aroclor 1254, and very high levels of polynuclear aromatic hydrocarbons (PAH) in Lauritzen Channel.« less

Influences of Electrification and Salt on Hydrophobicity of Sample Surface in Dynamic Drop Test

NASA Astrophysics Data System (ADS)

Shiibara, Daiki; Arata, Yoshihiro; Haji, Kenichi; Miyake, Takuma; Sakoda, Tatsuya; Otsubo, Masahisa

Studies on the development of deterioration/ performance evaluation method for outdoor electric insulation of polymer materials are pushed forward now in the International Council on Large Electric Systems (CIGRE). The small scale test method (Dynamic drop test; DDT) which could evaluate disappearance characteristics of hydrophobicity easily was suggested. This test is to evaluate resistance of a sample to loss of hydrophobicity due to moisture and simultaneous electric stress. As factors for deterioration of hydrophobicity on a sample in DDT, various factors such as electrical influence, physical influence by water droplets and so on were considered. In this study, we investigated two kinds of factors (electrification and salt) affecting deterioration of hydrophobicity on the surface of a silicone rubber until ignition of continuous electrical discharge in DDT.

Effects on fish and wildlife of chemical treatments of large areas

USGS Publications Warehouse

George, J.L.

1959-01-01

Summary: The history of field investigations of the effects of DDT on wildlife is reviewed briefly, from the initial studies in 1945 through the more recent studies of the effects of the large-scale programs for spruce-budworm control and gypsy-moth eradication. DDT dosages and procedures that are recommended for protection of wildlife are reviewed. Effects of aldrin, heptachlor, and toxaphene are discussed in connection with the grasshopper and Mormon cricket control programs. Delayed and indirect effects of chemical treatments are emphasized as an important current problem. Cited in this connection are fish losses in the Yellowstone and Miramichi rivers and losses of wildlife from eating earthworms a year after treatment of the area with DDT. Currently recommended procedures to safeguard wildlife in pesticidal programs are listed.

On the Initiation Mechanism in Exploding Bridgewire and Laser Detonators

NASA Astrophysics Data System (ADS)

Stewart, D. Scott; Thomas, Keith A.; Clarke, S.; Mallett, H.; Martin, E.; Martinez, M.; Munger, A.; Saenz, Juan

2006-07-01

Since its invention by Los Alamos during the Manhattan Project era the exploding bridgewire detonator (EBW) has seen tremendous use and study. Recent development of a laser-powered device with detonation properties similar to an EBW is reviving interest in the basic physics of the deflagration-to-detonation (DDT) process in both of these devices. Cutback experiments using both laser interferometry and streak camera observations are providing new insight into the initiation mechanism in EBWs. These measurements are being correlated to a DDT model of compaction to detonation and shock to detonation developed previously by Xu and Stewart. The DDT model is incorporated into a high-resolution, multi-material model code for simulating the complete process. Model formulation and the modeling issues required to describe the test data will be discussed.

Diagenetic fate of organic contaminants on the Palos Verdes Shelf, California

USGS Publications Warehouse

Eganhouse, R.P.; Pontolillo, J.; Leiker, T.J.

2000-01-01

Municipal wastes discharged through deepwater submarine outfalls since 1937 have contaminated sediments of the Palos Verdes Shelf. A site approximately 6-8 km downcurrent from the outfall system was chosen for a study of the diagenetic fate of organic contaminants in the waste-impacted sediments. Concentrations of three classes of hydrophobic organic contaminants (DDT + metabolites, polychlorinated biphenyls (PCBs), and the long-chain alkylbenzenes) were determined in sediment cores collected at the study site in 1981 and 1992. Differences between the composition of effluent from the major source of DDT (Montrose Chemical) and that found in sediments suggests that parent DDT was transformed by hydrolytic dehydrochlorination during the earliest stages of diagenesis. As a result, p,p'-DDE is the dominant DDT metabolite found in shelf sediments, comprising 60-70% of ??DDT. The p,p-DDE/p,p'-DDMU concentration ratio decreases with increasing sub-bottom depth in sediment cores, indicating that reductive dechlorination of p,p'-DDE is occurring. Approximately 9-23% of the DDE inventory in the sediments may have been converted to DDMU since DDT discharges began ca. 1953. At most, this is less than half of the decline in p,p'-DDE inventory that has been observed at the study site for the period 1981-1995. Most of the observed decrease is attributable to remobilization by processes such as sediment mixing coupled to resuspension, contaminant desorption, and current advection. Existing field data suggest that the in situ rate of DDE transformation is 102-103 times slower than rates determined in recent laboratory microcosm experiments (Quensen, J.F., Mueller, S.A., Jain, M.K., Tiedje, J.M., 1998. Reductive dechlorination of DDE to DDMU in marine sediment microcosms. Science, 280, 722-724.). This explains why the DDT composition (i.e. o,p'-, p,p'-isomers of DDE, DDD, DDT) of sediments from this site have not changed significantly since at least 1972. Congener-specific PCB compositions in shelf sediments are highly uniform and show no evidence of diagenetic transformation. Apparently, the agents/factors responsible for reductive dechlorination of DDE are not also effecting alteration of the PCBs. Two types of long-chain alkylbenzenes were found in the contaminated sediments. Comparison of chain length and isomer distributions of the linear alkylbenzenes in wastewater effluent and surficial sediment samples indicate that these compounds undergo biodegradation during sedimentation. Further degradation of the linear alkylbenzenes occurs after burial despite relatively invariant isomer compositions. The branched alkylbenzenes are much more persistent than the linear alkylbenzenes, presumably due to extensive branching of the alkyl side chain. Based on these results, p,p'-DDE, PCBs, and selected branched alkylbenzenes are sufficiently persistent for use in molecular stratigraphy. The linear alkylbenzenes may also provide information on depositional processes. However, their application as quantitative molecular tracers should be approached with caution.

Effects of estrogenic (o,p'-DDT; octylphenol) and anti-androgenic (p,p'-DDE) chemicals on indicators of endocrine status in juvenile male summer flounder (Paralichthys dentatus).

PubMed

Mills, L J; Gutjahr-Gobell, R E; Haebler, R A; Horowitz, D J; Jayaraman, S; Pruell, R J; McKinney, R A; Gardner, G R; Zaroogian, G E

2001-04-01

Laboratory experiments were conducted with male summer flounder to assess the value of selected measures of endocrine status in fish as indicators of exposure to endocrine-disrupting contaminants. Effects of 1,1,1-trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl) ethane (o,p'-DDT), octylphenol and 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) on hepatosomatic and gonadosomatic indices, plasma steroid hormone levels, vitellogenin production, and gonadal development were evaluated in laboratory-raised, juvenile male summer flounder. Flounder were injected twice with test chemical in a coconut oil carrier. Each chemical was tested at three different concentrations. Estrogenic (o,p'-DDT; octylphenol) and anti-androgenic (p,p'-DDE) chemicals were evaluated alone and in combination (octylphenol plus o,p'-DDT or p,p'-DDE). Additionally, some fish were treated with the natural ligand for the estrogen receptor, 17beta-estradiol. Blood and tissues from different fish in each treatment were sampled 4, 6 and 8 weeks after the first injection. Fish exposed to a combination of o,p'-DDT plus octylphenol were also sampled after 15 weeks. In all cases, responses of fish exposed to a test chemical were compared to control fish sampled at the same time. The following significant differences, relative to controls, were observed in at least one sampling time or at least one concentration of chemical. 17beta-Estradiol-treated flounder exhibited decreased gonadosomatic index (GSI), altered hepatosomatic index (HSI), elevated plasma estradiol, reduced plasma testosterone, and high levels of plasma vitellogenin. Fish treated with o,p'-DDT showed lower GSI, no change in HSI or plasma estradiol, depression of plasma testosterone, and induction of vitellogenesis. Octylphenol treatment resulted in lower GSI, no change in HSI, initially increased plasma estradiol and decreased testosterone, and no vitellogenin production. p,p'-DDE treatment did not significantly alter any indicator relative to controls. In experiments using combinations of chemicals, flounder receiving o,p'-DDT plus octylphenol had lower GSI after 8 weeks and elevated plasma estradiol after 15 weeks exposure. Fish treated with p,p'-DDE plus octylphenol for 8 weeks exhibited a significantly lower GSI. Overall, lower GSI and plasma testosterone levels, relative to controls, were consistent indicators of exposure to estrogenic chemicals in juvenile male flounder. No indicators were found that would identify exposure to the mammalian anti-androgen p,p'-DDE.

EFFECT OF 17B-ESTRADIOL, O,P'-DDT, OCTYLPHENOL AND P,P'-DDE ON GONADAL DEVELOPMENT AND LIVER AND KIDNEY PATHOLOGY IN JUVENILE MALE SUMMER FLOUNDER (PARALICHTYS DENTATUS)

EPA Science Inventory

The intent of this study was to compare histopathologically the effect of 17 -estradiol (E2), o,p' DDT, octylphenol and p,p' DDE on gonadal development and liver and kidney condition in sexually immature (juvenile) summer flounder (Paralichthys dentatus). The dorsal sinus of 2-...

Improvement, Verification, and Refinement of Spatially-Explicit Exposure Models in Risk Assessment - FishRand Spatially-Explicit Bioaccumulation Model Demonstration

DTIC Science & Technology

2015-08-01

21  Figure 4. Data-based proportion of DDD , DDE and DDT in total DDx in fish and sediment by... DDD dichlorodiphenyldichloroethane DDE dichlorodiphenyldichloroethylene DDT dichlorodiphenyltrichloroethane DoD Department of Defense ERM... DDD ) at the other site. The spatially-explicit model consistently predicts tissue concentrations that closely match both the average and the

DNA damage in Mexican children living in high-risk contaminated scenarios.

PubMed

Jasso-Pineda, Yolanda; Díaz-Barriga, Fernando; Yáñez-Estrada, Leticia; Pérez-Vázquez, Francisco Javier; Pérez-Maldonado, Ivan Nelinho

2015-06-15

The aim of this study was to evaluate the deoxyribonucleic acid (DNA) damage (as a biomarker of biological effects) in children living in areas at high risk of contamination in Mexico using the comet assay. The alkaline comet assay was performed in order to assess DNA damage levels in blood cells of 276 children living in eleven communities in four states of Mexico. Moreover, levels of arsenic and 1-hydroxypyrene (1-OHP) in urine and lead and total DDT [sum of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT)] in blood were quantified. We found urinary 1-OHP levels between

Factors predicting organochlorine pesticide levels in pregnant Latina women living in a United States agricultural area

PubMed Central

Bradman, Asa; Schwartz, Jackie M.; Fenster, Laura; Barr, Dana B.; Holland, Nina T.; Eskenazi, Brenda

2015-01-01

Organochlorine (OC) pesticide use was restricted starting in the 1970s in developed countries and the 1980s and 1990s in developing countries. Current exposure to OC pesticides – DDT, lindane (99% pure gamma-hexachlorocyclohexane (γ-HCH)), hexachlorobenzene (HCB) – occurs on a limited basis. We measured p,p′-DDE, p,p′-DDT, o,p′-DDT, HCB, beta (β)-HCH (the most persistent isomer of technical-grade HCH) and γ-HCH in serum from 426 low-income pregnant Latina women living in an agricultural community in California. Detection frequencies were 94-100%. Median levels (ng/g-lipid) of p,p′-DDE (1,052), p,p′-DDT (13), β-HCH (37) and HCB (65) were significantly higher than U.S. population levels. Multivariate analyses of p,p′-DDE, p,p′-DDT, o,p′-DDT, β-HCH and HCB indicate that time spent living outside the United States and birthplace in an area of Mexico with recent use of OC pesticides were significant predictors of exposure. Time spent living in the United States was associated with increased serum levels of p,p′-DDE and β-HCH, but the increase for each year lived in the United States was lower than for each year lived outside the United States. There was no difference between the increase of HCB levels over time spent in or outside the United States, suggesting current and thus preventable exposure routes. However, we observed no associations between serum levels of any OC compound and current intake of saturated fat or agricultural take-home exposure risk factors. Lactation history and recent weight gain were negatively associated with serum levels of some, but not all OC compounds studied. Smoking history was borderline associated with elevated HCB levels. We observed no significant associations with body mass index. Although the weight of evidence from this study indicates that most exposure occurred prior to moving to the United States, the results for HCB indicate the possibility of ongoing exposure in this country. PMID:17033681

Residues of DDT in lake trout (Salvelinus namaycush) and coho salmon (Oncorhynchus kisutch) from the Great Lakes

USGS Publications Warehouse

Reinert, Robert E.; Bergman, Harold L.

1974-01-01

Concentrations of DDT residues were higher in lake trout (Salvelinus namaycush) from southern Lake Michigan in 1966–70 (average 18.1 ppm in fish 558–684 mm long) than in lake trout of the same size-class from Lake Superior in 1968–69 (4.4 ppm), and higher in adult coho salmon (Oncorhynchus kisutch) from Lake Michigan in 1968–71 (averages for different year-classes, 9.9–14.0 ppm) than in those from Lake Erie in 1969 (2.2 ppm). Residues were significantly higher in lake trout from southern Lake Michigan than in those from the northern part of the lake. In lakes Michigan and Superior, the levels increased with length of fish and percentage oil. In Lake Michigan coho salmon, the residues remained nearly stable (2–4 ppm) from September of the 1st yr of lake residence through May or early June of the 2nd yr, but increased three to four times in the next 3 mo. Residues in Lake Erie coho salmon did not increase during this period, which preceded the spawning season. Although the concentrations of total residues in whole, maturing Lake Michigan coho salmon remained unchanged from August 1968 until near the end of the spawning season in January 1969, the residues were redistributed in the tissues of the spawning-run fish; concentrations in the loin and brain were markedly higher in January than in August. This relocation of DDT residues accompanied a marked decrease in the percentage of oil in the fish, from 13.2 in August to 2.8 in January. Concentrations of residues were relatively high in eggs of both lake trout (4.6 ppm) and coho salmon (7.4–10.2 ppm) from Lake Michigan. The percentage composition of the residues (p,p′DDE, o,p′/DDT, p,p′DDT, and p,p′DDT) did not differ significantly with life stage, size, age, or locality, or date of collection of lake trout or coho salmon.

Insecticide susceptibility and dengue vector status of wild Stegomyia albopicta in a strategically important area of Assam, India

PubMed Central

2014-01-01

Background Dengue vector control programmes are facing operational challenges due to resistance against commonly used insecticides throughout the endemic countries. Recently, there has been appreciable increase in the dengue cases in India, however, no recent data are available on susceptible status of dengue vectors. We have studied the susceptibility level of St. albopicta to commonly used insecticides in India. Adult mosquitoes were tested for the presence of dengue virus. Methods St. albopicta larval bioassays were carried out to determine the lethal concentrations (LC10, LC50 and LC99) and the resistance ratios (RR10, RR50 and RR99) for temephos. Susceptibility to 4% DDT, 0.05% deltamethrin and 5% malathion was assessed following standard procedure. Knock-down times (KDT10, KDT50 and KDT99) were estimated and knock-down resistance ratios (KRR10, KRR50 and KRR99) were calculated. VectorTest™ dengue antigen assay was used to detect the dengue virus in the field collected mosquitoes. Results In larval bioassays, the RR ranged from 1.4 (for RR99) to 1.7 (for RR50), which suggested that the tested St. albopicta were susceptible to temephos. There was no deviation among the lethal concentration data from linearity (r2 = 0.61). Adult St. albopicta mosquitoes were resistant to DDT, while fully susceptible to deltamethrin and malathion. The knock-down values (KDT10, KDT50 and KDT99) obtained for DDT displayed straight line in log-dose-probit analysis and follow linear regression model. The KRR99 for DDT was 4.9, which indicated a 4.9 folds increase in knock-down resistance to DDT. However, for malathion and deltamethrin, the KRR99 values were 1.6 and 1.5 respectively suggesting that mosquitoes were knock-down sensitive. None of the mosquito pool was dengue virus positive. Conclusion St. albopicta showed resistance to DDT and reduced sensitivity to deltamethrin and malathion. This data on insecticide resistance could help public health authorities in India to design more effective vector control measures. More dengue vector specimens need to be scanned to identify the potential dengue vector. PMID:24981885

Novel Chryseobacterium sp. PYR2 degrades various organochlorine pesticides (OCPs) and achieves enhancing removal and complete degradation of DDT in highly contaminated soil.

PubMed

Qu, Jie; Xu, Yang; Ai, Guo-Min; Liu, Ying; Liu, Zhi-Pei

2015-09-15

Long term residues of organochlorine pesticides (OCPs) in soils are of great concerning because they seriously threaten food security and human health. This article focuses on isolation of OCP-degrading strains and their performance in bioremediation of contaminated soil under ex situ conditions. A bacterium, Chryseobacterium sp. PYR2, capable of degrading various OCPs and utilizing them as a sole carbon and energy source for growth, was isolated from OCP-contaminated soil. In culture experiments, PYR2 degraded 80-98% of hexachlorocyclohexane (HCH) or 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) isomers (50 mg L(-1)) in 30 days. A pilot-scale ex situ bioremediation study of highly OCP-contaminated soil augmented with PYR2 was performed. During the 45-day experimental period, DDT concentration was reduced by 80.3% in PYR2-augmented soils (35.37 mg kg(-1) to 6.97 mg kg(-1)) but by only 57.6% in control soils. Seven DDT degradation intermediates (metabolites) were detected and identified in PYR2-augmented soils: five by GC/MS: 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD), 1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene (DDE), 1-chloro-2,2-bis (4-chlorophenyl) ethylene (DDMU), 1-chloro-2,2-bis (4-chlorophenyl) ethane (DDMS), and dichlorobenzophenone (DBP); and two by LC/MS: 4-chlorobenzoic acid (PCBA) and 4-chlorophenylacetic acid (PCPA). Levels of metabolites were fairly stable in control soils but varied greatly with time in PYR2-augmented soils. Levels of DDD, DDMU, and DDE in PYR2-augmented soils increased from day 0 to day 30 and then decreased by day 45. A DDT biodegradation pathway is proposed based on our identification of DDT metabolites in PYR2-augmented systems. PYR2 will be useful in future studies of OCP biodegradation and in bioremediation of OCP-contaminated soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Risk assessment of great horned owls (Bubo virginianus) exposed to polychlorinated biphenyls and DDT along the Kalamazoo River, Michigan, USA.

PubMed

Strause, Karl D; Zwiernik, Matthew J; Im, Sook Hyeon; Bradley, Patrick W; Moseley, Pamela P; Kay, Denise P; Park, Cyrus S; Jones, Paul D; Blankenship, Alan L; Newsted, John L; Giesy, John P

2007-07-01

The great horned owl (GHO; Bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyltrichloroethane (DDT) exposures at the Kalamazoo River Superfund Site (KRSS), Kalamazoo, Michigan, USA. The study examined risks from total PCBs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQWorld Health Organization [WHO]-Avian Toxicity Equivalency Factor [TEF]), and total DDTs (sum of DDT, dichlorodiphenyldichloroethylene [DDE], and dichlorodiphenyldichloroethane [DDD]; sigmaDDT) by measuring concentrations in eggs and nestling blood plasma in two regions of the KRSS (upper, lower) and an upstream reference area (RA). An ecological risk assessment compared concentrations of the contaminants of concern (COCs) in eggs or plasma to toxicity reference values. Productivity and relative abundance measures for KRSS GHOs were compared with other GHO populations. Egg shell thickness was measured to assess effects of p,p'-DDE. The concentrations of PCBs in eggs were as great as 4.7 x 10(2) and 4.0 x 10(4) ng PCB/g, wet weight at the RA and combined KRSS sites, respectively. Egg TEQ(WHO-Avian) calculated from aryl hydrocarbon receptor-active PCB congeners and WHO TEFs ranged to 8.0 and 1.9 x 10(2) pg TEQ(WHO-Avian)/g, (wet wt) at the RA and combined KRSS, respectively. Egg sigmaDDT concentrations were as great as 4.2 x 10(2) and 5.0 x 10(3) ng sigmaDDT/g (wet wt) at the RA and combined KRSS, respectively. Hazard quotients (HQs) for the upper 95% confidence interval (UCI) (geometric mean) and least observable adverse effect concentration (LOAEC) for COCs in eggs were < or = 1.0 for all sites. Hazard quotient values based on the no observable adverse effect concentration (NOAEC) 95% UCI in eggs were < or = 1.0, except at the LKRSS (PCB HQ = 3.1; TEQ(WHO-Avian) HQ = 1.3). Productivity and relative abundance measures indicated no population level effects in the UKRSS.

Central auditory processing disorder (CAPD) tests in a school-age hearing screening programme - analysis of 76,429 children.

PubMed

Skarzynski, Piotr H; Wlodarczyk, Andrzej W; Kochanek, Krzysztof; Pilka, Adam; Jedrzejczak, Wiktor W; Olszewski, Lukasz; Bruski, Lukasz; Niedzielski, Artur; Skarzynski, Henryk

2015-01-01

Hearing disorders among school-age children are a current concern. Continuing studies have been performed in Poland since 2008, and on 2 December 2011 the EU Council adopted Conclusions on the Early Detection and Treatment of Communication Disorders in Children, Including the Use of e-Health Tools and innovative Solutions. The discussion now focuses not only on the efficacy of hearing screening programmes in schoolchildren, but what should be its general aim and what tests it should include? This paper makes the case that it is important to include central auditory processing disorder (CAPD) tests. One such test is the dichotic digits test (DDT). The aim of the presented study was to evaluate the usefulness of the DDT in detecting central hearing disorders in school-age children. During hearing screening programmes conducted in Poland in 2008-2010, exactly 235,664 children (7-12-years-old) were screened in 9,325 schools. Of this number, 7,642 were examined using the DDT test for CAPD. Screening programmes were conducted using the Sense Examination Platform. With the cut-off criterion set at the 5th percentile, results for the DDT applied in a divided attention mode were 11.4% positive for 7-year-olds and 11.3% for 12-year-olds. In the focused attention mode, the comparable result for 12-year-olds was 9.7%. There was a clear right ear advantage. In children with positive DDT results, a higher incidence of other disorders, such as dyslexia, was observed. A test for CAPD should be included in the hearing screening of school-age children. The results of this study form the basis for developing Polish standards in this area.

Cross-resistance and synergism bioassays suggest multiple mechanisms of pyrethroid resistance in western corn rootworm populations

PubMed Central

Souza, Dariane; Zukoff, Sarah N.; Meinke, Lance J.; Siegfried, Blair D.

2017-01-01

Recently, resistance to the pyrethroid bifenthrin was detected and confirmed in field populations of western corn rootworm, Diabrotica virgifera virgifera LeConte from southwestern areas of Nebraska and Kansas. As a first step to understand potential mechanisms of resistance, the objectives of this study were i) to assess adult mortality at diagnostic concentration-LC99 to the pyrethroids bifenthrin and tefluthrin as well as DDT, ii) estimate adult and larval susceptibility to the same compounds as well as the organophosphate methyl-parathion, and iii) perform synergism experiments with piperonyl butoxide (PBO) (P450 inhibitor) and S,S,S-tributyl-phosphorotrithioate (DEF) (esterase inhibitor) in field populations. Most of the adult field populations exhibiting some level of bifenthrin resistance exhibited significantly lower mortality to both pyrethroids and DDT than susceptible control populations at the estimated LC99 of susceptible populations. Results of adult dose-mortality bioassays also revealed elevated LC50 values for bifenthrin resistant populations compared to the susceptible control population with resistance ratios ranging from 2.5 to 5.5-fold for bifenthrin, 28 to 54.8-fold for tefluthrin, and 16.3 to 33.0 for DDT. These bioassay results collectively suggest some level of cross-resistance between the pyrethroids and DDT. In addition, both PBO and DEF reduced the resistance ratios for resistant populations although there was a higher reduction in susceptibility of adults exposed to PBO versus DEF. Susceptibility in larvae varied among insecticides and did not correlate with adult susceptibility to tefluthrin and DDT, as most resistance ratios were < 5-fold when compared to the susceptible population. These results suggest that both detoxifying enzymes and target site insensitivity might be involved as resistance mechanisms. PMID:28628635

Dichlorodiphenyldichloroethylene Exposure during the First Trimester of Pregnancy Alters the Anal Position in Male Infants

PubMed Central

Torres-Sanchez, Luisa; Zepeda, Monica; Cebrián, Mariano E.; Belkind-Gerson, Jaime; Garcia-Hernandez, Rosa M.; Belkind-Valdovinos, Uri; López-Carrillo, Lizbeth

2016-01-01

Anogenital distance (AGD) at birth is regarded as a useful measurement that reflects the prenatal androgenic status in rodents. However, the impact of xenoantiandrogens on human development is largely unknown. The aim of this study was to evaluate the potential antiandrogenic impact of prenatal DDT metabolites (p,p′-DDE and p,p′-DDT) exposure on infant AGD, using a non-age–dependent anal position index (API). As part of an ongoing perinatal cohort study on the effects of organochlorine pesticides in children’s neurodevelopment, we conducted a cross-sectional study in 71 infants (37 males and 34 females). Maternal serum levels of DDT metabolites (p,p′-DDE and p,p′-DDT) before and during each trimester of pregnancy were determined by electron capture gas–liquid chromatography. During postnatal home visits at 3, 6, and 12 or 18 months of age, the children’s weight and API were evaluated. Multiple lineal regression models were used to estimate the potential endocrine disruptor activity of prenatal p,p′-DDE exposure. Boys had significantly higher API values than girls (0.6 versus 0.5; P < 0.001). Only among boys, a doubling increase of maternal p,p′-DDE serum levels during the first trimester of pregnancy, were associated with a significant reduction of API (β = −0.02; P = 0.02). No effect of p,p′-DDT on AGD was observed. Evidence of the effect of prenatal p,p′-DDE on external genital differentiation is scarce and not consistent in the literature. Further studies are needed to confirm a hormonal disruptive effect on the development of external genitalia, due not only to p,p′-DDE but also due to other antiandrogenic persistent compounds. PMID:18991914

Experimental study on incident wave speed and the mechanisms of deflagration-to-detonation transition in a bent geometry

NASA Astrophysics Data System (ADS)

Li, L.; Li, J.; Teo, C. J.; Chang, P. H.; Khoo, B. C.

2018-03-01

The study of deflagration-to-detonation transition (DDT) in bent tubes is important with many potential applications including fuel pipeline and mine tunnel designs for explosion prevention and detonation engines for propulsion. The aim of this study is to exploit low-speed incident shock waves for DDT using an S-shaped geometry and investigate its effectiveness as a DDT enhancement device. Experiments were conducted in a valveless detonation chamber using ethylene-air mixture at room temperature and pressure (303 K, 1 bar). High-speed Schlieren photography was employed to keep track of the wave dynamic evolution. Results showed that waves with velocity as low as 500 m/s can experience a successful DDT process through this S-shaped geometry. To better understand the mechanism, clear images of local explosion processes were captured in either the first curved section or the second curved section depending on the inlet wave velocity, thus proving that this S-shaped tube can act as a two-stage device for DDT. Owing to the curved wall structure, the passing wave was observed to undergo a continuous compression phase which could ignite the local unburnt mixture and finally lead to a local explosion and a detonation transition. Additionally, the phenomenon of shock-vortex interaction near the wave diffraction region was also found to play an important role in the whole process. It was recorded that this interaction could not only result in local head-on reflection of the reflected wave on the wall that could ignite the local mixture, and it could also contribute to the recoupling of the shock-flame complex when a detonation wave is successfully formed in the first curved section.

Rational ideation and empiric validation of an innovative digital dermographic tester.

PubMed

Lembo, C; Patruno, C; Balato, N; Ayala, F; Balato, A; Lembo, S

2018-04-01

Dermographism is a condition characterized by a weal response to a combination of pressure and traction on skin surface, and its diagnosis is based on medical history, clinical criteria and provocation test. The Dermographic Tester ® , a pen-sized tool containing a spring-loaded blunt tip, is the most widely used instrument for the provocation test, and it exerts increasing pressures on the skin surface according to an arbitrary units (AU) scale. Analysing the mechanism of function and trying to convert the AUs to SI units (g/mm 2 ), we found that this instrument had some defects and limits that would compromise a true and repeatable quantification of the weal response threshold. Consequently, we decided to develop a new instrument, the Digital Dermographic Tester (DDT), which is engineered with an inside force sensor to implement features lacking in the current tools, in the hope of enhancing the precision of the provocation test. To validate the effectiveness and accuracy of the DDT. We tested the DDT on 213 participants purposely sampled to obtain three groups, each with a different pattern of reaction to mechanical stimuli. Based on anamnestic, diagnostic and symptomatic criteria, patients were divided into dermographic urticaria (DU), spontaneous urticaria (SU) and healthy control (HC) groups. The DDT was used to apply 12 levels of pressure to the skin surface, and a frequency distribution of positive reactions was displayed for each group. A force of 36-40 g/mm 2 appropriately differentiated physiological from pathological conditions with high sensitivity and specificity. The DDT was found to be capable of differentiating patients with DU patients from those with SU and from HCs, and was able to precisely identify the weal elicitation threshold. © 2017 British Association of Dermatologists.

Organochlorine pesticide levels in female adipose tissue from Puebla, Mexico.

PubMed

Waliszewski, Stefan M; Sanchez, K; Caba, M; Saldariaga-Noreña, H; Meza, E; Zepeda, R; Valencia Quintana, R; Infanzon, R

2012-02-01

The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, pp'DDE, op'DDT and pp'DDT in adipose tissue of females living in Puebla, Mexico. Organochlorine pesticides were analyzed in 75 abdominal adipose tissue samples taken during 2010 by autopsy at the Forensic Services of Puebla. The results were expressed as mg/kg on fat basis. In analyzed samples the following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.464 mg/kg; p,p'-DDT in 96.0.% of samples at mean 0.105 mg/kg; op'DDT in 89.3% of monitored samples at mean 0.025 mg/kg and β-HCH in 94.7% of the samples at mean 0.108 mg/kg. To show if organochlorine pesticide levels in monitored female's adipose tissues are age dependant, the group was divided in three ages ranges (13-26, 26-57 and 57-96 years). The mean and median levels of all organochlorine pesticides increase significantly (p < 0.05) from the first to second and from the first to third group. At the same time, the increase of mean and medians levels from the second to third group were not statistically significant (p > 0.05). The present results compared to previous ones from 2008 indicates an increase in the concentrations during the 2010 study, but only the differences for pp'DDE and op'DDT were statistically significant. The 2010 group of females was older compared to the 2008 group. The presence of organochlorine pesticide residues is still observed, indicating uniform and permanent exposure to the pesticides by Puebla inhabitants.

Effects of DDT on the oribatid mite community (Acarina:oribatei) of an old-field herbaceous community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Folts, D.D.

1972-11-01

Oribatid mites make up approximately 40 to 50% of the total microarthropods in the litter and soil. They are saprophagous, primary consumers in the litter and soil, and as a group could be considered to be on one trophic level. It has been suggested that oribatid mites could affect soil structure and formation by aiding in humification and mineralization, by enhancing the formation of soil structure, and by increasing the depth of the humus (02) horizon. Nutrient cycling and the breakdown of organic matter is believed to be an important function of oribatids. The mites influence nutrient cycling indirectly throughmore » the control of fungal and bacterial populations. It is possible that pesticides affect nutrient cycling as an indirect result of changes in oribatid populations. The pesticide DDT, although it has been banned throughout the entire country, is still produced for foreign markets and is in widespread use in many developing countries. The persistance of DDT in soil has been verified by a number of workers. This persistance is of potential danger to the balance of soil microarthropod populations long after the initial effect of the pesticide has disappeared. The objectives of this study were: (1) to determine quantitative changes in numbers of individuals of oribatids as a whole and changes in numbers of individualson the specific level; (2) to determine changes in the structure of the oribatid community that occurred as a result of DDT treatment; and (3) to compare the effect of the DDT on the oribatids of the upper three cm of soil with the oribatids from the fourth cm of soil.« less

Behavioural response to combined insecticide and temperature stress in natural populations of Drosophila melanogaster.

PubMed

Fournier-Level, A; Neumann-Mondlak, A; Good, R T; Green, L M; Schmidt, J M; Robin, C

2016-05-01

Insecticide resistance evolves extremely rapidly, providing an illuminating model for the study of adaptation. With climate change reshaping species distribution, pest and disease vector control needs rethinking to include the effects of environmental variation and insect stress physiology. Here, we assessed how both long-term adaptation of populations to temperature and immediate temperature variation affect the genetic architecture of DDT insecticide response in Drosophila melanogaster. Mortality assays and behavioural assays based on continuous activity monitoring were used to assess the interaction between DDT and temperature on three field-derived populations from climate extremes (Raleigh for warm temperate, Tasmania for cold oceanic and Queensland for hot tropical). The Raleigh population showed the highest mortality to DDT, whereas the Queensland population, epicentre for derived alleles of the resistance gene Cyp6g1, showed the lowest. Interaction between insecticide and temperature strongly affected mortality, particularly for the Tasmanian population. Activity profiles analysed using self-organizing maps show that the insecticide promoted an early response, whereas elevated temperature promoted a later response. These distinctive early or later activity phases revealed similar responses to temperature and DDT dose alone but with more or less genetic variance depending on the population. This change in genetic variance among populations suggests that selection particularly depleted genetic variance for DDT response in the Queensland population. Finally, despite similar (co)variation between traits in benign conditions, the genetic responses across population differed under stressful conditions. This showed how stress-responsive genetic variation only reveals itself in specific conditions and thereby escapes potential trade-offs in benign environments. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The effect of elevated temperatures on the life history and insecticide resistance phenotype of the major malaria vector Anopheles arabiensis (Diptera: Culicidae).

PubMed

Oliver, Shüné V; Brooke, Basil D

2017-02-14

Temperature plays a crucial role in the life history of insects. Recent climate change research has highlighted the importance of elevated temperature on malaria vector distribution. This study aims to examine the role of elevated temperatures on epidemiologically important life-history traits in the major malaria vector, Anopheles arabiensis. Specifically, the differential effects of temperature on insecticide-resistant and susceptible strains were examined. Two laboratory strains of A. arabiensis, the insecticide-susceptible SENN and the insecticide-resistant SENN DDT strains, were used to examine the effect of elevated temperatures on larval development and adult longevity. The effects of various elevated temperatures on insecticide resistance phenotypes were also examined and the biochemical basis of the changes in insecticide resistance phenotype was assessed. SENN and SENN DDT larvae developed at similar rates at elevated temperatures. SENN DDT adult survivorship did not vary between control and elevated temperatures, while the longevity of SENN adults at constantly elevated temperatures was significantly reduced. SENN DDT adults lived significantly longer than SENN at constantly elevated temperatures. Elevated rearing temperatures, as well as a short-term exposure to 37 and 39 °C as adults, augmented pyrethroid resistance in adult SENN DDT, and increased pyrethroid tolerance in SENN. Detoxification enzyme activity was not implicated in this phenotypic effect. Quercertin-induced synergism of inducible heat shock proteins negated this temperature-mediated augmentation of pyrethroid resistance. Insecticide-resistant A. arabiensis live longer than their susceptible counterparts at elevated temperatures. Exposure to heat shock augments pyrethroid resistance in both resistant and susceptible strains. This response is potentially mediated by inducible heat shock proteins.

Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

USGS Publications Warehouse

Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

1999-01-01

Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (< 1-34 ng/g). PCBs are first detected in sediment deposited during the 1930's in Richardson Bay, about a decade earlier than the onset of detectable levels of DDTs. PCB inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

Evidence of detrimental effects of environmental contaminants on growth and reproductive physiology of white sturgeon in impounded areas of the Columbia River

USGS Publications Warehouse

Feist, G.W.; Webb, M.A.H.; Gundersen, D.T.; Foster, E.P.; Schreck, C.B.; Maule, A.G.; Fitzpatrick, M.S.

2005-01-01

This study sought to determine whether wild white sturgeon from the Columbia River (Oregon) were exhibiting signs of reproductive endocrine disruption. Fish were sampled in the free-flowing portion of the river (where the population is experiencing reproductive success) and from three reservoirs behind hydroelectric dams (where fish have reduced reproductive success). All of the 18 pesticides and almost all of the 28 polychlorinated biphenyls (PCBs) that were analyzed in livers and gonads were detected in at least some of the tissue samples. Metabolites of p,p???-dichlorodiphenyltrichloroethane (DDT) [p,p???-dichlorodiphenyldichloroethylene (DDE) and p,p???-1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD)] were consistently found at relatively high levels in fish. Some males and immature females showed elevated plasma vitellogenin; however, concentrations were not correlated with any of the pesticides or PCBs analyzed. Negative correlations were found between a number of physiologic parameters and tissue burdens of toxicants. Plasma triglycerides and condition factor were negatively correlated with total DDT (DDD + DDE + DDT), total pesticides (all pesticides detected - total DDT), and PCBs. In males, plasma androgens and gonad size were negatively correlated with total DDT, total pesticides, and PCBs. Fish residing in the reservoir behind the oldest dam had the highest contaminant loads and incidence of gonadal abnormalities, and the lowest triglycerides, condition factor, gonad size, and plasma androgens. These data suggest that endocrine-disrupting chemicals may be accumulating behind dams over time. Overall, results of this study indicate that exposure to environmental contaminants may be affecting both growth and reproductive physiology of sturgeon in some areas of the Columbia River.

Organochlorine pesticide residues in bed sediments of the San Joaquin River and its tributary streams, California

USGS Publications Warehouse

Gilliom, R.J.; Clifton, D.G.

1987-01-01

The distribution and concentrations of organochlorine pesticide residues in bed sediments were assessed from samples collected at 24 sites in the San Joaquin River and its tributaries in the San Joaquin Valley, California. Sampling was designed to collect the finest grained bed sediments present in the vicinity of each site. One or more of the 14 pesticides analyzed were detected at every site. Pesticides detected at one or more sites were chlordane, DDD, DDE, DDT, dieldrin, endosulfan, mirex, and toxaphene. Pesticides not detected were endrin, heptachlor, heptachlor epoxide, lindane, methoxychlor, and perthane. The most frequently detected pesticides were DDD (83% of sites), DDE (all sites), DDT (33% of sites), and dieldrin (58% of sites). Maximum concentrations of these pesticides, which were correlated with each other and with the amount of organic carbon in the sample, were DDD, 260 micrograms/kg; DDE, 430 micrograms/kg; DDT, 420 micrograms/kg; and dieldrin, 8.9 micrograms/kg. Six small tributary streams that drain agricultural areas west of the San Joaquin River had the highest concentrations. Water concentrations and loads were estimated for each pesticide from its concentration in bed sediments, the concentration of suspended sediment, and streamflow. Estimated loadings of DDD, DDE, DDT, and dieldrin from tributaries to the San Joaquin River indicate that most of the loading to the river at the time of the study was probably from the westside tributaries. Estimated water concentrations exceeded the aquatic life criterion for the sum of DDD, DDE, and DDt of 0.001 microgram/L at nine of the 24 sites sampled. Five of the nine sites are westside tributaries and one is the San Joaquin River near Vernalis. (Author 's abstract)

Occurrence, enantiomeric signature and ecotoxicological risk assessment of HCH isomers and DDT metabolites in the sediments of Kabul River, Pakistan.

PubMed

Aamir, Muhammad; Khan, Sardar; Niu, Lili; Zhu, Siyu; Khan, Anwarzeb

2017-08-01

Hexachlorocyclohexane (HCH) isomers and dichlorodiphenyltrichloroethane (DDT) metabolites were analyzed in sediments of three different depths (0-10, 10-20 and 20-30 cm) collected from Kabul River, Pakistan, in February 2014. The occurrence levels, enantiomer fractions and potential ecological risk of these organochlorine pesticides (OCPs) were evaluated. The total concentrations of ∑HCHs and ∑DDTs in surface sediments ranged from 4.9-23.9 ng g -1 and from 6.4-18.8 ng g -1 (dry weight basis), respectively. The vertical contamination profile of DDTs was found in order of 20-30 cm >10-20 cm >0-10 cm, indicated that the residue levels of DDTs gradually decreased after it was banned. The ratios of β-HCH/HCHs ranged from 0.04 to 0.73 (69 % of samples below 0.5) suggesting the fresh input of HCHs, while isomeric ratios of α-HCH/γ-HCH (ranged from 0.02 to 7.94), with 76 % of samples less than 3, indicating the cocktail use of technical grade HCH and lindane in the study area. The ratio of (DDE + DDD)/DDTs (ranged from 0.42 to 0.90) indicated long-term biodegradation of parent DDT. The enantiomer of α-HCH was generally racemic or close to racemic for most of the samples, with enantiomeric fraction (EF) value <0.5 for some of the samples indicated the preferential biodegradation of (+)-α-HCH enantiomer, while for o,p'-DDT the EF values >0.5 indicated the depletion of (-)-o,p'-DDT enantiomer in most of the samples. According to sediment quality guidelines (SQGs), HCH contamination is the main concern for ecotoxicological risk in Kabul River.

Differentially expressed microRNAs associated with changes of transcript levels in detoxification pathways and DDT-resistance in the Drosophila melanogaster strain 91-R.

PubMed

Seong, Keon Mook; Coates, Brad S; Kim, Do-Hyup; Hansen, Allison K; Pittendrigh, Barry R

2018-01-01

Dichloro-diphenyl-trichloroethane (DDT) resistance among arthropod species is a model for understanding the molecular adaptations in response to insecticide exposures. Previous studies reported that DDT resistance may involve one or multiple detoxification genes, such as cytochrome P450 monooxygenases (P450s), glutathione S-transferases (GSTs), esterases, and ATP binding cassette (ABC) transporters, or changes in the voltage-sensitive sodium channel. However, the possible involvement of microRNAs (miRNAs) in the post-transcriptional regulation of genes associated with DDT resistance in the Drosophila melanogaster strain 91-R remains poorly understood. In this study, the majority of the resulting miRNAs discovered in small RNA libraries from 91-R and the susceptible control strain, 91-C, ranged from 16-25 nt, and contained 163 precursors and 256 mature forms of previously-known miRNAs along with 17 putative novel miRNAs. Quantitative analyses predicted the differential expression of ten miRNAs between 91-R and 91-C, and, based on Gene Ontology and pathway analysis, these ten miRNAs putatively target transcripts encoding proteins involved in detoxification mechanisms. RT-qPCR validated an inverse correlation between levels of differentially-expressed miRNAs and their putatively targeted transcripts, which implies a role of these miRNAs in the differential regulation of detoxification pathways in 91-R compared to 91-C. This study provides evidence associating the differential expression of miRNAs in response to multigenerational DDT selection in Drosophila melanogaster and provides important clues for understanding the possible roles of miRNAs in mediating insecticide resistance traits.

Toxicity of DDT to Japanese quail as influenced by body weight, breeding condition, and sex

USGS Publications Warehouse

Gish, C.D.; Chura, N.J.

1970-01-01

Controlled experiments were utilized to simulate the stresses on wild birds of breeding condition and of weight loss due to migration. Light conditions in the laboratory were manipulated to produce Japanese quail (Coturnix coturnix japonica) in breeding condition and not in breeding condition. Within each of these groups, some birds were partially starved before dosage and some were fully fed. Birds were then fed dietary levels of 0, 700, 922, 1214, or 1600 ppm dry weight of p,p?-DDT for a period of 20 days or until death. Birds partially starved before dosage were more susceptible to DDT intoxication than nonstarved ones, and birds not in breeding condition were slightly more so than birds in breeding condition. Similarly, males died earlier than females, and the birds of the lighter weight strain used in the second half of the study died earlier than the birds of the heavier strain used in the first half. The heavier birds of each sex not only survived longer than lighter individuals receiving the same treatments, but they also lost a greater proportion of their weight before death. During the early portion of the dosage period, females in breeding condition were less sensitive to DDT than were females not in breeding condition and males. After 10 days on dosage, however, the cumulative mortality of females in breeding condition rapidly approached that of males and of females not in breeding condition. Food restriction prior to dosage, strains of quail, breeding conditions, and sexes resulted in weight differences and a corresponding accentuation or delay of the effects of the different levels of DDT.

Changes in Neuronal Signaling and Cell Stress Response Pathways are Associated with a Multigenic Response of Drosophila melanogaster to DDT Selection

PubMed Central

Coates, Brad S; Sun, Weilin; Clark, John M; Pittendrigh, Barry R

2017-01-01

Abstract The adaptation of insect populations to insecticidal control is a continual threat to human health and sustainable agricultural practices, but many complex genomic mechanisms involved in this adaption remain poorly understood. This study applied a systems approach to investigate the interconnections between structural and functional variance in response to dichlorodiphenyltrichloroethane (DDT) within the Drosophila melanogaster strain 91-R. Directional selection in 6 selective sweeps coincided with constitutive gene expression differences in DDT resistant flies, including the most highly upregulated transcript, Unc-115 b, which plays a central role in axon guidance, and the most highly downregulated transcript, the angiopoietin-like CG31832, which is involved in directing vascular branching and dendrite outgrowth but likely may be under trans-regulatory control. Direct functions and protein–protein interactions mediated by differentially expressed transcripts control changes in cell migration, signal transduction, and gene regulatory cascades that impact the nervous system. Although changes to cellular stress response pathways involve 8 different cytochrome P450s, stress response, and apoptosis is controlled by a multifacetted regulatory mechanism. These data demonstrate that DDT selection in 91-R may have resulted in genome-wide adaptations that impacts genetic and signal transduction pathways that converge to modify stress response, cell survival, and neurological functions. This study implicates the involvement of a multigenic mechanism in the adaptation to a chemical insecticide, which impact interconnected regulatory cascades. We propose that DDT selection within 91-R might act systemically, wherein pathway interactions function to reinforce the epistatic effects of individual adaptive changes on an additive or nonadditive basis. PMID:29211847

Apparatus and method for defect testing of integrated circuits

DOEpatents

Cole, Jr., Edward I.; Soden, Jerry M.

2000-01-01

An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V.sub.DD, to an IC under test and measures a transient voltage component, V.sub.DDT, signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V.sub.DDT signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V.sub.DDT signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.

Organochlorine Pesticides Residues in Human Breast Milk from the Middle Governorates in Jordan in 2013/2014.

PubMed

Al Antary, Tawfiq M; Alawi, Mahmoud A; Estityah, Hussein; Haddad, Nizar

2017-07-01

One hundred samples of mother breast milk were gathered from six middle governorates and districts in Jordan in 2013/2014 to monitor Organochlorine pesticides pollutants. The results showed clearly that banned organochlorine pesticides are still detected in the monitored samples in low concentration despite banning of these persistent pollutants in Jordan since 36 years ago. However, the results indicated that 1% of the contaminated samples contained β-HCH, 5% γ-HCH, 3% p,p'-DDD, 2% heptachlor, 45% p,p'-DDE and 3% p,p'-DDT. In addition, these monitored samples had no residues of aldrin, dieldrin, α-endosulfan, β-endosulfan, HCB, o,p'-DD, o,p'-DDT and o,p'-DDE. In conclusion, there was a decline in the residues of Organochlorine pesticides, particularly DDT group members.

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

USGS Publications Warehouse

Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Anh, Nguyen; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.

2014-01-01

Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4′-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts.

Deflagrations, Detonations, and the Deflagration-to-Detonation Transition in Methane-Air Mixtures

DTIC Science & Technology

2011-04-27

we attempt to answer the question: Given a large enough volume of flammable mixture of NG and air, can a weak spark ignition develop into a...detonation? Large -scale numerical simulations, in conjunction with experimental work conducted at the National Institute for Occupational Safety and...12 2.3.3. Flame Acceleration and DDT in Channels with Obstacles . . . . . . . . . . . . . 14 2.3.4. DDT in Large Spaces

DDE residues in young wood ducks (Aix sponsa) near a former DDT manufacturing plant

USGS Publications Warehouse

Fleming, W.J.; Cromartie, E.

1981-01-01

Breast muscle DDE residues were as high as 5.8 ppm wet-weight basis and 280 ppm lipid-weight basis in young wood ducks (Aix Sponsa) collected on Wheeler National Wildlife Refuge near a former DDT manufacturing plant in northern Alabama. The average DDE residue in wood ducks collected nearest the plant was 46 times background levels 74 km from the plant.

Levels and Distribution of Pollutants in the Waters of an Aquatic Ecosystem in Northern Mexico

PubMed Central

Ochoa-Rivero, Jesús Manuel; Reyes-Fierro, Ana Victoria; Peralta-Pérez, Ma. Del Rosario; Zavala-Díaz de la Serna, Francisco Javier; Ballinas-Casarrubias, Lourdes; Salmerón, Ivan; Rubio-Arias, Héctor; Rocha-Gutiérrez, Beatriz A.

2017-01-01

The availability of good quality water resources is essential to ensure healthy crops and livestock. The objective of this study was to evaluate the level of pollution in Bustillos Lagoon in northern Mexico. Physical-chemical parameters like sodium, chloride, sulfate, electrical conductivity, nitrates, and the pesticide dichlorodiphenyltrichloroethane (DDT) were analyzed to determine the water quality available in the lagoon. Although DDT has been banned in several countries, it is still used for agricultural purposes in Mexico and its presence in this area had not been analyzed previously. Bustillos Lagoon was divided into three zones for the evaluation: (1) industrial; (2) communal lands; and (3) agricultural. The highest concentrations of sodium (2360 mg/L) and SAR (41 meq/L) reported in the industrial zone are values exceeding the United Nations Food and Agricultural Organization (FAO) irrigation water quality guidelines. DDT and its metabolites were detected in all of the 21 sites analyzed, in the agricultural zone ∑DDTs = 2804 ng/mL, this level is much higher than those reported for other water bodies in Mexico and around the world where DDT has been used heavily. The water in the communal zone is the least contaminated, but can only be recommended for irrigation of plants with high stress tolerance and not for crops. PMID:28441345

Role of a guanine nucleotide-binding protein in. cap alpha. /sub 1/-adrenergic receptor-mediated Ca/sup 2 +/ mobilization in DDT/sub 1/ MF-2 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cornett, L.E.; Norris, J.S.

1987-11-01

In this study the mechanisms involved in ..cap alpha../sub 1/-adrenergic receptor-mediated Ca/sup 2 +/ mobilization at the level of the plasma membrane were investigated. Stimulation of /sup 45/Ca/sup 2 +/ efflux from saponin-permeabilized DDT/sub 1/ MF-2 cells was observed with the addition of either the ..cap alpha../sub 1/-adrenergic agonist phenylephrine and guanosine-5'-triphosphate or the nonhydrolyzable guanine nucleotide guanylyl-imidodiphosphate. In the presence of (/sup 32/P) NAD, pertussis toxin was found to catalyze ADP-ribosylation of a M/sub r/ = 40,500 (n = 8) peptide in membranes prepared from DDT/sub 1/, MF-2 cells, possibly the ..cap alpha..-subunit of N/sub i/. However, stimulation ofmore » unidirectional /sup 45/Ca/sup 2 +/ efflux by phenylephrine was not affected by previous treatment of cells with 100 ng/ml pertussis toxin. These data suggest that the putative guanine nucleotide-binding protein which couples the ..cap alpha../sub 1/-adrenergic receptor to Ca/sup 2 +/ mobilization in DDT/sub 1/ MF-2 cells is not a pertussis toxin substrate and may possibly be an additional member of guanine nucleotide binding protein family.« less

Human health risk of dietary intake of organochlorine pesticide residues in bovine meat and tissues from Veracruz, México.

PubMed

Pardío, Violeta; Martínez, David; Flores, Argel; Romero, Dora; Suárez, Víctor; López, Karla; Uscanga, Roxana

2012-12-01

Tissue distribution patterns of organochlorine pesticides in bovine carcasses varied significantly among seasons, geographic locations and tissues. The highest concentrations of Σ-DDT during the dry season were detected in lungs from Paso de Ovejas (2,834.90μg/kg lipid) and, during the rainy season, Lindane and Σ-HCH in muscle and lung samples from Paso de Ovejas (995.80 and 1,690.10μg/kg lipid). Estimated daily intakes of γ-HCH and Σ-DDT (3.35 and 1.22μg/kg bw/day) through consumption of muscle tissues from Paso de Ovejas and Puente Nacional during the rainy season showed the highest contribution. During the rainy season the highest non-cancer Hazard Ratios estimated corresponded to γ-HCH (3.97) and Σ-DDT (4.39) detected in muscle samples from Puente Nacional. The highest Hazard Ratios of cancer risk to the 95th centile daily consumption through meat corresponded to p,p'-DDT from Alvarado (7.76E+06) and from Paso de Ovejas for γ-HCH (1.50E+05) during rainy season. The results indicate potential non- and carcinogenic risks to consumer health through meat consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.

Organochlorine pesticide levels in adipose tissue of pregnant women in Veracruz, Mexico.

PubMed

Herrero-Mercado, Margarita; Waliszewski, S M; Valencia-Quintana, R; Caba, M; Hernández-Chalate, F; García-Aguilar, E; Villalba, R

2010-06-01

DDT and Lindane (gamma-HCH) which were used until 1999 in Mexico, have provided great benefits in the combat of vectors that spread infection-borne diseases and in agriculture for crop protection. The persistence in the environment and their accumulative properties results in bioconcentration in lipid rich tissues of the human body that reflect the extent of environmental pollution. Human adipose tissue samples were taken during 2009 from abdominal cavities of 69 pregnant women by cesarean surgery and from 34 samples of control donors by autopsy in Veracruz State. The samples were analyzed by gas chromatography with ECD. The results of mean levels (mg/kg on fat basis) were higher in controls compared to pregnant women beta-HCH 0.064 vs 0.027; pp'DDE 1.187 vs. 0.745; op'DDT 0.016 vs. 0.011; pp'DDT 0.117 vs. 0.099 and Sigma-DDT 1.337 vs. 0.854. The pregnant women group was divided according to age: up to 20, 20-30, and more than 30 years, and presented an increase for the more persistent pesticides with age in terms of mean concentrations and a more pronounced higher correlation in medians levels. Pairing Body Mass Index to organochlorine pesticide mean levels revealed no correlation between these factors in pregnant women.

Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection.

PubMed

Mzilahowa, T; Ball, A J; Bass, C; Morgan, J C; Nyoni, B; Steen, K; Donnelly, M J; Wilding, C S

2008-09-01

Bioassays for insecticide resistance in adult mosquitoes were conducted on samples of Anopheles gambiae Giles s.l. (Diptera: Culicidae) species collected as larvae from breeding sites in the lower Shire Valley, Malawi. The results indicate full susceptibility to permethrin, deltamethrin and malathion, but reduced susceptibility to DDT in one sample from Thom (LT(50) of 8.39 min for females and 25.09 min for males). Polymerase chain reaction-based species identification of the mosquitoes assayed revealed a mixture of Anopheles arabiensis Patton and Anopheles quadriannulatus (Theobold). The LT(50) did not differ significantly between species. Genotyping of the L1014F and L1014S kdr alleles showed all mosquito specimens to be homozygous wild type; thus the reduced susceptibility detected is not attributable to target site insensitivity and instead is likely to be metabolic in nature. Anopheles quadriannulatus is characteristically zoophagic and exophilic. Indeed, of 82 Anopheles collected through knockdown collections within dwellings, only one was An. quadriannulatus and the rest were An. arabiensis. They are unlikely, therefore, to have been exposed to selection pressure arising from insecticide-treated net usage or to DDT indoor residual spraying. Therefore, it is suggested that this example of reduced susceptibility to DDT in An. quadriannulatus reflects selection in the larval stages.

Levels and Distribution of Pollutants in the Waters of an Aquatic Ecosystem in Northern Mexico.

PubMed

Ochoa-Rivero, Jesús Manuel; Reyes-Fierro, Ana Victoria; Peralta-Pérez, Ma Del Rosario; Zavala-Díaz de la Serna, Francisco Javier; Ballinas-Casarrubias, Lourdes; Salmerón, Ivan; Rubio-Arias, Héctor; Rocha-Gutiérrez, Beatriz A

2017-04-25

The availability of good quality water resources is essential to ensure healthy crops and livestock. The objective of this study was to evaluate the level of pollution in Bustillos Lagoon in northern Mexico. Physical-chemical parameters like sodium, chloride, sulfate, electrical conductivity, nitrates, and the pesticide dichlorodiphenyltrichloroethane (DDT) were analyzed to determine the water quality available in the lagoon. Although DDT has been banned in several countries, it is still used for agricultural purposes in Mexico and its presence in this area had not been analyzed previously. Bustillos Lagoon was divided into three zones for the evaluation: (1) industrial; (2) communal lands; and (3) agricultural. The highest concentrations of sodium (2360 mg/L) and SAR (41 meq/L) reported in the industrial zone are values exceeding the United Nations Food and Agricultural Organization (FAO) irrigation water quality guidelines. DDT and its metabolites were detected in all of the 21 sites analyzed, in the agricultural zone ∑DDTs = 2804 ng/mL, this level is much higher than those reported for other water bodies in Mexico and around the world where DDT has been used heavily. The water in the communal zone is the least contaminated, but can only be recommended for irrigation of plants with high stress tolerance and not for crops.

Deflagration-to-detonation transition in gases in tubes with cavities

NASA Astrophysics Data System (ADS)

Smirnov, N. N.; Nikitin, V. F.; Phylippov, Yu. G.

2010-12-01

The existence of a supersonic second combustion mode — detonation — discovered by Mallard and Le Chatelier and by Berthélot and Vieille in 1881 posed the question of mechanisms for transition from one mode to the other. In the period 1959-1969, experiments by Salamandra, Soloukhin, Oppenheim, and their coworkers provided insights into this complex phenomenon. Since then, among all the phenomena related to combustion processes, deflagration-to-detonation transition is, undoubtedly, the most intriguing one. Deflagration-to-detonation transition (DDT) in gases is connected with gas and vapor explosion safety issues. Knowing mechanisms of detonation onset control is of major importance for creating effective mitigation measures addressing two major goals: to prevent DDT in the case of mixture ignition, or to arrest the detonation wave in the case where it has been initiated. A new impetus to the increase in interest in deflagration-to-detonation transition processes was given by the recent development of pulse detonation devices. The probable application of these principles to creation of a new generation of engines put the problem of effectiveness of pulse detonating devices at the top of current research needs. The effectiveness of the pulse detonation cycle turned out to be the key factor characterizing the Pulse Detonation Engine (PDE), whose operation modes were shown to be closely related to periodical onset and degeneration of a detonation wave. Those unsteady-state regimes should be self-sustained to guarantee a reliable operation of devices using the detonation mode of burning fuels as a constitutive part of their working cycle. Thus deflagration-to-detonation transition processes are of major importance for the issue. Minimizing the predetonation length and ensuring stability of the onset of detonation enable one to increase the effectiveness of a PDE. The DDT turned out to be the key factor characterizing the PDE operating cycle. Thus, the problem of DDT control in gaseous fuel-air mixtures became very acute. This paper contains results of theoretical and experimental investigations of DDT processes in combustible gaseous mixtures. In particular, the paper investigates the effect of cavities incorporated in detonation tubes at the onset of detonation in gases. Extensive numerical modeling and simulations allowed studying the features of deflagration-to-detonation transition in gases in tubes incorporating cavities of a wider cross section. The presence of cavities substantially affects the combustion modes being established in the device and their dependence on the governing parameters of the problem. The influence of geometrical characteristics of the confinement and flow turbulization on the onset of detonation and the influence of temperature and fuel concentration in the unburned mixture are discussed. It was demonstrated both experimentally and theoretically that the presence of cavities of wider cross section in the ignition part of the tube promotes DDT and shortens the predetonation length. At the same time, cavities incorporated along the whole length or in the far-end section inhibit detonation and bring about the onset of low-velocity galloping detonation or galloping combustion modes. The presence of cavities in the ignition section turns an increase in the initial mixture temperature into a DDT-promoting factor instead of a DDT-inhibiting factor.

Burning to Detonation Transition in Porous Beds of a High Energy Propellant

DTIC Science & Technology

1979-11-01

deflagration to detonation transition (DDT) behavior of porous charges of a high-energy propellant (VL-U) has been stualed at both high and low...transition (DDT) behavior of porous charges of a high-eneryy propellant (VLU) has been studied at both high confinement (steel tube) and low confinement...plastic tube). The physical nature of thet propellant ised to construct the porous beds was varied: shredded, powdered CI ,-: and cuboid materials were

Entomological Issues during the Korean War, 1950-1953

DTIC Science & Technology

2008-11-16

users access to individually authored sections f proceedings, annals, symposia, etc. However, the component should be considered within [he context of the...insecticide (Hurlbut 1960). However, authorities in the US felt that DDT was adequate and that the problem lay in its application or in a bad batch of the...which strongly Vivax malaria, a parasitic mosquito- suggested louse resistance to DDT. The borne disease, was of great concern, with US authorities

Recent Advances in Durability and Damage Tolerance Methodology at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Ransom, J. B.; Glaessgen, E. H.; Raju, I. S.; Harris, C. E.

2007-01-01

Durability and damage tolerance (D&DT) issues are critical to the development of lighter, safer and more efficient aerospace vehicles. Durability is largely an economic life-cycle design consideration whereas damage tolerance directly addresses the structural airworthiness (safety) of the vehicle. Both D&DT methodologies must address the deleterious effects of changes in material properties and the initiation and growth of damage that may occur during the vehicle s service lifetime. The result of unanticipated D&DT response is often manifested in the form of catastrophic and potentially fatal accidents. As such, durability and damage tolerance requirements must be rigorously addressed for commercial transport aircraft and NASA spacecraft systems. This paper presents an overview of the recent and planned future research in durability and damage tolerance analytical and experimental methods for both metallic and composite aerospace structures at NASA Langley Research Center (LaRC).

Organochlorine residues in bat guano from nine Mexican caves, 1991.

PubMed

Clark, D R; Moreno-Valdez, A; Mora, M A

1995-08-01

: Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering residues from use of DDT years ago in the Ojuela area of perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p'-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbamate insecticides now in extensive use are unknown.

Organochlorine residues in bat guano from nine Mexican caves, 1991

USGS Publications Warehouse

Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

1995-01-01

Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering residues from use of DDT years ago in the Ojuela area of perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbamate insecticides now in extensive use are unknown.

Organochlorine residues in bat guano from nine Mexican caves, 1991

USGS Publications Warehouse

Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

1995-01-01

Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering resides from use of DDT years ago in the Ojuela area or perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p'-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbonate insecticides now in extensive use are unknown.

Nutrients, suspended sediment, and pesticides in waters of the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1970-90

USGS Publications Warehouse

Tornes, L.H.; Brigham, M.E.

1994-01-01

A relatively large fraction of stream samples had detectable quantities of 2,4-D, a- and y-HCH, and atrazine. These samples covered time spans of as much as 15 years and were from sites downstream from large drainage basins; however, concentrations were well below US EPA MCLs. One county-level study showed higher 2,4-D concentrations at upstream sites than at the outlet from a small basin. This indicates that downstream sites may fail to show impaired water-quality and the fate of pesticides used in the basin. Following the 1972 ban on DDT, concentrations of DDT in fish samples from the Red River of the North quickly decreased. Fish concentrations of DDE and DDD decreased more slowly. Low levels of DDE and DDD were detected in fish 14 years after the DDT ban.

White-faced ibis DDE-related reproductive problems continue at Carson Lake, Nevada

USGS Publications Warehouse

Henny, C.J.; Herron, G.B.

1988-01-01

Organochlorine, mercury, and selenium contamination was studied in White-faced Ibis (Plegadis chihi) nesting at Carson Lake, Nevada in 1985 and 1986. DDE was detected in 138 of 140 eggs sampled. Eggshell thickness was negatively correlated with residues of DDE. DDE residues in ibis eggs, unlike residues in most other wading bird eggs from the Great Basin have not declined during the last decade. At DDE levels in eggs above 4 ppm (wet weight), clutch size and productivity decreased, and the incidence of cracked eggs increased. Assuming that 4 ppm DOE is the critical residue level, 40% of the nesting population in 1985 and 1986 was adversely impacted by DDE, with a net loss of 20% of the population' s expected .production. Most eggs containing high levels (up to 29 ppm) also contained DDT, which implies the source was recently-used DDT. No evidence of breeding ground DDE-DDT contamination was found.

Review on factors affecting the performance of pulse detonation engine

NASA Astrophysics Data System (ADS)

Tripathi, Saurabh; Pandey, Krishna Murari

2018-04-01

Now a day's rocket engines (air-breathing type) are being used for aerospace purposes but the studies have shown that these are less efficient, so alternatives are being searched for these. Pulse Detonation Engine (PDE) is one such efficient engine which can replace the rocket engines. In this review paper, different researches have been cited. As can be observed from various researches, insertion of obstacles is better. Deflagration to Detonation(DDT) transition process is found to be most important factor. So a lot of researches are being done considering this DDT chamber. Also, the ignition chamber and ejector were found to improve the effectiveness of PDE. The PDE works with a range of Mach 0-4. Flame acceleration is also found to increase the DDT process. Use of valve and valveless engine has also been compared. Various other factors have been focused in this review paper which is found to boost PDE performance.

Dechlorination of 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane by Aerobacter aerogenes

USGS Publications Warehouse

Wedemeyer, Gary

1967-01-01

Whole cells or cell-free extracts of Aerobacter aerogenes catalyze the degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in vitro to at least seven metabolites: 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE); 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD); 1-chloro-2,2-bis(p-chlorophenyl)ethylene (DDMU); 1-chloro-2,2-bis(p-chlorophenyl)ethane (DDMS); unsym-bis(p-chlorophenyl)ethylene (DDNU); 2,2-bis(p-chlorophenyl)acetate (DDA); and 4,4′-dichlorobenzophenone (DBP). The use of metabolic inhibitors together with pH and temperature studies indicated that discrete enzymes are involved. By use of the technique of sequential analysis, the metabolic pathway was shown to be: DDT → DDD →DDMU →DDMS → DDNU → DDA → DBP, or DDT → DDE. Dechlorination was marginally enhanced by light-activated flavin mononucleotide.

Deflagration to Detonation Transition (DDT) Simulations of HMX Powder Using the HERMES Model

NASA Astrophysics Data System (ADS)

White, Bradley; Reaugh, John; Tringe, Joseph

2017-06-01

We performed computer simulations of DDT experiments with Class I HMX powder using the HERMES model (High Explosive Response to MEchanical Stimulus) in ALE3D. Parameters for the model were fitted to the limited available mechanical property data of the low-density powder, and to the Shock to Detonation Transition (SDT) test results. The DDT tests were carried out in steel-capped polycarbonate tubes. This arrangement permits direct observation of the event using both flash X-ray radiography and high speed camera imaging, and provides a stringent test of the model. We found the calculated detonation transition to be qualitatively similar to experiment. Through simulation we also explored the effects of confinement strength, the HMX particle size distribution and porosity on the computed detonation transition location. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

Effectiveness of organo-phosphorus insecticides against houseflies and mosquitos

PubMed Central

Lindquist, A. W.

1957-01-01

The paper describes the research being undertaken on organo-phosphorus insecticides for the control of houseflies and mosquitos. The information obtained from laboratory and field tests indicates that these insecticides are at present effective substitutes for DDT and other chlorinated-hydrocarbon insecticides for use against resistant houseflies and culicine mosquitos, but the residual applications are not as long lasting as those of DDT and therefore will probably not be as efficient in anopheline control. PMID:13413645

Evaluation and Validation (E&V) Team Public Report. Volume 2.

DTIC Science & Technology

1985-11-30

Byron, Countess of Lovelace. The Countess was an associate of Charles Babbage and is presumed to be the world’s first programmer (Barnes, 1982:2...by DDT&E, STARS, and AJPO personnel, as appropriate. 4.20.9 Focal Point The DDT&E and STARS focal points, respectively, are indicated below Charles K...Technology For Adaptable, Reliable Systems Major Charles W. Lillie from Headquarters Air Force Systems Command gave a presentation concerning Software For

Modeling malaria control intervention effect in KwaZulu-Natal, South Africa using intervention time series analysis.

PubMed

Ebhuoma, Osadolor; Gebreslasie, Michael; Magubane, Lethumusa

The change of the malaria control intervention policy in South Africa (SA), re-introduction of dichlorodiphenyltrichloroethane (DDT), may be responsible for the low and sustained malaria transmission in KwaZulu-Natal (KZN). We evaluated the effect of the re-introduction of DDT on malaria in KZN and suggested practical ways the province can strengthen her already existing malaria control and elimination efforts, to achieve zero malaria transmission. We obtained confirmed monthly malaria cases in KZN from the malaria control program of KZN from 1998 to 2014. The seasonal autoregressive integrated moving average (SARIMA) intervention time series analysis (ITSA) was employed to model the effect of the re-introduction of DDT on confirmed monthly malaria cases. The result is an abrupt and permanent decline of monthly malaria cases (w 0 =-1174.781, p-value=0.003) following the implementation of the intervention policy. The sustained low malaria cases observed over a long period suggests that the continued usage of DDT did not result in insecticide resistance as earlier anticipated. It may be due to exophagic malaria vectors, which renders the indoor residual spraying not totally effective. Therefore, the feasibility of reducing malaria transmission to zero in KZN requires other reliable and complementary intervention resources to optimize the existing ones. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Changing sources and environmental factors reduce the rates of decline of organochlorine pesticides in the Arctic Atmosphere

NASA Astrophysics Data System (ADS)

Becker, S.; Halsall, C. J.; Tych, W.; Kallenborn, R.; Schlabach, M.; Manø, S.

2009-01-01

An extensive database of organochlorine (OC) pesticide concentrations measured at the Norwegian Arctic Monitoring Station was analysed to assess longer-term trends in the Arctic atmosphere. Dynamic Harmonic Regression (DHR) is employed to investigate the seasonal and cyclical behaviour of chlordanes, DDTs and hexachlorobenzene (HCB), and to isolate underlying inter-annual trends. Although a simple comparison of annual mean concentrations (1994-2005) suggest a decline for all of the OCs investigated, the longer-term trends identified by DHR only show a significant decline for p,p'-DDT. Indeed, HCB shows an increase from 2003-2005. This is thought to be due to changes in source types and the presence of impurities in current use pesticides, together with retreating sea ice affecting air-water exchange. Changes in source types were revealed by using isomeric ratios for the chlordanes and DDTs. Declining trends in ratios of trans-chlordane/cis-chlordane (TC/CC) indicate a shift from primary sources, to more ''weathered'' secondary sources, whereas an increasing trend in o,p'-DDT/p,p'-DDT ratios indicate a shift from use of technical DDT to dicofol. Continued monitoring of these OC pesticides is required to fully understand the influence of a changing climate on the behaviour and environmental cycling of these chemicals in the Arctic as well as possible impacts from ''new'' sources.

Changing sources and environmental factors reduce the rates of decline of organochlorine pesticides in the Arctic atmosphere

NASA Astrophysics Data System (ADS)

Becker, S.; Halsall, C. J.; Tych, W.; Kallenborn, R.; Schlabach, M.; Manø, S.

2012-05-01

An extensive database of organochlorine (OC) pesticide concentrations measured at the Norwegian Arctic monitoring station at Ny-Ålesund, Svalbard, was analysed to assess longer-term trends in the Arctic atmosphere. Dynamic Harmonic Regression (DHR) is employed to investigate the seasonal and cyclical behaviour of chlordanes, DDTs and hexachlorobenzene (HCB), and to isolate underlying inter-annual trends. Although a simple comparison of annual mean concentrations (1994-2005) suggest a decline for all of the OCs investigated, the longer-term trends identified by DHR only show a significant decline for p,p'-DDT. Indeed, HCB shows an increase from 2003-2005. This is thought to be due to changes in source types and the presence of impurities in current use pesticides, together with retreating sea ice affecting air-water exchange. Changes in source types were revealed by using isomeric ratios for the chlordanes and DDTs. Declining trends in ratios of trans-chlordane/cis-chlordane (TC/CC) indicate a shift from primary sources, to more "weathered" secondary sources, whereas an increasing trend in o,p'-DDT/p,p'-DDT ratios indicate a shift from use of technical DDT to dicofol. Continued monitoring of these OC pesticides is required to fully understand the influence of a changing climate on the behaviour and environmental cycling of these chemicals in the Arctic as well as possible impacts from "new" sources.

Modelling shock to detonation transition in PETN using HERMES and CREST

NASA Astrophysics Data System (ADS)

Maheswaran, Mary-Ann; Curtis, John; Reaugh, Jack

2013-06-01

The High Explosive Response to MEchanical Stimulus (HERMES) model has been developed to address High Explosive Violent Response (HEVR). It is a material model for use in the both the LS-DYNA finite element and ALE3D hydrocodes that enables the modelling of both shock to detonation (SDT) and deflagration to detonation (DDT) transition. As part of its ongoing development and application, model parameters for the explosive PETN were found by using experimental data for PETN at different densities. PETN was selected because of the availability of both SDT and DDT data. To model SDT and DDT, HERMES uses a subset of the CREST reactive burn model with the Mie-Gruneisen equation of state (EOS) for the unreacted explosive and a look-up table for the gas EOS as generated by Cheetah. The unreacted EOS parameters were found first by calculating the principal isentrope of unreacted PETN at TMD from PETN shock Hugoniot data. Then Pop-plot data for PETN was used to fit the CREST parameters at each density. The resulting new PETN HERMES material model provides a platform for further investigations of SDT and DDT in low density PETN powder. JER's activity was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344, and partially funded by the Joint US DoD/DOE Munitions Technology Development Program.

[Susceptibility of Aedes aegypti to DDT, deltamethrin, and lambda-cyhalothrin in Colombia].

PubMed

Santacoloma Varón, Liliana; Chaves Córdoba, Bernardo; Brochero, Helena Luisa

2010-01-01

To assess the susceptibility status of 13 natural populations of Aedes aegypti (collected from sites in Colombia where dengue is a serious public health problem) to the pyrethroids, deltamethrin and lambda-cyhalothrin, and to the organochlorine, DDT, and to identify any biochemical mechanisms associated with resistance. Immature forms of the vector were collected from natural breeding spots at each site and then raised under controlled conditions. Using the F2 generation, bioassays were performed using the World Health Organization's 1981 methodology (impregnated paper) and United States Centers for Disease Control and Prevention's 1998 methodology (impregnated bottles). In populations where mortality rates were consistent with decreased susceptibility, levels of nonspecific esterases (NSE), mixed-function oxidases (MFO), and acetylcholinesterase (AChE) were measured using colorimetric tests. All of the mosquito populations that were tested showed resistance to the organochlorine DDT. In the case of the pyrethroids, widespread resistance to lambda-cyhalothrin was found, but not to deltamethrin. Assessing the biochemical resistance mechanisms showed that 7 of the 11 populations had elevated NSE, and one population, increased MFO. Physiological cross-resistance between DDT and lambda-cyhalothrin in the A. aegypti populations tested was dismissed. Physiological resistance to lambda-cyhalothrin appears to be associated with increased NSE. The differences in susceptibility levels and enzyme values among the populations were associated with genetic variations and chemicals in use locally.

Organochlorine pesticide residue levels in blood serum of inhabitants from Veracruz, Mexico.

PubMed

Waliszewski, Stefan M; Caba, M; Herrero-Mercado, M; Saldariaga-Noreña, H; Meza, E; Zepeda, R; Martínez-Valenzuela, C; Gómez Arroyo, S; Villalobos Pietrini, R

2012-09-01

The objective of the present study was to monitor the levels of organochlorine pesticides HCB; α-, β-, γ-HCH; pp'DDE; op'DDT; and pp'DDT in blood serum of Veracruz, Mexico inhabitants. Organochlorine pesticides were analyzed in 150 blood serum samples that constituted that which remained after clinical analyses, using gas chromatography-electron-capture detection (GC-ECD). The results were expressed as milligrams per kilogram on fat basis and micrograms per liter on wet weight. Only the following pesticides were detected: p,p'-DDE was the major organochlorine component, detected in 100% of samples at mean 15.8 mg/kg and 8.4 μg/L; p,p'-DDT was presented in 41.3.% of monitored samples at mean 3.1 mg/kg and 1.4 μg/L; β-HCH was found in 48.6% of the samples at mean 4.9 mg/kg and 2.7 μg/L; op'DDT was determined to be in only 3.3% of monitored samples at mean 2.7 mg/kg and 1.4 μg/L. The pooled samples divided according to sex showed significant differences of β-HCH and pp'DDE concentrations in females. The samples grouped according to age presented the third tertile as more contaminated in both sexes, indicating age as a positively associated factor with serum organochlorine pesticide levels in Veracruz inhabitants.

Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

PubMed

Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

2011-12-01

Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides.

Polychlorinated biphenyls, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p{prime}-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p{prime}-DDE) in human plasma related to fish consumption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asplund, L.; Eriksson, U.; Jansson, B.

1994-11-01

Fatty fish species, e.g., salmon and herring, in the Baltic Sea have high levels of polychlorinated biphenyls (PCBs) and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p{prime}-DDT), and its main metabolite: 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p{prime}-DDE). We determined levels of 10 different PCB congeners, including non- and mono-ortho-PCBs, as well as DDT and DDE, in human blood plasma from 37 subjects with varying intake of fish (0-1 750 g/wk) from the Baltic Sea. With respect to all of the PCB congeners we investigated, as well as for DDT and DDE, there were statistically significant associations with fish intake. Thus, fish from the Baltic Sea is a major source ofmore » exposure to these compounds in Swedes. Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) had been determined earlier in 29 of the subjects. The PCB contribution to {open_quotes}dioxin-like{close_quotes} effects among high consumers of fish (calculated as Nordic TCDD equivalents) was almost 80%, whereas that from PCDD and PCDF was only 20%. 32 refs., 3 figs., 9 tabs.« less

DDE in sediments of the Palos Verdes shelf, California: In situ transformation rates and geochemical fate

USGS Publications Warehouse

Eganhouse, R.P.; Pontolillo, J.

2008-01-01

From 1947 to 1971 the world's largest manufacturer of DDT discharged process wastes into the sewers of Los Angeles County. Roughly 870-1450 t of DDT were released to the ocean off Palos Verdes, CA, a portion of which (???100 t) resides in sediments on the continental shelf and slope. The most abundant DDT compound in the sediments, p,p???-DDE, is degrading by reductive dechlorination, butthe rate of transformation and factors controlling it are not well understood. In order to estimate in situ transformation rates and predict the long-term fate of p,p???-DDE, box cores were collected in 1992 and 2003 from a single location on the Palos Verdes Shelf and analyzed for 8 DDT compounds and 84 polychlorinated biphenyl (PCB) congeners. The PCBs show no evidence of dechlorination, and inventories did not change between 1992 and 2003. By contrast, the inventory of p,p???-DDE decreased by 43%, whereas that of p,p???-DDMU, the putative reductive dechlorination product increased by 34%. The first-order transformation rate for p,p???-DDE at the study site is 0.051 ?? 0.006 yr-1. A multistep reaction model suggests that inventories of p,p???-DDE and p,p???-DDMU will continue to decline, whereas that of p,p???-DDNU will reach a maximum around 2014.

Highly luminescent InP/GaP/ZnS QDs emitting in the entire color range via a heating up process.

PubMed

Park, Joong Pill; Lee, Jae-Joon; Kim, Sang-Wook

2016-07-20

InP-based quantum dots (QDs) have attracted much attention for use in optical applications, and several types of QDs such as InP/ZnS, InP/ZnSeS, and InP/GaP/ZnS have been developed. However, early synthetic methods that involved rapid injection at high temperatures have not been able to reproducibly produce the required optical properties. They were also not able to support commercialization efforts successfully. Herein, we introduce a simple synthetic method for InP/GaP/ZnS core/shell/shell QDs via a heating process. The reaction was completed within 0.5 h and a full color range from blue to red was achieved. For emitting blue color, t-DDT was applied to prevent particle growth. From green to orange, color variation was achieved by adjusting the quantity of myristic acid. Utilizing large quantities of gallium chloride led to red color. With this method, we produced high-quality InP/GaP/ZnS QDs (blue QY: ~40%, FWHM: 50 nm; green QY: ~85%, FWHM: 41 nm; red QY: ~60%, FWHM: 65 nm). We utilized t-DDT as a new sulfur source. Compared with n-DDT, t-DDT was more reactive, which allowed for the formation of a thicker shell.

Highly luminescent InP/GaP/ZnS QDs emitting in the entire color range via a heating up process

PubMed Central

Park, Joong Pill; Lee, Jae-Joon; Kim, Sang-Wook

2016-01-01

InP-based quantum dots (QDs) have attracted much attention for use in optical applications, and several types of QDs such as InP/ZnS, InP/ZnSeS, and InP/GaP/ZnS have been developed. However, early synthetic methods that involved rapid injection at high temperatures have not been able to reproducibly produce the required optical properties. They were also not able to support commercialization efforts successfully. Herein, we introduce a simple synthetic method for InP/GaP/ZnS core/shell/shell QDs via a heating process. The reaction was completed within 0.5 h and a full color range from blue to red was achieved. For emitting blue color, t-DDT was applied to prevent particle growth. From green to orange, color variation was achieved by adjusting the quantity of myristic acid. Utilizing large quantities of gallium chloride led to red color. With this method, we produced high-quality InP/GaP/ZnS QDs (blue QY: ~40%, FWHM: 50 nm; green QY: ~85%, FWHM: 41 nm; red QY: ~60%, FWHM: 65 nm). We utilized t-DDT as a new sulfur source. Compared with n-DDT, t-DDT was more reactive, which allowed for the formation of a thicker shell. PMID:27435428

Highly luminescent InP/GaP/ZnS QDs emitting in the entire color range via a heating up process

NASA Astrophysics Data System (ADS)

Park, Joong Pill; Lee, Jae-Joon; Kim, Sang-Wook

2016-07-01

InP-based quantum dots (QDs) have attracted much attention for use in optical applications, and several types of QDs such as InP/ZnS, InP/ZnSeS, and InP/GaP/ZnS have been developed. However, early synthetic methods that involved rapid injection at high temperatures have not been able to reproducibly produce the required optical properties. They were also not able to support commercialization efforts successfully. Herein, we introduce a simple synthetic method for InP/GaP/ZnS core/shell/shell QDs via a heating process. The reaction was completed within 0.5 h and a full color range from blue to red was achieved. For emitting blue color, t-DDT was applied to prevent particle growth. From green to orange, color variation was achieved by adjusting the quantity of myristic acid. Utilizing large quantities of gallium chloride led to red color. With this method, we produced high-quality InP/GaP/ZnS QDs (blue QY: ~40%, FWHM: 50 nm green QY: ~85%, FWHM: 41 nm red QY: ~60%, FWHM: 65 nm). We utilized t-DDT as a new sulfur source. Compared with n-DDT, t-DDT was more reactive, which allowed for the formation of a thicker shell.

Post-Remediation Biomonitoring of Pesticides and Other Contaminants in Marine Waters and Sediment Near the United Heckathorn Superfund Site, Richmond, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

LD Antrim; NP Kohn

This report, PNNL-1 3059 Rev. 1, was published in July 2000 and replaces PNNL-1 3059 which is dated October 1999. The revision corrects tissue concentration units that were reported as dry weight but were actually wet weight, and updates conclusions based on the correct reporting units. Marine sediment remediation at the United Heckathorn Superfund Site was completed in April 1997. Water and mussel tissues were sampled in February 1999 from four stations near Lauritzen Canal in Richmond, California, for Year 2 of post-remediation monitoring of marine areas near the United Heckathom Site. Dieldrin and dichlorodiphenyl trichloroethane (DDT) were analyzed inmore » water samples, tissue samples from resident mussels, and tissue samples from transplanted mussels deployed for 4 months. Concentrations of dieldrin and total DDT in water and total DDT in tissue were compared with Year 1 of post-remediation monitoring, and with preremediation data from the California State Mussel Watch program (tissue s) and the Ecological Risk Assessment for the United Heckathorn Superfund Site (tissues and water). Mussel tissues were also analyzed for polychlorinated biphenyls (PCB), which were detected in sediment samples. Chlorinated pesticide concentrations in water samples were similar to preremediation levels and did not meet remediation goals. Mean dieldrin concentrations in water ranged from 0.62 ng/L to 12.5 ng/L and were higher than the remediation goal (0.14 ng/L) at all stations. Mean total DDT concentrations in water ranged from 14.4 ng/L to 62.3 ng/L and exceeded the remediation goal (0.59 ng/L) at all stations. The highest concentrations of both DDT and dieldrin were found at the Lauritzen Canal/End station. Despite exceedence of the remediation goals, chlorinated pesticide concentrations in Lauritzen Canal water samples were notably lower in 1999 than in 1998. PCBS were not detected in water samples in 1999.« less

Resistance management strategies in malaria vector mosquito control. Baseline data for a large-scale field trial against Anopheles albimanus in Mexico.

PubMed

Penilla, R P; Rodríguez, A D; Hemingway, J; Torres, J L; Arredondo-Jiménez, J I; Rodríguez, M H

1998-07-01

A high level of DDT resistance and low levels of resistance to organophosphorus, carbamate and pyrethroid insecticides were detected by discriminating dose assays in field populations of Anopheles albimanus in Chiapas, southern Mexico, prior to a large-scale resistance management project described by Hemingway et al. (1997). Biochemical assays showed that the DDT resistance was caused by elevated levels of glutathione S-transferase (GST) activity leading to increased rates of metabolism of DDT to DDE. The numbers of individuals with elevated GST and DDT resistance were well correlated, suggesting that this is the only major DDT resistance mechanism in this population. The carbamate resistance in this population is conferred by an altered acetylcholinesterase (AChE)-based resistance mechanism. The level of resistance observed in the bioassays correlates with the frequency of individuals homozygous for the altered AChE allele. This suggests that the level of resistance conferred by this mechanism in its heterozygous state is below the level of detection by the WHO carbamate discriminating dosage bioassay. The low levels of organophosphate (OP) and pyrethroid resistance could be conferred by either the elevated esterase or monooxygenase enzymes. The esterases were elevated only with the substrate pNPA, and are unlikely to be causing broad spectrum OP resistance. The altered AChE mechanism may also be contributing to the OP but not the pyrethroid resistance. Significant differences in resistance gene frequencies were obtained from the F1 mosquitoes resulting from adults obtained by different collection methods. This may be caused by different insecticide selection pressures on the insects immediately prior to collection, or may be an indication that the indoor- and outdoor-resting A. albimanus collections are not from a randomly mating single population. The underlying genetic variability of the populations is currently being investigated by molecular methods.

National contaminant biomonitoring program: Residues of organochlorine chemicals in U.S. Freshwater Fish, 1976–1984

USGS Publications Warehouse

Schmitt, Christopher J.; Zajicek, Jim L.; Peterman, Paul H.

1990-01-01

The U.S. Fish and Wildlife Service periodically determines concentrations of organochlorine chemicals in freshwater fish collected from a nationwide network of stations as part of the National Contaminant Biomonitoring Program (NCBP, formerly a part of the National Pesticide Monitoring Program). From late 1984 to early 1985, a total of 321 composite fish samples were collected from 112 stations and analyzed for organochlorine chemical residues. The mean concentrations of total DDT did not change from 1980–81 to 1984, following a period of steady decline through the 1970's; however, the mean concentrations ofp,p′-DDT declined significantly. The most persistent DDT homolog (p,p′-DDE) was detected at 98% of the stations sampled in 1984, and constituted 73% of total DDT residues, up from 70% in 1974–79. Collectively, these findings indicate a low rate of influx and continued weathering of DDT in the environment. Residues of polychlorinated biphenyls (PCBs) also remained widespread, but a significant downward trend in total PCBs was evident, and early eluting PCB components were present at fewer stations than in the past. Mean concentrations of dieldrin have not changed since 1978–79; concentrations remained highest in Hawaii and in the Great Lakes. Toxaphene concentrations declined from 1980–81 to 1984, especially in the Great Lakes, and the incidence of toxaphene declined from 88% of the stations sampled in 1980–81 to 69% in 1984. Mean chordane concentrations did not change from 1980–81 to 1984, following a period of decline; however,trans-nonachlor replacedcis-chlordane as the most abundant component, suggesting a lower influx of chlordane to the aquatic environment. Residues of other organochlorines—mirex, pentachloroanisole (PCA), benzene hexachloride (BHC) isomers, endrin, heptachlor, hexachlorobenzene (HCB), and Dacthal® (DCPA)—were either found at relatively few (<25%) of the stations sampled in 1984 or were characterized by relatively low concentrations. In general, organochlorine concentrations were lower in 1984 than at any time reported previously.

Biomonitoring of organochlorines in women with benign and malignant breast disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddiqui, M.K.J.; Anand, M.; Mehrotra, P.K.

2005-06-01

Established risk factors for breast cancer explain breast cancer risk only partially. Organochlorines are considered to be a possible cause for hormone-dependent cancers. A hospital-based case-control study, the first from India, was conducted among 50 women undergoing surgery for breast disease to examine the association between organochlorine exposure and breast cancer risk. Blood, tumor, and surrounding adipose tissue of the breast were collected from the subjects with benign (control) and malignant breast (study) lesions and analyzed to determine organochlorine insecticides using a gas-liquid chromatograph equipped with an electron capture detector. The {alpha}, {beta}, {gamma}, and {delta} isomers of hexachlorocyclohexane (HCH),more » p,p'-dichlorodiphenyltrichloroethane (DDT), o,p'-DDT, p,p-dichlorodiphenyldichloroethylene, and p,p'-dichlorodiphenyldichloroethane were frequently detected in three specimens. Total HCH and total DDT levels were higher in the blood of the study group (25 cases) than in those of the controls (25 cases) with only {gamma}-HCH being significantly different (P0.05). However, both total HCH and total DDT were higher in the tumor tissues of the controls than in those of the study group; {gamma}-HCH was significantly different (P0.05). The level of total HCH ({alpha}-HCH was significantly different, P0.05) was higher in the breast adipose tissue of the study group, whereas total DDT was higher in the breast adipose tissue of the control group. The distribution of known confounders of breast cancer including age, body mass index, age at menarche and menopause, duration of breast feeding, and family history related to breast disease did not differ significantly between benign and malignant groups. This pilot study with limited statistical power does not support a positive association between exposure to organochlorines and risk of breast cancer but paves the way for a larger Indian study with greater statistical power encompassing different regions of the country to enable statistically sound conclusions.« less

Satellite telemetry and prey sampling reveal contaminant sources to Pacific Northwest Ospreys.

PubMed

Elliott, John E; Morrissey, Christy A; Henny, Charles J; Inzunza, Ernesto Ruelas; Shaw, Patrick

2007-06-01

Migratory behavior can be an important factor in determining contaminant exposure in avian populations. Accumulation of organochlorine (OC) pesticides while birds are wintering in tropical regions has been cited often as the reason for high concentrations in migrant populations. To explore this issue, we satellite tracked 16 Ospreys (Pandion haliaetus) over the period 1996-2003 from breeding sites in British Columbia, Canada, and integrated the results into a database on 15 Ospreys that were satellite tracked over the period 1995-1999, from breeding locations in Washington and Oregon, USA. Data on wintering sites of 31 Ospreys in Mexico and Central America were used for spatially targeted sampling of prey fish. Concentrations of the main organochlorine contaminant, p,p'-dichloro-diphenyl-dichloroethylene (DDE), in fish composites from Mexico ranged from 0.005 to 0.115 nicrog/g wet mass. Significant differences existed among fish families in p,p'-DDE, total dichloro-diphenyl-trichloroethane (sigmaDDT), sigmachlordanes, and total polychlorinated biphenyls (sigmaPCBs). Catfish (family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, sigmachlordanes, sigmaPCBs, and hexachlorobenzene. Eggs collected from 16 nests throughout the Pacific Northwest (nine from British Columbia, seven from Oregon and Washington) where Ospreys had been satellite tagged, showed marked variation in levels of DDT metabolites (p,p'-DDE; range 0.02-10.14 microg/g). Wintering site had no significant effect on contaminant concentrations in sample eggs from those specific Ospreys; rather concentrations of p,p'-DDE, were predicted by breeding sites with highest levels in eggs of Ospreys breeding in the lower Columbia River, consistent with published reports of continued high concentrations of DDT and related compounds in that system.

Satellite telemetry and prey sampling reveal contaminant sources to pacific northwest ospreys

USGS Publications Warehouse

Elliott, J.E.; Morrissey, C.A.; Henny, C.J.; Inzunza, E.R.; Shaw, P.

2007-01-01

Migratory behavior can be an important factor in determining contaminant exposure in avian populations. Accumulation of organochlorine (OC) pesticides while birds are wintering in tropical regions has been cited often as the reason for high concentrations in migrant populations. To explore this issue, we satellite tracked 16 Ospreys (Pandion haliaetus) over the period 1996-2003 from breeding sites in British Columbia, Canada, and integrated the results into a database on 15 Ospreys that were satellite tracked over the period 1995-1999, from breeding locations in Washington and Oregon, USA. Data on wintering sites of 31 Ospreys in Mexico and Central America were used for spatially targeted sampling of prey fish. Concentrations of the main organochlorine contaminant, p,p???-dichloro-diphenyl-dichloroethylene (DDE), in fish composites from Mexico ranged from 0.005 to 0.115 ??g/g wet mass. Significant differences existed among fish families in p,p???-DDE, total dichloro- diphenyltrichloroethane (??DDT), ??chlordanes, and total polychlorinated biphenyls (??PCBs). Catfish (family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, ??chlordanes, ??PCBs, and hexachlorobenzene. Eggs collected from 16 nests throughout the Pacific Northwest (nine from British Columbia, seven from Oregon and Washington) where Ospreys had been satellite tagged, showed marked variation in levels of DDT metabolites (p,p???-DDE; range 0.02-10.14 ??g/g). Wintering site had no significant effect on contaminant concentrations in sample eggs from those specific Ospreys; rather concentrations of p,p???-DDE, were predicted by breeding sites with highest levels in eggs of Ospreys breeding in the lower Columbia River, consistent with published reports of continued high concentrations of DDT and related compounds in that system. ?? 2007 by the Ecological Society of America.

Development and Execution of a Large-scale DDT Tube Test for IHE Material Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Gary Robert; Broilo, Robert M.; Lopez-Pulliam, Ian Daniel

Insensitive High Explosive (IHE) Materials are defined in Chapter IX of the DOE Explosive Safety Standard (DOE-STD-1212-2012) as being materials that are massdetonable explosives that are so insensitive that the probability of accidental initiation or transition from burning to detonation is negligible1. There are currently a number of tests included in the standard that are required to qualify a material as IHE, however, none of the tests directly evaluate for the transition from burning to detonation (aka deflagration-to-detonation transition, DDT). Currently, there is a DOE complex-wide effort to revisit the IHE definition in DOE-STD-1212-2012 and change the qualification requirements. Themore » proposal lays out a new approach, requiring fewer, but more appropriate tests, for IHE Material qualification. One of these new tests is the Deflagration-to-Detonation Test. According to the redefinition proposal, the purpose of the new deflagration-todetonation test is “to demonstrate that an IHE material will not undergo deflagration-to-detonation under stockpile relevant conditions of scale, confinement, and material condition. Inherent in this test design is the assumption that ignition does occur, with onset of deflagration. The test design will incorporate large margins and replicates to account for the stochastic nature of DDT events.” In short, the philosophy behind this approach is that if a material fails to undergo DDT in a significant over-test, then it is extremely unlikely to do so in realistic conditions. This effort will be valuable for the B61 LEP to satisfy their need qualify the new production lots of PBX 9502. The work described in this report is intended as a preliminary investigation to support the proposed design of an overly conservative, easily fielded DDT test for updated IHE Material Qualification standard. Specifically, we evaluated the aspects of confinement, geometry, material morphology and temperature. We also developed and tested a thermally robust igniter system.« less

Field Assessment and Groundwater Modeling of Pesticide Distribution in the Faga`alu Watershed in Tutuila, American Samoa

NASA Astrophysics Data System (ADS)

Welch, E.; Dulai, H.; El-Kadi, A. I.; Shuler, C. K.

2017-12-01

To examine contaminant transport paths, groundwater and surface water interactions were investigated as a vector of pesticide migration on the island Tutuila in American Samoa. During a field campaign in summer 2016, water from wells, springs, and streams was collected across the island to analyze for selected pesticides. In addition, a detailed watershed-study, involving sampling along the mountain to ocean gradient was conducted in Faga`alu, a U.S. Coral Reef Task Force priority watershed that drains into the Pago Pago Harbor. Samples were screened at the University of Hawai`i for multiple agricultural chemicals using the ELISA method. The pesticides analyzed include glyphosate, azoxystrobin, imidacloprid and DDT/DDE. Field data was integrated into a MODFLOW-based groundwater model of the Faga`alu watershed to reconstruct flow paths, solute concentrations, and dispersion of the analytes. In combination with land-use maps, these tools were used to identify potential pesticide sources and their contaminant contributions. Across the island, pesticide concentrations were well below EPA regulated limits and azoxystrobin was absent. Glyphosate had detectable amounts in 56% of collected groundwater and 62% of collected stream samples. Respectively, 72% and 36% had imidacloprid detected and 98% and 97% had DDT/DDE detected. The highest observed concentration of glyphosate was 0.3 ppb, of imidacloprid was 0.17 ppb, and of DDT was 3.7 ppb. The persistence and ubiquity of DDT/DDE in surface and groundwater since its last island-wide application decades ago is notable. Groundwater flow paths modeled by MODFLOW imply that glyphosate sources match documented agricultural land-use areas. Groundwater-derived pesticide fluxes to the reef in Faga`alu are 977 mg/d of glyphosate and 1642 mg/d of DDT/DDE. Our study shows that pesticides are transported not only via surface runoff, but also via groundwater through the stream's base flow and are exiting the aquifer via submarine groundwater discharge (SGD) in the coastal region as well.

A circumpolar perspective of atmospheric organochlorine pesticides (OCPs): Results from six Arctic monitoring stations in 2000-2003

NASA Astrophysics Data System (ADS)

Su, Yushan; Hung, Hayley; Blanchard, Pierrette; Patton, Gregory W.; Kallenborn, Roland; Konoplev, Alexei; Fellin, Phil; Li, Henrik; Geen, Charles; Stern, Gary; Rosenberg, Bruno; Barrie, Leonard A.

Air concentrations of organochlorine pesticides (OCPs) were measured on a weekly basis in 2000-2003 at six Arctic stations, which include Alert, Kinngait, and Little Fox Lake in Canada; Point Barrow in the USA; Valkarkai in Russia; and Zeppelin in Norway. These stations cover a large region in the Arctic, providing a comprehensive perspective on OCPs in the circumpolar atmosphere. Currently used pesticide endosulfan I had similar concentrations across the stations in November-May, whereas large spatial divergence was found in June-October. This implies the extensive usage of endosulfan during summertime followed by long-range transport to the Arctic. The median air concentration of endosulfan I was 3.2 pg m -3 ( n=245). Seasonally and spatially uniform concentrations of legacy chlordane-related compounds indicated that the influence of primary emissions on Arctic air has become less important than volatilization emissions. Median air concentrations (pg m -3) of trans-chlordane, cis-chlordane, trans-nonachlor, oxychlordane, and heptachlor exo-epoxide were 0.20 ( n=413), 0.58 ( n=413), 0.44 ( n=413), 0.30 ( n=245), and 0.54 ( n=244), respectively. Although extensive usage was banned in the 1970s, large spatial variations reflected that DDT-related compounds were not well mixed in Arctic air. Concentrations of DDT-related compounds were low in general, and median concentrations of p, p'-DDT, o, p'-DDT, p, p'-DDE, o, p'-DDE, and ∑ 4DDT were 0.10, 0.18, 0.37, 0.10, and 0.79 pg m -3 ( n=418), respectively. Air concentrations of pentachloroanisole and dieldrin showed strong seasonal/spatial variations with median values of 3.8 and 0.48 pg m -3 ( n=245). Uniform concentrations were observed for octachlorostyrene with a median of 0.32 pg m -3 ( n=245). Arctic air concentrations of other measured OCPs, such as endrin, heptachlor, methoxychlor, mirex, photomirex, tetrachloroveratrole, trichloroveratrol, and trifluralin, were generally low and mostly below method detection limits.

Sequential evaluation of coronary flow patterns after primary angioplasty in acute anterior ST-elevation myocardial infarction predicts recovery of left ventricular systolic function.

PubMed

Sharif, Dawod; Sharif-Rasslan, Amal; Makhoul, Nabeel; Shefer, Arie; Hassan, Amin; Rosenschein, Uri

2014-05-01

Function of the microcirculation after primary percutaneous coronary intervention (PCI) is dynamic and contributes to unpredictability of recovery of left ventricular (LV) systolic function. This study was conducted to evaluate sequential Doppler velocity parameters of the left anterior descending coronary artery (LAD) in predicting recovery of global and regional LV systolic function. Thirty-five consecutive patients, 24 males, age 59 ± 12 years, with acute anterior ST-elevation myocardial infarction (STEMI) who had primary PCI were studied. Thrombolysis in myocardial infarction (TIMI) and myocardial blush grades were evaluated. Transthoracic echocardiographic (TTE) studies, evaluation of left ventricular ejection fraction (LVEF), LAD territory wall-motion score index (WMSI), and sampling of LAD Doppler velocities up to 6 hours post-PCI, 48 hours postprocedure, and predischarge were performed. Thrombolysis in myocardial infarction grade before PCI averaged 0.86 ± 1.19 and post-PCI 2.89 ± 0.32, P < 0.05. Myocardial blush grade before PCI was 0.41 ± 0.98 and after PCI 2.22 ± 0.93, P < 0.05. Diastolic velocity deceleration time (DDT) in the LAD early after PCI was less than 600 ms in 16 subjects. Immediately after PCI, in subjects with DDT > 600 ms, LVEF was 38.5 ± 6% and predischarge 49.2 ± 8.7%, P = 9.77 × 10−5 and LAD-WMSI decreased from 2 ± 0.38 to 1.4 ± 0.48, P = 0.000163. In subjects with DDT < 600 ms LAD-WMSI did not change significantly. Early and minimal LAD-DDT correlated with improvement in LV systolic function, r = 0.6, whereas post-PCI blush grade had lower correlation with LVEF, r = 0.39. Global and regional LV systolic function after PCI in acute anterior MI can be predicted by LAD-DDT better than by post-PCI myocardial blush.

Pesticides and PCBs in sediments and fish from the Salton Sea, California, USA.

PubMed

Sapozhnikova, Yelena; Bawardi, Ola; Schlenk, Daniel

2004-05-01

The Salton Sea, the largest manmade lake in California, is officially designated by the State of California as an agricultural drainage reservoir. The purpose of this study was to determine organochlorine and organophosphorous pesticides, as well as polychlorinated biphenyl (PCB) concentrations in sediments and fish tissues in the Salton Sea and evaluate the relative ecological risk of these compounds. Sediment samples were taken during 2000-2001 and fish tissues (Tilapia mossambique, Cynoscion xanthulu) were collected in May 2001. All samples were analyzed for 12 chlorinated pesticides, 6 organophosphorus pesticides, and 55 polychlorinated biphenyl (PCB) congeners. SigmaDichlorodiphenyltrichloroethane (SigmaDDT) and total PCB concentrations observed in sediments ranged from 10 to 40 and 116 to 304 ng/g dry wt, respectively. DDT/DDD ratios in sediments and fish tissues of the northern Sea in 2001 indicated recent DDT exposure. Lindane, dieldrin, dichlorodiphenylethane (DDE) and total PCB concentrations detected in sediments exceeded probable effect levels established for freshwater ecosystems, and pp-DDE and total PCB concentrations were higher than effect range-median values developed for marine and estuarine sediments. In fish liver, concentrations of endrin and SigmaDDT exceeded threshold effect level established for invertebrates. SigmaDDT concentrations detected in fish tissues were higher than threshold concentrations for the protection of wildlife consumers of aquatic biota. DDE concentrations in fish muscles tissues were above the 50 ng/g concentration threshold for the protection of predatory birds. Dimethoate, diazinon, malathion, chlorpyrifos, disulfoton varied from < or = 0.15 to 9.5 ng/g dry wt in sediments and from < or = 0.1 to 80.3 ng/g wet wt in fish tissues. Disulfoton was found in relatively high concentrations (up to 80.3 ng/g) in all organs from Tilapia and Corvina. These results demonstrate continued contamination of specific organochlorine compounds in sediments and resident fish species of the Salton Sea.

Organochlorine compounds in bed sediment and fish tissue in the South Platte River Basin, USA, 1992-1993

USGS Publications Warehouse

Tate, C.M.; Heiny, J.S.

1996-01-01

Bed-sediment and fish-tissue samples were collected in the South Platte River Basin to determine the occurrence and distribution of organochlorine compounds in the basin. During August-November 1992 and August 1993, bed sediment (23 sites) and fish tissue (subset of 19 sites) were sampled and analyzed for 32 organochlorine compounds in bed sediment and 27 compounds in fish tissue. More types of organochlorine compounds were detected in fish tissue than in bed sediment. Total DDT, p,p???-DDE, o,p???-DDE, p,p???-DDD, total PCS, Dacthal??, dieldrin, cis-chlordane, cis-nonachlor, trans-nonachlor, and p,p???-DDT were detected in fish tissue at >25% of the sites; p,p???-DDE, total DDT, cis-chlordane, and trans-chlordane were detected in bed sediment at >25% of the sites. Organochlorine concentrations in bed sediment and fish tissue were related to land-use settings. Few organochlorine compounds were detected at minimally impacted sites located in rangeland, forest, and built-up land-use settings. Chlordane-related compounds and p,p???-methoxychlor in bed sediment and fish tissue, endrin in fish tissue, and endosulfan I in bed sediment were associated with urban and mixed (urban and agricultural) sites. Dacthal?? in bed sediment and fish tissue was associated with agricultural sites. The compounds HCB, ??-HCH, PCA, and toxaphene were detected only at mixed land-use sites. Although DDT and DDT-metabolites, dieldrin, and total PCB were detected in urban, mixed, and agricultural land-use settings, highest mean concentrations were detected at mixed land-use sites. Mixed land-use sites had the greatest number of organochlorine compounds detected in fish tissue, whereas urban and mixed sites had the greatest number of organochlorine compounds detected in bed sediment. Measuring concentrations of organochlorine compounds in bed sediment and fish tissue at the same site offers a more complete picture of the persistence of organochlorine compounds in the environment and their relation to land-use settings.

Organochlorine insecticides DDT and chlordane in relation to survival following breast cancer.

PubMed

Parada, Humberto; Wolff, Mary S; Engel, Lawrence S; White, Alexandra J; Eng, Sybil M; Cleveland, Rebecca J; Khankari, Nikhil K; Teitelbaum, Susan L; Neugut, Alfred I; Gammon, Marilie D

2016-02-01

Organochlorine insecticides have been studied extensively in relation to breast cancer incidence, and results from two meta-analyses have been null for late-life residues, possibly due to measurement error. Whether these compounds influence survival remains to be fully explored. We examined associations between organochlorine insecticides [p,p'-DDT (dichlorodiphenyltrichloroethane), its primary metabolite, p,p'-DDE, and chlordane] assessed shortly after diagnosis and survival among women with breast cancer. A population-based sample of women diagnosed with a first primary invasive or in situ breast cancer in 1996-1997 and with available organochlorine blood measures (n = 633) were followed for vital status through 2011. After follow-up of 5 and 15 years, we identified 55 and 189 deaths, of which 36 and 74, respectively, were breast cancer-related. Using Cox regression models, we estimated the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for lipid-adjusted organochlorine concentrations with all-cause and breast cancer-specific mortality. At 5 years after diagnosis, the highest tertile of DDT concentration was associated with all-cause (HR = 2.19; 95% CI: 1.02, 4.67) and breast cancer-specific (HR = 2.72; 95% CI: 1.04, 7.13) mortality. At 15 years, middle tertile concentrations of DDT (HR = 1.42; 95% CI 0.99, 2.06) and chlordane (HR = 1.42; 95% CI: 0.94, 2.12) were modestly associated with all-cause and breast cancer-specific mortality. Third tertile DDE concentrations were inversely associated with 15-year all-cause mortality (HR = 0.66; 95% CI: 0.44, 0.99). This is the first population-based study in the United States to show that DDT may adversely impact survival following breast cancer diagnosis. Further studies are warranted given the high breast cancer burden and the ubiquity of these chemicals. © 2015 UICC.

Extent of cutaneous metabolism during percutaneous absorption of xenobiotics.

PubMed

Bronaugh, R L; Stewart, R F; Storm, J E

1989-07-01

In vitro percutaneous absorption studies generally do not determine whether biotransformation occurs during passage of a substance through the skin. Since it has recently been demonstrated that several chemicals are metabolized during skin permeation, we investigated the metabolism of five additional compounds (14C-labeled) after application to fuzzy rat skin: caffeine, p,p'-DDT, butylated hydroxytoluene (BHT), salicylic acid, and acetyl ethyl tetramethyltetralin (AETT). The viability of skin was maintained with a tissue culture medium. Radioactivity of each substrate and any metabolites in skin and receptor fluid was measured so that the absorption and metabolism of water-insoluble compounds would be accurately determined. Percutaneous absorption ranged from a low of 13% of the applied dose for BHT to a high of 49% for DDT. BHT was metabolized in skin to 4-hydroxy-BHT and an unknown metabolite. Of the absorbed radioisotope, 6.6% was isolated in biotransformed products found mainly in the receptor fluid. AETT was also metabolized during absorption, with 1.9% of the absorbed radioisotope found in two unknown peaks. Caffeine, DDT, and salicylic acid were not metabolized during skin permeation. Skin and liver microsomal metabolism was measured for all compounds except DDT. Metabolism in skin was observed only for the compounds also biotransformed in the diffusion cell; BHT and AETT were metabolized at 113 and 2.5 pmol/min/mg protein, respectively. In this study, as in others, skin metabolism was substantially less than the corresponding metabolism in liver. Therefore, a low rate of liver metabolism such as that found for caffeine, salicylic acid, and DDT might often be predictive of the absence of measurable metabolism during skin permeation. It seems likely that for many compounds, the biotransformations in skin will be small in terms of the percentage of absorbed material that is metabolized. Nevertheless, with potent compounds, even small quantities of a metabolite can be important and for pharmacokinetic studies, viability of skin must be maintained.

Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

USGS Publications Warehouse

DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

1996-01-01

Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

Synergistic effects of adenosine A1 and P2Y receptor stimulation on calcium mobilization and PKC translocation in DDT1 MF-2 cells.

PubMed

Fredholm, Bertil B; Assender, Jean W; Irenius, Eva; Kodama, Noriko; Saito, Naoaki

2003-06-01

1. The effect of adenosine analogues and of nucleotides, alone or in combination, on intracellular calcium, accumulation of inositol (1,4,5) trisphosphate (InsP3), and on activation of protein kinase C (PKC) was studied in DDT1 MF2 cells derived from a Syrian hamster myosarcoma. These cells were found to express mRNA for A1 and some as yet unidentified P2Y receptor(s). 2. Activation of either receptor type stimulated the production of InsP3 and raised intracellular calcium in DDT1 MF2 cells. Similarly, the A1 selective agonist N6-cyclopentyladenosine (CPA) increased PKC-dependent phosphorylation of the substrate MBP(4-14) and induced a PKC translocation to the plasma membrane as determined using [3H]-phorbol dibutyrate (PDBu) binding in DDT1 MF-2 cells. However, neither adenosine nor CPA induced a significant translocation of transiently transfected gamma-PKC-GFP from the cytosol to the cell membrane. In contrast to adenosine analogues, ATP and UTP also caused a rapid but transient translocation of gamma-PKC-GFP and activation of PKC. 3. Doses of the A1 agonist CPA and of ATP or UTP per se caused barely detectable increases in intracellular Ca2+ but when combined, they caused an almost maximal stimulation. Similarly, adenosine (0.6 microM) and UTP (or ATP, 2.5 microM), which per se caused no detectable translocation of either gamma- or epsilon-PKC-GFP, caused when combined a very clear-cut translocation of both PKC subforms, albeit with different time courses. These results show that simultaneous activation of P2Y and adenosine A1 receptors synergistically increases Ca2+ transients and translocation of PKC in DDT1 MF-2 cells. Since adenosine is rapidly formed by breakdown of extracellular ATP, such interactions may be biologically important.

Long-term trends of atmospheric organochlorine pollutants and polycyclic aromatic hydrocarbons over the southeastern Tibetan Plateau.

PubMed

Wang, Chuanfei; Wang, Xiaoping; Gong, Ping; Yao, Tandong

2018-05-15

Long-term monitoring in remote regions is essential for revealing pollution trends at the global scale but relevant studies remain limited. In the present study, a six-year continuous monitoring of atmospheric persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) was carried out at Lulang in the southeastern Tibetan Plateau (TP). Average concentrations of hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), polychlorinated biphenyls (PCBs) and PAHs were 13.5, 8.9, 41.7, 1.8pg/m 3 and 6.2ng/m 3 , respectively. Obvious seasonality was found for all the target compounds. HCHs, DDTs and PCBs had their highest concentrations in summer (monsoon season) and lowest in winter, which is consistent with the fluctuation of the Indian monsoon. Meanwhile, HCB and 5-6-ring PAHs showed opposite variations, possibly induced by local sources and the westerly flow in winter. Declining trends were observed for most of the chemicals, except o,p'-DDE, HCB and PCBs. A declining trend in the α/γ-HCH ratio indicated a shift from technical HCHs to lindane. An increasing trend in the o,p'/p,p'-DDT ratio suggested a likely shift from technical DDTs to dicofol. For PAHs, the contribution from high-temperature combustion has increased recently. The half-lives of α-HCH, γ-HCH, o,p'-DDT, p,p'-DDT were 6.1, 108, 77.6 and 14.2years, respectively. The half-lives of γ-HCH, o,p'-DDT and p,p'-DDT were higher than those in the Arctic, indicating these compounds will persist in the TP for a longer period. The temporal trends in atmospheric POPs were possibly induced by emissions in India and likely driven by wind speed in Lulang. This study contributes toward a better understanding of the behavior and transport of POPs in the TP region. Copyright © 2017 Elsevier B.V. All rights reserved.

Dichlorodiphenyltrichloroethane (DDT): A Weapon Missing From the U.S. Department of Defense’s Vector Control Arsenal

DTIC Science & Technology

2013-01-01

mosquitoes . As COL Christian F. Ockenhouse of the U.S. Army’s Medical Corps stated: “More so than any other infectious disease, malaria has all too often... mosquito abatement programs throughout the world would include DDT. By 1959, the United States, Europe, portions of the Soviet Union, Chile, and several...concerns raised over the primary insect repellant currently used by the U.S. military, N,N-diethyl-3-methylbenzamide, also known as DEET. DEET targets

Deflagration to detonation transition in mechanoactivated mixtures of ammonium perchlorate with aluminum

NASA Astrophysics Data System (ADS)

Shevchenko, A. A.; Dolgoborodov, A. Yu; Kirilenko, V. G.; Brazhnikov, M. A.

2016-11-01

Deflagration-to-detonation transition (DDT) in aluminum-ammonium perchlorate (Al/AP) loose-packed charges (80% porosity) has been studied. The charges were manufactured from preliminary mechanoactivated mixtures. The mixtures placed in steel tubes 10 mm in diameter were ignited by Nichrome wire. It was found that it is possible to distinguish three parts corresponding to different stages of DDT process development. Steady-state detonation velocity reached the level of 2500 m/s at the distance of 90 mm from the ignition point.

Proceedings of a Seminar on Attaining Water Quality Goals through Water Management Procedures, 17-18 February 1982, Dallas, Texas,

DTIC Science & Technology

1982-02-01

slightly above the level of detection. In both projects low-level accumulation of petroleum hydrocarbons was observed. Because of the complex nature of... petroleum hydrocarbons , PCB, total DDT, Cd and lig in test and control organisms surviving a 10-day, solid phlase bioassay for project A. Organisms...of petroleum hydrocarbons , PCB, total DDT, Cd and Hig in test and control organisms surviving a 10-day solid phase bioassay for project B. Organisms

DDT Characteristics of Laser Driven Exploding Bridgewire Detonators

NASA Astrophysics Data System (ADS)

Welle, Eric

2005-07-01

The initiation and performance characteristics of Laser Exploding Bridgewire (LEBW) detonators loaded with CL-20, CP and BNCP were examined. LEBW devices, in name, as well as in function, exhibit similarities to their electrically driven counterparts with the exception that the means for energy deposition into the driving metal media results from photon absorption instead of electrical joule heating. CP and BNCP were chosen due to their well-known propensity to rapidly undergo a deflagration-to-detonation transition (DDT) and CL-20 was chosen to explore its utility as a DDT explosive. The explosive loading within the LEBW detonators were similar in nature to traditional EBW devices with regard to %TMD loading of the initial increment as well as quantity of energetic materials. Comparisons of the energy fluences required for initiation of the explosives will be discussed. Additionally, streak camera measurements will be reviewed that were conducted at what would be considered ``hard-fire'' fluence levels as well as conditions closer to the mean firing fluence levels of initiation.

Reconstruction of organochlorine compound inputs in the Tagus Prodelta.

PubMed

Mil-Homens, Mário; Vicente, Maria; Grimalt, Joan O; Micaelo, Cristina; Abrantes, Fátima

2016-01-01

Twenty century time-resolved variability of riverine deposits of polychlorobiphenyls (PCBs), DDTs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) was studied in three (210)Pb dated sediment cores collected in a depositional shelf area adjacent to the Tagus estuary (the Tagus Prodelta). The geographic and temporal distribution patterns were consistent with discharge of these organochlorine compounds (OCs) in the area associated with the Tagus mouth. Their concentrations were not correlated with the sedimentary total organic carbon. The PCB down-core profiles were dominated by CB138 and CB153 (hexa-CBs) congeners followed by CB180 (hepta-CBs). Principal Component Analysis of the congener distributions of these compounds did not define temporal down-core trends. The ratios of DDT metabolites (p,p'-DDE/p,p'-DDT) were consistent with recent DDT inputs into the environment and/or earlier applications and long-term residence in soils/sediments until these were eroded and remobilized. Copyright © 2015 Elsevier B.V. All rights reserved.

Atmospheric organochlorine pesticides in the western Canadian Arctic: Evidence of transpacific transport

NASA Astrophysics Data System (ADS)

Bailey, R.; Barrie, L. A.; Halsall, C. J.; Fellin, P.; Muir, D. C. G.

2000-05-01

Concentrations of hexachlorocyclohexanes (HCHs), chlordane, and dichlorodiphenyltrichloroethane (DDT) were measured in ambient air samples on a weekly basis between December 1992 and January 1995 at Tagish Yukon, Canada. In winter, unusually high air concentrations of HCHs, DDT, and chlordanes at Tagish were predominantly influenced by transpacific long-range atmospheric transport from eastern Asia that generally occurred within 5 days. HCH and heptachlor epoxide concentrations were correlated with the time that air spent over eastern Asia prior to arrival at Tagish. Chlordane and DDT, which also increase with transpacific transport, do not show a correlation with the time the upwind airshed included Asia as the composition of these pesticides in the atmosphere is affected by differences in usage patterns, application methods, variable composition of parent pesticides and metabolites in the soil, and rates of volatilization. Air masses originating from North America had the highest concentrations of HCHs and chlordanes when the 5-day upwind airshed included the western United States. Concentrations of HCHs may also be influenced by lindane usage in Canada.

Post-Remediation Biomonitoring of Pesticides in Marine Waters Near the United Heckathorn Site, Richmond, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antrim, Liam D.; Kohn, Nancy P.

Marine sediment remediation at the United Heckathorn Superfund Site was completed in April 1997. Water and mussel tissues were sampled in January 1998 from four stations near Lauritzen Canal in Richmond, California, for the first post-remediation monitoring of marine areas near the United Heckathorn Site. Dieldrin and DDT were analyzed in water samples, tissue samples from resident mussels, and tissue samples from transplanted mussels deployed for 4 months. Concentrations of dieldrin and total DDT in water and total DDT in tissue were compared to pre-remediation data available from the California State Mussel Watch program (tissues) and the Ecological Risk Assessmentmore » for the United Heckathorn Superfund Site (tissues and water). Biomonitoring results indicated that pesticides were still bioavailable in the water column, and have not been reduced from pre-remediation levels. Annual biomonitoring will continue to assess the effectiveness of remedial actions at the United Heckathorn Site.« less

Stress regime in the Philippine Sea slab beneath Kanto, Japan

NASA Astrophysics Data System (ADS)

Nakajima, Junichi; Hasegawa, Akira; Hirose, Fuyuki

2011-08-01

We determine the focal mechanisms of earthquakes within the Philippine Sea slab beneath the Tokyo metropolitan area, and perform stress tensor inversions to investigate the detailed stress field within the slab. The results show a characteristic spatial variation in earthquake-generating stress. Slab stress in northeastern part of the PHS slab is characterized by down-dip tension (DDT), except for the uppermost tip of the seismic portion of the slab where down-dip compression (DDC) stress is dominant. We interpret that DDT is caused by the net slab pull and DDC is attributable to local resistance to subduction at the tip of the slab. In southwestern part of the PHS slab, σ1 and σ3 are generally rotated oblique to the dip of the slab, suggesting that earthquakes occur under stress conditions of neither DDC nor DDT. The rotations in σ1 and σ3 may be related to stress accumulation by the slip deficit along the asperity of the 1923 Kanto earthquake (M7.9).

Analysis of embolic signals with directional dual tree rational dilation wavelet transform.

PubMed

Serbes, Gorkem; Aydin, Nizamettin

2016-08-01

The dyadic discrete wavelet transform (dyadic-DWT), which is based on fixed integer sampling factor, has been used before for processing piecewise smooth biomedical signals. However, the dyadic-DWT has poor frequency resolution due to the low-oscillatory nature of its wavelet bases and therefore, it is less effective in processing embolic signals (ESs). To process ESs more effectively, a wavelet transform having better frequency resolution than the dyadic-DWT is needed. Therefore, in this study two ESs, containing micro-emboli and artifact waveforms, are analyzed with the Directional Dual Tree Rational-Dilation Wavelet Transform (DDT-RADWT). The DDT-RADWT, which can be directly applied to quadrature signals, is based on rational dilation factors and has adjustable frequency resolution. The analyses are done for both low and high Q-factors. It is proved that, when high Q-factor filters are employed in the DDT-RADWT, clearer representations of ESs can be attained in decomposed sub-bands and artifacts can be successfully separated.

The Preliminary Study of Organochlorine Pesticide Residues on Sediments of Bivalvia Fishing Ground at Eastern Part of Coastal Semarang

NASA Astrophysics Data System (ADS)

Adhi Suryono, Chrisna; Subagyo; Setyati, Wilis Ari; Sri Susilo, Endang; Rochaddi, Baskoro; Triaji Mahendrajaya, Robertus

2018-02-01

This paper presents the occurrence level of organochlorine contamination in marine sediments of Semarang coastal areas as a fishing ground of Bivalvia. Five compounds (Heptachlor, Aldrin, Endosulfan, Endrin and pp-DDT) of contaminant have been determined in the sediments surface of Semarang coastal waters. The samples were then analyzed by using gas chromatography and followed by using the method of Standard Method Examination. The result showed that the average concentration of organochlorine pesticides Heptachlor, Aldrin, Endosulfan, Endrin and pp-DDT were 25.5, bellow detected, 7.1, 37.2, 28.6 μ g/L, respectively. The high concentration of pesticide showed on Endrin (65,84 ppb), pp-DDT (29,53 μ g/L), and heptachlor (25,45 μ g/L). The low concentrations were detected on aldrin (bellow detected) and endosulfan (0,92 μ g/L). The concentration of organochlorine pesticides in these areas might contribute on four rivers which deposited the sediment in these coastal waters

Northern Alabama colonies of the endangered grey bat Myotis grisescens: Organochlorine contamination and mortality

USGS Publications Warehouse

Clark, D.R.; Bagley, F.M.; Johnson, W.W.

1988-01-01

From 1976 to 1986, dead and dying grey bats Myotis grisescens and grey bat guano were collected from caves along the Tennessee River in northern Alabama to determine the possible role of organochlorine chemicals.sbd.in particular wastes from a former DDT manufacturing plant near Huntsville.sbd.in the mortalities. Concentrations of chemical residues in brains were less than known lethal levels: certain observations and analyses did indicate the possibility of past organochlorine-induced bat deaths. Levels of contaminants in bats declined slowly during the 10-year sampling period, but heavy residue burdens persist. The high ratio of DDD to DDE in residue from the former DDT plant made them identifiable as far as 140 km downriver. Grey bats concentrated chemical rsidues to higher levels and demonstrated the presence of these residues over much greater distances than did red-winged blackbirds Agelaius phoeniceus. Grey bats may be the most sensitive indicator available for monitoring the contamination from this former DDT manufacturing site.

OBSERVATIONS ON THE EFFECT OF RESIDUAL INSECTICIDES IN EXPERIMENTAL HUTS IN MASAKA DISTRICT, UGANDA.

PubMed

CULLEN, J R; DEZULUETA, J

1964-01-01

Observations made in Kigezi District, Uganda, had shown a great reduction in the number of Anopheles gambiae entering an experimental hut treated with DDT. The work reported in this paper confirms the phenomenon of reduced entry by A. gambiae and A. funestus in two experiments carried out in Masaka, another district of Uganda, using mud-walled huts, roofed with thatch or corrugated-iron sheets and sprayed with DDT and dieldrin. The fact that no similar reduction was observed with Mansonia (mansonioides) uniformis, a common species in the area, indicates the need to determine and take into account any reduction in the number of entering mosquitos when assessing the effect of residual insecticides. Of interest in these experiments was the finding that DDT and dieldrin produced satisfactory kills with all the local anopheline species in spite of their rapid sorption by the mud walls, an indication of the importance of thatch or metal roofs as a source of active insecticide.

Observations on the effect of residual insecticides in experimental huts in Masaka District, Uganda*

PubMed Central

Cullen, J. R.; de Zulueta, J.

1964-01-01

Observations made in Kigezi District, Uganda, had shown a great reduction in the number of Anopheles gambiae entering an experimental hut treated with DDT. The work reported in this paper confirms the phenomenon of reduced entry by A. gambiae and A. funestus in two experiments carried out in Masaka, another district of Uganda, using mud-walled huts, roofed with thatch or corrugated-iron sheets and sprayed with DDT and dieldrin. The fact that no similar reduction was observed with Mansonia (mansonioides) uniformis, a common species in the area, indicates the need to determine and take into account any reduction in the number of entering mosquitos when assessing the effect of residual insecticides. Of interest in these experiments was the finding that DDT and dieldrin produced satisfactory kills with all the local anopheline species in spite of their rapid sorption by the mud walls, an indication of the importance of thatch or metal roofs as a source of active insecticide. PMID:14153414

Organochlorine pesticide residues in ground water of Thiruvallur district, India.

PubMed

Jayashree, R; Vasudevan, N

2007-05-01

Modern agriculture practices reveal an increase in use of pesticides and fertilizers to meet the food demand of increasing population which results in contamination of the environment. In India crop production increased to 100% but the cropping area has increased marginally by 20%. Pesticides have played a major role in achieving the maximum crop production, but maximum usage and accumulation of pesticide residues was highly detrimental to aquatic and other ecosystem. The present study was chosen to know the level of organochlorines contamination in ground water of Thiruvallur district, Tamil Nadu, India. The samples were highly contaminated with DDT, HCH, endosulfan and their derivatives. Among the HCH derivatives, Gamma HCH residues was found maximum of 9.8 microg/l in Arumbakkam open wells. Concentrations of pp-DDT and op-DDT were 14.3 microg/l and 0.8 microg/l. The maximum residue (15.9 microg/l) of endosulfan sulfate was recorded in Kandigai village bore well. The study showed that the ground water samples were highly contaminated with organochlorine residues.

Cell type-specific regulation of beta2-adrenoceptor mRNA by agonists.

PubMed

Danner, S; Lohse, M J

1997-07-16

Prolonged agonist stimulation of beta2-adrenoceptors results in receptor down-regulation which is often paralleled by a reduction of the corresponding mRNA. In this study, we investigated the agonist-dependent regulation of beta2-adrenoceptor mRNA in DDT1-MF2 smooth muscle cells and C6 glioma cells. In DDT1-MF2 cells the half-life of the mRNA was 12 h in monolayer compared to 2 h in suspension cultures. Under both conditions, the agonist isoproterenol reduced this half-life by a factor of 2. In contrast, in C6 glioma cells isoproterenol had no effect on the mRNA stability, even though it reduced mRNA levels by approximately 50%. Isoproterenol-induced downregulation of beta2-adrenoceptor mRNA was completely blocked in C6 cells by the presence of a protein synthesis inhibitor, while this was not so in DDT1-MF2-cells. These data show that beta2-adrenoceptor downregulation occurs via cell-type specific mechanisms.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in sediments from an urban- and industrial-impacted subtropical estuary (Babitonga Bay, Brazil).

PubMed

Rizzi, Juliane; Taniguchi, Satie; Martins, César C

2017-06-15

Babitonga Bay is a large estuary, which has been under pressure from anthropogenic activities coexisting with a natural area of Atlantic rainforest and mangrove systems. The concentration of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was determined to evaluate the contamination status and the determine possible pollution sources in the estuary. The ∑DDT (sum of DDT, DDE and DDD concentrations) was the predominant OCP group, with concentrations ranging from

Characteristics and transport of organochlorine pesticides in urban environment: air, dust, rain, canopy throughfall, and runoff.

PubMed

Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun

2010-11-01

Characteristics and transport of organochlorine pesticides (OCPs) in urban multiple environments, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the environment has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban environments with a fresh signature may originate from the atmospheric transport from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were transported from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly transported from dust, and HCHs were mainly from rain and canopy throughfall.

Potential interactions between metazoan parasites of the Mayan catfish Ariopsis assimilis and chemical pollution in Chetumal Bay, Mexico.

PubMed

Vidal-Martínez, V M; Aguirre-Macedo, M L; Noreña-Barroso, E; Gold-Bouchot, G; Caballero-Pinzón, P I

2003-06-01

The effect of pollutants on the intensity of infection of metazoan parasites in the Mayan catfish, Ariopsis assimilis was investigated. Data were collected on pollutants and metazoan parasites from 76 catfish from five localities in Chetumal Bay in October, 1996. Nineteen pollutants (pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs)) were found in the catfish livers. Heavy metal content was not determined. Nineteen metazoan parasite species were recovered. After controlling for fish length and sampling station, there was a significant negative linear relationship between the intensity of the larval digenean Mesostephanus appendiculatoides and 1,1,1,-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) concentrations. This negative relationship may be explained either by the effect of the pesticide on the mortality of (i) free-living larval forms, (ii) metacercariae in the fish, (iii) infected fish or (iv) intermediate host snails. There were significant differences between fish parasitized and not parasitized with M. appendiculatoides with respect to their DDT concentrations. There were also significant differences between the variances of the mean Clark's coefficient of condition values between catfish parasitized and not parasitized by M. appendiculatoides, with the variance of non-parasitized catfish being significantly larger. The results provided statistical evidence that DDT has a detrimental effect on M. appendiculatoides infection intensity. Furthermore, the significantly larger variance value of Clark's coefficient for non-parasitized fish suggested that DDT affects both the parasite and general host condition.

[Susceptibility and insecticide resistance mechanisms in Anopheles albimanus from the southern Yucatan Peninsula, Mexico].

PubMed

Dzul, Felipe A; Patricia Penilla, R; Rodríguez, Américo D

2007-01-01

To diagnose susceptibility levels and insecticide resistance mechanisms in Anopheles albimanus from the southern Yucatan Peninsula (YP), Mexico. F1 generation of An. albimanus females, collected from November to December 2005 in six villages in the Othon P. Blanco municipality in Quintana Roo and the Calakmul municipality in Campeche, were exposed to deltamethrin, DDT, pirimiphos-methyl and bendiocarb in susceptibility tests, as well as to biochemical assays in order to calculate the enzyme levels related to insecticide resistance. High levels of DDT and deltamethrin resistance were found in An. albimanus collected from the six villages, and a high resistance to pirimiphos-methyl was found in those from La Union, Quintana Roo. Biochemical assays showed high levels of glutathione S-transferase (GST), cytochrome P450 and esterases (with pNPA substrate) in all villages. The frequency of An. albimanus with altered acetylcholinesterase (AChE) was high in La Union (33%). The An. albimanus populations collected in the south of the YP are resistant to DDT and deltamethrin, whereas resistance to pirimiphos-methyl was significant only in those collected from La Union. The mechanisms explaining this resistance are based on high concentrations of GST, cytochrome P450 and esterasas, the former being responsible for DDT metabolism and the others for pyrethroid metabolism. The altered AChE was the mechanism correlated to pirimiphos-methyl resistance in La Union. The results of the present study have important practical consequences for the chemical control of An. albimanus in the south of the YP.

Organochlorine pollutants in small cetaceans from the Pacific and south Atlantic Oceans, November 1968-June 1976

USGS Publications Warehouse

O'Shea, T.J.; Brownell, R.L.; Clark, D.R.; Walker, W.A.; Gay, M.L.; Lamont, T.G.

1980-01-01

Organochlorine residues were analyzed in blubber, brain, or muscle tissues of 69 individuals representing 10 species of small cetaceans. Collections were made from November 1968 through June 1976 at localities in the Eastern Tropical Pacific and along the coasts of California, Hawaii, Japan, and Uruguay, Relations of residue concentrations between tissues are described for DDE and PCBs in two dolphin species. sigma DDT and PCB residues in blubber of most of the 19 individuals of the five southern California species sampled exceed concentrations that are associated with reproductive impairment in pinnipeds, although the nature of such associations is not well defined. The sigma DDT residue of 2,695 ppm in blubber of one California coastal Tursiops truncatus is one of the highest concentrations reported in tissues of members of any population of wild mammals. Except for one rough-toothed dolphin (Steno bredanensis) from Maui, Hawaii, all individuals from all localities surveyed were contaminated with organochlorine compounds. Seventeen different organochlorines were detected; greatest diversity occurred near Japan and California. This is the first report of several of these compounds in tissues of any species of marine mammals. The o,p'-isomers and metabolites of DDT were detected unusually frequently. Ratios of p,p'-DDT to p,p'-DDE in blubber of cetaceans from waters off countries where use of this pesticide has been relatively recent and ongoing were at least an order of magnitude higher than in cetaceans from United States waters.

Organo-halogenated contaminants (OHCs) in the sediments from the Soan River, Pakistan: OHCs(adsorbed TOC) burial flux, status and risk assessment.

PubMed

Malik, Riffat Naseem; Mehboob, Fouzia; Ali, Usman; Katsoyiannis, Athanasios; Schuster, Jasmin K; Moeckel, Claudia; Jones, Kevin C

2014-05-15

In this study, regression analysis revealed that TOC is the principal factor in controlling the fate of organo-halogenated contaminants (OHCs: PCBs, PBDEs, OCPs) in Soan River, Pakistan. The OHCs(adsorbed TOC) burial flux (OHCs(adsorbed TOC)Bf; mg/cm(2)·yr) was calculated in the following ranges: ∑PCBs (0.07-0.31), ∑PBDEs (0.005-0.029), ∑HCHs (0.015-0.046) and ∑DDTs (0.007-0.039). Apart from OHCs(adsorbed TOC)Bf, the levels of OHCs were in the following order: PCBs>DDTs>PBDEs>HCH>Chlordane>HCB. PBDEs and PCB congener patterns showed following order respectively: BDE-149>-153>-18>-138>-44 and PCB-149>-153>-18>-138>-44. DDT isomers and metabolites' pattern were p,p'-DDT>p,p'-DDD>p,p'-DDE>o,p'-DDT>o,p'-DDD>o,p'-DDE and HCHs were β-HCH>α-HCH>γ-HCH>δ-HCH. PBDE composition had similarities to penta-BDE and DE-71 mixtures and PCBs with commercial products Aroclor-1254 and -1260. (DDE+DDD)/∑DDTs and p,p'-DDT/p,p'-DDE suggested the recent input of DDTs in sediments while α/γ-HCH indicated past usage of lindane and technical mixtures. Risk assessment suggested that Soan River and its tributaries are potentially at risk against most of the OHCs. Copyright © 2014 Elsevier B.V. All rights reserved.

Organochlorine pesticide residues in bed sediments of the San Joaquin River, California

USGS Publications Warehouse

Gilliom, Robert J.; Clifton, Daphne G.

1990-01-01

Bed sediments of the San Joaquin River and its tributaries were sampled during October 7–11, 1985, and analyzed for organochiorine pesticide residues in order to determine their areal distribution and to evaluate and prioritize needs for further study. Residues of DDD, DDE, DDT, and dieldrin are widespread in the fine-grained bed sediments of the San Joaquin River and its tributaries despite little or no use of these pesticides for more than 15 years. The San Joaquin River has among the highest bed-sediment concentrations of DDD, DDE, DDT, and dieldrin residues of major rivers in the United States. Concentrations of all four pesticides were correlated with each other and with the amount of organic carbon and fine-grained particles in the bed sediments. The highest concentrations occurred in bed sediments of westside tributary streams. Potential tributary loads of DDD, DDE, DDT, and dieldrin to the San Joaquin River were computed from bed-sediment concentrations and data on streamfiow and suspended-sediment concentration in order to identify the general magnitude of differences between streams and to determine study priorities. The estimated loads indicate that the most important sources of residues during the study period were Salt Slough because of a high load of fine sediment, and Newman Wasteway, Orestimba Creek, and Hospital Creek because of high bed-sediment concentrations. Generally, the highest estimated loads of DDD, DDE, DDT, and dieldrin were in Orestimba and Hospital Creeks.

Assessing variability and trends in Arctic sea ice distribution using satellite data

USGS Publications Warehouse

Belchansky, G.I.; Mordvintsev, Ilia N.; Douglas, David C.

1996-01-01

A survey of organochlorine residues in woodcock wings was undertaken to determine whether these wings are suitable for showing regional differences in residues and to obtain a baseline in 1970-71 for later comparisons. Woodcock wings were obtained from the annual hunter's wing survey. Samples came from eight States (Louisiana, Maine, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, and Wisconsin) and one tri-State area (North Carolina, South Carolina, and Georgia). Wings from the tri-State area contained significantly higher (P<0.01) concentrations of DDT (including DDT, DDD, and DDE) than those from other States. Concentrations of polychlorinated biphenyls (PCB's) also were significantly higher (P<0.05) in samples from these three States. Wings from Louisiana and the tri-State area had significantly higher (P<0.01) concentrations of dieldrin than wings from the other States, and those from Louisiana had significantly higher (P < 0.01) concentrations of mirex than those from other States. (Residues are on lipid base) The compounds detected and the ranges of residue means for all sampling areas were as follows: Total DDT (5.89--65.15 ppm); DDT (0.34 m--14.93 ppm); DDE (4.66--47.47 ppm); DDD (0.11--3.44 ppm); mirex (0.76--16.93 ppm); dieldrin (0.09--3.06 ppm); and PCB's (4.27--8.63 ppm). Woodcock wings appear to be suitable for determining regional differences in organochlorine residues in this species.

Good medicine for conservation biology: The intersection of epidemiology and conservation theory

USGS Publications Warehouse

Lafferty, Kevin D.; Gerber, Leah R.

2002-01-01

A survey of organochlorine residues in woodcock wings was undertaken to determine whether these wings are suitable for showing regional differences in residues and to obtain a baseline in 1970-71 for later comparisons. Woodcock wings were obtained from the annual hunter's wing survey. Samples came from eight States (Louisiana, Maine, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, and Wisconsin) and one tri-State area (North Carolina, South Carolina, and Georgia). Wings from the tri-State area contained significantly higher (P<0.01) concentrations of DDT (including DDT, DDD, and DDE) than those from other States. Concentrations of polychlorinated biphenyls (PCB's) also were significantly higher (P<0.05) in samples from these three States. Wings from Louisiana and the tri-State area had significantly higher (P<0.01) concentrations of dieldrin than wings from the other States, and those from Louisiana had significantly higher (P < 0.01) concentrations of mirex than those from other States. (Residues are on lipid base) The compounds detected and the ranges of residue means for all sampling areas were as follows: Total DDT (5.89--65.15 ppm); DDT (0.34 m--14.93 ppm); DDE (4.66--47.47 ppm); DDD (0.11--3.44 ppm); mirex (0.76--16.93 ppm); dieldrin (0.09--3.06 ppm); and PCB's (4.27--8.63 ppm). Woodcock wings appear to be suitable for determining regional differences in organochlorine residues in this species.

Effects of boundary layer on flame propagation generated by forced ignition behind an incident shock wave

NASA Astrophysics Data System (ADS)

Ishihara, S.; Tamura, S.; Ishii, K.; Kataoka, H.

2016-09-01

To study the effects of the boundary layer on the deflagration to detonation transition (DDT) process, the mixture behind an incident shock wave was ignited using laser breakdown. Ignition timing was controlled so that the interaction of the resulting flame with a laminar or turbulent boundary layer could be examined. In the case of the interaction with a laminar boundary layer, wrinkling of the flame was observed after the flame reached the corner of the channel. On the other hand, interaction with the turbulent boundary layer distorted the flame front and increased the spreading rate of the flame followed by prompt DDT. The inner structure of the turbulent boundary layer plays an important role in the DDT process. The region that distorted the flame within the turbulent boundary layer was found to be the intermediate region 0.01< y/δ < 0.4, where y is the distance from the wall and δ is the boundary layer thickness. The flame disturbance by the turbulent motions is followed by the flame interaction with the inner layer near the wall, which in turn generates a secondary-ignition kernel that produced a spherical accelerating flame, which ultimately led to the onset of detonation. After the flame reached the intermediate region, the time required for DDT was independent of the ignition position. The effect of the boundary layer on the propagating flame, thus, became relatively small after the accelerating flame was generated.

Organochlorine pollutants in small cetaceans from the Pacific and south Atlantic Oceans, November 1968-June 1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Shea, T.J.; Brownell, R.L. Jr.; Clark, D.R. Jr.

1980-09-01

Organochlorine residues were analyzed in blubber, brain, or muscle tissues of 69 individuals representing 10 species of small cetaceans. Collections were made from November 1968 through June 1976 at localities in the Eastern Tropical Pacific and along the coasts of California, Hawaii, Japan, and Uruguay, Relations of residue concentrations between tissues are described for DDE and PCBs in two dolphin species. sigma DDT and PCB residues in blubber of most of the 19 individuals of the five southern California species sampled exceed concentrations that are associated with reproductive impairment in pinnipeds, although the nature of such associations is not wellmore » defined. The sigma DDT residue of 2,695 ppm in blubber of one California coastal Tursiops truncatus is one of the highest concentrations reported in tissues of members of any population of wild mammals. Except for one rough-toothed dolphin (Steno bredanensis) from Maui, Hawaii, all individuals from all localities surveyed were contaminated with organochlorine compounds. Seventeen different organochlorines were detected; greatest diversity occurred near Japan and California. This is the first report of several of these compounds in tissues of any species of marine mammals. The o,p'-isomers and metabolites of DDT were detected unusually frequently. Ratios of p,p'-DDT to p,p'-DDE in blubber of cetaceans from waters off countries where use of this pesticide has been relatively recent and ongoing were at least an order of magnitude higher than in cetaceans from United States waters.« less

Dynamics of DDT in the terrestrial snail Otala lactea (Stylommatophora:Helicidae)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wurzinger, K.H.; Dindal, D.L.

1975-01-01

Seventy specimens of Otala lactea (Mueller) were fed 40 ..mu..g radiolabelled DDT.gram/sup -1/ body weight and analyzed by liquid scintillation spectrometry to determine the body distribution and dynamics of the DDT within the snail's tissues. More than 50% of the pesticide fed to the animals was excreted in the feces after 1 to 2 days. Residues in the body accumulated mostly in the hepatopancreas. All tissues assayed contained measureable quantities of DDT. Five patterns of residue distribution/time were apparent. Pattern I, exhibited by the buccal mass, esophagus, crop, stomach and intestine, showed a general decrease in residue concentrations over themore » 14 day test period. Pattern II, exhibited by the hepatopancreas, kidney, ovotestis, sperm-oviduct, albumen gland and mucous gland, showed a general increase in residue concentrations. Pattern III, exhibited by the salivary gland, spermatheca, circumesophageal nerve ring, lung, collar (mantle edge), foot and vagina + dart sack, showed a fairly constant level of residues. Pattern IV, exhibited by the retractor muscles, epidermis and heart, showed a cyclical distribution of residue levels. Pattern V, exhibited by the penis, showed a cyclical distribution of residue levels that were different from Pattern IV. A double compartment scheme was utilized to explain those trends. Period A, corresponding to the fast compartment, is due to the initial ingestionof insecticide. Periods B and C, corresponding to the slow compartment, are due to the redistribution of residues within the organism.« less

DDT Behavior of Waxed Mixtures of RDX, HMX, and Tetryl

DTIC Science & Technology

1977-10-18

HMX (689*; Class A, 6 ’ 200p), RDX (659; Class E, 6 P 15p), tetryl (812; 6 s 470p), carnauba wax (134; 6 r 125p). The mixing procedure was that used...NSWC/WOL TR 77-96 O DDT BEHAVIOR OF WAXED MIXTURES OF " RDX, HMX, AND TETRYL BY DONNA PRICE and RICHARD R. BERNECKER RESEARCH AND TECHNOLOGY...BEFORE COMPLETING FORM RY PORT NUM ER 2. GOVT ACCESSION No. 3. RECIPIENT’S CATALOG NUMBER S. TYPE OF REPORT & PERIOD COVERED PDT Behavior of Waxed Mixtures

Auxiliary Gas Loading of Explosives and Their Sensitivity to DDT (Deflagration to Detonation Transition),

DTIC Science & Technology

1984-06-25

the weight mean particle sizes were:ammonium picrate (285um), TNT (325pm), RDX (200um) and tetryl (470 and 160m). The carnauba wax (125pm) and the...WORDS (enti.e n reverse side if noceemdy and bnt, ock ,by br) PBXN103 ’"mber) Gas loading RDX Expl D PBXW-108 Sensitivity 91/9 ROX/ wax Cast H-6 PBXN...porous HE for their susceptibility to undergoing DDT. Granuiar explosives studied were RDX, waxed RDX, tetryl, TNT, and Explosive D; cast HE, TNT based

Space Shuttle External Tank Project status

NASA Technical Reports Server (NTRS)

Davis, R. M.

1980-01-01

The External Tank Project is reviewed with emphasis on the DDT&E and production phases and the lightweight tank development. It is noted that the DDT&E phase is progressing well with the structural and ground vibration test article programs complete, the propulsion test article program progressing well, and the component qualification and verification testing 92% complete. New tools and facilities are being brought on line to support the increased build rate for the production phase. The lightweight tank, which will provide additional payload in orbit, is progressing to schedule with first delivery in early 1982.

Space Tug Docking Study. Volume 5: Cost Analysis

NASA Technical Reports Server (NTRS)

1976-01-01

The cost methodology, summary cost data, resulting cost estimates by Work Breakdown Structure (WBS), technical characteristics data, program funding schedules and the WBS for the costing are discussed. Cost estimates for two tasks of the study are reported. The first, developed cost estimates for design, development, test and evaluation (DDT&E) and theoretical first unit (TFU) at the component level (Level 7) for all items reported in the data base. Task B developed total subsystem DDT&E costs and funding schedules for the three candidate Rendezvous and Docking Systems: manual, autonomous, and hybrid.

Passive air sampling of persistent organic pollutants (POPs) and emerging compounds in Kolkata megacity and rural mangrove wetland Sundarban in India: An approach to regional monitoring.

PubMed

Pozo, Karla; Sarkar, Santosh Kumar; Estellano, Victor H; Mitra, Soumita; Audi, Ondrej; Kukucka, Petr; Přibylová, Petra; Klánová, Jana; Corsolini, Simonetta

2017-02-01

Polyurethane foam (PUF) disk passive air samplers were deployed concurrently at five sites across Kolkata megacity and the rural mangrove wetland of Sundarban (UNESCO World Heritage Site) between January-March in 2014. Samples were analyzed for hexachlorocyclohexanes (HCHs), dichlorodiphenyltricholoroethanes (DDTs), polychlorinated biphenyls (PCBs) and, polybrominated diphenyl ethers (PBDEs) using gas chromatography and mass spectrometry (GC-MS). Derived air concentrations (pg/m 3 ) for Kolkata ranged: for ∑α- and γ-HCH between 70 and 207 (114 ± 62), ∑ 6 DDTs: 127-216 (161 ± 36), ∑ 7 PCBs: 53-213 (141 ± 64), and ∑ 10 PBDEs: 0.30-23 (11 ± 9). Low values for all the studied POPs were recorded in the remote area of the Sundarban site (with the exception of DDTs: o,p'-DDT and p,p'-DDT), where ∑ 4 DDTs was 161 ± 36. In particular, the site of Ballygunge, located in the southern part of Kolkata, showed the highest level of all the metabolites/congeners of POPs, suggesting a potential hot spot of usage and emissions. From HCHs, α-/γ-HCH isomers ratio was low (0.67-1.96) indicating a possible sporadic source of lindane. γ-HCH dominated the HCH signal (at 3 sites) reflecting wide spread use of lindane both in Kolkata and the Sundarban region; however, isomeric composition in Kolkata also suggests potential technical HCHs use. Among DDT metabolites, both o,p'-DDT and p,p'-DDT shared the dominant percentages accounting for ∼26-46% of total DDTs followed by p,p'-DDE (∼12-19%). The PCB congener profile was dominated by tri- and tetra-Cl at the southern and eastern part of Kolkata. These results are one of the few contributions that reports air concentrations of POPs, concurrently, at urban and remote villages in India. These data are useful to assess atmospheric pollution levels and to motivate local and regional authorities to better understand the potential human exposure risk associated to urban areas in India. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multiple insecticide resistance mechanisms in Anopheles gambiae s.l. populations from Cameroon, Central Africa.

PubMed

Nwane, Philippe; Etang, Josiane; Chouaїbou, Mouhamadou; Toto, Jean Claude; Koffi, Alphonsine; Mimpfoundi, Rémy; Simard, Frédéric

2013-02-22

Increasing incidence of DDT and pyrethroid resistance in Anopheles mosquitoes is seen as a limiting factor for malaria vector control. The current study aimed at an in-depth characterization of An. gambiae s.l. resistance to insecticides in Cameroon, in order to guide malaria vector control interventions. Anopheles gambiae s.l. mosquitoes were collected as larvae and pupae from six localities spread throughout the four main biogeographical domains of Cameroon and reared to adults in insectaries. Standard WHO insecticide susceptibility tests were carried out with 4% DDT, 0.75% permethrin and 0.05% deltamethrin. Mortality rates and knockdown times (kdt50 and kdt95) were determined and the effect of pre-exposure to the synergists DEF, DEM and PBO was assessed. Tested mosquitoes were identified to species and molecular forms (M or S) using PCR-RFLP. The hot ligation method was used to depict kdr mutations and biochemical assays were conducted to assess detoxifying enzyme activities. The An. arabiensis population from Pitoa was fully susceptible to DDT and permethrin (mortality rates>98%) and showed reduced susceptibility to deltamethrin. Resistance to DDT was widespread in An. gambiae s.s. populations and heterogeneous levels of susceptibility to permethrin and deltamethrin were observed. In many cases, prior exposure to synergists partially restored insecticide knockdown effect and increased mortality rates, suggesting a role of detoxifying enzymes in increasing mosquito survival upon challenge by pyrethroids and, to a lower extent DDT. The distribution of kdr alleles suggested a major role of kdr-based resistance in the S form of An. gambiae. In biochemical tests, all but one mosquito population overexpressed P450 activity, whereas baseline GST activity was low and similar in all field mosquito populations and in the control. In Cameroon, multiple resistance mechanisms segregate in the S form of An. gambiae resulting in heterogeneous resistance profiles, whereas in the M form and An. arabiensis insecticide tolerance seems to be essentially mediated by enzyme-based detoxification. Synergists partially restored susceptibility to pyrethroid insecticides, and might help mitigate the impact of vector resistance in the field. However, additional vector control tools are needed to further impact on malaria transmission in such settings.

Persistent organic pollutants in wetlands of the Mekong Basin

USGS Publications Warehouse

Triet, Tran; Barzen, Jeb Anthony; Choowaew, Sansanee; Engels, Jon Michael; Ni, Duong Van; Mai, Nguyen Anh; Inkhavilay, Khamla; Soben, Kim; Sethik, Rath; Gomotean, Bhuvadol; Thuyen, Le Xuan; Kyi, Aung; Du, Nguyen Huy; Nordheim, Richard; Lam, Ho Si Tung; Moore, Dorn M.; Wilson, Scott

2013-01-01

In this study, the presence and concentration of persistent organic pollutants (POP) were assessed in surface sediments collected from a wide variety of wetlands located throughout the Mekong Basin in Myanmar, Lao People’s Democratic Republic (PDR), Thailand, Cambodia, and Vietnam. Of the 39 POPs tested in 531 sediment samples, dichlorodiphenyltrichloroethane (DDT) and its metabolites endosulfan, hexachlorobenzene (HCB), and endrin were most commonly detected. Even though DDT was banned in the 1990s, some use of DDT may still be occurring in the Mekong Basin. The amount of metabolites for DDT—dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)—found, however, suggests that use of DDT is on the decline throughout the region. HCB and endrin were found distributed broadly throughout the Mekong Basin but not in high amounts. The concentration and distribution of endosulfan and its metabolites represent a serious problem requiring further study and management action. While the total loading of POPs in wetland sediments of the Mekong Basin was generally low, hotspot sites occurred where concentrations exceeded established ecological risk thresholds. For example, wetlands of the open, dry dipterocarp forest of northern Cambodia and Vietnam as well as wetlands in the Mekong Delta of Vietnam contained high concentrations of some POPs. High concentrations of POPs were detected in some wetlands important for biodiversity conservation. Hotspots identified in wetlands such as the Tonle Sap not only had concentrations of DDT and DDE that exceeded Canadian and U.S. benchmarks, but fauna sampled in the area also showed high degrees of bioaccumulation of the same substances. Further and more extensive attention to monitoring POP presence in water birds, fish, and other aquatic organisms is warranted because of the bioaccumulation of these chemicals at higher levels in the food chain. This study represents a collaboration of eight universities from five countries in the Mekong Region (Myanmar, Lao PDR, Thailand, Cambodia and Vietnam) and four universities and research institutions from the United States. Funding for the study came from the Lower Mekong Initiative, U.S. Department of State.

Gradient distribution of persistent organic contaminants along northern slope of central-Himalayas, China.

PubMed

Wang, Xiao-Ping; Yao, Tan-Dong; Cong, Zhi-Yuan; Yan, Xing-Liang; Kang, Shi-Chang; Zhang, Yong

2006-12-15

High mountains may serve as condenser for persistent organic pollutants (POPs) and the vegetation in remote areas has been used as a means to characterized atmospheric concentrations of air pollutants. In this study, organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in Himalayan spruce needle samples from Zhangmu-Nyalam region (central-Himalayas) were analyzed and the altitudinal gradient of these pollutants was investigated. Total HCHs and DDTs concentration in needles were in the range of 1.3-2.9 ng g(-1) dry weight and 1.7-11 ng g(-1) dry weight, which were lower than concentrations reported in spruce needles from Alps, however higher than concentrations in conifer needles from mountain areas of Alberta. Total Himalayan spruce needle PAHs was below 600 ng g(-1) and fluorene, phenanthrene and acenaphthene were abundant individual compounds measured. The ratios of alpha-HCH/gamma-HCH in pine needles were similar with the usual values for technical HCH, implying technical HCHs might be used in this region. The high ratios of o-p'-DDT/p-p'-DDT and no p-p'-DDE measured in this study led to the suspicion that a new source of o-p'-DDT and/or p-p'-DDT existed in this region. In addition, higher ratios of low molecular weight-/high molecular weight-PAHs in this region indicated that petroleum combustion, vehicle emission and low-temperature combustion might be the major contributions of PAH source. To examine the POPs distillation, the analyte concentrations were correlated with altitude. The more volatile OCPs, alpha-HCH, gamma-HCH, aldrin and alpha-endosulfan positively correlated with altitude, however, less volatile OCPs (DDT and DDD) inversely related with elevation. Almost all PAHs detected in this area showed positive correlations with altitude. It is worthy to note that heavy PAHs (Benzo[k] fluoranthene and Benzo[a]anthracene) displayed positive correlation, which implied the sources of PAHs were near the sampling sites. The distillation of POPs was strongly affected by the proximity between sampling sites and contaminant sources. If the contaminant sources are close to the mountains, it may be the dominant factor that controls the concentration gradient.

Determination of n-octanol/water partition coefficient for DDT-related compounds by RP-HPLC with a novel dual-point retention time correction.

PubMed

Han, Shu-ying; Qiao, Jun-qin; Zhang, Yun-yang; Yang, Li-li; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

2011-03-01

n-Octanol/water partition coefficients (P) for DDTs and dicofol were determined by reversed-phase high performance liquid chromatography (RP-HPLC) on a C(18) column using methanol-water mixture as mobile phase. A dual-point retention time correction (DP-RTC) was proposed to rectify chromatographic retention time (t(R)) shift resulted from stationary phase aging. Based on this correction, the relationship between logP and logk(w), the logarithm of the retention factor extrapolated to pure water, was investigated for a set of 12 benzene homologues and DDT-related compounds with reliable experimental P as model compounds. A linear regression logP=(1.10±0.04) logk(w) - (0.60±0.17) was established with correlation coefficient R(2) of 0.988, cross-validated correlation coefficient R(cv)(2) of 0.983 and standard deviation (SD) of 0.156. This model was further validated using four verification compounds, naphthalene, biphenyl, 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (p,p'-DDD) and 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (p,p'-DDE) with similar structure to DDT. The RP-HPLC-determined P values showed good consistency with shake-flask (SFM) or slow-stirring (SSM) results, especially for highly hydrophobic compounds with logP in the range of 4-7. Then, the P values for five DDT-related compounds, 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1,1-trichloroethane (o,p'-DDT), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethane (o,p'-DDD), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethene (o,p'-DDE), and 2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol (dicofol) and its main degradation product 4,4'-dichlorobenzophenone (p,p'-DBP) were evaluated by the improved RP-HPLC method for the first time. The excellent precision with SD less than 0.03 proved that the novel DP-RTC protocol can significantly increases the determination accuracy and reliability of P by RP-HPLC. Copyright © 2011 Elsevier Ltd. All rights reserved.