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Sample records for percent ddt aerosol

  1. Relationship between lead levels on painted surfaces and percent lead in the particles aerosolized during lead abatement.

    PubMed

    Choe, Kyoo T; Trunov, Mikhaylo; Menrath, William; Succop, Paul; Grinshpun, Sergey A

    2002-08-01

    Quantifying airborne lead on lead abatement work sites is critical in assessing worker lead exposures. Airborne lead levels depend on both the concentration of aerosolized particles and the percent lead in those particles. The lead level on the painted surface being abated may affect the percent lead in aerosolized particles. Experiments were performed in the University of Cincinnati Environmental Test Chamber (volume approximately 24.3 m3) using wood doors painted with lead-based paint. Three methods were used for paint removal: dry scraping, wet scraping, and dry machine sanding. Particles aerosolized during lead abatement activities were collected on filters using the Button Personal Inhalable Aerosol Samplers (SKC Inc., Eighty Four, PA) mounted in the workers' breathing zone. The filters were subsequently analyzed for percent lead in the particles. A portable X-ray fluorescence (XRF) instrument (NITON-700, NITON Inc., Bedford, MA) was used to measure surface lead levels of the doors. The accuracy of the XRF instrument was verified by testing standard reference materials prepared by the National Institute of Standards and Technology (NIST) and by Princeton Gamma Tech Inc. It was also verified by relating XRF results from painted door surfaces to laboratory lead analysis data obtained from paint chip samples taken from the same painted surfaces (r2 = 0.81, p < 0.001). A highly significant relationship (r2 = 0.83, p < 0.001) was found between the XRF readings and the percent lead in the particles aerosolized during dry scraping. No significant relationship was found for wet scraping (r2 = 0.09, p = 0.56) or dry machine sanding (r2 = 0.002, p = 0.92). The relationship between surface lead levels and percent lead in particles was found to be dependent on the paint removal method. This variation was attributed to the difference in water absorption property of the paint layers and the different particle aerosolization mechanisms inherent in each paint removal method.

  2. Manual on DDT Insecticide

    DTIC Science & Technology

    1944-01-01

    where darker oil stains are to be avoided, as in galleys, for residual effect on walls, and on mattresses ( bedbug control). (4) Fortified oil solutions...mosquito larvae, flies, bedbugs , lice, and roaches. A. Against Adult Mosquitoes. ~ 1. 5 percent DDT in kerosene, light oil or emulsion, when sprayed...infested) practically free of flies for 36 days. D. Bedbugs . Sanitation officers need no longer live in dread of bedbugs . When properly applied, DDT will

  3. 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)

  4. Aerosols

    Atmospheric Science Data Center

    2013-04-17

    ... article title:  Aerosols over Central and Eastern Europe     View Larger Image ... last weeks of March 2003, widespread aerosol pollution over Europe was detected by several satellite-borne instruments. The Multi-angle ...

  5. 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

  6. 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…

  7. 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

  8. DDT contamination at Wheeler National Wildlife Refuge

    USGS Publications Warehouse

    O'Shea, T.J.; Fleming, W.J.; Cromartie, E.

    1980-01-01

    Disposal of industrial waste resulted in massive DDT contamination atWheeler National Wildlife Refuge, Alabama. Nearly a decade after the cessation of DDT manufacturing at the facility responsible, concentrations of DDT residues in the local fauna are still high enough to suggest avian reproductive impairment and mortality. Populations of fish-eating birds are low, endangered species are being exposed, and muscle lipids of game birds contain up to 6900 parts of DDT (isomers and metabolites) per million.

  9. 40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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....

  10. 40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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....

  11. 40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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....

  12. 40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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....

  13. 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....

  14. 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

  15. Using Information on Uncertainty to Improve Environmental Fate Modeling: A Case Study on DDT

    SciTech Connect

    Schenker, Urs; Scheringer, Martin; Sohn, Michael D.; Maddalena, Randy L.; McKone, Thomas E.; Hungerbuhler, Konrad

    2008-10-01

    Present and future concentrations of DDT in the environment are calculated with the global multi-media model CliMoChem. Monte Carlo simulations are used to assess the importance of uncertainties in substance property data, emission rates, and environmental parameters for model results. Uncertainties in the model results, expressed as 95percent confidence intervals of DDT concentrations in various environmental media, in different geographical locations, and at different points in time are typically between one and two orders of magnitude. An analysis of rank correlations between model inputs and predicted DDT concentrations indicates that emission estimates and degradation rate constants, in particular in the atmosphere, are the most influential model inputs. For DDT levels in the Arctic, temperature dependencies of substance properties are also influential parameters. A Bayesian Monte Carlo approach is used to update uncertain model inputs based on measurements of DDT in the field. The updating procedure suggests a lower value for half-life in air and a reduced range of uncertainty for KOW of DDT. As could be expected, the Bayesian updating yields model results that are closer to observations, and model uncertainties have decreased. The combined sensitivity analysis and Bayesian Monte Carlo approach provide new insight into important processes that govern the global fate and persistence of DDT in the environment.

  16. Characterization and genome functional analysis of the DDT-degrading bacterium Ochrobactrum sp. DDT-2.

    PubMed

    Pan, Xiong; Xu, Tianheng; Xu, Haoyu; Fang, Hua; Yu, Yunlong

    2017-03-17

    A strain of Ochrobactrum sp. DDT-2 that was capable of degrading DDT as the sole carbon and energy source was isolated and sequenced, and its biodegradation characteristics and metabolism mechanism were examined. The genome sequence of the isolate DDT-2 was composed of 4,630,303bp with a GC content of 55.99% and 4454 coding genes. The degradation rate of DDT by the isolate DDT-2 increased with the increasing substrate concentration (0.1-10mg/l) and temperature (20-40°C). The degradation half-life of DDT in the presence of the isolate DDT-2 at pH7.0 was obviously shorter than those at pH5.0 and 9.0. Potential DDT degradation genes were found in the isolate DDT-2 genome by a BLASTx search against a DDT degradation genes (DDGs) database. A common biodegradation pathway of DDT was proposed based on the combined analysis of genome annotation and mass spectrometry. DDT was initially dechlorinated to form DDD and DDE. Then, it was transformed into DDMU and DDA via dechlorination and carboxylation, and it may ultimately be mineralized to carbon dioxide. The results suggested that the isolate DDT-2 could be useful for the bioremediation of DDT and its metabolite residues.

  17. Toxicity and Carcinogenicity of Dichlorodiphenyltrichloroethane (DDT)

    PubMed Central

    Harada, Takanori; Takeda, Makio; Kojima, Sayuri; Tomiyama, Naruto

    2016-01-01

    Dichlorodiphenyltrichloroethane (DDT) is still used in certain areas of tropics and subtropics to control malaria and other insect-transmitted diseases. DDT and its metabolites have been extensively studied for their toxicity and carcinogenicity in animals and humans and shown to have an endocrine disrupting potential affecting reproductive system although the effects may vary among animal species in correlation with exposure levels. Epidemiologic studies revealed either positive or negative associations between exposure to DDT and tumor development, but there has been no clear evidence that DDT causes cancer in humans. In experimental animals, tumor induction by DDT has been shown in the liver, lung, and adrenals. The mechanisms of hepatic tumor development by DDT have been studied in rats and mice. DDT is known as a non-genotoxic hepatocarcinogen and has been shown to induce microsomal enzymes through activation of constitutive androstane receptor (CAR) and to inhibit gap junctional intercellular communication (GJIC) in the rodent liver. The results from our previously conducted 4-week and 2-year feeding studies of p,p′-DDT in F344 rats indicate that DDT may induce hepatocellular eosinophilic foci as a result of oxidative DNA damage and leads them to hepatic neoplasia in combination with its mitogenic activity and inhibitory effect on GJIC. Oxidative stress could be a key factor in hepatocarcinogenesis by DDT. PMID:26977256

  18. DDT-resistant Culex quinquefasciatus: the effect of DDT on the mosquito's size, fecundity and survival.

    PubMed

    Kerdpibule, V; Sucharit, S; Deesin, T

    1981-03-01

    Resistant strains of Culex quinquefasciatus were selected in the larval stage by exposure to sublethal doses of DDT. The size, body weight and fecundity of DDT-resistant mosquitoes were significantly decreased. There was no significant difference between the longevity of females in the original strain and the DDT selected strains, however, there was a significant difference in the males of the DDT-resistant strains than those of the original strain.

  19. DDT, epigenetic harm, and transgenerational environmental justice

    PubMed Central

    2014-01-01

    Although the environmentally harmful effects of widespread dichlorodiphenyltrichloroethane (DDT) use became well-known following Rachel Carson’s Silent Spring (1962), its human health effects have more recently become clearer. A ban on the use of DDT has been in place for over 30 years, but recently DDT has been used for malaria control in areas such as Africa. Recent work shows that DDT has transgenerational effects in progeny and generations never directly exposed to DDT. These effects have health implications for individuals who are not able to have any voice in the decision to use the pesticide. The transgenerational effects of DDT are considered in light of some widely accepted ethical principles. We argue that this reframes the decision to use DDT, requiring us to incorporate new considerations, and new kinds of decision making, into the deliberative process that determines its ongoing use. Ethical considerations for intergenerational environmental justice are presented that include concern and respect for autonomy, nonmaleficence, and justice. Here, we offer a characterization of the kinds of ethical considerations that must be taken into account in any satisfactory decisions to use DDT. PMID:25086599

  20. DDT, epigenetic harm, and transgenerational environmental justice.

    PubMed

    Kabasenche, William P; Skinner, Michael K

    2014-08-02

    Although the environmentally harmful effects of widespread dichlorodiphenyltrichloroethane (DDT) use became well-known following Rachel Carson's Silent Spring (1962), its human health effects have more recently become clearer. A ban on the use of DDT has been in place for over 30 years, but recently DDT has been used for malaria control in areas such as Africa. Recent work shows that DDT has transgenerational effects in progeny and generations never directly exposed to DDT. These effects have health implications for individuals who are not able to have any voice in the decision to use the pesticide. The transgenerational effects of DDT are considered in light of some widely accepted ethical principles. We argue that this reframes the decision to use DDT, requiring us to incorporate new considerations, and new kinds of decision making, into the deliberative process that determines its ongoing use. Ethical considerations for intergenerational environmental justice are presented that include concern and respect for autonomy, nonmaleficence, and justice. Here, we offer a characterization of the kinds of ethical considerations that must be taken into account in any satisfactory decisions to use DDT.

  1. 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)

  2. Dichlorodiphenyltrichloroethane (DDT): ubiquity, persistence, and risks.

    PubMed Central

    Turusov, Vladimir; Rakitsky, Valery; Tomatis, Lorenzo

    2002-01-01

    Due to uncontrolled use for several decades, dichlorodiphenyltrichloroethane (DDT), probably the best known and most useful insecticide in the world, has damaged wildlife and might have negative effects on human health. This review gives a brief history of the use of DDT in various countries and presents the results of epidemiologic and experimental studies of carcinogenesis. Even though its use has been prohibited in most countries for ecologic considerations, mainly because of its negative impact on wildlife, it is still used in some developing countries for essential public health purposes, and it is still produced for export in at least three countries. Due to its stability and its capacity to accumulate in adipose tissue, it is found in human tissues, and there is now not a single living organism on the planet that does not contain DDT. The possible contribution of DDT to increasing the risks for cancers at various sites and its possible role as an endocrine disruptor deserve further investigation. Although there is convincing experimental evidence for the carcinogenicity of DDT and of its main metabolites DDE and DDD, epidemiologic studies have provided contrasting or inconclusive, although prevailingly negative, results. The presence and persistence of DDT and its metabolites worldwide are still problems of great relevance to public health. Efficient pesticides that do not have the negative properties of DDT, together with the development of alternative methods to fight malaria, should be sought with the goal of completely banning DDT. PMID:11836138

  3. Abiotic transformation of DDT in aqueous solutions.

    PubMed

    Pirnie, Erica F; Talley, Jeffrey W; Hundal, Lakhwinder S

    2006-11-01

    Significant concentrations of chlorinated pesticides such as 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) and its two main transformation products, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE) are still present in soil and sediment systems more than 30 years after DDT use was banned in the United States. DDT enters waterways via the runoff from industrial point sources, agricultural lands and atmospheric deposition. We evaluated zero-valent iron (Fe(0)), ferrous sulfide (FeS), as well as combining them with hydrogen peroxide (H(2)O(2)) as viable treatment technologies for degrading DDT in an aqueous solution. Treatment of DDT with Fe(0) and FeS resulted in approximately 88% and 56% transformation of DDT within 150h, respectively. DDE production was insignificant in all systems. The DDT removal was slower with FeS than with Fe(0), but the amounts of DDD and DDE produced did not exceed baseline. Treatment with a 1:1 mixture of Fe(0)-FeS removed about 95% of the added mass of DDT within 4days and generated significant amounts of DDD and minor amounts of DDMU. When small amounts of H(2)O(2) were introduced halfway through the Fe(0) and FeS treatment times, the mass of DDT decreased by 87% and 96%, respectively, within 2days. Our results demonstrate that mixtures of Fe(0)-FeS in combination with H(2)O(2) can be used for rapid and efficient removal of DDT from aqueous solutions.

  4. 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.

  5. 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.

  6. 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

  7. Inactivation of DDT deposits on mud surfaces*†

    PubMed Central

    Bordas, E.; Downs, W. G.; Navarro, L.

    1953-01-01

    The problem of the inactivation of DDT deposits on dry mud surfaces is presented and its causes outlined. The phenomenon is found to be due to adsorption of the DDT crystals present on the surface; this adsorption appears to be the initial step in the catalytic decomposition of DDT by the iron oxides present in soils, since there is a direct relation between the amount of oxides present and their capacity to inactivate DDT deposits. The DDT-inactivating capacity of soils can be determined by testing them for catalytic activity in the thermal decomposition of DDT. The adsorption of DDT by soil is influenced by environmental relative humidity. Inactivated deposits may be reactivated by increase of the atmospheric humidity. Several substances proposed for the protection of the DDT deposit from inactivation were tested without success. Reference is made, however, to the encouraging findings of some other workers. Limewashing is recommended for the protection of DDT deposits. PMID:13082389

  8. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false DDT, DDD and DDE. 129.101 Section 129... POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE. (a) Specialized definitions. (1) DDT Manufacturer means a manufacturer, excluding any source which...

  9. 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.

  10. Effects of five-year DDT application on breeding bird population

    USGS Publications Warehouse

    Robbins, C.S.; Springer, P.F.; Webster, C.G.

    1951-01-01

    Aerial applications of DDT in oil at the rate of 2 pounds per acre applied over a four-year interval on bottomland forest resulted in a 26 percent decrease in the breeding bird population by the fifth spring. The American redstart, parula warbler, and red-eyed vireo suffered decreases of 44 percent, 40. percent, and 28 percent, respectively, over the four-year period. Only the redstart decreased significantly immediately following application of the spray; a few days after the first, second, and fifth annual sprayings an average of 23 percent of redstart territories were deserted. No significant decrease was observed for other species, either immediately following spraying, or over the four-year period.

  11. 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.

  12. 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.

  13. UPTAKE AND PHYTOTRANSFORMATION OF O,P'-DDT AND P,P'-DDT BY AXENICALLY CULTIVATED AQUATIC PLANTS

    EPA Science Inventory

    The uptake and phytotransformation of o,p'-DDT and p,p'-DDT were investigated in vitro using three axenically cultivated aquatic plants: parrot feather (Mariophyllum aquaticum), duckweed (Spirodela oligorrhiza), and elodea (Elodea canadensis). The decay profile of DDT from the aq...

  14. Insecticides: Effects on Cutthroat Trout of Repeated Exposure to DDT.

    PubMed

    Allison, D; Kallman, B J; Cope, O B; Van Valin, C C

    1963-11-15

    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.

  15. 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.

  16. Percents Are Not Natural Numbers

    ERIC Educational Resources Information Center

    Jacobs, Jennifer A.

    2013-01-01

    Adults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated…

  17. Inspiration: One Percent and Rising

    ERIC Educational Resources Information Center

    Walling, Donovan R.

    2009-01-01

    Inventor Thomas Edison once famously declared, "Genius is one percent inspiration and ninety-nine percent perspiration." If that's the case, then the students the author witnessed at the International Student Media Festival (ISMF) last November in Orlando, Florida, are geniuses and more. The students in the ISMF pre-conference workshop…

  18. textbf{Historical Usage Inventories of DDT in China}

    NASA Astrophysics Data System (ADS)

    Qiang, Wang; Lijuan, Zhao; Jianxin, Hu

    2010-05-01

    Dichlorodiphenyltrichloroethane (DDT) is one of organochlorine pesticides and listed as one of the persistent organic pollutants to be reduced and finally eliminated in the Stockholm Convention on Persistent Organic Pollutants, because of its great persistence, toxics, bio-accumulation and potential for long-range transport. It is critical to create national DDT usage/emission inventories for China to carry out source-receptor relation analysis, risk assessment, and other research related to DDT in this country. Chinese inventories of DDT to the year1983 have been published; however, DDT is still being used indirectly in the dicifol producing and being applied for malaria control in case. Therefore it is needed to supplement and update the inventories. DDT production in China can be divided into three phases. Prior to 1965 is the first stage with an annual output of no more than 10,000 tons; 1966-1983 is the second phase. At this stage DDT was produced with an average annual production of 15,500 tons. After 1984 is the third production phase, of which the average annual DDT production was 6,465 tons. Before 1983, DDT was mainly used for agriculture, forestry and pesticides.China used a total of 270,000 tons of DDT during 1951 - 1983. According to China's cropland area, Li Yi-fan create China's DDT usage inventory of 1951-1983. In 1983 the State Council decided to ban DDT producing and DDT is no longer used in agriculture any more, but it is still being used in the producing of dicofol, malaria prevention and treatment anda small amount for export. To this end, this paper calculated theusage inventory of China's DDT from 1984 to 2003. Using sown areas of cotton, apple, citrus, tea and vegetable as surrogate data, usage of dicifolwas calculated, then the usage inventory of DDT resulting from dicofol use and DDT applied for malaria control with prefecture resolution was created. From 1984 to 2003, China used 15,312 tons of DDT, including 12,912 tons of DDT resulting

  19. DDT residues in human milk samples from Delhi, India

    SciTech Connect

    Zaidi, S.S.A.; Bhatnagar, V.K.; Banerjee, B.D.; Balakrishnan, G.; Shah, M.P.

    1989-03-01

    The widespread use of DDT in India has resulted in increased levels of the insecticide in the ecosystem and, therefore, the potential possible health hazards has been voiced. DDT-residues excreted in milk have been reported from different parts of the world; however, very few reports did appear from India. In fact, there is no report on DDT-content in human milk from Delhi area where higher levels of DDT and BHC in human adipose tissues and blood have already been reported. Higher bioaccumulation of DDT might reflect the higher excretion of residues in milk. The authors have, therefore, attempted a systematic study to monitor DDT-residues in human milk samples collected from various hospitals of Delhi (India).

  20. Effects of DDT, DDE, and PCBs on mitochondrial respiration. [Cockroaches

    SciTech Connect

    Khan, H.M.; Cutkomp, L.K.

    1982-11-01

    Data dealing with the action of DDT, its metabolite DDE and other related chlorinated compounds such as polychlorinated biphenyls (PCBs) are presented in this study. Results show that both DDT and DDE effectively reduce oxidative phosphorylation as determined from cockroach muscle mitochondria. DDT is more effective as was also determined for inhibition of oligomycin-sensitive Mg/sup 2 +/ATPase. The PCBs tested were uncouplers of oxidative phosphorylation. (JMT)

  1. Differential response of DDT susceptible and resistant Drosophila melanogaster strains to DDT and oxidative stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolic DDT resistance in Drosophila melanogaster is associated with increased cytochrome P450 expression. Increased P450 activity is also associated with increased oxidative stress. In contrast, increased glutathione S transferase (GST) expression has been associated with a greater ability of o...

  2. 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

  3. 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

  4. 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.

  5. p,p'-DDT induces microcytic anemia in rats.

    PubMed

    Tomita, Mariko; Yoshida, Toshinori; Fukumori, Junko; Yamaguchi, Satoru; Kojima, Sayuri; Fukuyama, Tomoki; Ohnuma-Koyama, Aya; Takahashi, Naofumi; Takeuchi-Kashimoto, Yukiko; Kuwahara, Maki; Nakashima, Nobuaki; Ohtsuka, Ryoichi; Takeda, Makio; Kosaka, Tadashi; Harada, Takanori

    2013-01-01

    Emerging evidence suggests that chronic exposure to DDT and its derivatives is associated with a variety of human disorders such as anemia. The present study demonstrated that p,p'-DDT caused microcystic anemia in a dose-dependent manner (0, 5, 50, and 500 ppm) in the long-term study up to 2 years. To elucidate the mechanism(s) by which p,p'-DDT induces anemia, certain hematological parameters were assessed in rats fed specific doses of p,p'-DDT for 2 weeks, and the effect of lipopolysaccharide on anemia of inflammation was also examined in p,p'-DDT-treated rats. The parameters included the content of hemoglobin per reticulocyte, mean corpuscular volume of reticulocytes and mature erythrocytes, corpuscular hemoglobin concentration mean of mature erythrocytes, and saturation levels of transferrin and iron. During the 2-week treatment period, hypochromic microcytic reticulocytes and hypochromic normocytic mature erythrocytes were observed in p,p'-DDT-treated rats, with no evidence of alteration in plasma iron levels. p,p'-DDT enhanced microcytosis of reticulocytes, as well as mature erythrocytes, which occurred due to severe hypoferremia resulting from anemia of inflammation; however, plasma iron levels were attenuated probably through the inhibition of interleukin-6. Our data suggests that long-term treatment with p,p'-DDT induces microcytic anemia, possibly because of the impairment of iron utility in erythrocytes.

  6. 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...

  7. 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.

  8. DDT remediation in contaminated soils: a review of recent studies.

    PubMed

    Sudharshan, Simi; Naidu, Ravi; Mallavarapu, Megharaj; Bolan, Nanthi

    2012-11-01

    Over the past few decades significant progress has been made in research on DDT degradation in the environment. This review is an update of some of the recent studies on the degradation and biodegradation pathways of DDT and its metabolites, particularly in soils. The latest reports on human toxicity shows that DDT intake is still occurring even in countries that banned its use decades ago. Ageing, sequestration and formation of toxic metabolites during the degradation processes pose environmental challenges and result in difficulties in bioremediation of DDT contaminated soils. Degradation enhancement strategies such as the addition of chelators, low molecular organic acids, co-solvent washing and the use of sodium and seaweeds as ameliorant have been studied to accelerate degradation. This review describes and discusses the recent challenges and degradation enhancement strategies for DDT degradation by potentially cost effective procedures based on bioremediation.

  9. Unusual persistence of DDT in some western USA soils

    SciTech Connect

    Hitch, R.K.; Day, H.R. )

    1992-02-01

    Agricultural use of DDT (1,1,1-trichloro-2,2,2-bis (p-chlorophenyl) ethane) was canceled in 1972. By the late 1970's and early 1980's, the National Soils Monitoring Program of the US Environmental Protection Agency (EPA) was consistently finding higher soil residues of the degradate DDE (1,1-dichloro 2,2-bis (p-chlorophenyl) ethylene) than of parent DDT. Similarly, the US Fish and Wildlife Service (FWS) had been finding during the late 1970's that DDT and related compounds had been decreasing in birds throughout the US. During 1984 and 1985, the EPA and the agriculture departments of Texas and New Mexico, in response to the FWS, conducted soil sampling in 13 areas where contaminated birds had been collected. It was agreed that soil samples containing higher levels of DDT than DDE would serve as a possible indicator of illegal DDT use. This was an intensive soil sampling program; over 236 fields were sampled. A controversy developed as to whether high ratios of DDT and DDE might corroborate the accusations of recent illegal use of DDT products. Dell City area soils containing higher levels of DDT than of DDE became classified as suspicious soils. Soils bearing the expected higher level of DDE were dubbed as normal. To resolve the controversy, the authors, in 1989, conducted a DDT soil metabolism study with representative samples of the suspicious and normal soils. It was felt that a soil metabolism study could, once and for all, determine if there was, indeed, something unusual about the rate at which the suspicious soils degrade DDT.

  10. 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.

  11. Occupational exposure to DDT among mosquito control sprayers

    SciTech Connect

    Nhachi, C.F.B.; Kasilo, O.J. )

    1990-08-01

    DDT, a broad action insecticide whose use is restricted or banned in most industrialized countries is still often used for vector control in many tropical and developing countries. Despite the fact that DDT is accumulative and persistant in the ecosystem use of such substitutes as malathion or propoxur is not popular because these increases costs by 3.4 to 8.5 fold. As such DDT is economically attractive to poorer countries. As far as can be ascertained no systemic poisoning has resulted from occupational exposure to DDT. Due to the large particle size, the amount of DDT inhaled by workers is far less than the amount reaching exposed portions of skin. As such occupational exposure is mainly dermal or tropical. Occupational exposure to DDT studies have been done before. The present study is an analysis of some characteristics, (i.e. age, body size, relationship between plasma vitamin A and DDE levels, and smoking habits), of occupational exposure to DDT among spraymen in a Zimbabwe population.

  12. Responses of hepatocytes to DDT and methyl mercury exposure.

    PubMed

    Bussolaro, D; Filipak Neto, F; Ribeiro, C A Oliveira

    2010-09-01

    The aim of the current work was to investigate the effects of dichlorodiphenyltrichloroethane (DDT) and monomethyl mercury (MeHg) on hepatocytes from tropical fish Hypostomus commersoni (cascudo). In order to verify DDT and MeHg impacts on the redox milieu, cells were exposed for 4 days to 50 nM of DDT, 0.25 and 2.5 microM of MeHg and to a combination of 50 nM of DDT and 0.25 microM of MeHg. These concentrations were compared with those previously published (Filipak Neto et al., 2008) for the predator fish Hoplias malabaricus (traíra). The effects were mostly noticeable on reduced glutathione concentration and delta-aminolevulinic acid dehydratase and glutathione S-transferase activity. Catalase activity increased in the group exposed to 2.5 microM of MeHg and hydrogen peroxide levels decreased in all exposed groups. Also, superoxide anion levels decreased in the groups exposed to 2.5 microM of MeHg and DDT *MeHg group. Cell viability decreased only in the DDT exposed group, demonstrating that the antioxidant defense mechanism of H. commersoni hepatocytes is more efficient than H. malabaricus. These results corroborate the resistance of H. commersoni to polluted areas and support the hypothesis that this species is more resistant to DDT and MeHg than H. malabaricus species.

  13. 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.

  14. Total DDT and dieldrin content of human adipose tissue

    SciTech Connect

    Ahmad, N.; Harsas, W.; Marolt, R.S.; Morton, M.; Pollack, J.K.

    1988-12-01

    As far as the authors could ascertain only 4 well-documented analytical studies have been carried out in Australia determining the total DDT and dieldrin content of human adipose tissue. The latest of these studies was published over 16 years ago. Therefore it is timely and important to re-examine the total DDT and dieldrin concentration within the adipose tissue of the Australian population. The present investigation has analyzed 290 samples of human adipose tissue obtained from Westmead Hospital situated in an outer suburb of Sydney, New South Wales for their content of total DDT and dieldrin.

  15. International Advocacy against DDT and Other Public Health Insecticides for Malaria Control

    DTIC Science & Technology

    2011-01-19

    existing data or the results of epidemiological analyses. The claims are being used to justify the Secretariat’s plan to eliminate DDT production by...The claims are being used to justify the Secretariat?s plan to eliminate DDT production by 2017. DDT is still needed for effective control of malaria...Control Programs (NMCPs) to use DDT is threatened by the Secretariat’s plan for total elimination of DDT in 2020. An urgent push to meet these deadlines

  16. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  17. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  18. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

  19. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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...

  20. 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.

  1. Spermatogenesis in bald eagles experimentally fed a diet containing DDT

    USGS Publications Warehouse

    Locke, L.N.; Chura, N.J.; Stewart, P.A.

    1966-01-01

    When Bald Eagles were fed DDT in the diet at the level of 10 ppm (dry weight basis) for periods of 60 and 120 days, there was no interference with spermatogenic activity. Degenerative testicular changes were produced only by levels of DDT that produced abnormal neurological signs and usually resulted in death. Histological examination of these testes indicates that Bald Eagles have a seasonal testicular cycle similar to that reported for many other birds of the Northern Hemisphere.

  2. DDT of hot, thermally damaged PBX 9501 in heavy confinement

    SciTech Connect

    Parker, Gary R; Dickerson, Peter M; Asay, Blaine W; Mc Afee, John M

    2010-01-01

    The research presented examines DDT of cylinders of PBX 9501 damaged above 180 C in heavy confinement for 0-3 hours and end-ignited or ramped until self-ignition (cookoff) occurred. Progression of luminous reaction was observed by streak photography through a glass-filled slit running the length of the cylinder. Post-mortem analysis of the steel DDT tubes was also done for correlation with the optical records. Results indicate that repeatable, Type I DDT was observed to occur in hot, thermally damaged PBX 9501 with low levels of porosity. It was demonstrated that multiple parameters affect DDT behavior, most likely in a coupled fashion. These parameters are porosity, ignition temperature and thermal soak duration. Conditions leading up to cookoff were shown to sensitize the HE to DDT by increasing likelihood and decreasing run length. Over the range of porosities (0-37%) and ignition temperatures (180-235 C), run lengths and detonation velocities varied, respectively, from approximately 22-109 mm and 6.0-8.3 mm {micro}s{sup -1}. This work fills a valuable and realistic space in the understanding of high explosive violent reaction, including DDT, in abnormal thermal environments.

  3. Global environmental cycling of gamma-HCH and DDT in the 1980s--a study using a coupled atmosphere and ocean general circulation model.

    PubMed

    Guglielmo, Francesca; Lammel, Gerhard; Maier-Reimer, Ernst

    2009-09-01

    A coupled atmosphere-ocean general circulation model, ECHAM5-MPIOM, was used to study the multicompartmental cycling and long-range transport of persistent and semivolatile organics. Multiphase systems in air and ocean are covered by submodels for atmospheric aerosols, HAM, and marine biogeochemistry, HAMOCC5, respectively. The model, furthermore, encompasses 2D surface compartments, i.e. top soil, vegetation surfaces and sea-ice. The total environmental fate of gamma-hexachlorocyclohexane (gamma-HCH, lindane) and dichlorophenyltrichloroethane (DDT) in agriculture were studied. DDT is mostly present in the soils, the water-soluble gamma-HCH in soils and ocean. DDT has the longest residence time in almost all compartments. Quasi-steady state with regard to substance accumulation is reached within a few years in air and vegetation surfaces. In seawater the partitioning to suspended and sinking particles contributes to the vertical transport of substances. On the global scale deep water formation is, however, found to be more efficient. Up to 30% of DDT but only less than 0.2% of gamma-HCH in seawater are stored in particulate matter. On the time scale studied (1 decade) and on global scale substance transport in the environment is determined by the fast atmospheric circulation. The meridional transport mechanism, for both compounds, is significantly enhanced by multi-hopping. Net meridional transport in the ocean is effective only regionally, mostly by currents along the western boundaries of Africa and the Americas. The total environmental burdens of the substances experience a net northward migration from their source regions, which is more pronounced for DDT than for gamma-HCH. Due to the application distribution, however, after 10 years of simulation 21% of the global environmental burden of gamma-HCH and 12% of DDT have accumulated in the Arctic.

  4. 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.

  5. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  6. 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

  7. The Algebra of the Cumulative Percent Operation.

    ERIC Educational Resources Information Center

    Berry, Andrew J.

    2002-01-01

    Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Effects of DDT on eggshell quality and calcium adenosine triphosphatase.

    PubMed

    Kolaja, G J; Hinton, D E

    1977-11-01

    Adult mallard ducks were fed a diet containing 50 ppm DDT for 6 months. Eggs laid during this period were collected and eggshell weight, thickness, and calcium were determined. Chronic ingestion of DDT resulted in production of eggshells that were significantly thinner and lighter than those of controls. Total calcium of thinned eggshells was also reduced; however, calcium per gram of eggshell was not altered, indicating that other eggshell constituents were not incorporated as well. Calcium adenosine triphosphatase activity in the microsomal fraction of eggshell gland epithelium was assayed in control and DDT-fed ducks. Enzyme activity in DDT-fed ducks was reduced to 65% of control values. Since Ca-ATPase has been shown to be associated with calcium transport, enzyme inhibition may be responsible for decreased eggshell weight and thickness. Electron microscopic evaluation of microsomal fractions showed elements of the plasma membrane, including cilia and microvilli, as well as rough and smooth endoplasmic reticulum. Inhibition of calcium transport at the plasma membrane of mucosal epithelium is proposed as a possible mechanism of DDT-induced eggshell thinning.

  13. Beyond Marbles: Percent Change and Social Justice

    ERIC Educational Resources Information Center

    Denny, Flannery

    2013-01-01

    In the author's eighth year of teaching, she hit a wall teaching percent change. Percent change is one of the few calculations taught in math classes that shows up regularly in the media, and one that she often does in her head to make sense of the world around her. Despite this, she had been teaching percent change using textbook problems about…

  14. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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.

  17. Inert plug formation in the DDT of granular energetic materials

    SciTech Connect

    Son, S.F.; Asay, B.W.; Bdzil, J.B.

    1996-05-01

    A mechanism is proposed to explain the {open_quotes}plugs{close_quotes} that have been observed in deflagration-to-detonation transition (DDT) of granular explosives. Numerical simulations are performed that demonstrate the proposed mechanism. Observed trends are reproduced. {copyright} {ital 1996 American Institute of Physics.}

  18. 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.…

  19. Organochlorine residues in bats after a forest spraying with DDT

    USGS Publications Warehouse

    Henny, C.J.; Maser, C.; Whitaker, J.O.; Kaiser, T.E.

    1982-01-01

    Background levels of DDT and its metabolites (ZDDT) were extremely low or not detected in five species of forest-dwelling bats in northeastern Oregon, i.e., areas not sprayed with DDT in 1974. Other organochlorine pesticides were rarely found and no polychlotinated biphenyls (PCBs) were detected at any time during the study. Four of five species of bats showed significant changes in Z:DDT residues in, their carcasses following the single DDT spray application. Myotis californicus and M. volans showed the highest postspray carcass residues, 6.90 and 6.21 ppm (wet weight). respectively. Lasionycteris noctivagans and Eptesicus fuscus also showed an increase; however, M. evotis exhibited no significant postspray change. By 1977 (3 years postspray), residues declined and only M. californicus and M. volans contained levels that were significantly above those in the nonspray (control) area. We are uncertain if the elevated residue levels resulting from the DDTspray project adversely affected any of the bats. An attempt to relate bat catcass ZDDT residues to food habits, through analysis of stomach contents, yielded no clear relationships.

  20. Endocrine disruption mechanism of o,p'-DDT in mature male tilapia (Oreochromis niloticus)

    SciTech Connect

    Leanos-Castaneda, Olga . E-mail: olgalidia09@yahoo.com; Kraak, Glen van der; Rodriguez-Canul, Rossanna; Gold, G.

    2007-06-01

    The aim of the present study was to evaluate, in vivo, the potential of o,p'-DDT to disrupt the endocrine system of mature male tilapia. In particular, the possibility that o,p'-DDT effects were mediated directly via the estrogen receptor (ER). Compounds with known ability to bind to the ER were employed: estradiol to induce and tamoxifen to inhibit the estrogenic effects result of the activation of the ER. In addition, an aromatase inhibitor, 4-hydrxyandrostenedione (4-OHA), was used to assess the ability of o,p'-DDT to induce estrogenic effects in a surrounding of low estradiol concentration. The effects of estradiol and o,p'-DDT were studied alone or in the presence of tamoxifen or 4-OHA at the end of a 12-day period of exposure. The main endpoints measured were plasma alkaline-labile phosphorous (ALP; an indirect indicator of vitellogenin), estradiol, testosterone and o,p'-DDT. It was found that o,p'-DDT was able to induce the vitellogenesis (measured as plasma ALP increase) and decrease the circulating levels of estradiol and testosterone. Interestingly, o,p'-DDT kept this ability in whole fish with low concentrations of estradiol which would exclude endogenous estradiol as indirect mediator of the estrogenic effects induced by o,p'-DDT. In addition, the plasma concentration of o,p'-DDT, instead of that of estradiol, was closely related to the plasma ALP increase induced by o,p'-DDT. This indicates that o,p'-DDT could have directly activated the vitellogenesis. The antiestrogenic action of tamoxifen to inhibit the vitellogenesis and the decrease on plasma estradiol induced by o,p'-DDT indicates that o,p'-DDT can bind directly to the ER. In conclusion, this in vivo study shows that o,p'-DDT has the potential to disrupt the endocrine system and strongly supports that the estrogenic actions of o,p'-DDT involve binding to the ER.

  1. Endocrine disruption mechanism of o,p'-DDT in mature male tilapia (Oreochromis niloticus).

    PubMed

    Leaños-Castañeda, Olga; van der Kraak, Glen; Rodríguez-Canul, Rossanna; Gold, G

    2007-06-01

    The aim of the present study was to evaluate, in vivo, the potential of o,p'-DDT to disrupt the endocrine system of mature male tilapia. In particular, the possibility that o,p'-DDT effects were mediated directly via the estrogen receptor (ER). Compounds with known ability to bind to the ER were employed: estradiol to induce and tamoxifen to inhibit the estrogenic effects result of the activation of the ER. In addition, an aromatase inhibitor, 4-hydrxyandrostenedione (4-OHA), was used to assess the ability of o,p'-DDT to induce estrogenic effects in a surrounding of low estradiol concentration. The effects of estradiol and o,p'-DDT were studied alone or in the presence of tamoxifen or 4-OHA at the end of a 12-day period of exposure. The main endpoints measured were plasma alkaline-labile phosphorous (ALP; an indirect indicator of vitellogenin), estradiol, testosterone and o,p'-DDT. It was found that o,p'-DDT was able to induce the vitellogenesis (measured as plasma ALP increase) and decrease the circulating levels of estradiol and testosterone. Interestingly, o,p'-DDT kept this ability in whole fish with low concentrations of estradiol which would exclude endogenous estradiol as indirect mediator of the estrogenic effects induced by o,p'-DDT. In addition, the plasma concentration of o,p'-DDT, instead of that of estradiol, was closely related to the plasma ALP increase induced by o,p'-DDT. This indicates that o,p'-DDT could have directly activated the vitellogenesis. The antiestrogenic action of tamoxifen to inhibit the vitellogenesis and the decrease on plasma estradiol induced by o,p'-DDT indicates that o,p'-DDT can bind directly to the ER. In conclusion, this in vivo study shows that o,p'-DDT has the potential to disrupt the endocrine system and strongly supports that the estrogenic actions of o,p'-DDT involve binding to the ER.

  2. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  3. Metabolic and target-site mechanisms combine to confer strong DDT resistance in Anopheles gambiae.

    PubMed

    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.

  4. Parachuting cats and crushed eggs the controversy over the use of DDT to control malaria.

    PubMed

    O'Shaughnessy, Patrick T

    2008-11-01

    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.

  5. 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

  6. Breathing 100 percent oxygen compared with 50 percent oxygen:50 percent nitrogen reduces altitude-induced venous gas emboli

    NASA Technical Reports Server (NTRS)

    Webb, James T.; Pilmanis, Andrew A.

    1993-01-01

    The study investigates effects of 40 zero-prebreathe decompressions of male subjects to 8.3-6.8 psia for 6 h while they were breathing 100 percent oxygen and performing moderate exercise. No decompression sickness (DCS) symptoms were observed. Severe venous gas emboli (VGE) were not detected at 8.3 psia, but were present during 10, 20, and 40 percent of the exposures at 7.8, 7.3, and 6.8 psia, respectively. Zero-prebreathe decompression while breathing 100 percent oxygen results in significantly lower VGE and DCS risk levels than while breathing a 50:50 mix. It is shown that 7.3 psia EVA pressure suits with 100 percent oxygen should be safer than 8.3 psia suits with a 50:50 mix.

  7. DDT AND ITS METABOLITES IN BREAST MILK FROM THE MADEIRA RIVER BASIN IN THE AMAZON, BRAZIL

    PubMed Central

    Azeredo, Antonio; Torres, João P. M.; de Freitas Fonseca, Márlon; Britto, José Lailson; Bastos, Wanderley Rodrigues; Azevedo e Silva, Cláudio E.; Cavalcanti, Giselle; Meire, Rodrigo Ornellas; Sarcinelli, Paula N.; Claudio, Luz; Markowitz, Steven; Malm, Olaf

    2008-01-01

    Until the 1990’s the 1,1,1-trichloro-bis-2,2′-(4chlorophenyl) ethane (DDT) was sprayed in the walls of the house in the along the Madeira River basin, Brazilian Amazon, a region well known by its large number of malaria cases. In the 1910, the relate of Oswaldo Cruz about health conditions in Madeira River region describes the presence of malaria in rates ranging until 100% of infected people in some localities. Data available in the literature points to the DDT contamination in fishes captured in Madeira River region. Fish is the major source of dietary protein to this people. DDT tends to accumulate in lipid rich tissues being eliminated by different events, including lactation. Considering the importance of the breast milk to the children feeding, the associated risks of DDT exposure via breast milk intake to children must be assessed. This is the main objective of this work: to analyse the presence of the p,p′-DDT and its metabolites p,p′-DDE and p,p′-DDD in 69 human milk samples and to estimate the intake of DDT and its metabolite in terms of total DDT (total DDT = p,p′-DDE+ p,p′-DDD+ p,p′-DDT). All sample showed contamination with DDT and its metabolites ranging from 25.4 to 9361.9 ng of total DDT / g of lipid (median=369.6 ng of total DDT / g of lipid) and 8.7 % of the Estimated Daily Intake (EDI), in terms of total DDT, was higher than the Acceptable Daily Intake proposed by the WHO. Key words: DDT, breast milk, children, organochlorine pesticide, fish. PMID:18495200

  8. 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.

  9. High levels of DDT in breast milk: intake, risk, lactation duration, and involvement of gender.

    PubMed

    Bouwman, Hindrik; Kylin, Henrik; Sereda, Barbara; Bornman, Riana

    2012-11-01

    We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean ΣDDT levels in breast milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest ΣDDT level ever reported for breast milk from South Africa (140 mg/kg mf). Understanding the causes for these differences would be informative for exposure reduction intervention. The Provisional Tolerable Daily Intake (PTDI) for DDT by infants, and the Maximum Residue Limit (MRL) were significantly exceeded. DDT had no effect on duration of lactation. There were indications (not significant) from DDT-sprayed villages that first-born female infants drink milk with more ΣDDT than first-born male infants, and vice versa for multipara male and female infants, suggesting gender involvement on levels of DDT in breast milk - requiring further investigation.

  10. Melting glaciers: a probable source of DDT to the Antarctic marine ecosystem.

    PubMed

    Geisz, Heidi N; Dickhut, Rebecca M; Cochran, Michele A; Fraser, William R; Ducklow, Hugh W

    2008-06-01

    Persistent organic pollutants reach polar regions by long-range atmospheric transport and biomagnify through the food web accumulating in higher trophic level predators. We analyzed Adélie penguin (Pygoscelis adeliae) samples collected from 2004 to 2006 to evaluate current levels of sigmaDDT (p,p'-DDT + p,p'-DDE) in these birds, which are confined to Antarctica. Ratios of p,p'-DDT to p,p'-DDE in Adélie penguins have declined significantly since 1964 indicating current exposure to old rather than new sources of sigmaDDT. However, sigmaDDT has not declined in Adélie penguins from the Western Antarctic Peninsula for more than 30 years and the presence of p,p'-DDT in these birds indicates that there is a current source of DDT to the Antarctic marine food web. DDT has been banned or severely restricted since peak use in the 1970s, implicating glacier meltwater as a likely source for DDT contamination in coastal Antarctic seas. Our estimates indicate that 1-4 kg x y(-1) sigmaDDT are currently being released into coastal waters along the Western Antarctic Ice Sheet due to glacier ablation.

  11. DDT concentration in fish from the Tapajós River in the Amazon region, Brazil.

    PubMed

    Mendes, Rosivaldo de Alcântara; Lopes, Anna Sylmara da Costa; de Souza, Larissa Costa; Lima, Marcelo de Oliveira; Santos, Lourivaldo da Silva

    2016-06-01

    DDT and metabolites were measured in six species of fish collected from the Tapajós River in the village of Barreiras, near the town of Itaituba in the Brazilian Amazon region. The selected fish were the most consumed and economically important to the local people. DDT was used frequently in this region for malaria control. Fish samples were analyzed after extraction by microwave-assisted extraction in hexane/acetone (8:2, v/v) by gas chromatography with electron capture detector. Residues of op'-DDT and pp'-DDT and metabolites were detected, including pp'-DDE, pp'-DDD, op'-DDT, and op'-DDE, in 98% of the samples, with a greater abundance of pp'-DDT. Total DDT levels were 7.1-249.5 ng g(-1) wet weight (w.w). The DDE/DDT ratio was low, indicating recent exposure to DDT. The study area that may be related to generated waste used in public health campaigns to combat mosquitos (Anopheles spp.), still present in the Amazon environment, that transmit malaria. DDT levels and metabolites found in fish species do not present risks to human health because they are below acceptable limits for consumption.

  12. Enantiomeric fraction and isomeric composition to assess sources of DDT residues in soils.

    PubMed

    Bosch, Carme; Grimalt, Joan O; Fernández, Pilar

    2015-11-01

    Chiral pesticides such as o,p'-DDT can undergo enantioselective microbial degradation in soil. Hence, the enantiomeric fraction (EF) of o,p'-DDT was used as an approach to assess potential recent inputs of DDT in the lower part of the Ebro River basin (NE Spain), a region heavily impacted by agricultural and industrial activities, including a dicofol production and a chloro-alkali plants. The EFs of five out of nineteen soils were not different from the racemic value (0.505±0.010), confirming that the Ebro River and some of its tributaries, Segre and Cinca rivers, transported fresh DDT residues despite its ban in Spain during the 90 s. o,p'-DDT/p,p'-DDT ratios in soils suggest that recent use of technical DDT and/or DDT-contaminated dicofol may be responsible for the fresh DDT inputs in the Segre River, while in the Ebro River, they indicate a dominant contribution of technical DDT, likely related to the residues accumulated by the chloro-alkali plant discharges.

  13. 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.

  14. The transport of DDT from chylomicrons to adipocytes does not mimic triacylglycerol transport.

    PubMed

    Kohan, Alison B; Vandersall, Abbey E; Yang, Qing; Xu, Min; Jandacek, Ronald J; Tso, Patrick

    2013-02-01

    Despite being banned in the U.S., organochlorine toxins such as DDT are frequently detected in human adipose tissue. The main route of exposure is through the consumption of contaminated foods and subsequent intestinal packaging of DDT into chylomicrons. These chylomicrons, which also contain dietary triacylglycerol (TG), are delivered directly to peripheral tissues without first being metabolized by the liver. The physiological process by which these compounds are delivered from chylomicrons to adipose is not well understood, but is clinically relevant since it bypasses first-pass metabolism. Based on its highly lipophilic nature, it has been assumed that DDT is transferred to peripheral tissues similar to TG; however, this has not been measured. Here, we use the lymph fistula rat to isolate chylomicrons containing both DDT and TG. These chylomicrons are the in vivo DDT delivery vehicle. Using 3T3-L1 adipocytes, we investigated the rate at which DDT transfers from chylomicrons to adipocytes, and mediators of this process. This novel approach closely approximates the in vivo DDT exposure route. We show that: 1) DDT repartitions from chylomicrons to adipocytes, 2) this transport does not require hydrolysis of TG within the chylomicron, and is stimulated by the inhibition of LPL, 3) albumin does not inhibit DDT uptake, 4) DDT dissolved in DMSO does not appropriately mimic in vivo DDT transport; and most importantly, 5) DDT uptake from chylomicrons does not mimic the uptake of TG from the same particles. Understanding these factors is important for designing interventions for human populations exposed to DDT.

  15. DDT in fuel air mixtures at elevated temperatures and pressures

    NASA Astrophysics Data System (ADS)

    Card, J.; Rival, D.; Ciccarelli, G.

    2005-11-01

    An experimental study was carried out to investigate flame acceleration and deflagration-to-detonation transition (DDT) in fuel air mixtures at initial temperatures up to 573 K and pressures up to 2 atm. The fuels investigated include hydrogen, ethylene, acetylene and JP-10 aviation fuel. The experiments were performed in a 3.1-m long, 10-cm inner-diameter heated detonation tube equipped with equally spaced orifice plates. Ionization probes were used to measure the flame time-of-arrival from which the average flame velocity versus propagation distance could be obtained. The DDT composition limits and the distance required for the flame to transition to detonation were obtained from this flame velocity data. The correlation developed by Veser et al. (run-up distance to supersonic flames in obstacle-laden tubes. In the proceedings of the 4th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions, France (2002)) for the flame choking distance proved to work very well for correlating the detonation run-up distance measured in the present study. The only exception was for the hydrogen air data at elevated initial temperatures which tended to fall outside the scatter of the hydrocarbon mixture data. The DDT limits obtained at room temperature were found to follow the classical d/λ = 1 correlation, where d is the orifice plate diameter and λ is the detonation cell size. Deviations found for the high-temperature data could be attributed to the one-dimensional ZND detonation structure model used to predict the detonation cell size for the DDT limit mixtures. This simple model was used in place of actual experimental data not currently available.

  16. Allinea DDT as a Parallel Debugging Alternative to Totalview

    SciTech Connect

    Antypas, K.B.

    2007-03-05

    Totalview, from the Etnus Corporation, is a sophisticated and feature rich software debugger for parallel applications. As Totalview has gained in popularity and market share its pricing model has increased to the point where it is often prohibitively expensive for massively parallel supercomputers. Additionally, many of Totalview's advanced features are not used by members of the scientific computing community. For these reasons, supercomputing centers have begun to search for a basic parallel debugging tool which can be used as an alternative to Totalview. As the cost and complexity of Totalview has increased over the years, scientific computing centers have started searching for a viable parallel debugging alternative. DDT (Distributed Debugging Tool) from Allinea Software is a relatively new parallel debugging tool which aims to provide much of the same functionality as Totalview. This review outlines the basic features and limitations of DDT to determine if it can be a reasonable substitute for Totalview. DDT was tested on the NERSC platforms Bassi, Seaborg, Jacquard and Davinci with Fortran90, C, and C++ codes using MPI and OpenMP for parallelism.

  17. Anaerobic bioventing of unsaturated zone contaminated with DDT and DNT.

    PubMed

    Shah, J K; Sayles, G D; Suidan, M T; Mihopoulos, P; Kaskassian, S

    2001-01-01

    Initial degradation of highly chlorinated compounds and nitroaromatic compounds found in munition waste streams is accelerated under anaerobic conditions followed by aerobic treatment of the degradation products. The establishment of anaerobic environment in a vadose zone can be accomplished by feeding appropriate anaerobic gas mixture, i.e., "anaerobic bioventing". The gas mixture contains an electron donor for the reduction of these compounds. Lab scale study was conducted to evaluate potential of anaerobic bioventing for the treatment of an unsaturated zone contaminated with 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and 2,4-dinitrotoluene (DNT). Hydrogen was used as the electron donor. Using the soil columns innoculate with anaerobic microorganisms, it was observed that by feeding a gas mixture of 1% hydrogen, 1% carbon dioxide and nitrogen, methanogenic conditions were established and DDT was reductively dechlorinated. 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) accumulated as the intermediate product. The half life of DDT was calculated to be 8.5 months. DNT completely disappeared after six months of operation and no intermediates could be detected.

  18. Predicting Percent Body Fat from Circumference Measurements

    DTIC Science & Technology

    1993-01-01

    A268 695 DTIC ELECTE AUG 3 0 1993 dI I Public . MILITARY MEDICINE, 158, 1:026, 1993 A Predicting Percent Body Fat from Circumference Measurements LT...are required to meet percent Introduction body fat (%BF) standards as a condition of military service. Naval personnel who exceed standards for %BF...or 31-35.9% body fat (%BF), and with 22%BF or greater and women with 30%BF or greater. Val- obese as 26 or 36%BF or greater for men and women, respec

  19. Selection of surfactant in remediation of DDT-contaminated soil by comparison of surfactant effectiveness.

    PubMed

    Guo, Ping; Chen, Weiwei; Li, Yueming; Chen, Tao; Li, Linhui; Wang, Guanzhu

    2014-01-01

    With an aim to select the most appropriate surfactant for remediation of DDT-contaminated soil, the performance of nonionic surfactants Tween80, TX-100, and Brij35 and one anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in enhancement of DDT water solubility and desorption of DDT from contaminated soil and their adsorption onto soil and ecotoxicities were investigated in this study. Tween80 had the highest solubilizing and soil-washing ability for DDT among the four experimental surfactants. The adsorption loss of surfactants onto soil followed the order of TX-100 > Tween80 > Brij35 > SDBS. The ecotoxicity of Tween80 to ryegrass (Lolium perenne L.) was lowest. The overall performance considering about the above four aspects suggested that Tween80 should be selected for the remediation of DDT-contaminated soil, because Tween80 had the greatest solubilizing and soil-washing ability for DDT, less adsorption loss onto soil, and the lowest ecotoxicity in this experiment.

  20. 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

  1. Role of intestinal microflora in the degradation of DDT by rainbow trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, G.

    1968-01-01

    Though liver homogenates show apparent microsomal enzyme DDT-dehydrochlorinase activity, in the intact fish the intestinal microflora play a major role in DDT detoxication. Since the presence of this microflora in fish depends on the recent intake of food (12), the rate of detoxication and hence the toxicity of ingested DDT to the rainbow trout will probably depend somewhat on the available food supply.

  2. 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.

  3. 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.

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

    PubMed Central

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

    2016-01-01

    Background: 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. Objective: We hypothesized that perinatal DDT exposure causes hypertension in adult mice. Methods: 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. Results: 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. Conclusions: 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 PMID:27325568

  5. 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

  6. Effect of DDT, fauna and flooding on microsomal growth in soil.

    PubMed

    Tu, C M

    1981-01-01

    Laboratory experiments were conducted to determine the effect of DDT, fauna and flooding on microbial growth in a sandy loam. Results indicated that soil microorganisms can tolerate the presence of DDT. Earthworms singly or in combination with springtails affected the average population of fungi in the DDT-untreated samples and of aerobic bacteria in the DDT-treated soils. Soil animals did not appear to have any effect on the populations of anaerobic bacteria. However, waterlogging brought about a decrease in aerobic bacteria and fungal populations, and an increase in anaerobic bacteria in both soils.

  7. Cross-sectional study of a community with exceptional exposure to DDT

    SciTech Connect

    Kreiss, K.; Zack, M.M.; Kimbrough, R.D.; Needham, L.L.; Smrek, A.L.; Jones, B.T.

    1981-05-15

    The geometric mean level of total DDT in serum samples (76.2 ng/mL) from 499 persons living downstream from a defunct DDT-manufacturing plant was several times the national geometric mean (15.0 ng/mL). DDE isomers, metabolites of DDT, accounted for an average of 86.7% of total DDT. Total DDT levels increased with age, even when controlled for other independent variables also significantly associated with DDT: race, sex, fish consumption, years of residence, socioeconomic status, alcohol consumption, and serum triglyceride levels. Fish consumption, the second strongest determinant of DDT level, had one third the predictive power of age. Total DDT levels were not associated with specific illness or ill health. However, total DDT levels were positively associated with levels of serum cholesterol, triglyceride, and gamma-glutamyl transpeptidase. The finding that serum DDE levels increase with age suggests that no equilibrium in body burden has been reached or that pharmacokinetics or serum/adipose partition may vary with age.

  8. 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

  9. 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 DDT in the eggs of the Grey Heron Ardea cinerea. This suggests that the DDT we found in frogs may have contributed to DDT loadings higher in the food web. These findings, combined with other studies from this area, support the need to reduce and eventually move away from DDT in malaria control safely and sustainably.

  10. Glutathion S-transferase activity and DDT-susceptibility of Malaysian mosquitos.

    PubMed

    Lee, H L; Chong, W L

    1995-03-01

    Comparative DDT-susceptibility status and glutathion s-transferase (GST) activity of Malaysian Anopheles maculatus, Culex quinquefasciatus and Aedes aegypti was investigated to ascertain the role of this enzyme in DDT resistance. The standardised WHO dose-mortality bioassay tests were used to determine DDT susceptibility in these mosquitos, whilst GST microassay (Brogdon and Barber, 1990) was conducted to measure the activity of this enzyme in mosquito homogenate. It appeared that DDT susceptibility status of Malaysian mosquitos was not correlated with GST activity.

  11. Degradation and mineralization of DDT by the ectomycorrhizal fungi, Xerocomus chrysenteron.

    PubMed

    Huang, Yi; Wang, Jie

    2013-08-01

    One strain of ectomycorrhizal fungi, Xerocomus chrysenteron, had been investigated for its ability to degrade 1,1,1-trichloro-2,2-bis(4-chlorophe-nyl) ethane (DDT) by measuring unlabeled DDT and identifying its metabolites, and determining the mineralization of [(13)C]DDT in pure cultures. After 45d incubation, about 55% of the added DDT disappeared from the culture system, less than 5% remained in the nutrient solution, and about 44% was retained in the mycelium. Inoculation with mycelium enhanced the degradation of DDT in soil, and alleviated enrichment of DDT in plants. The metabolites identified by gas chromatography-mass spectrometry were 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (DDD), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), and 4,4'-dichlorobenzophenone (DBP). There were significant differences in the δ(13)C of released CO2 between [(13)C]DDT and DDT cultures, which indicated X. chrysenteron was able to mineralize DDT to CO2.

  12. Stratospheric Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

    1998-01-01

    Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses

  13. Studying DDT susceptibility at discriminating time interval focusing maximum limit of exposure time survived by DDT resistant Phlebotomus argentipes (Diptera: Psychodidae) - an investigatory report.

    PubMed

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

    2017-02-28

    Extensive application of routine insecticide i.e., Dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of Visceral leishmaniasis (VL) in India, had evoked the problem of resistance/ tolerance against DDT, eventually nullifying the DDT dependent strategies to handle the nuisance caused by them. Because tolerating an hour exposure of DDT is not so challenging for resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes trivial and futile task.Therefore, present bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes combat its effect 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 minutes and concluded that highly resistant sand flies can withstand up to 420 minutes of this insecticide exposure. Also, the Lethal time (LT) for female P. argentipes were observed to be higher than that of male suggesting its nature of being highly resistant to its toxicity. The result is supportive for monitoring the tolerance limit with respect to time and hence attribute towards an urgent need of change in rhetoric form of WHO protocol for susceptibility identification in resistant P. argentipes.

  14. 13 percent remain AIDS-free.

    PubMed

    1995-01-01

    Researchers predict that approximately thirteen percent of homosexual/bisexual men infected with HIV at an early age will be long-term survivors, remaining free of disease for more than twenty years. Researchers with the Multicenter AIDS Cohort Study based their predictions on data from the ongoing study of 1,809 HIV-positive men. Stable immune markers and no use of antiretrovirals were the criteria used to define long-term.

  15. A P450 gene associated with robust resistance to DDT in ciliated protozoan, Tetrahymena thermophila by efficient degradation.

    PubMed

    Feng, Lifang; Fu, Chengjie; Yuan, Dongxia; Miao, Wei

    2014-04-01

    Analysis of metabolic mechanisms of dichlorodiphenyltrichloroethane (DDT) accumulation and degradation in microorganisms, which could be used to reduce its hazard to higher organisms at the higher in the food chain, have not been investigated. Robust resistance to DDT (grows well in 256 mg/L DDT) and a surprising ability to degrade DDT (more than 70% DDT within 4h) were found in the ciliated protozoan Tetrahymena thermophila. A P450 gene (CYP5013C2) was found to respond specifically to DDT treatment. In the presence of 256 mg/L DDT, cells with overexpressing CYP5013C2 (p450-OE) grew faster and degraded DDT more efficiently than wild-type (WT) cells, while cells with CYP5013C2 partially knocked down (p450-KD) grew slower and exhibited reduced ability to degrade DDT compared to WT cells. Both dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were detected in cells after exposure to DDT, and the concentration of DDD in the p450-OE strain gradually decreased from 0.5 to 4h. Thus, we argue that this P450 gene (CYP5013C2), by efficiently degrading DDT to DDD, is associated with robust resistance to DDT in Tetrahymena, and that a strain overexpressing this gene has the potential to serve as bioreactor that degrades environmental DDT.

  16. ATP-binding cassette transporter enhances tolerance to DDT in Tetrahymena.

    PubMed

    Ning, YingZhi; Dang, Huai; Liu, GuangLong; Xiong, Jie; Yuan, DongXia; Feng, LiFang; Miao, Wei

    2015-03-01

    The reuse of dichlorodiphenyltrichloroethane (DDT) as an indoor residual spray was permitted by the World Health Organization in 2007, and approximately 14 countries still use DDT to control disease vectors. The extensive exposure of insects to DDT has resulted in the emergence of DDT resistance, especially in mosquitoes, and the mechanism for this resistance in mosquitoes has been widely reported. Spraying can also introduce DDT directly into surface water, and DDT can subsequently accumulate in microorganisms, but the mechanism for the resistance to DDT degradation in microorganisms is unclear. Using whole-genome microarray analysis, we detected an abcb15 gene that was up-regulated in a specific manner by DDT treatment in T. thermophile. The deduced ABCB15 peptide sequence had two transmembrane domains (TMDs) and two nucleotide-binding domains (NBDs) to form the structure TMD-NBD-TMD-NBD, and each NBD contained three conserved motifs: Walker-A, C-loop, and Walker-B, which indicated the T. thermophila abcb15 was a typical ABC transporter gene. The expression of ABCB15 fused with a C-terminal green fluorescent protein was found to be on the periphery of the cell, suggesting that ABCB15 was a membrane pump protein. In addition, cells with abcb15 partially knocked down (abcb15-KD) grew slower than wild-type cells in the presence of 256 mg L(-1) DDT, indicating the tolerance of abcb15-KD strain to DDT exposure was decreased. Thus, we suggest that in Tetrahymena, the membrane pump protein encoded by ABCT gene abcb15 can enhance the tolerance to DDT and protect cells from this exogenous toxin by efficiently pumping it to the extracellular space.

  17. The search for reliable aqueous solubility (Sw) and octanol-water partition coefficient (Kow) data for hydrophobic organic compounds; DDT and DDE as a case study

    USGS Publications Warehouse

    Pontolillo, James; Eganhouse, R.P.

    2001-01-01

    The accurate determination of an organic contaminant?s physico-chemical properties is essential for predicting its environmental impact and fate. Approximately 700 publications (1944?2001) were reviewed and all known aqueous solubilities (Sw) and octanol-water partition coefficients (Kow) for the organochlorine pesticide, DDT, and its persistent metabolite, DDE were compiled and examined. Two problems are evident with the available database: 1) egregious errors in reporting data and references, and 2) poor data quality and/or inadequate documentation of procedures. The published literature (particularly the collative literature such as compilation articles and handbooks) is characterized by a preponderance of unnecessary data duplication. Numerous data and citation errors are also present in the literature. The percentage of original Sw and Kow data in compilations has decreased with time, and in the most recent publications (1994?97) it composes only 6?26 percent of the reported data. The variability of original DDT/DDE Sw and Kow data spans 2?4 orders of magnitude, and there is little indication that the uncertainty in these properties has declined over the last 5 decades. A criteria-based evaluation of DDT/DDE Sw and Kow data sources shows that 95?100 percent of the database literature is of poor or unevaluatable quality. The accuracy and reliability of the vast majority of the data are unknown due to inadequate documentation of the methods of determination used by the authors. [For example, estimates of precision have been reported for only 20 percent of experimental Sw data and 10 percent of experimental Kow data.] Computational methods for estimating these parameters have been increasingly substituted for direct or indirect experimental determination despite the fact that the data used for model development and validation may be of unknown reliability. Because of the prevalence of errors, the lack of methodological documentation, and unsatisfactory data

  18. Sorption/desorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane(4,4'-DDT) on a sandy loam soil.

    PubMed

    Erdem, Ziya; Cutright, Teresa J

    2015-02-01

    1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane(4,4'-DDT) is a pesticide well-known for its negative health and environmental effects. Despite being banned by a majority of world countries more than 30 years ago, its persistence in the environment is a continuing problem even today. The objective of the study was the investigation of sorption/desorption behavior of 4,4'-DDT in sandy loam soil. The impact of contaminant concentration and age was observed with three different experiments. The sorption percentages at the end of the short time step (8 h) were 50 and 92 %, for initial concentrations 2.26 and 5.28 mg/L, respectively. When freshly spiked soil was subjected to a conventional sorption study, 82 to 99.6 % of the initial aqueous DDT concentrations were sorbed within 24 h. When modeled with a Freundlich isotherm, the log K f was found to be 3.62. After six consecutive 24 h desorption steps, 33 to 96.6 % still remained in the soil. This was more pronounced for soils that had been aged for 60 days. After seven consecutive 24 h desorption steps of aged soil, the percent remaining sorbed to the soil were 44, 64, and 77 %, for 25, 250, and 500 mg/kg, respectively. All results show that 4,4-DDT has a tendency of sorbing to the soil rapidly and showing resistance to desorption. When comparing desorption values, aged soils were seen to desorb less than non-aged soils. This result was attributed to stronger binding to soil with increased contact time.

  19. 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...

  20. Studies on the Mechanism of DDT Resistance in Culex pipiens fatigans

    PubMed Central

    Kalra, R. L.

    1970-01-01

    The mechanism of DDT resistance in Culex pipiens fatigans is poorly understood. Earlier studies indicated that the dehydrochlorination of DDT does not explain resistance in this species. Studies on the role of lipids as a mechanism of resistance included the estimation of lipid content and the determination of the proportions of different classes of lipids in the larvae of susceptible and resistant strains. There was no evidence of any correlation between the lipid content and DDT resistance in this species and the proportions of neutral lipids, phospholipids and fatty acids of different strains did not indicate any consistent correlation with DDT resistance. Within one strain, the larvae containing the higher amount of lipids were able to resist better the toxic effect of DDT. Analysis of fatty acids of the larvae that survived and died as a result of treatment with DDT did not reveal any difference. Neither p,p′-DDT nor o,p′-DDT at sublethal concentration affected the lipids of the larvae of susceptible and resistant strains. PMID:5310957

  1. 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.

  2. 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

  3. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    acetate, polymerized rapidly and produced some polymer film encapsulation of the aerosol droplets. A two-stage microcapsule generator was designed...encapsulating material, the generator also produced microcapsules of dibutyl phosphite in polyethylene, nitrocellulose, and natural rubber.

  4. Percent Agricultural Land Cover on Steep Slopes

    EPA Pesticide Factsheets

    Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type. High amounts of agriculture on steep slopes can increase the amount of soil erosion leading to increased sediment in surface water. Agricultural land cover on steep slopes (AGSL) is the percent of agriculture on slopes greater than or equal to 9%. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  5. Bioaugmentation of DDT-contaminated soil by dissemination of the catabolic plasmid pDOD.

    PubMed

    Gao, Chunming; Jin, Xiangxiang; Ren, Jingbei; Fang, Hua; Yu, Yunlong

    2015-01-01

    A plasmid transfer-mediated bioaugmentation method for the enhancement of dichlorodiphenyltrichloroethane (DDT) degradation in soil was developed using the catabolic plasmid pDOD from Sphingobacterium sp. D-6. The pDOD plasmid could be transferred to soil bacteria, such as members of Cellulomonas, to form DDT degraders and thus accelerate DDT degradation. The transfer efficiency of pDOD was affected by the donor, temperature, moisture, and soil type. Approximately 50.7% of the DDT in the contaminated field was removed 210 days after the application of Escherichia coli TG I (pDOD-gfp). The results suggested that seeding pDOD into soil is an effective bioaugmentation method for enhancing the degradation of DDT.

  6. 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.

  7. Lidar backscattering measurements of background stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Remsberg, E. E.; Northam, G. B.; Butler, C. F.

    1979-01-01

    A comparative lidar-dustsonde experiment was conducted in San Angelo, Texas, in May 1974 in order to estimate the uncertainties in stratospheric-aerosol backscatter for the NASA Langley 48-inch lidar system. The lidar calibration and data-analysis procedures are discussed. Results from the Texas experiment indicate random and systematic uncertainties of 35 and 63 percent, respectively, in backscatter from a background stratospheric-aerosol layer at 20 km.

  8. 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.

  9. Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes.

    PubMed

    Zhu, Zhi-qiang; Yang, Xiao-e; Wang, Kai; Huang, Hua-gang; Zhang, Xincheng; Fang, Hua; Li, Ting-qiang; Alva, A K; He, Zhen-li

    2012-10-15

    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 strategy for fields co-contaminated with cadmium (Cd), dichlorodiphenyltrichloroethane (DDT), and its metabolites 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethylene (DDE) and 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethane (DDD) (DDT, DDE, and DDD are collectively called DDs) using an identified Cd-hyperaccumulator plant Sedum alfredii (SA) and DDT-degrading microbes (DDT-1). Initially, inoculation with DDT-1 was shown to increase SA root biomass in a pot experiment. When SA was applied together with DDT-1, the levels of Cd and DDs in the co-contaminated soil decreased by 32.1-40.3% and 33.9-37.6%, respectively, in a pot experiment over 18 months compared to 3.25% and 3.76% decreases in soil Cd and DDs, respectively, in unplanted, untreated controls. A subsequent field study (18-month duration) in which the levels of Cd and DDs decreased by 31.1% and 53.6%, respectively, confirmed the beneficial results of this approach. This study demonstrates that the integrated bioremediation strategy is effective for the remediation of Cd-DDs co-contaminated soils.

  10. Reproductive and developmental effects of transovarian exposure to o,p'-DDT in Japanese quails.

    PubMed

    Kamata, Ryo; Shiraishi, Fujio; Takahashi, Shinji; Shimizu, Akira; Shiraishi, Hiroaki

    2009-04-01

    Avian species have the possible risk of embryonic exposure to persistent, lipophilic environmental contaminants, such as dichlorodiphenyltrichloroethane (DDT), by transfer of chemicals accumulated in mother birds to eggs. To model developmental and reproductive disorders of wild birds living in contaminated areas, we exposed Japanese quails in ovo to o,p'-DDT prior to incubation. A positive estrogenic substance diethylstilbestrol (DES; 1 and 10 ng/g of egg) and o,p'-DDT (1-100 microg/g of egg) were injected into the yolk before incubation. Treatment with o,p'-DDT (10 or 100 microg/g) but not with DES significantly reduced the hatchability of eggs. After sexual maturation, o,p'-DDT affected eggshell formation in female quails but had little influence on laying; high doses of o,p'-DDT significantly reduced eggshell strength, shell weight, and shell thickness, and several females treated with 100 microg o,p'-DDT/g laid eggs lacking shells. Diethylstilbestrol decreased egg production itself but had little effect on the eggshell. Both o,p'-DDT and DES caused dose-dependent shortening of the left oviduct and abnormal development of the right oviduct in females, while testis asymmetry was observed in males treated with a high dose of DES. In the uterus of the oviduct, the mRNAs for calcium-regulating factors osteopontin and calbindin D28K were reduced by both treatments, particularly that with o,p'-DDT. The results indicated that transovarian exposure to o,p'-DDT could bring about population declines in avian species through loss of fecundity caused by depression of hatchability and dysfunction of the reproductive tract.

  11. Assessment of DDT and DDE levels in soil, dust, and blood samples from Chihuahua, Mexico.

    PubMed

    Martínez, Fernando Díaz-Barriga; Trejo-Acevedo, Antonio; Betanzos, Angel F; Espinosa-Reyes, Guillermo; Alegría-Torres, Jorge Alejandro; Maldonado, Iván Nelinho Pérez

    2012-02-01

    The aim of this study was to assess levels of DDT and DDE in two environmental matrices (soil and dust) and to investigate the blood levels of these insecticides in exposed children living in a north Mexican state (Chihuahua) where DDT was sprayed several years ago during (1) health campaigns for the control of malaria and (2) agricultural activities. DDT and DDE were analyzed by gas chromatography/mass spectrometry. In general, lower levels were found in household outdoor samples. The levels in outdoor samples ranged from 0.001 to 0.788 mg/kg for DDT and from 0.001 to 0.642 mg/kg for DDE. The levels in indoor samples ranged from 0.001 to 15.47 mg/kg for DDT and from 0.001 to 1.063 mg/kg for DDE. Similar results to those found in indoor soil were found in dust, in which the levels ranged from 0.001 to 95.87 mg/kg for DDT and from 0.001 to 0.797 mg/kg for DDE. Moreover, blood levels showed that all of the communities studied had been exposed to DDT and/or DDE, indicating a general past or present exposure to DDT. It is important to note that the quotient DDT/DDE in all matrices was always >1. Whether the people living in our study area are at risk is an issue that deserves further analysis. However, applying precautionary principles, it is important to initiate a risk-reduction program to decrease exposure to DDT and its metabolites in people living in this area.

  12. Dieldrin and DDT: accumulation from water and food by lake trout (Salvelinus namaycush) in the laboratory

    USGS Publications Warehouse

    Reinert, Robert E.; Stone, Linda J.; Bergman, Harold L.

    1974-01-01

    In the laboratory we measured the amounts of dieldrin and p,p'DDT accumulated by fish from contaminated water and food to determine how fish from Lake Michigan accumulate high concentrations of these insecticides from an environment where the concentrations in water are generally less than 0.01 ppb. Eight groups of yearling lake trout (Salvelinus namaycush) were exposed to different combinations of dieldrin and p,p'DDT in water and food. Concentrations of dieldrin and p,p'DDT ranged from 0.006 to 0.010 ppb in water and from 1,700 to 2,300 ppb in food (Oregon moist pellets). After 152 days of exposure to insecticides in water, fish had accumulated an average of 478 ppb dieldrin or 352 ppb p,p'DDT. Fish exposed to dieldrin and p,p'DDT in food accumulated 470 and 648 ppb, respectively. However, it was difficult to determine exactly how much of either insecticide was accumulated from the food because trace amounts (0.003-0.004 ppb) had leached from food or feces. After exposure to the insecticide was terminated, fish eliminated dieldrin at a much faster rate than p,p'DDT. In fish exposed to a combination of dieldrin and p,p'DDT in water and then held for 125 days in uncontaminated water, the total amount of dieldrin (I?g) declined 89%, but the total amount of p,p'DDT remained unchanged. We used data from this study to estimate how much p,p'DDT adult Lake Michigan coho salmon (Oncorhynchus kisutch) accumulated from water and from food during a 104-day period (May-August 1968). The estimates suggest that during these months coho salmon accumulated most of the body burden of p,p'DDT from food.

  13. How I Love My 80 Percenters

    NASA Technical Reports Server (NTRS)

    Maturo, Anthony J.

    2002-01-01

    Don't ever take your support staff for granted. By support staff, I mean the people in personnel, logistics, and finance; the ones who can make things happen with a phone call or a signature, or by the same token frustrate you to no end by their inaction; these are people you must depend on. I've spent a lot of time thinking about how to cultivate relationships with my support staff that work to the advantage of both of us. The most important thing that have learned working with people, any people--and I will tell you how I learned this in a minute--is there are some folks you just can't motivate, so forget it, don't try; others you certainly can with a little psychology and some effort; and the best of the bunch, what I call the 80 percenters, you don't need to motivate because they're already on the team and performing beautifully. The ones you can't change are rocks. Face up to it, and just kick them out of your way. I have a reputation with the people who don't want to perform or be part of the team. They don't come near me. If someone's a rock, I pick up on it right away, and I will walk around him or her to find someone better. The ones who can be motivated I take time to nurture. I consider them my projects. A lot of times these wannabes are people who want to help but don't know how. Listen, you can work with them. Lots of people in organizations have the mindset that all that matters are the regulations. God forbid if you ever work outside those regulations. They've got one foot on that regulation and they're holding it tight like a baby holds a blanket. What you're looking for is that first sign that their minds are opening. Usually you hear it in their vocabulary. What used to sound like "We can't do that ... the regulations won't allow it ... we have never done this before," well, suddenly that changes to "We have options ... let's take a look at the options ... let me research this and get back to you." The 80 percenters you want to nurture too, but

  14. 18-percent efficient terrestrial silicon solar cells

    NASA Technical Reports Server (NTRS)

    Blakers, A. W.; Green, M. A.; Jiqun, S.; Keller, E. M.; Wenham, S. R.; Godfrey, R. B.; Szpitalak, T.; Willison, M. R.

    1984-01-01

    Silicon solar cells are described which operate at energy conversion efficiencies in excess of 18 percent under standard terrestrial test conditions (AM1.5, 100 mW/sq cm, 28 C). These are believed to be the most efficient silicon cells reported to date. The high efficiency is a result of the combination of high open-circuit voltage due to the careful attention paid to passivation of the top surface of the cell; high fill factors due to the high open-circuit voltage and low parasitic resistance losses; and high short-circuit current due to the use of shallow diffusions, a low grid coverage, and an optimized double-layer antireflection coating.

  15. DDT in northern pike (Esox lucius) from the Richelieu River, Québec, Canada, 1974-75.

    PubMed

    Boileau, S; Baril, M; Alary, J G

    1979-12-01

    Concentrations of DDT, TDE, DDE, and sigma DDT were determined in homogenized whole fish samples of 129 northern pike (Esox lucius). These fish were netted between June 1974 and June 1975 in the first 10 km of the Richelieu River flowing in Canadian territory. Two years after the banning of DDT, sigma DDT levels ranged from 0.2 ppm fresh body weight in two-year-old specimens to 1.5 ppm in a six-year-old pike. Residues increased greatly with age, and significant seasonal variations in the sigma DDT levels were found in five- and six-year-old pike.

  16. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  17. 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.

  18. 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

  19. Comparison study of the sensitivities of some indices of DDT exposure in human blood and urine

    SciTech Connect

    Nhachi, C.F.B.; Loewenson, R. )

    1989-10-01

    Although exposure to DDT (2,2-bis(p-chlorophenyl1)1,1,1,-trichloroethane) is not normally associated with fatality or chronic adverse effects to human life, it is a known hazard to the ecosystem. Blood levels of DDT and some of its derivatives have been used to assess extent of exposure or the body load of DDT in humans. In experimental studies, ingestion of DDT has been associated with reduced liver stores of vitamin A, and increased serum levels of vitamin A. The same study also revealed a significant correlation of vitamin A and DDE serum levels. Generally an increase in excreted 17-B-hydroxycortisone has been associated with DDT exposure. Increased excretion of 6-B-hydroxycortisol has been noted in workers who were involved in the formulation of DDT. The objective of this study was to compare the sensitivities of some indices of DDT exposure in humans. The indices which were compared are serum vitamin A and DDE levels and urinary 17-B-hydroxycortisol.

  20. 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.

  1. 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.

  2. 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.

  3. Effects of DDT on bird population of scrub forest

    USGS Publications Warehouse

    Robbins, C.S.; Stewart, R.E.

    1949-01-01

    An oil spray of DDT was applied at the rate of five pounds per acre to a 90-acre tract of 5-year-old scrub and sapling growth at Beltsville, Maryland. Bird population studies were carried on in a 30-acre plot at the center of the sprayed area, and in a 30-acre check area of the same habitat one-half mile away. Of the five commonest species in the sprayed area, the Maryland yellowthroat, prairie warbler, and house wren were reduced 80 per cent, and the red-eyed towhee was apparently reduced 35 per cent; while no appreciable change in the numbers of yellow-breasted chats was noted. The total decrease for the five commonest species, which represented 77 per cent of the original population, was 65 per cent.

  4. The lack of endocrine disrupting effects in catfish (Clarias gariepinus) from a DDT sprayed area.

    PubMed

    Brink, Kerry; van Vuren, Johan Jansen; Bornman, Riana

    2012-05-01

    The exposure and response of the catfish, Clarias gariepinus, was studied in male specimens collected in the vicinity of a DDT spraying programme to control malaria. Two sites were situated in the DDT sprayed areas and one site upstream from exposed areas, used as a reference site. The collected specimens were analysed for DDT bioaccumulation and the extent of associated effects. The concentration of all DDT metabolites including p,p'-and o,p'-forms of DDT, DDE and DDD, were measured in the adipose tissue, whilst the effects were measured using a range of biomarkers. This included assessing the effectiveness of plasma calcium, magnesium, zinc and alkali-labile phosphates (ALPs) as indirect measures of vitellogenin (VTG). Gonad condition was determined by calculating the gonadosomatic index (GSI) for each individual and comparing it with the gonad mass that were adjusted with Analysis of Covariance (ANCOVA). The presence of intersex in gonads was identified and the overall body condition determined using the condition factor (CF). Overall, none of the biomarkers showed significant change in the presence of high levels of DDT nor lindane, dieldrin and endosulfan II. Subtle responses in the plasma concentrations of calcium, ALP and gonad condition were evident in the catfish where DDT concentrations were highest, whilst no effects related to intersex and body condition were evident. Overall this study highlighted the tolerance of C. gariepinus to DDT contamination, the practical implications of using biomarkers in developing countries, and the need for further research into developing biomarkers for much needed biomonitoring programmes in areas where malarial control programmes continue to use DDT.

  5. 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

  6. 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.

  7. 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

  8. P,p-DDT and p,p'-DDE effects on egg production, eggshell thickness, and reproduction of Japanese quail.

    PubMed

    Davison, K L; Engebretson, K A; Cox, J H

    1976-03-01

    p,p' -DDT and p,p' -DDE were investigated for effects on egg production and eggshell thickness in Japanese quail. p,p' -DDT was examined for effects on hatchability and fertility. DDE was tested at 0, 2, 10, 40, and 200 ppm in the diet. No evidence suggested that DDE affected number of eggs laid, egg weight, or eggshell thickness at any level of DDE tested. DDT was tested at 1,2.5, 10 and 40 ppm in the diet. In one experiment, quail fed DDT at 40 ppm and caged in male-female pairs broke more eggs than quail caged similarly but fed lower amounts of DDT or than quail fed an equal amount of DDT but caged alone. DDT did not detectably reduce eggshell thickness, number of eggs laid, fertility, or hatchability. However, paired quail laid fewer eggs than did single quail in two experiments and laid eggs with thinner shells in one experiment.

  9. Percent area coverage through image analysis

    NASA Astrophysics Data System (ADS)

    Wong, Chung M.; Hong, Sung M.; Liu, De-Ling

    2016-09-01

    The notion of percent area coverage (PAC) has been used to characterize surface cleanliness levels in the spacecraft contamination control community. Due to the lack of detailed particle data, PAC has been conventionally calculated by multiplying the particle surface density in predetermined particle size bins by a set of coefficients per MIL-STD-1246C. In deriving the set of coefficients, the surface particle size distribution is assumed to follow a log-normal relation between particle density and particle size, while the cross-sectional area function is given as a combination of regular geometric shapes. For particles with irregular shapes, the cross-sectional area function cannot describe the true particle area and, therefore, may introduce error in the PAC calculation. Other errors may also be introduced by using the lognormal surface particle size distribution function that highly depends on the environmental cleanliness and cleaning process. In this paper, we present PAC measurements from silicon witness wafers that collected fallouts from a fabric material after vibration testing. PAC calculations were performed through analysis of microscope images and compare them to values derived through the MIL-STD-1246C method. Our results showed that the MIL-STD-1246C method does provide a reasonable upper bound to the PAC values determined through image analysis, in particular for PAC values below 0.1.

  10. Evaluation of the potential carcinogenicity of DDT (50-29-3). Final report

    SciTech Connect

    Not Available

    1988-06-01

    DDT is a probable human carcinogen, classified as weight-of-evidence Group B2 under the EPA Guidelines for Carcinogen Risk Assessment. Evidence on potential carcinogenicity from animal studies is Sufficient. and the evidence from human studies is Inadequate. The potency factor (F) for DDT is estimated to be 5.58 (mg/kg/day)(-1), placing it in potency group 2 according to the CAG's methodology for evaluating potential carcinogens. Combining the weight-of-evidence group and the potency group, DDT is assigned a MEDIUM hazard ranking.

  11. 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

  12. DDT inhibits the functional activation of murine macrophages and decreases resistance to infection by Mycobacterium microti.

    PubMed

    Nuñez G, María Andrea; Estrada, Iris; Calderon-Aranda, Emma S

    2002-06-05

    DDT is still widely used in several parts of the world to control malaria, typhoid and dengue vectors, even though its use was banned in many countries based on toxicity data in wild life species. DDT has been shown to have immunotoxic effects in mice and to increase susceptibility to intracellular pathogens such as Mycobacterium leprae. However, little is known about the mechanisms underlying this effect. Activated macrophages play an important defensive role against intracellular pathogens, therefore our objective was to evaluate the effect of in vitro exposure to technical grade DDT (a mixture of three forms: 1,1,1-thricloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT) (85%), o,p'-DDT (15%) and o,o'-DDT (trace amounts)), p,p'-DDT, 1,1-dicloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane on the functional activation of J774A.1 macrophages and their capability to limit growth of intracellular pathogens, using Mycobacterium microti as a model. We evaluated cytotoxicity and the effect on cell proliferation of 2.5, 5.0 and 10 microg/ml of DDT compounds. Functional macrophage activity (NO(*) and O(2)(-) production, and mRNA expression of TNF-alpha, IL-1beta and iNO synthase) and the ability of treated cells to limit infection by M. microti in IFN-gamma-activated macrophages were evaluated in cells exposed to 2.5 microg/ml of DDT compounds. Doses of 5 and 10 microg/ml induced direct cytotoxic effects precluding meaningful analysis of the above parameters, whereas 2.5 microg/ml of all DDT compounds inhibited macrophage activity and reduced their ability to limit the intracellular growth of M. microti without inducing cytotoxicity. Technical grade DDT and p,p'-DDE were the more potent compounds. Therefore, exposure to DDT compounds could represent an important risk for infection development by those intracellular pathogens against which NO(*) and/or O(2)(-) production represent the main immune protective mechanism.

  13. Influence of Cougar Reservoir Drawdown on Sediment and DDT Transport and Deposition in the McKenzie River Basin, Oregon, Water Years 2002-04

    USGS Publications Warehouse

    Anderson, Chauncey W.

    2007-01-01

    bags, was greatest downstream of Cougar and Blue River Reservoirs (1.0 and 1.2 percent of total sediments, respectively). Deposition was least in the high-energy, unregulated environments (about 0.25 percent) of the South Fork McKenzie River above Cougar Reservoir and in the mainstem above the South Fork, and intermediate near Vida, the most downstream site on the mainstem. DDT, applied throughout much of the upper McKenzie River drainage basin to control spruce budworm during the 1950s, was detected in the South Fork near Rainbow in the form of its metabolites DDD and DDE in fine sediment captured in the infiltration bags. DDE also was detected in infiltration bags deployed in the McKenzie River near Vida, downstream of the South Fork. All concentrations of DDD and DDE were less than the aquatic-life criterion for bed sediment. DDT species were not detected in water samples, including samples collected during large storms. The reservoir apparently acted as a trap for sediment and DDT throughout the course of its existence, facilitating degradation of the trapped DDT, and may have been a source for both during the construction period in 2002-05, but the lack of detections during storms indicates that DDT transport was small. Transport of detectable amounts of DDT likely was limited to periods of high suspended-sediment concentrations (greater than 75-100 milligrams per liter). Infiltration bags were deployed during August 2003-July 2004 and were a useful device for measuring fine-sediment deposition and for chemical analysis of the deposited material. Deposition of fine-grained sediment downstream of the flood-control dams may be reduced if bed-moving events can be periodically reintroduced to those reaches.

  14. FISH TISSUE RESIDUE-BASED WILDLIFE VALUES FOR PISCIVOUOUS WILDLIFE: CHLORDANE, DDT, DIELDRIN, HEXACHLOROBENZENE

    EPA Science Inventory

    Fish tissue residue-based wildlife values were derived for chlordane, DDT, dieldrin, endrin, hexachlorobenzene, mercury and PCBs. Piscivorous wildlife for which these benchmarks were derived include belted kingfisher, river otter and mink. Toxic endpoint selection, criteria for t...

  15. DDT vs. wildlife: Relationships between quantities ingested, toxic effects and tissue storage

    USGS Publications Warehouse

    DeWitt, J.B.; Derby, J.V.; Mangan, G.F.

    1955-01-01

    Symptoms appeared when quail and pheasants were fed diets containing 0.025-0.050% DDT. Symptoms appeared sooner as percentages increased. Young birds seemed more resistant than adults. Median lethal quantity for adult quail was about 1,200 mg./Kg. Young quail showed no ill-effects after ingesting 3,000 mg./Kg. during 10-week period. Adult pheasants died after ingesting 200-300 mg./Kg. Approximately 600 mg./Kg. were required to kill young pheasants. Quantities of DDT stored in tissues were not proportional to amounts administered or to duration of exposure, but were related to severity of symptoms. Concentration of DDT in breast muscles of birds killed by DDT was about 34 micrograms/Gm. in adult quail and 22 micrograms/Gm. in adult pheasants.

  16. Increased contraction frequency in rat uterine strips treated in vitro with o,p prime -DDT

    SciTech Connect

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

    1991-05-01

    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 the technical grade preparation) on pregnant rat uterine tissue.

  17. 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.

  18. Cost-comparison of DDT and alternative insecticides for malaria control.

    PubMed

    Walker, K

    2000-12-01

    In anti-malaria operations the use of DDT for indoor residual spraying has declined substantially over the past 30years, but this insecticide is still considered valuable for malaria control, mainly because of its low cost relative to alternative insecticides. Despite the development of resistance to DDT in some populations of malaria vector Anopheles mosquitoes (Diptera: Culicidae), DDT remains generally effective when used for house-spraying against most species of Anopheles, due to excitorepellency as well as insecticidal effects. A 1990 cost comparison by the World Health Organization (WHO) found DDT to be considerably less expensive than other insecticides, which cost 2 to 23 times more on the basis of cost per house per 6 months of control. To determine whether such a cost advantage still prevails for DDT, this paper compares recent price quotes from manufacturers and WHO suppliers for DDT and appropriate formulations of nine other insecticides (two carbamates, two organophosphates and five pyrethroids) commonly used for residual house-spraying in malaria control programmes. Based on these 'global' price quotes, detailed calculations show that DDT is still the least expensive insecticide on a cost per house basis, although the price appears to be rising as DDT production declines. At the same time, the prices of pyrethroids are declining, making some only slightly more expensive than DDT at low application dosages. Other costs, including operations (labour), transportation and human safety may also increase the price advantages of DDT and some pyrethroids vs. organophosphates and carbamates, although possible environmental impacts from DDT remain a concern. However, a global cost comparison may not realistically reflect local costs or effective application dosages at the country level. Recent data on insecticide prices paid by the health ministries of individual countries showed that prices of particular insecticides can vary substantially in the open market

  19. 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

  20. DDT and HCH, two discontinued organochlorine insecticides in the Great Lakes region: isomer trends and sources.

    PubMed

    Venier, Marta; Hites, Ronald A

    2014-08-01

    The uses of the insecticides 1,1'-(2,2,2-trichloroethylidene)bis[4-chlorobenzene] (p,p'-DDT) and γ-hexachlorocyclohexane (γ-HCH) have been discontinued for several years, but they are still consistently detected in air samples collected on the shores of the Great Lakes. Although the agricultural uses of DDT have been restricted in the United States since 1972, DDT continued to be used to manufacture the miticide, dicofol, up until 2011. The use of the technical HCH mixture in North America was restricted in the 1970s, when it was replaced by one of its purified conformers, γ-HCH, also known as lindane. In this study, we have focused on isomer-specific data to gain insights on the temporal trends and possible sources of these compounds. In particular, we calculated ratios of the concentrations of p,p'-DDE+p,p'-DDD versus the sum of the concentrations of the three p,p' isomers. These ratios are about the same at all five of our sampling sites and are about the same as observed globally. We also calculated the ratio of the concentrations of o,p'-DDT versus the sum of concentrations of o,p'-DDT+p,p'-DDT. This ratio has increased significantly at all five sites over the last 15-20 years. We suggest that dicofol, which contained about 11% o,p'-DDT, may now be a significant, additional source of DDT to the Great Lakes. The average ratio of the concentration of γ-HCH (lindane) versus the sum of the concentrations of γ-HCH+α-HCH did not vary significantly with time, but it did show an urban signature, suggesting that cities may be more important sources of these compounds than previously suspected.

  1. 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.

  2. Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.

    PubMed

    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.

  3. Residues of DDT, dieldrin, and heptachlor in earthworms during two years following application

    USGS Publications Warehouse

    Gish, C.D.; Hughes, D.L.

    1982-01-01

    Study was conducted at the Patuxent Wildlife Research Center in December 1963. Plots were treated with DDT, dieldrin, or heptachlor. Earthworms and soils were sampled from each plot when treated and 0.5, 1.2, 4, 6, 8, 10, 12, 16, 20 and 24 months thereafter. Samples were analyzed by gas chromatography for residues of aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, chlordane, BHC, DDT and DDE.

  4. Model ecosystem determination of the metabolic and environmental fate of tetrachloro-DDT

    SciTech Connect

    Cole, R.B.; Metcalf, R.L.

    1987-01-01

    A potential hazardous waste site investigation was conducted by the Environmental Protection Agency to determine whether ground water, surface water, or area soils and sediments were contaminated as a result of waster water discharges or improper solid waste disposal practices of a pesticide manufacturer. One of the compounds discharged into the environment was 1,1,1,2-tetrachloro-2,2-bis(p-chlorophenyl)ethane, commonly referred to as tetrachloro-DDT. Unlike a great many of the DDT analogs, tetrachloro-DDT has come under only limited scrutiny, mainly because it was dismissed as having poor insecticidal properties relative to DDT and other analogs. Its metabolism in ingesting organisms, and degradative pathways in the environment have consequently been left uncertain. This model ecosystem study was undertaken to examine the unanswered questions concerning the metabolic and environmental fate of tetrachloro-DDT. The relevance of this study pertains to disposal practices of pesticide manufacturers who use tetrachloro-DDT as a product precursor.

  5. Responses of laboratory exposed catfish (Clarias gariepinus) to environmentally relevant concentrations of p,p'-DDT.

    PubMed

    Brink, Kerry; van Vuren, Johan; Bornman, Riana

    2012-11-01

    Technical grade DDT is annually sprayed for malaria control in many under developed countries world wide. Despite the controversy surrounding the use of DDT, minimal research concerning the effects on indigenous fish species in these areas has been conducted. In this study, the objectives were to identify some of the effects of sprayed p,p'-DDT on the common African sharptooth catfish species (Clarias gariepinus) under laboratory conditions. The effects were assessed by exposing specimens to three environmentally relevant concentrations of p,p'-DDT (0.66, 1.36 and 2.72 μg/l) for 21 days and analysing a suite of biomarkers in the plasma, gonads and body morphometrics. The biomarkers were specifically selected based on their practicality in developing countries, which could potentially be utilised for continued monitoring, and included alkali-labile phosphate (ALP), calcium, magnesium and zinc as the indirect measures of vitellogenin, gonadosomatic index, gonad mass manipulated using analysis of covariance, and condition factor. The results showed no significant (p<0.05) dose-dependent changes in the plasma, gonads and body condition of C. gariepinus, indicating that these species were not responsive to the p,p'-DDT concentrations when exposed sub-chronically. This lack of a response suggested that mature C. gariepinus are tolerant to 21 days exposure of low levels of p,p'-DDT.

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

    SciTech Connect

    Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling; Gorman, Michael A.; Morton, Craig J.; Pyke, James; McConville, Malcolm J.; Bieri, Michael; Mok, Yee-Foong; Robin, Charles; Gooley, Paul R.; Parker, Michael W.; Batterham, Philip

    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 of 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.

  7. Assessment of the levels of DDT and DDE in soil and blood samples from Tabasco, Mexico.

    PubMed

    Torres-Dosal, Arturo; Martinez-Salinas, Rebeca Isabel; Hernandez-Benavides, Diego; Perez-Vazquez, Francisco Javier; Ilizaliturri-Hernandez, Cesar; Perez-Maldonado, Ivan Nelinho

    2012-12-01

    In Mexico, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was used until the year 2000, principally in agriculture and anti-paludal program health campaigns. The southeastern region of Mexico was an important area of malaria, and from 1957 DDT was applied indoors every 6 months, with a coverage of 2 g/m(2). The current study was performed in Tabasco, a Mexican state located in the southeastern region of Mexico. DDT and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (DDE) were analyzed by gas chromatography/mass spectrometry. In general, low levels were found in household outdoor samples; the levels of DDT ranged from not detectable to 0.048 mg/kg, and of DDE from 0.001 to 0.068 mg/kg. An important finding was that, in all communities where DDT in blood was analyzed, exposure to DDT was found, indicating both past and present exposure. Although the levels found in this study were lower than other studies in Mexico, there is a need to evaluate whether the people living in the study area are at risk.

  8. 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

  9. Effects of sublethal doses of DDT on the reproduction and susceptibility of Culex pipiens L.

    PubMed

    Zaghloul, T M; Brown, A W

    1968-01-01

    The effect of non-selecting doses of DDT on the induction of resistance was investigated in the house mosquito, Culex pipiens. Sublethal doses of DDT were applied to the adults in each generation, at levels which just fell short of causing mortality in these adults. A susceptible strain, a DDT-resistant strain, and a slightly DDT-tolerant strain were so treated for 6-7 generations.It was found that the treatment initially caused approximately 25% of the ovaries to degenerate, and reduced the proportion of females that fed and oviposited. This reduction in biotic potential became aggravated in successive generations of the DDT-resistant and DDT-tolerant strains, which failed to show any material increase in resistance level. In the susceptible strain, however, the biotic potential became enhanced, and considerable resistance was developed. It was concluded that the increase of resistance in this strain was due to hidden selection, of eggs in the ovary, and of females which failed to oviposit.

  10. Levels of dichloro-dyphenyl-trichloroethane (DDT) metabolites in maternal milk and their determinant factors.

    PubMed

    Torres-Arreola, L; López-Carrillo, L; Torres-Sánchez, L; Cebrián, M; Rueda, C; Reyes, R; López-Cervantes, M

    1999-01-01

    To document the levels and the determinants of dichloro-dyphenyl-trichloroethane (DDT) metabolites in maternal milk, we conducted a cohort study of 50 adult females who lived in Mexico City. We measured social and dietary characteristics via interview. Levels of DDT metabolites were determined by gas-liquid chromatography. The mean values (lipid milk basis) were 0.162 ppm p,p'-DDT; 0.138 ppm o,p'-DDT; and 0.594 ppm 2,2(bis)p-chlorophyenyl-1-1-dichloroethylene (DDE). The main determinants of DDT metabolites were maternal age, lifetime lactation, history of living in an agricultural area, and consumption of salted meat and fish. We estimated that 6.0% of the breast-fed babies had daily intakes of DDT above the level of 0.005 mg/kg d recommended by the World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO). Health-outcomes research among children is needed, and investigators should design or adjust current surveillance programs.

  11. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    materials determine the range of applicability of each method. A useful microencapsulation method, based on coagulation by inertial force was developed...The generation apparatus, consisting of two aerosol generators in series, was utilized to produce many kinds of microcapsules . A fluid energy mill...was found useful for the production of some microcapsules . The permeability of microcapsule films and the effect of exposure time and humidity were

  12. Storage stability of DDT water-dispersible powders*

    PubMed Central

    Pearce, George W.; Goette, Mary B.; Sedlak, Vincent A.

    1959-01-01

    The authors describe a study of the change in suspensibility of two series of 75% DDT water-dispersible powders during storage in simulated commercial packages at 27°C, 50°C and 65°C and as “shelf” samples at ambient temperatures. All the products tested in both series were made under the conditions of regular commercial production, and all those in the second series were prepared in 1954 under contract to the International Cooperation Administration (ICA) and according to ICA specifications. The results showed that: (a) a high initial suspensibility is no criterion of “shelf” life; (b) the suspensibility after the so-called “tropical storage pre-treatment” is no criterion of stability, except perhaps in the case of very poorly formulated products; (c) periodic observations, made over a period of a month or more, of the suspensibility of powders stored in commercial or simulated commercial packages at 50°C and 65°C will provide an indication as to the probable long-term stability of the products in question; and (d) it seems likely that a reasonable estimate of long-term storage stability at ambient temperatures could be obtained by subjecting the samples to high temperatures for a very short period. PMID:14431216

  13. Development of a laser ignited all secondary explosive DDT detonator

    SciTech Connect

    Woods, C.M.; Spangler, E.M.; Beckman, T.M.; Kramer, D.P.

    1992-09-01

    A hermetic, stand alone, laser-ignited deflagration-to-detonation transition (DDT) detonator has been developed. The detonator uses the secondary explosive HMX (cyclotetramethylenetetranitramine) and was originally developed for use with the US Navy`s Laser Initiated Transfer Energy subsystem (LITES). The design of the new detonator allows for its use with a variety of laser fire sets. A high density blend 6f 830 cm2/g HMX with 3% carbon black by weight was used for the ignition charge. Deflagration-to-detonation transition was achieved with a transition charge of undoped 830 cm2/g HMX. Using a 12-ms ND-YAG laser pulse coupled to the detonator via a 1-mm diameter optical fiber, the ignition threshold was determined to be approximately 30 mJ. Full detonating outputs were demonstrated by function testing in Navy detonation sensitivity fittings. Finally, the detonator was tested in several configurations with shielded mild detonating chord (SNMC) endrips to determine its capability for lighting transfer lines.

  14. Changes in Retinol-Binding Protein Concentrations and Thyroid Homeostasis with Nonoccupational Exposure to DDT

    PubMed Central

    Delport, Rhena; Bornman, Riana; MacIntyre, Una E.; Oosthuizen, Nicholette M.; Becker, Piet J.; Aneck-Hahn, Natalie H.; de Jager, Christiaan

    2011-01-01

    Background The insecticide dichlorodiphenyltrichloroethane (DDT) has been used for malaria vector control in the northern and eastern parts of the Vhembe District of Limpopo Province, South Africa, since 1945. Bioaccumulation of DDT raises concern because it reportedly affects thyroid function. Objective Our objective was to investigate the association between DDT uptake (as reflected in plasma concentrations) and thyroid homeostasis while considering related factors. Methods We compared dietary intake, serum retinol-binding protein (RBP), transthyretin (TTR) and albumin concentrations, and liver and thyroid function between cases with evidence of a body burden of DDT in the circulation (concentration of any DDT isomer ≥ 0.02 μg/g lipid; n = 278) and controls (concentration of all DDT isomers < 0.02 μg/g lipid; n = 40) in a cross-sectional study. Further analyses were performed to assess the relevance of changes in RBP status associated with DDT uptake. Results RBP concentrations below the reference range were more prevalent in cases (54% vs. 10% in controls; χ2 = 27.4; p < 0.001), which could not be explained by nutrient intake. We observed significantly lower thyroid hormone concentrations among cases (p ≤ 0.01). We also observed a significant linear trend for serum concentrations of free thyroxine and free triiodothyronine (p < 0.001) and a significant quadratic trend for serum thyroid-stimulating hormone (p = 0.025) and TTR (p < 0.001) across the control group and case groups with normal and relatively low RBP concentrations. Relatively low RBP concentrations were associated with significantly higher DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) isomer concentrations and with a higher DDE/DDT ratio (p ≤ 0.01), which signifies long-term exposure. Inadequate intake of vitamin A and zinc were observed in 84% and 58%, respectively, of the total study population. Conclusion RBP concentrations appear to decrease in the presence of long-term DDT

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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 ...

  17. The dawn of DDT and its experimental use by the Rockefeller Foundation in Mexico, 1943-1952.

    PubMed

    Stapleton, D H

    1998-06-01

    The Rockefeller Foundation played an important early role in promoting the use of DDT for malaria control. During World War II the Foundation helped test DDT in the United States. North Africa and Italy. From 1945 to 1952 the Foundation carried out an experimental anti-malaria program in Mexico as part of its global mission to diffuse knowledge of how to control malaria-bearing mosquitoes with DDT.

  18. 48 CFR 1852.219-76 - NASA 8 percent goal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false NASA 8 percent goal. 1852... 1852.219-76 NASA 8 percent goal. As prescribed in 1819.7003 insert the following clause: NASA 8 Percent... and daily business operations are controlled by one or more women. (b) The NASA Administrator...

  19. 48 CFR 1852.219-76 - NASA 8 percent goal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false NASA 8 percent goal. 1852... 1852.219-76 NASA 8 percent goal. As prescribed in 1819.7003 insert the following clause: NASA 8 Percent... and daily business operations are controlled by one or more women. (b) The NASA Administrator...

  20. 48 CFR 1852.219-76 - NASA 8 percent goal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false NASA 8 percent goal. 1852... 1852.219-76 NASA 8 percent goal. As prescribed in 1819.7003 insert the following clause: NASA 8 Percent... and daily business operations are controlled by one or more women. (b) The NASA Administrator...

  1. 48 CFR 1852.219-76 - NASA 8 percent goal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false NASA 8 percent goal. 1852... 1852.219-76 NASA 8 percent goal. As prescribed in 1819.7003 insert the following clause: NASA 8 Percent... and daily business operations are controlled by one or more women. (b) The NASA Administrator...

  2. 48 CFR 1852.219-76 - NASA 8 percent goal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true NASA 8 percent goal. 1852... 1852.219-76 NASA 8 percent goal. As prescribed in 1819.7003 insert the following clause: NASA 8 Percent... and daily business operations are controlled by one or more women. (b) The NASA Administrator...

  3. Comparative use of bendiocarb and DDT to control Anopheles pseudopunctipennis in a malarious area of Mexico.

    PubMed

    Loyola, E G; Vaca, M A; Bown, D N; Pérez, E; Rodriguez, M H

    1991-04-01

    The state of Sinaloa has one of the highest and most persistent malaria transmission levels in Mexico. Due to this situation, with resistance of the vector Anopheles pseudopunctipennis Theobald to DDT, the carbamate insecticide bendiocarb was evaluated as an alternative to DDT for residual house-spraying in village-scale trials during 1985-87. Application rates of the active ingredient per square metre of sprayable surface (ai/m2) were 0.4 g bendiocarb 80% wettable powder (80WP) and 2 g DDT 75% WP. Both insecticides failed to control mosquito populations. Human-bait mosquito densities were not altered as a result of insecticide spraying and human-bait collected mosquito mortality rates were low, suggesting little pre-biting insecticide contact due to avoidance or insufficient resting time indoors. Lower densities of indoor-resting mosquitoes were observed with DDT as opposed to bendiocarb treated houses. Anopheline mortality was higher (98-100%) when exposed for 1 h to 1% bendiocarb in standard WHO susceptibility tests and wall bioassays. Mortality-rates of 15-48% due to 1 h exposure to 4% DDT indicated that this insecticide may continue to be partially effective. House curtain and mark-recapture mosquito studies indicated that DDT produced higher excito-repellency than bendiocarb, as reflected by more mosquito landings but lower feeding rates, shorter resting period and earlier exit time from DDT sprayed houses. In the absence of insecticide, more than 50% of blood-fed An.pseudopunctipennis females exited from houses within 2-4 h of release, showing exophilic behaviour. The outdoor/indoor density ratio indicated that the majority were exophagic. These behavioural characteristics limit the usefulness of any residual insecticide against An.pseudopunctipennis.

  4. 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.

  5. 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.

  6. Cycling of DDT in the global environment 1950-2002: World ocean returns the pollutant

    NASA Astrophysics Data System (ADS)

    Stemmler, Irene; Lammel, Gerhard

    2009-12-01

    The global distribution and fate of the insecticide DDT was modeled for the first time using a spatially resolved global multicompartment chemistry-transport model comprising a 3D coupled atmosphere and ocean GCM, coupled to 2D vegetation surfaces and top soils. DDT enters the model environment as a pesticide in agriculture only. Final sinks of DDT in the total environment are degradation in air (hydroxyl radical reaction), on vegetation surfaces, in ocean sediments and soils. The process resolution of the ocean compartment, i.e., either a fixed or variable size and sinking velocity of suspended particles, has almost no effect on the large-scale cycling and fate of DDT. The residence times in various ocean basins were declining but varied regionally. The global ocean absorbed until 1977 and since then has been losing DDT, while large sea areas are still accumulating the pollutant. The main sink is volatilization to the atmosphere. In 1990, the year when emissions ceased, 292 kt of DDT were deposited to the global ocean, 301 kt were volatilized, and 41 kt were exported from the surface layer to the deeper levels. The sea region that has been representing the most significant (secondary) DDT source is the western N Atlantic (Gulf stream and N Atlantic Drift regions). It has been a source since approximately 1970. Also large parts of the tropical ocean and the southern mid-latitude ocean have turned net volatilizational (i.e., volatilization flux > deposition flux) during the 1980s. Despite the emissions migrating southward as a consequence of substance ban in mid latitudes, the geographic distribution of the contaminant (and, hence, environmental exposure) has been migrating steadily northward since the 1960s.

  7. Interactions of gonadal steroids and pesticides (DDT, DDE) on gonaduct growth in larval tiger salamanders, Ambystoma tigrinum.

    PubMed

    Clark, E J; Norris, D O; Jones, R E

    1998-01-01

    In view of the current worldwide decline in amphibian populations, exploratory studies are needed to assess the potential for environmental contaminants to act as endocrine disrupters of the amphibian reproductive system. The present study investigated the effects of DDT dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) on the development of amphibian gonaducts. Larval male and female tiger salamanders (Ambystoma tigrinum), with immature gonads, were immersed in a sublethal solution of p,p'-DDE or technical-grade DDT (80% p,p'-DDT and 20% o,p'-DDT). Additionally, larvae were injected with the steroid hormones estradiol or dihydrotestosterone (DHT). Morphometrics were used to analyze the effects and interactions of steroid and pesticide treatments on larval gonaducts. Estradiol and DHT stimulated cell proliferation and hypertrophy of the müllerian duct epithelium in both sexes. Wolffian duct epithelium, however, was stimulated only by DHT treatment. The pesticide DDT antagonized the estrogenic actions of the steroid treatments, and p,p'-DDE acted as an estrogen on the müllerian ducts of females only. The müllerian ducts of males, and the wolffian ducts of both sexes, were unaffected by DDT or DDE alone. While confirming the previously reported estrogenic actions of estradiol and DHT on urodelean gonaducts, the results contradict the expected estrogenic actions of DDT and antiandrogenic actions of p,p'-DDE. Instead, in A. tigrinum, technical-grade DDT had an antiestrogenic action and p,p'-DDE an estrogenic action.

  8. Distinct mechanisms of endocrine disruption of DDT-related pesticides toward estrogen receptor α and estrogen-related receptor γ.

    PubMed

    Zhuang, Shulin; Zhang, Jing; Wen, Yuezhong; Zhang, Chunlong; Liu, Weiping

    2012-11-01

    Dichlorodiphenyltrichloroethane (DDT) is ubiquitous in the environment, and the exposure to DDT and its related pesticides has long been linked to endocrine disruption. The mechanism of endocrine disruption toward targeted receptors, however, remains unclear. Probing the molecular recognition of DDT analogs by targeted receptors at the atomic level is critical for deciphering this mechanism. Molecular dynamics (MD) simulations were applied to probe the molecular recognition process of DDT and its five analogs, including dichlordiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), methoxychlor (MXC), p,p'-hydroxy-DDT (HPTE), and dicofol by human estrogen receptor (ER) α and human ER-related receptor (ERR) γ. Van der Waals interactions mainly drive the interactions of DDT analogs with ERα ligand-binding domain (LBD) and ERRγ LBD. Minor structural changes of DDT analogs in the number and position of chlorine and phenolic hydroxyl moiety cause differences in binding modes through aromatic stacking and hydrogen bonding and thus affect differently conformational changes of ERα LBD and ERRγ LBD. The binding of DDT analogs affects the helix 12 orientation of ERα LBD but causes no rearrangement of helix 12 of ERRγ LBD. These results extend our understanding of how DDT analogs exert their estrogen-disrupting effects toward different receptors via multiple mechanisms.

  9. 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.

  10. 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.

  11. 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.

  12. Effect of organic matter additions on uptake of weathered DDT by Cucurbita pepo ssp. pepo cv. Howden.

    PubMed

    Lunney, Alissa I; Rutter, Allison; Zeeb, Barbara A

    2010-01-01

    Greenhouse studies were conducted to assess the impact of organic matter additions on plant uptake of DDT [2,2-bis(chlorophenyl)-1,1,1-trichloroethane] from weathered soil. Cucurbita pepo ssp. pepo cv. Howden pumpkins were grown in 100 g of DDT contaminated soil ([DDT] - 1100 ng/g) mixed with equal volumes of either clean soil, perlite, vermiculite, peat, potting soil, or granular activated carbon (GAC) to give total organic carbon contents of 2.4%, 2.5%, 2.6%, 11.5%, 12.2%, and 27.3%, respectively. As in other studies, root DDT concentrations were significantly lower in soils with high organic matter. Root bioaccumulation factors (BAF = [DDT]root/[DDT]soil) approximated this trend. Root concentrations correlated with organic matter concentrations and not with soil DDT concentrations. Conversely, shoot DDT concentrations, shoot BAFs and translocation factors (TLF = BAF(shoot)/BAF(root)) were not significantly different between treatment groups, except for plants grown in GAC/DDT soil. This suggests that amendments with a range of organic matter contents may be added to improve soil conditions at industrial sites without significant adverse effects on phytoextraction potential of C. pepo ssp. pepo.

  13. Guidance on Compatibility of UST Systems with Ethanol Blends Greater Than 10 Percent and Biodiesel Blends Greater Than 20 Percent

    EPA Pesticide Factsheets

    EPA guidance on complying with the federal compatibility requirement for underground storage tank (UST) systems storing gasoline containing greater than 10 percent ethanol or diesel containing greater than 20 percent biodiesel.

  14. Impact of aerosol size representation on modeling aerosol-cloud interactions

    DOE PAGES

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; ...

    2002-11-07

    In this study, we use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach.more » The modal approach with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

  15. Impact of aerosol size representation on modeling aerosol-cloud interactions

    SciTech Connect

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; Abdul-Razzak, H.

    2002-11-07

    In this study, we use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach. The modal approach with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).

  16. DDT (2,2,bis(p-chlorophenyl) 1,1,1-trichloroethane) induced structural changes in adrenal glands of rats

    SciTech Connect

    Chowdhury, A.R.; Gautam, A.K.; Venkatakrishna-Bhatt, H. )

    1990-08-01

    Oldest chlorinated hydrocarbon insecticide, DDT was used widely to control pest and vector borne diseases in developing countries. Malaria and vector borne diseases can be econometrically controlled by DDT. Chronic and acute exposures to DDT result in systemic disorders in human as well as this confirmed in animals. Experimental study revealed that DDT caused the structural and functional changes in thyroid and reproductive system. The effects of DDT on adrenal glands are not well documented. Therefore this experimental investigation was undertaken to evaluate the histomorphological changes of adrenal gland after the treatment with DDT in rats.

  17. 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

  18. DDT contamination of benthic macroinvertebrates and sediments from tributaries of Wheeler Reservoir, Alabama.

    PubMed

    Webber, E C; Bayne, D R; Seesock, W C

    1989-09-01

    Residues of DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) were measured quarterly during 1983-84 in bottom sediments and benthic macroinvertebrates from heavily contaminated sections of Huntsville Spring Branch (HSB) and Indian Creek (IC), backwater streams on Wheeler Reservoir (Alabama). Bottom muds from both channel and overbank locations contained mean concentrations of DDTR (DDT and its metabolites) ranging from 12 to 2,730 ppm (dry weight). Sediment DDTR were highest in HSB at stations closest to the original DDT source. Stations in IC, downstream from HSB, had progressively lower DDTR as distance from the DDT source increased. Macroinvertebrate DDTR measured from several stations suggested bioaccumulation of residues mainly through food webs; however, at the most contaminated locations, substrate and mode of life appeared to override trophic level effects in determining DDTR in the benthos. There is apparently an upper limit to the amount of DDTR these organisms usually accumulate. For example, detritivore DDTR from channel sediments at two stations just downstream from the DDT source averaged 125.1 and 157.9 ppm, respectively, although sediment DDTR at these two sites averaged 2,730 ppm and 96 ppm, respectively. Benthic macroinvertebrates in the highly contaminated sediments of HSB and IC apparently acquire DDTR from water, sediments, and food.

  19. Flame acceleration and DDT in channels with obstacles: Effect of obstacle spacing

    SciTech Connect

    Gamezo, Vadim N.; Oran, Elaine S.; Ogawa, Takanobu

    2008-10-15

    We study flame acceleration and deflagration-to-detonation transition (DDT) in obstructed channels using 2D reactive Navier-Stokes numerical simulations. The energy release rate for the stoichiometric hydrogen-air mixture is modeled by one-step Arrhenius kinetics. Computations performed for channels with symmetrical and staggered obstacle configurations show two main effects of obstacle spacing S. First, more obstacles per unit length create more perturbations that increase the flame surface area more quickly, and therefore the flame speed grows faster. Second, DDT occurs more easily when the obstacle spacing is large enough for Mach stems to form between obstacles. These two effects are responsible for three different regimes of flame acceleration and DDT observed in simulations: (1) Detonation is ignited when a Mach stem formed by the diffracting shock reflecting from the side wall collides with an obstacle, (2) Mach stems do not form, and the detonation is not ignited, and (3) Mach stems do not form, but the leading shock becomes strong enough to ignite a detonation by direct collision with the top of an obstacle. Regime 3 is observed for small S and involves multiple isolated detonations that appear between obstacles and play a key role in final stages of flame and shock acceleration. For Regime 1 and staggered obstacle configurations, we observe resonance phenomena that significantly reduce the DDT time when S/2 is comparable to the channel width. Effects of imposed symmetry and stochasticity on DDT phenomena are also considered. (author)

  20. Impact of environmental DDT concentrations on gill adaptation to increased salinity in the tilapia Sarotherodon melanotheron.

    PubMed

    Riou, Virginie; Ndiaye, Awa; Budzinski, Hélène; Dugué, Rémi; Le Ménach, Karyn; Combes, Yan; Bossus, Maryline; Durand, Jean-Dominique; Charmantier, Guy; Lorin-Nebel, Catherine

    2012-06-01

    Estuaries of tropical developing countries suffering from severe droughts induced by climate change are habitats to fish, which face drastic salinity variations and the contact with pollutants. The Western Africa tilapia Sarotherodon melanotheron is highly resistant to hypersalinity, but the effect of human-released xenobiotics on its adaptation is barely known. Controlled experiments were conducted to observe S. melanotheron gill adaptation to abrupt salinity variations in the presence of waterborne DDT, at concentrations detected in their natural habitat. The gills appeared as an important site of DDT conversion to DDD and/or depuration. A 12-days DDT exposure resulted in decreased gill epithelium thickness at all salinities (from fresh- to hypersaline-water), and the structure of gills from freshwater fish was particularly altered, relative to controls. No unbalance in tilapia blood osmolality was observed following DDT exposure, which however caused a decrease in branchial Na(+)-K(+)-ATPase (NKA) activity. Gill cellular NKA expression was reduced in salt-water, together with the expression of the CFTR chloride channel in hypersaline water. Although S. melanotheron seems very resistant (especially in seawater) to short-term waterborne DDT contamination, the resulting alterations of the gill tissue, cells and enzymes might affect longer term respiration, toxicant depuration and/or osmoregulation in highly fluctuating salinities.

  1. Population characteristics of young African women influencing prenatal exposure to DDT (Manhiça, Mozambique).

    PubMed

    Manaca, Maria N; Grimalt, Joan O; Sunyer, Jordi; Guinovart, Caterina; Sacarlal, Jahit; Menendez, Clara; Alonso, Pedro L; Dobaño, Carlota

    2013-05-01

    The concentrations of dichlorodiphenyltrichloroethane (DDT) compounds in cord blood of 214 children born between 2003 and 2006 in Manhiça (Mozambique) have been determined. In this time interval, corresponding to the period before DDT reintroduction for indoor residual spraying, the observed values averaged 0.8 and 0.4 ng/ml for 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) and 4,4'-DDT, respectively, and were similar to those found in western countries. However, the 4,4'-DDT/4,4'-DDE ratio was high indicating that the inputs of these compounds arriving to children in utero originated from recent uses of the insecticide. The strongest factor affecting DDT concentration was parity. A well-defined decreasing concentration trend was observed for the cord blood concentrations in the period of study. The trend was also observed for multiparae and primiparae mothers independently. Children from multiparae women showed much lower concentrations than primiparae women. Children from mothers with secondary school level exhibited lower concentrations of these pesticides than mothers with lower degree of education.

  2. Oil-in-water microemulsions enhance the biodegradation of DDT by Phanerochaete chrysosporium.

    PubMed

    Zheng, Guanyu; Selvam, Ammaiyappan; Wong, Jonathan W C

    2012-12-01

    A novel approach was developed using oil-in-water (O/W) microemulsions formed with non-ionic surfactant, cosurfactant (1-pentanol) and linseed oil, at the cosurfactant to surfactant ratio (C/S ratio, w/w) of 1:3 and oil to surfactant ratio (O/S ratio, w/w) of 1:10, to enhance the biodegradation of DDT by the white rot fungus Phanerochaete chrysosporium. Results showed that microemulsions formed with Tween 80 effectively enhanced the biodegradation of DDT by P. chrysosporium and the enhancement was about two times that of Tween 80 solution, while microemulsion formed with Triton X-100 exhibited negative effect. Further studies revealed that microemulsion formed with Tween 80 enhanced the biodegradation of DDT through transporting DDT from crystalline phase to mycelium as well as their positive effect on the growth of P. chrysosporium; of these, the former is likely the most important and pre-requisite for the biodegradation of DDT by P. chrysosporium.

  3. 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.

  4. Cooperative actions to achieve malaria control without the use of DDT.

    PubMed

    Chanon, Keith E; Méndez-Galván, Jorge F; Galindo-Jaramillo, Jose Manuel; Olguín-Bernal, Hector; Borja-Aburto, Victor H

    2003-08-01

    The success of regional networks to provide incentives and mechanisms for sharing information is illustrated through the North American Regional Action Plan on DDT (NARAP). This NARAP was designed to reduce human and environmental exposure to DDT and its metabolites in North America through cooperative efforts. The increasing role of environmental concerns in the planning and design of Mexico's DDT phase-out program motivated the Mexican Ministry of Health to undertake an alternative program for malaria control maximizing community participation without negatively affecting human and ecosystem health. This program relies on: 1) elimination of parasites in people, 2) improvement of personal and household hygiene, and 3) use of environmental management practices to eliminate mosquito breeding sites. This new strategy resulted in the elimination of DDT for malaria control in Mexico in the year 2000. While malaria and its corresponding vectors show considerable variability within a single country and certainly around the globe, the case example of Mexico provides a methodology for developing alternatives to DDT.

  5. Persistence in earthworms and potential hazards to birds of soil applied DDT, dieldrin, and heptachlor

    USGS Publications Warehouse

    Beyer, W.N.; Gish, C.D.

    1980-01-01

    (1) DDT, dieldrin, and heptachlor were each applied to separate replicate plots in a hay field at 0.6, 2.2, or 9.0 kg/ha. For 11 yr thereafter, soil and earthworms were analysed for residues. (2) The average ratios of residues in earthworms (dry weight) to residues in soil (dry weight) were: total DDT, 5; dieldrin, 8; and heptachlor epoxide, 10. The average time for the initial residues in soil to be reduced by 50% were: total DDT, 3.2 yr; dieldrin, 5.1 yr; and heptachlor epoxide, 3.2 yr. The corresponding times for residues in earthworms were: total DDT, 3.2 yr; dieldrin, 2.6 yr; and heptachlor epoxide, 3.0 yr. (3) DDE was most persistent, and in plots treated at 9.0 kg/ha its concentration remained constant at about 0.4 ppm in soil and about 7 ppm in earthworms. (4) When applied at 9.0 kg/ha, DDT accumulated in earthworms to concentrations (32 ppm) which laboratory studies have shown to be hazardous to some sensitive bird species. When heptachlor was applied at 2.2 or 9.0 kg/ha, heptachlor epoxide in earthworms reached concentrations (8 ppm) potentially hazardous to woodcock. Dieldrin remained at potentially hazardous concentrations (8 ppm) for 3 yr in plots treated with 2.2 kg/ha and for 11 yr in plots treated with 9.0 kg/ha.

  6. Global Atmospheric Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

    2012-01-01

    Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

  7. Behavioral response of Anopheles darlingi to DDT-sprayed house walls in Amazonia.

    PubMed

    Roberts, D R; Alecrim, W D

    1991-01-01

    The behavioral response of Anopheles darlingi females to spraying of house walls with DDT was studied along the Ituxi River in Amazonas, Brazil, using a house sprayed with 2 g DDT per square meter of wall surface and an untreated house serving as a control. It was found that hardly any An. darlingi females entered, exited, or took blood meals inside the treated house after it was sprayed with DDT, and that specimens marked and released inside the house tended to depart immediately. This behavior appears to constitute true repellency rather than contact irritability. Since the typical house in the vicinity of the study site had only two walls, the persistence of malaria in the local area was probably due to home construction practices.

  8. DDT reintroduction for malaria control: the cost-benefit debate for public health.

    PubMed

    Guimarães, Raphael Mendonça; Asmus, Carmen Ildes Rodrigues Fróes; Meyer, Armando

    2007-12-01

    DDT is a persistent insecticide that was widely used in the world from the 1940s until the 70s, when it was banned in the United States and other countries. Most of its toxic effects are not observed in the acute forms, but particularly after chronic exposure. These long-term issues include reproductive effects, varying according to the time of life in which the individuals were exposed. The aims of the current study were to review the principal toxicological effects of DDT on reproduction, stratifying by physiological periods of exposure, and based on the magnitude of these effects, to discuss the cost-benefit relationship of reintroducing DDT with the specifically defined vector control criteria.

  9. Chlorinated pesticides (2,4-D and DDT) biodegradation at high concentrations using immobilized Pseudomonas fluorescens.

    PubMed

    Santacruz, Germán; Bandala, Erick R; Torres, Luis G

    2005-01-01

    Degradation of two chlorinated pesticides (2,4-D and DDT) using a 54-mL glass column packed with tezontle (a low-cost basaltic scoria) was tested. Bacteria were cultured in YPG (yeast, peptone, and glucose) liquid medium at 32 degrees C. The rich medium was pumped during 24 h through the column to inoculate it. Later, the wasted medium was discharged and the pesticide added. Optical densities, TOC, and pesticide concentration were determined. Pesticide removals for 2,4-D (with initial concentration between 100 and 500 mg/L) were about 99%. DDT removal (at initial concentration of up to 150 mg/L) was as high as 55-99%. TOC removals for 2,4-D was in the 36-87% interval, whereas for DDT they were as high as 36-78%.

  10. Transient power supply voltage (v{sub DDT}) analysis for detecting IC defects

    SciTech Connect

    Cole, E.I. Jr.; Soden, J.M.; Beegle, R.W.

    1997-04-01

    Transient power supply voltage (V{sub DDT}) analysis is a new testing technique demonstrated as a powerful alternative and complement to I{sub DDQ} testing. V{sub DDT} takes advantage of the limited response time of a voltage supply to the changing power demands of an IC during operation. Changes in the V{sub DD} response time are used to detect increases in power demand with resolutions of 100 nA at 100 kHz, 1 {mu}A at 1 MHz, and 2.5 {mu}A at 1.5 MHz. These current sensitivities have been shown for ICs with quiescent currents < 0.1 {mu}A and > 300 {mu}A. The V{sub DDT} signal acquisition protocols, frequency versus sensitivity tradeoffs, hardware considerations and limitations, data examples, and areas for future research are described.

  11. The insecticide DDT decreases membrane potential and cell input resistance of cultured human liver cells.

    PubMed

    Schefczik, K; Buff, K

    1984-10-03

    The resting membrane potential, Em, and the cell input resistance, Rinp, of cultured human Chang liver cells were measured using the single electrode 'double-pulse' current clamp technique, following exposure of the cells to the insecticide DDT (20 microM). In control (unexposed) cells, the mean Em was -24 mV, and the mean Rinp was 30 M omega. Neither parameter was significantly impaired after 1 h of cell exposure to DDT. But after 7 and 48 h, the Em was depolarized by 15 and 25 mV, respectively, in parallel with a decrease of the cell input resistance. The strongly time-delayed effect of DDT on Chang liver cell membranes may indicate a mode of interaction different from excitable membranes.

  12. Effects of DDT on birds at the Patuxent Wildlife Research Refuge

    USGS Publications Warehouse

    Stewart, R.E.; Cope, J.B.; Robbins, C.S.; Brainerd, J.W.

    1946-01-01

    The spraying of DDT at the rate of 2 pounds per acre on a tract of land within the well-drained bottomland forest at the Patuxent Research Refuge on June 5, 1945, had little or no effect on the bird population of the area, with the possible exception of the redstart (Setophaga ruticilla). Considerable evidence was accumulated showing that this species was probably somewhat reduced. The effective dose for the treated area as a whole was decidedly less than 2 pounds of DDT per acre. Some spray was blown away to be deposited on nearby areas, and much of it was screened out by the dense forest canopy. The redstarts, being tree top feeders, were exposed to more DDT than most of the local birds.

  13. Mechanisms of Disruptive Action of Dichlorodiphenyltrichloroethane (DDT) on the Function of Thyroid Follicular Epitheliocytes.

    PubMed

    Yaglova, N V; Yaglov, V V

    2015-12-01

    The mechanism of disruptive action of dichlorodiphenyltrichloroethane (DDT) on the function of thyroid follicular epitheliocytes was examined in mature male Wistar rats administered with a daily dose of DDT (2 μg/kg) for 6 or 10 weeks. In 6 weeks, the serum level of Na(+)/I(-) symporter responsible for the transport of iodides into follicular thyrocytes decreased, while serum concentration of thyroperoxidase increased. In 10 weeks, both the number of follicles in the thyroid gland and serum level of Na(+)/I(-) symporter increased. In circulating blood, the concentrations of thyroglobulin as well as α and β receptors of the thyroid hormones did not change. DDT down-regulated the iodine-accumulated function of follicular thyrocytes by suppressing Na(+)/I(-) symporter synthesis. Recovery of Na(+)/I (-) symporter production resulted from up-regulation of the proliferative processes in thyroid gland.

  14. 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.

  15. Aerosol gels

    NASA Technical Reports Server (NTRS)

    Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)

    2010-01-01

    An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.

  16. 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.

  17. Destruction of DDT wastes in two preheater/precalciner cement kilns in China.

    PubMed

    Yan, Dahai; Peng, Zheng; Karstensen, Kåre Helge; Ding, Qiong; Wang, Kaixiang; Wang, Zuguang

    2014-04-01

    The destruction of DDT formulations and DDT contaminated soil was conducted by feeding wastes into the flue gas chamber at the kiln inlet of two different preheater/precalciner cement kilns in China. The concentration of DDT, PCDD/PCDFs and HCB were measured in the flue gas of the main stack, in the solid material under baseline conditions and when feeding DDT-wastes. The destruction efficiency and the destruction and removal efficiency for DDT were in the range of 99.9335%-99.9998% and 99.9984%-99.9999%, respectively. The emissions of PCDD/PCDFs and HCB in the flue gas varied in the range of 0.0019-0.0171 ng I-TEQ/Nm(3) and 0.0064-0.0404 μg/Nm(3), respectively. The emission factor for PCDD/PCDF and HCB varied from 0.0137 to 0.0281 μg/ton and from 17.32 to 109.34 μg/ton of clinker, respectively. The concentration of PCDD/PCDFs and HCB in solid samples decreased as follows: cement kiln dust, 4.1-5 ng I-TEQ/kg and 0.70-0.71 μg/kg, respectively; >raw meal, 0.82-0.97 ng I-TEQ/kg and 0.18 μg/kg, respectively; >cement clinker, 0.09-0.22 ng I-TEQ/kg and 0.14-0.18 μg/kg, respectively. This study indicates that the feeding of DDT and POPs-wastes to the lower temperature part of a cement kiln system possibly to create a buildup of trace not-destroyed compounds in the system and might cause emissions; the technical feasibility and the environmental acceptability of this practice need to be investigated thoroughly.

  18. 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.

  19. 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.

  20. Perinatal exposure of mice to the pesticide DDT impairs energy expenditure and metabolism in adult female offspring.

    PubMed

    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.

  1. 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

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

    PubMed

    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.

  3. 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

  4. 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.

  5. 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

  6. Aerosol Correction for Improving OMPS/LP Ozone Retrieval

    NASA Technical Reports Server (NTRS)

    Chen, Zhong; Bhartia, Pawan K.; Loughman, Robert

    2015-01-01

    The Ozone Mapping and Profiler Suite Limb Profiler (OMPS-LP) on board the Suomi National Polar-orbiting Partnership (SNPP) satellite was launched on Oct. 28, 2011. Limb profilers measures the radiance scattered from the Earth's atmospheric in limb viewing mode from 290 to 1000 nm and infer ozone profiles from tropopause to 60 km. The recently released OMPS-LP Version 2 data product contains the first publicly released ozone profiles retrievals, and these are now available for the entire OMPS mission, which extends from April, 2012. The Version 2 data product retrievals incorporate several important improvements to the algorithm. One of the primary changes is to turn off the aerosol retrieval module. The aerosol profiles retrieved inside the ozone code was not helping the ozone retrieval and was adding noise and other artifacts. Aerosols including polar stratospheric cloud (PSC) and polar mesospheric clouds (PMC) have a detectable effect on OMPS-LP data. Our results show that ignoring the aerosol contribution would produce an ozone density bias of up to 10 percent in the region of maximum aerosol extinction. Therefore, aerosol correction is needed to improve the quality of the retrieved ozone concentration profile. We provide Aerosol Scattering Index (ASI) for detecting aerosols-PMC-PSC, defined as ln(Im-Ic) normalized at 45km, where Im is the measured radiance and Ic is the calculated radiance assuming no aerosols. Since ASI varies with wavelengths, latitude and altitude, we can start by assuming no aerosol profiles in calculating the ASIs and then use the aerosol profile to see if it significantly reduces the residuals. We also discuss the effect of aerosol size distribution on the ozone profile retrieval process. Finally, we present an aerosol-PMC-PSC correction scheme.

  7. Impact of climate fluctuations on deposition of DDT and hexachlorocyclohexane in mountain glaciers: evidence from ice core records.

    PubMed

    Wang, Xiaoping; Gong, Ping; Zhang, Qianggong; Yao, Tandong

    2010-02-01

    How do climate fluctuations affect DDT and hexachlorocyclohexane (HCH) distribution in the global scale? In this study, the interactions between climate variations and depositions of DDT and HCH in ice cores from Mt. Everest (the Tibetan Plateau), Mt. Muztagata (the eastern Pamirs) and the Rocky Mountains were investigated. All data regarding DDT/HCH deposition were obtained from the published results. Concentrations of DDT and HCH in an ice core from Mt. Everest were associated with the El Nino-Southern Oscillation. Concentrations of DDT in an ice core from Mt. Muztagata were significantly correlated with the Siberia High pattern. Concentrations of HCH in an ice core from Snow Dome of the Rocky Mountains responded to the North Atlantic Oscillation. These associations suggested that there are some linkages between climate variations and the global distribution of persistent organic pollutants.

  8. PCBs have declined more than DDT-group residues in Arctic ringed seals (Phoca hispida) between 1972 and 1981

    SciTech Connect

    Addison, R.F.; Zinck, M.E.; Smith, T.G.

    1986-03-01

    Mean DDT-group concentrations in the blubber of western Arctic ringed seals (Phoca hispida) sampled in 1981 were less than 1..mu..g.g/sup -1/ wet weight. Male seals had higher concentrations than did females. PCB concentrations were about half of those in a sample of the same population taken in 1972, when allowance was made for the variation of residue concentrations with age, sex, and condition. This decline probably results from the ban on PCB manufacture and use imposed in the early 1970s. Concentrations of DDT-group residues did not show any clear decline over the same interval, and the relative proportions of p,p'-DDT and p,p'-DDE suggested that there is a continuing supply of DDT to the western Arctic. The most probable source of this is by atmospheric or water transport from the Far East, where DDT was used until at least the late 1970s.

  9. 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.

  10. Interference of xenoestrogen o,p'-DDT on the action of endogenous estrogens at environmentally realistic concentrations.

    PubMed

    Zhong, Lingying; Xiang, Xiao; Lu, Wei; Zhou, Pei; Wang, Lumei

    2013-05-01

    Estrogenic effects of individual chemicals and mixtures of 17β-estradiol (E2) and o,p'-DDT were examined using pS2 and PR gene expressions in MCF-7 cells. Interactions between E2 and o,p'-DDT were evaluated by a statistical method based on factorial design. At levels close to environmentally realistic concentrations, no significant interactions between E2 and o,p'-DDT were observed, suggesting that the xenoestrogen (o,p'-DDT) could act in an additive way with the endogenous estrogen (E2). These results demonstrated the utility of this statistical method in a mixture study, and highlight the potential interference and health risk of low-level xenoestrogens, such as o,p'-DDT.

  11. Aerosol typing - key information from aerosol studies

    NASA Astrophysics Data System (ADS)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  12. Climate studies with a multilayer energy balance model. III - Climatic impact of stratospheric volcanic aerosols

    NASA Technical Reports Server (NTRS)

    Chou, M.-D.; Arking, A.; Peng, L.

    1984-01-01

    A multilayer energy balance model is applied in an examination of the sensitivity of climate to stratospheric aerosols induced by volcanic eruptions. Zonally and annually averaged quantities are considered, with ocean and land temperatures computed separately and the atmosphere below the 200 mb level divided into eight layers of 24 sublayers each. The aerosol is assumed to form in the 150-200 mb range. Aerosol parameters for radiative transfer calculations are reflection in the solar spectral region and absorption in the solar and IR regions. A 75 percent aqueous solution of sulfuric acid is assumed for the aerosols. The sensitivity of the hemispherically averaged surface temperature is enhanced 37 percent, with a 20 percent uncertainty, when the thermal IR radiation is excluded. The solar radiation enhances the surface temperatures to a higher degree than the thermal radiation. The maximum response to the evenly distributed aerosols is in the 60-70 deg N latitudes and propagates, weakening, to lower latitudes.

  13. Effects of transovarian exposure to p,p'-DDT and p,p'-DDE on avian reproduction using Japanese quails.

    PubMed

    Kamata, Ryo; Shiraishi, Fujio; Takahashi, Shinji; Shimizu, Akira; Nakajima, Daisuke; Kageyama, Shiho; Sasaki, Takushi; Temma, Kyosuke

    2013-01-01

    In the 1950s to 1970s developed countries reported declines in populations of raptorial and fish-eating birds and dichlorodiphenyltrichloroethane (DDT) and its metabolites were considered causative substances because they accumulated significantly in the tissues of wild birds and animals. However, except for the estrogenic effects of o,p'-DDT, a minor component of commercial DDT, there has been no compelling evidence that DDT directly affects avian reproductive systems. To assess the possible impact of DDT on development and reproduction of birds, exposure experiments to the major component of commercial DDT, p,p'-DDT, and its persistent metabolite, p,p'-dichlorodiphenyldichloroethylene (DDE), were performed using Japanese quail (Coturnix japonica) eggs; the test substances (3 to 100 μg/g) were injected into the yolk prior to incubation, and hatched chicks were raised to adulthood. p,p'-DDT had no significant effects on the morphology and function of the reproductive systems, although the hatchability of treated eggs was reduced at the highest dose (100 μg/g). High doses of p,p'-DDE slightly enhanced the eggshell forming ability of female quails; eggshell mass and thickness were increased at 30 μg/g or more although no morphological changes were observed in the oviduct. Transcriptions of the CYP11A1 gene in the ovaries, and of AHR and ARNT in the livers, of adult females were significantly increased at 3 μg/g or more of p,p'-DDT. Except for low hatchability, transovarian exposure to p,p'-DDT or p,p'-DDE did not markedly impair the avian reproductive systems, but the hormonal actions of these compounds are likely to change reproductive and hepatic functions even after maturation.

  14. 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.

  15. Sediment toxicity, contamination and amphipod abundance at a DDT- and dieldrin-contaminated site in San Francisco Bay

    SciTech Connect

    Swartz, R.C.; Cole, F.A.; Lamberson, J.O.; Ferraro, S.P.; Schults, D.W.

    1994-01-01

    Sediment toxicity to the amphipod Eohaustorius estuarius, sediment contamination, and the abundance of amphipods were examined along a contamination gradient in the Lauritzen Channel and adjacent parts of Richmond Harbor, California. Dieldrin and DDT were formulated and ground at this site from 1945 to 1966. Sediment contamination by both dieldrin and the sum of DDT and its metabolites (DDT's) was positively correlated with sediment toxicity and negatively correlated with the abundance of amphipods excluding Grandidierella japonica. The maximum dieldrin and DDT's concentrations in toxic units were 0.018 and 9.43, respectively, indicating that DDT's was the dominant ecotoxicological factor. Concentrations of PAHs, PCBs, and metals were not sufficient to cause appreciable toxicity, except at one PAH-contaminated station. Relations between DDT's, sediment toxicity, and amphipod abundance are similar at three DDT's-contaminated sites. The 10-d LC50 for DDT's in field-collected sediment was 2,500 micrograms/gram organic carbon (OC) for Eohaustorius estuarius in the study, 1,040 micrograms/gram OC for Rhepoxynius abronius exposed to Palos Verdes Shelf, California, sediment, and 2,580 micrograms/gram OC for Hyalella azteca exposed to sediment from a freshwater stream system near Huntsville, Alabama. The threshold for 10-d sediment toxicity occurred at about 300 micrograms DDT's/gram OC. The abundance of amphipods (except Grandidierella japonica) was reduced at DDT's concentrations >100 micrograms/gram OC. Correlations between toxicity, contamination, and biology indicate that acute sediment toxicity to Eohaustorius estuarius, Rhopoxynius abronius, or Hyalella azteca in lab tests provides reliable evidence of biologically adverse sediment contamination in the field.

  16. 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...

  17. Four Percent Fallacy Revisited: Urban and Rural Differences.

    ERIC Educational Resources Information Center

    Haas, William H., III; Haas, Marilyn L.

    Cross sectional data indicate that about four percent of elderly persons reside in nursing homes. Yet many studies, some using death certificates, show actual risk of institutionalization is upwards of 25 percent. This paper presents a death registration study that examined all deaths in North Carolina and analyzed rural and urban differences. The…

  18. 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

  19. Effects of PCBs, DDT, and mercury compounds in chickens and Japanese quail.

    PubMed

    Scott, M L

    1977-05-01

    In well-controlled experiments using white leghorn chickens and Japanese quail, dietary polychlorinated biphenyls (PCBs), DDT and related compounds produced no detrimental effects on eggshell quality. A drastic reduction in hatchability of chicks occurred with 10-20 ppm PCBs, but no detrimental effects on eggshell quality, egg production or hatchability were found with 0.5 and 1.0 ppm PCBs, or DDT up to 100 ppm. Dietary PCBs potentiated a vitamin E-selenium deficiency in the chick, increased exudative diathesis, and decreased plasma glutathione peroxidase levels. Dietary PCBs induced hepatic microsomal benzopyrine hydroxylase. Dietary levles of 100 or 200 ppm inorganic mercury as HgSO4 or HgCl2 had little effect on egg production, hatchability, shell quality, morbidity and mortality. Methylmercury chloride, however, at levels providing 10 or 20 mg Hg/kg of diet, severely affected all of these parameters. Even though the present experiments demonstrate that neither DDT nor PCBs has any effect on eggshell quality in chickens and Japanese quail, they may cause thinning of eggshells in other species. Controlled experiments are lacking. Eagles, ospreys and pelicans all consume fish which in many areas of the world are known to contain methyl mercury. The thinning of eggshells in the species in the wild may have been due, at least in part, to environmental contamination with methylmercury rather than DDT, DDE or PCBs, as has been claimed.

  20. 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.

  1. DDT AND DIELDRIN IN RIVERS: A REPORT OF THE NATIONAL WATER QUALITY NETWORK.

    PubMed

    BREIDENBACH, A W; LICHTENBERG, J J

    1963-09-06

    As a part of the waterquality surveillance activities of the National Water Quality Network at 101 sampling stations, insecticides were identified in 38 samples from ten rivers during the period May through December 1962. Both DDT and dieldrin were identified by infrared and gas chromatographic analysis of carbon adsorption extracts.

  2. 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...

  3. Reductive dechlorination of methoxychlor and DDT by human intestinal bacterium Eubacterium limosum under anaerobic conditions.

    PubMed

    Yim, You-Jin; Seo, Jiyoung; Kang, Su-Il; Ahn, Joong-Hoon; Hur, Hor-Gil

    2008-04-01

    Methoxychlor [1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane], a substitute for 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), is a compound of environmental concern because of potential long-term health risks related to its endocrine-disrupting and carcinogenic potency. In order to determine the metabolic fate of methoxychlor and DDT in the human intestinal gut, Eubacterium limosum (ATCC 8486), a strict anaerobe isolated from the human intestine that is capable of O-demethylation toward O-methylated isoflavones, was used as a model intestinal microbial organism. Under anaerobic incubation conditions, E. limosum completely transformed methoxychlor and DDT in 16 days. Based on gas chromatography-mass chromatography analyses, the metabolites produced from methoxychlor and DDT by E. limosum were confirmed to be 1,1-dichloro-2,2-bis(p-methoxyphenyl)ethane (methoxydichlor) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), respectively. This study suggests that E. limosum in the human intestinal gut might be a participant in the reductive dechlorination of methoxychlor to the more antiandrogenic active methoxydichlor.

  4. Detecting Associations between Early-Life DDT Exposures and Childhood Growth Patterns: A Novel Statistical Approach.

    PubMed

    Heggeseth, Brianna; Harley, Kim; Warner, Marcella; Jewell, Nicholas; Eskenazi, Brenda

    2015-01-01

    It has been hypothesized that environmental exposures at key development periods such as in utero play a role in childhood growth and obesity. To investigate whether in utero exposure to endocrine-disrupting chemicals, dichlorodiphenyltrichloroethane (DDT) and its metabolite, dichlorodiphenyldichloroethane (DDE), is associated with childhood physical growth, we took a novel statistical approach to analyze data from the CHAMACOS cohort study. To model heterogeneity in the growth patterns, we used a finite mixture model in combination with a data transformation to characterize body mass index (BMI) with four groups and estimated the association between exposure and group membership. In boys, higher maternal concentrations of DDT and DDE during pregnancy are associated with a BMI growth pattern that is stable until about age five followed by increased growth through age nine. In contrast, higher maternal DDT exposure during pregnancy is associated with a flat, relatively stable growth pattern in girls. This study suggests that in utero exposure to DDT and DDE may be associated with childhood BMI growth patterns, not just BMI level, and both the magnitude of exposure and sex may impact the relationship.

  5. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya.

    PubMed

    Wanjala, Christine L; Mbugi, Jernard P; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A; Atieli, Harrysone E; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

    2015-12-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non-pyrethroid-based vector control tools may be preferable for malaria prevention in this region.

  6. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya

    PubMed Central

    Wanjala, Christine L.; Mbugi, Jernard P.; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A.; Atieli, Harrysone E.; Zhou, Guofa; Githeko, Andrew K.

    2015-01-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non–pyrethroid-based vector control tools may be preferable for malaria prevention in this region. PMID:26583525

  7. DDT and the decline of free-tailed bats (Tadarida brasiliensis) at Carlsbad Cavern, New Mexico.

    PubMed

    Clark, D R

    2001-05-01

    DDT is believed to have caused the population of Brazilian free-tailed bats (Tadarida brasiliensis mexicana) at Carlsbad Cavern to decline severely after 1936. Nevertheless, previous data supporting this hypothesis are limited to a single study from 1974, which indicated that 20% of young free-tails from the cavern may have died of DDE poisoning during their first southward migration. In this study I compared organochlorine residues among samples of free-tails collected in Carlsbad Cavern in 1930, 1956, 1965, 1973, and 1988. Samples of skin cut from dry museum specimens were chemically analyzed, except for the 1973 data, which were derived from analyses of whole bats minus gastrointestinal tracts. Accumulated residue levels of DDT compounds in bats from 1965 and 1956 exceeded those in 1973 bats by approximately 4.8 times and approximately 2.7 times, respectively. This suggests that lethal effects of DDT compounds were substantially greater in the 1950s and 1960s than in the 1970s. Residues in 1988 bats resembled those for 1973 bats. It is concluded that DDT played a major role in this severe population decline. These results can be applied by management personnel in evaluating the present and future status of this population regarding persisting organochlorine insecticides as well as other agricultural chemicals now in use. The case of the Carlsbad colony is discussed relative to the general issue of other bat population declines.

  8. Particle size distributions of several commonly used seeding aerosols

    NASA Technical Reports Server (NTRS)

    Crosswy, F. L.

    1985-01-01

    During the course of experimentation, no solid particle powder could be found which produced an aerosol with a narrow particle size distribution when fluidization was the only flow process used in producing the aerosol. The complication of adding particle size fractionation processes to the aerosol generation effort appears to be avoidable. In this regard, a simple sonic orifice is found to be effective in reducing the percentage of agglomerates in the several metal oxide powders tested. Marginally beneficial results are obtained for a 0.5/99.5 percent by weight mixture of the flow agent and metal oxide powder. However, agglomeration is observed to be enhanced when the flow agent percentage is increased to 5 percent. Liquid atomization using the Collison nebulizer as well as a version of the Laskin nozzle resulted in polydispersed aerosols with particle size distributions heavily weighted by the small particle end of the size spectrum. The aerosol particle size distributions produced by the vaporization/condensation seeder are closer to the ideal monodispersed aerosol than any of the other aerosols tested. In addition, this seeding approach affords a measure of control over particle size and particle production rate.

  9. Tazarotene 0.1 percent cream plus clindamycin 1 percent gel versus tretinoin 0.025 percent gel plus clindamycin 1 percent gel in the treatment of facial acne vulgaris.

    PubMed

    Tanghetti, Emil; Dhawan, Sunil; Torok, Helen; Kircik, Leon

    2007-07-13

    Topical retinoids are the cornerstone of therapy for acne vulgaris. Nevertheless, the adjunctive use of other anti-acne agents can help enhance the efficacy of topical retinoids still further. Given that tazarotene 0.1 percent gel has previously shown significantly greater efficacy than tretinoin 0.025 percent gel, it is likely that tazarotene plus clindamycin offers superior efficacy to tretinoin plus clindamycin, which has recently become available as a combination product. A total of 150 patients with facial acne vulgaris were randomly assigned to receive either tazarotene 0.1 percent cream plus clindamycin 1 percent gel, or tretinoin 0.025 percent gel plus clindamycin 1 percent gel. Each medication was applied once daily in the evening (clindamycin followed by the retinoid 5-10 minutes later) for up to 12 weeks. At week 12, the reduction from baseline in lesion counts was greater with tazarotene/clindamycin than tretinoin/clindamycin for both the non-inflammatory lesion count (71% vs. 52%, p< or =.01) and the inflammatory lesion count (77% vs. 67%, P=.053). Tazarotene/clindamycin also resulted in a significantly higher incidence of patients achieving > or = 50 percent global improvement (incidence of 88% vs. 75% at week 12; p< or =.05). Both regimens were similarly well tolerated. In the treatment of facial acne vulgaris, tazarotene plus clindamycin offers significantly greater efficacy than tretinoin plus clindamycin and has comparable tolerability.

  10. Selected fretting-wear-resistant coatings for titanium - 6-percent-aluminum - 4-percent-vanadium alloy

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1976-01-01

    A titanium - 6-percent-aluminum - 4-percent-vanadium alloy (Ti-6Al-4V) was subjected to fretting-wear exposures against uncoated Ti-6Al-4V as a baseline and against various coatings and surface treatments applied to Ti-6Al-4V. The coatings evaluated included plasma-sprayed tungsten carbide with 12 percent cobalt, aluminum oxide with 13 percent titanium oxide, chromium oxide, and aluminum bronze with 10 percent aromatic polyester; polymer-bonded polyimide, polyimide with graphite fluoride, polyimide with molybdenum disulfide (MoS2), and methyl phenyl silicone bonded MoS2, preoxidation surface treatment, a nitride surface treatment, and a sputtered MoS2 coating. Results of wear measurements on both the coated and uncoated surfaces after 300,000 fretting cycles indicated that the polyimide coating was the most wear resistant and caused the least wear to the uncoated mating surface.

  11. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  12. 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.

  13. Biomagnification of DDT and its metabolites in four fish species of a tropical lake.

    PubMed

    Deribe, Ermias; Rosseland, Bjørn Olav; Borgstrøm, Reidar; Salbu, Brit; Gebremariam, Zinabu; Dadebo, Elias; Skipperud, Lindis; Eklo, Ole Martin

    2013-09-01

    The concentrations and biomagnifications of dichlorodiphenyltrichloroethane (DDT) and its metabolites were examined in four fish species (Clarias gariepinus, Oreochromis niloticus, Tilapia zillii, and Carassius auratus) from Lake Ziway, Rift Valley, Ethiopia. Paired stomach content analysis, and stable isotope ratio of nitrogen (δ(15)N, ‰) and carbon (δ(13)C, ‰) were used to study the trophic position of the fish species in the lake. 4,4'-DDE, 4,4'-DDT and 4,4'-DDD were the main DDTs identified in the fish samples, with 4,4'-DDE as the most predominant metabolite, with mean concentration ranging from 1.4 to 17.8 ng g(-1) wet weight (ww). The concentrations of DDTs found in fish from Lake Ziway were, in general lower than those found in most studies carried out in other African Lakes. However, the presence of DDT in all tissue samples collected from all fish species in the lake indicates the magnitude of the incidence. Moreover, the observed mean 4,4'-DDE to 4,4'-DDT ratio below 1 in C. auratus from Lake Ziway may suggest a recent exposure of these species to DDT, indicating that a contamination source is still present. 4,4'-DDE was found to biomagnify in the fish species of the lake, and increases with trophic level, however, the biomagnification rate was generally lower than what has been reported from other areas. Significantly higher concentrations of 4,4'-DDE were found in the top consumer fish in Lake Ziway, C. gariepinus than in O. niloticus (t=2.6, P<0.01), T. zillii (t=2.5, P<0.02) and C. auratus (t=2.2, P<0.03).

  14. Reproductive effects of occupational DDT exposure among male malaria control workers.

    PubMed Central

    Salazar-García, Félix; Gallardo-Díaz, Esperanza; Cerón-Mireles, Prudencia; Loomis, Dana; Borja-Aburto, Victor H

    2004-01-01

    To assess potential effects of human DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] exposure, we evaluated the reproductive history of 2,033 workers in the antimalaria campaign of Mexico. Data on occupational exposure to DDT and reproductive outcomes were gathered through a questionnaire, and workers provided information about 9,187 pregnancies. We estimated paternal exposure to DDT before each pregnancy using three approaches: a) a dichotomous indicator for pregnancies before and after exposure began, b) a qualitative index of four exposure categories, and c) an estimation of the DDT metabolite DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] accumulated in fat. To assess associations, we used logistic regression models that accounted for correlated observations and adjusted for parents' age at each child's birth, exposure to other pesticides, exposure to chemical substances in other employment, smoking, and alcohol consumption. The odds ratio for birth defects comparing pregnancies after and before the first exposure was 3.77 [95% confidence interval (95% CI), 1.19-9.52]. Compared with the lowest quartile of estimated DDE in fat, the ORs were 2.48 (95% CI, 0.75-8.11), 4.15 (95% CI, 1.38-12.46), and 3.76 (95% CI, 1.23-11.44) for quartiles 2, 3, and 4, equivalent to p,p -DDE in fat of 50, 82, and 298 microg/g fat, respectively. No significant association was found for spontaneous abortion or sex ratio. We found an increased risk of birth defects associated with high occupational exposure to DDT in this group of workers. The significance of this association at lower exposure levels found in the general population remains uncertain. PMID:15064158

  15. 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

  16. Effect of DDT on hepatic gap junctional intercellular communication in rats.

    PubMed

    Tateno, C; Ito, S; Tanaka, M; Oyamada, M; Yoshitake, A

    1994-03-01

    The effects of in vivo exposure to DDT on hepatic gap junctional intercellular communication (GJIC) and connexin gene/protein expression in Sprague-Dawley rats were examined by in vivo/in vitro dye-transfer assay, immunohistochemical staining, and by Western and Northern blot analyses. In the dose-response study, three dose levels of DDT (5, 25 and 50 mg/kg/day) were administered orally to rats once a day for 2 weeks. The average size of the dye spread after injection of Lucifer Yellow and the area of Cx32 spots per hepatocyte decreased in a dose-dependent manner, but there was no effect on the number of Cx32 spots per hepatocyte. In the time-course study, DDT (50 mg/kg/day) was administered orally once a day for up to 6 weeks. Hepatic GJIC decreased at week 1 but recovered at week 6. The average area of Cx32 spots per hepatocyte gradually decreased at weeks 2 and 4, and remained at the same level at week 6, correlating with the decreased Cx32 protein level in plasma membranes. The average area of Cx26 spots per hepatocyte in the peripheral zones clearly decreased at week 1, but quickly recovered at week 2 and increased at week 6; however, no clear change of the Cx26 protein level in plasma membranes was observed. No changes of Cx32 and Cx26 mRNA levels were observed in DDT groups. These results suggest that DDT, a liver tumor-promoting agent, inhibits hepatic GJIC in vivo dose-dependently in rats and that aberrant Cx32 and Cx26 protein expression and/or localization may be responsible for this effect.

  17. Anaerobic transformation of DDT related to iron(III) reduction and microbial community structure in paddy soils.

    PubMed

    Chen, Manjia; Cao, Fang; Li, Fangbai; Liu, Chengshuai; Tong, Hui; Wu, Weijian; Hu, Min

    2013-03-06

    We studied the mechanisms of microbial transformation in functional bacteria on 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in two different field soils, Haiyan (HY) and Chenghai (CH). The results showed that microbial activities had a steady dechlorination effect on DDT and its metabolites (DDx). Adding lactate or glucose as carbon sources increased the amount of Desulfuromonas, Sedimentibacter, and Clostridium bacteria, which led to an increase in adsorbed Fe(II) and resulted in increased DDT transformation rates. The electron shuttle of anthraquinone-2,6-disulfonic disodium salt resulted in an increase in the negative potential of soil by mediating the electron transfer from the bacteria to the DDT. Moreover, the DDT-degrading bacteria in the CH soil were more abundant than those in the HY soil, which led to higher DDT transformation rates in the CH soil. The most stable compound of DDx was 1,1-dichloro-2,2-bis(p-chloro-phenyl)ethane, which also was the major dechlorination metabolite of DDT, and 1-chloro-2,2-bis-(p-chlorophenyl)ethane and 4,4'-dichlorobenzo-phenone were found to be the terminal metabolites in the anaerobic soils.

  18. 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.

  19. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  20. Improved solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  1. Solid aerosol generator

    DOEpatents

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  2. Solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  3. Assessment of the global impact of aerosols on tropospheric oxidants

    NASA Astrophysics Data System (ADS)

    Tie, Xuexi; Madronich, Sasha; Walters, Stacy; Edwards, David P.; Ginoux, Paul; Mahowald, Natalie; Zhang, Renyi; Lou, Chao; Brasseur, Guy

    2005-02-01

    heterogeneous reactions of HO2 and CH2O on sulfate have an important impact on HOx (OH + HO2) concentrations, while the heterogeneous reaction of O3 on soot has a minor effect on O3 concentrations in the lower troposphere. The heterogeneous reactions on dust have very important impacts on HOx and O3 in the region of dust mobilization, where the reduction of HOx and O3 concentrations can reach a maximum of 30% and 20%, respectively, over the Sahara desert. Dust, organic carbon, black carbon, and sulfate aerosols have important impacts on photolysis rates. For example, the photodissociation frequencies of ozone and nitrogen dioxide are reduced by 20% at the surface in the Sahara, in the Amazon, and in eastern Asia, leading to 5-20% reduction in the concentration of HOx and to a few percent change in the O3 abundance in these regions.

  4. Long term aerosol and trace gas measurements in Central Amazonia

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Barbosa, Henrique M. J.; Ferreira de Brito, Joel; Carbone, Samara; Rizzo, Luciana V.; Andreae, Meinrat O.; Martin, Scot T.

    2016-04-01

    The central region of the Amazonian forest is a pristine region in terms of aerosol and trace gases concentrations. In the wet season, Amazonia is actually one of the cleanest continental region we can observe on Earth. A long term observational program started 20 years ago, and show important features of this pristine region. Several sites were used, between then ATTO (Amazon Tall Tower Observatory) and ZF2 ecological research site, both 70-150 Km North of Manaus, receiving air masses that traveled over 1500 km of pristine tropical forests. The sites are GAW regional monitoring stations. Aerosol chemical composition (OC/EC and trace elements) is being analysed using filters for fine (PM2.5) and coarse mode aerosol as well as Aerodyne ACSM (Aerosol Chemical Speciation Monitors). VOCs are measured using PTR-MS, while CO, O3 and CO2 are routinely measured. Aerosol absorption is being studied with AE33 aethalometers and MAAP (Multi Angle Absorption Photometers). Aerosol light scattering are being measured at several wavelengths using TSI and Ecotech nephelometers. Aerosol size distribution is determined using scanning mobility particle sizer at each site. Lidars measure the aerosol column up to 12 Km providing the vertical profile of aerosol extinction. The aerosol column is measures using AERONET sun photometers. In the wet season, organic aerosol comprises 75-85% of fine aerosol, and sulfate and nitrate concentrations are very low (1-3 percent). Aerosols are dominated by biogenic primary particles as well as SOA from biogenic precursors. Black carbon in the wet season accounts for 5-9% of fine mode aerosol. Ozone in the wet season peaks at 10-12 ppb at the middle of the day, while carbon monoxide averages at 50-80 ppb. Aerosol optical thickness (AOT) is a low 0.05 to 0.1 at 550 nm in the wet season. Sahara dust transport events sporadically enhance the concentration of soil dust aerosols and black carbon. In the dry season (August-December), long range transported

  5. Aerosol algorithm evaluation within aerosol-CCI

    NASA Astrophysics Data System (ADS)

    Kinne, Stefan; Schulz, Michael; Griesfeller, Jan

    Properties of aerosol retrievals from space are difficult. Even data from dedicated satellite sensors face contaminations which limit the accuracy of aerosol retrieval products. Issues are the identification of complete cloud-free scenes, the need to assume aerosol compositional features in an underdetermined solution space and the requirement to characterize the background at high accuracy. Usually the development of aerosol is a slow process, requiring continuous feedback from evaluations. To demonstrate maturity, these evaluations need to cover different regions and seasons and many different aerosol properties, because aerosol composition is quite diverse and highly variable in space and time, as atmospheric aerosol lifetimes are only a few days. Three years ago the ESA Climate Change Initiative started to support aerosol retrieval efforts in order to develop aerosol retrieval products for the climate community from underutilized ESA satellite sensors. The initial focus was on retrievals of AOD (a measure for the atmospheric column amount) and of Angstrom (a proxy for aerosol size) from the ATSR and MERIS sensors on ENVISAT. The goal was to offer retrieval products that are comparable or better in accuracy than commonly used NASA products of MODIS or MISR. Fortunately, accurate reference data of ground based sun-/sky-photometry networks exist. Thus, retrieval assessments could and were conducted independently by different evaluation groups. Here, results of these evaluations for the year 2008 are summarized. The capability of these newly developed retrievals is analyzed and quantified in scores. These scores allowed a ranking of competing efforts and also allow skill comparisons of these new retrievals against existing and commonly used retrievals.

  6. Impact of Aerosols on Photolysis Frequencies during CALNEX-LA

    NASA Astrophysics Data System (ADS)

    Grossberg, N.; Lefer, B. L.; Stutz, J.

    2010-12-01

    The transmission of solar UV radiation through the atmosphere is impacted by the presence of aerosols. Aerosol composition, size, shape, and single scattering albedo influence the intensity of actinic flux. Changes in photolysis rates directly affect the photochemical ozone production and loss. Measurements of photolysis frequencies were made at the Caltech campus (altitude 0.264 km) and at JPL’s CLARS Observatory at Mount Wilson (altitude 1.74 km) during the summer of 2010 as part of the CALNEX-LA campaign. Of particular interest are the periods when aerosol optical depth is high (greater than 0.2 at 340 nm). During these times, jNO2 photolysis rates were approximately 10 percent lower at CalTech with respect to Mount Wilson. The NCAR Tropospheric Ultraviolet and Visible (TUV) radiation model was used to calculate actinic flux and photolysis frequencies in cloud and aerosol free conditions, as well as with the default urban aerosol profile. Neither of these TUV simulations accurately described the photolysis frequency observations at Caltech. This highlights the importance of correctly paramaterizing aerosol optical properties in radiative transfer models. This error has a significant impact on photochemical ozone production in air quality forecasts. Comparison of TUV j-values at Mount Wilson with standard aerosol profiles shows how well the model performs in an environment with lower aerosol optical depth.

  7. [Alteration of thyroid hormone secretion after long-term exposure to low doses of endocrine disruptor DDT].

    PubMed

    Iaglova, N V; Iaglov, V V

    2014-01-01

    Endocrine disruptors are exogenous substances that exhibit hormone-like action and consequently disrupt homeostatic action of endogenous hormones. DDT is the most common disruptor. The objective was to evaluate changes in thyroid hormone secretion after long-term exposure to low doses of DDT. The experiment was performed on male Wistar rats. The rats were given DDT at doses of 1.89±0.86 мg/kg/day and 7.77±0.17 мg/kg/day for 6 and 10 weeks. Dose dependent increase of serum total thyroxine, total triiodthyronine, and thyroid peroxidase was revealed after 6 weeks exposure. After 10 weeks free thyroxine secretion was reduced. Such alterations of the thyroid status are typical for iodine deficient goiter. The data obtained indicate that the main mechanism of DDT action includes disruption of thyroxine secretion by thyrocytes, but not inhibition of deiodinase activity and decrease of blood thyroid binding proteins.

  8. Calcium-45 uptake by shell gland, oviduct, plasma and eggshell of DDT-dosed ducks and chickens.

    PubMed

    Davison, K L

    1978-01-01

    Experiments were conducted with ducks and chickens to determine the effects of acute doses of DDT and DDE on calcium-45 balance and calcium-45 distribution among plasma, femur, tibia, oviduct, shell gland, and eggshell. Species differences in distribution of calcium-45 were evident between control ducks and control chickens. Ducks contained more radiocalcium in plasma, shell glands, tibias, and femurs than chickens and eliminated less radiocalcium in their droppings than chickens. The percentage of radiocalcium deposited in eggshells by control birds of either species was about equal. Ducks and chickens treated with DDT or DDE contained more radiocalcium in their shell glands than their respective controls. Treatment with DDT or DDE caused eggshell thinning in ducks but not in chickens; however, treatment with DDT or DDE did not alter significantly the percentage of radiocalcium that appeared in eggshells of either species.

  9. Early Warning Look Ahead Metrics: The Percent Milestone Backlog Metric

    NASA Technical Reports Server (NTRS)

    Shinn, Stephen A.; Anderson, Timothy P.

    2017-01-01

    All complex development projects experience delays and corresponding backlogs of their project control milestones during their acquisition lifecycles. NASA Goddard Space Flight Center (GSFC) Flight Projects Directorate (FPD) teamed with The Aerospace Corporation (Aerospace) to develop a collection of Early Warning Look Ahead metrics that would provide GSFC leadership with some independent indication of the programmatic health of GSFC flight projects. As part of the collection of Early Warning Look Ahead metrics, the Percent Milestone Backlog metric is particularly revealing, and has utility as a stand-alone execution performance monitoring tool. This paper describes the purpose, development methodology, and utility of the Percent Milestone Backlog metric. The other four Early Warning Look Ahead metrics are also briefly discussed. Finally, an example of the use of the Percent Milestone Backlog metric in providing actionable insight is described, along with examples of its potential use in other commodities.

  10. Synergistic genotoxicity caused by low concentration of titanium dioxide nanoparticles and p,p'-DDT in human hepatocytes.

    PubMed

    Shi, Yun; Zhang, Jiang-Hua; Jiang, Ming; Zhu, Li-Hua; Tan, He-Qing; Lu, Bin

    2010-04-01

    The use of titanium dioxide nanoparticles (nano-TiO(2)) for the degradation of dichlorodiphenyltrichloroethane (p,p'-DDT) increases the risk of exposure to trace nano-TiO(2) and p,p'-DDT mixtures. The interaction of p,p'-DDT and nano-TiO(2) at low concentrations may alter toxic response relative to nano-TiO(2) or p,p'-DDT alone. In this work, the combined genotoxicity of trace nano-TiO(2) and p,p'-DDT on human embryo L-02 hepatocytes without photoactivation was studied. Nano-TiO(2) (0.1 g/L) was mixed with 0.01-1 mmol/L p,p'-DDT to determine adsorption isotherms. L-02 cells were exposed to different levels of p,p'-DDT (0, 0.001, 0.01, and 0.1 mumol/L) and nano-TiO(2) (0, 0.01, 0.1, and 1 microg/mL) respectively. The adsorption of p,p'-DDT by nano-TiO(2) was approximately 0.3 mmol/g. Cell viability, apoptosis, and DNA double strand breaks were similar among all test groups. Nano-TiO(2) alone (0.01-1 microg/mL) increased the levels of oxidative stress and oxidative DNA adducts (8-OHdG), but it did not induce DNA breaks or chromosome damage. Addition of trace nano-TiO(2) with trace p,p'-DDT synergistically enhanced genotoxicity via increasing oxidative stress, oxidative DNA adducts, DNA breaks, and chromosome damage in L-02 cells. Low concentrations of nano-TiO(2) and p,p'-DDT increased oxidativestress by reactive oxygen species (ROS) formation and lipid oxidation. Oxidative stress is a major pathway for DNA and chromosome damage. Dose-dependent synergistic genotoxicity induced by combined exposure of trace p,p'-DDT and nano-TiO(2) suggests a potential environmental risk of nano-TiO(2) assisted photocatalysis.

  11. 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.

  12. Reduction of Microbial Aerosols by Automatic Toilet Bowl Cleaners.

    ERIC Educational Resources Information Center

    Yahya, Moyasar; And Others

    1992-01-01

    A study of the impact of automatic toilet bowl cleaners on aerosol generation. Three toilet bowl cleaners containing 2.5, 6.7 or 18.2 percent surfactant materials were evaluated. Results indicate these cleaners significantly (p 0.05) reduce bacteria ejected from the bowl, and the cleaner containing the greatest amount of surfactant was the most…

  13. Comparative pharmacodynamics of CYP2B induction by DDT, DDE, and DDD in male rat liver and cultured rat hepatocytes.

    PubMed

    Nims, R W; Lubet, R A; Fox, S D; Jones, C R; Thomas, P E; Reddy, A B; Kocarek, T A

    1998-03-27

    In this study the pharmacodynamics were characterized of rat hepatic cytochrome P-450 2B (CYP2B) induction by the pesticide DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] and its metabolites DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], which is bioretained, and DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane], which is metabolized further and therefore less prone to bioaccumulate. DDT, DDE, and DDD were each found to be pure phenobarbital-type cytochrome P-450 inducers in the male F344/NCr rat, causing induction of hepatic CYP2B and CYP3A, but not CYP1A. The ED50 values for CYP2B induction (benzyloxyresorufin O-dealkylation) by DDT, DDE, and DDD were, respectively, 103, 88, and > or = 620 ppm in diet (14 d of exposure). The efficacies (Emax values) for induction of benzyloxyresorufin O-dealkylation by DDT, DDE, and DDD were 24-, 22-, and > or = 1-fold, respectively, compared to control values. The potencies of the three congeners for CYP2B induction appeared also to be similar, with EC50 values (based on total serum DDT equivalents) of 1.5, 1.8, and > or = 0.51 microM, respectively. The EC50 values based on DDT equivalents in hepatic tissue were 15, 16, and > or = 5.9 micromol/kg liver tissue, respectively. In primary cultures of adult rat hepatocytes, DDT, DDE, and DDD each displayed ability to induce total cellular RNA coding for CYP2B (ED50 values of 0.98, 0.83, and > or = 2.7 microM, respectively). These results suggest that DDT, DDE, and DDD each possess a high degree of intrinsic CYP2B-inducing ability for rat liver, despite marked differences in bioretention among the congeners.

  14. 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.

  15. 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

  16. Development of high efficiency (14 percent) solar cell array module

    NASA Technical Reports Server (NTRS)

    Iles, P. A.; Khemthong, S.; Olah, S.; Sampson, W. J.; Ling, K. S.

    1980-01-01

    Most effort was concentrated on development of procedures to provide large area (3 in. diameter) high efficiency (16.5 percent AM1, 28 C) P+NN+ solar cells. Intensive tests with 3 in. slices gave consistently lower efficiency (13.5 percent). The problems were identified as incomplete formation of and optimum back surface field (BSF), and interaction of the BSF process and the shallow P+ junction. The problem was shown not to be caused by reduced quality of silicon near the edges of the larger slices.

  17. ModelE2-TOMAS development and evaluation using aerosol optical depths, mass and number concentrations

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Adams, P. J.; Shindell, D. T.

    2014-09-01

    The TwO-Moment Aerosol Sectional microphysics model (TOMAS) has been integrated into the state-of-the-art general circulation model, GISS ModelE2. TOMAS has the flexibility to select a size resolution as well as the lower size cutoff. A computationally efficient version of TOMAS is used here, which has 15 size bins covering 3 nm to 10 μm aerosol dry diameter. For each bin, it simulates the total aerosol number concentration and mass concentrations of sulphate, pure elementary carbon (hydrophobic), mixed elemental carbon (hydrophilic), hydrophobic organic matter, hydrophilic organic matter, sea salt, mineral dust, ammonium, and aerosol-associated water. This paper provides a detailed description of the ModelE2-TOMAS model and evaluates the model against various observations including aerosol precursor gas concentrations, aerosol mass and number concentrations, and aerosol optical depths. Additionally, global budgets in ModelE2-TOMAS are compared with those of other global aerosol models, and the TOMAS model is compared to the default aerosol model in ModelE2, which is a bulk aerosol model. Overall, the ModelE2-TOMAS predictions are within the range of other global aerosol model predictions, and the model has a reasonable agreement with observations of sulphur species and other aerosol components as well as aerosol optical depth. However, ModelE2-TOMAS (as well as the bulk aerosol model) cannot capture the observed vertical distribution of sulphur dioxide over the Pacific Ocean possibly due to overly strong convective transport. The TOMAS model successfully captures observed aerosol number concentrations and cloud condensation nuclei concentrations. Anthropogenic aerosol burdens in the bulk aerosol model running in the same host model as TOMAS (ModelE2) differ by a few percent to a factor of 2 regionally, mainly due to differences in aerosol processes including deposition, cloud processing, and emission parameterizations. Larger differences are found for naturally

  18. 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.

  19. The development of DDT-resistance in Musca domestica and Protophormia terraenovae*

    PubMed Central

    Derbeneva-Uhova, V. P.; Lineva, V. A.; Drobozina, V. P.

    1966-01-01

    In the course of studies on the effect of sublethal doses of DDT on flies, it has been observed that such doses cause disturbances in the process of oogenesis among both laboratory strains and wild populations of Musca domestica and Protophormia terraenovae. Changes in the susceptibility of a fly population to DDT are accompanied by changes in the percentage of females with disturbances of oogenesis, but further observations under natural conditions are needed before it can be said whether it is possible to use the proportion of females with such disturbances as a true indicator of the degree of development of resistance and consequently of the need to change the insecticide or the method of control. PMID:5296542

  20. The value of a spreading agent in larvicidal formulations containing DDT

    PubMed Central

    Msangi, A. S.

    1959-01-01

    The value of a spreading agent in a 5% solution of DDT in oil was assessed under semifield conditions using third-stage laboratory-bred larvae of Anopheles gambiae. These larvae were treated with known dosages of the larvicide with and without the addition of spreading agent, and the mortalities produced by the two forms of the larvicide were compared. An attempt was also made to compare the efficacy of the two forms under field conditions. The trials described seem to have shown quite conclusively that, so far as a 5% solution of DDT in oil is concerned, there is no advantage to be gained by adding spreading agents to the larvicide. PMID:14424863

  1. DDT and HCH isomer levels in soils, carrot root and carrot leaf samples.

    PubMed

    Waliszewski, S M; Carvajal, O; Gómez-Arroyo, S; Amador-Muñoz, O; Villalobos-Pietrini, R; Hayward-Jones, P M; Valencia-Quintana, R

    2008-10-01

    Agricultural cultivation assists organochlorine pesticide migration from contaminated soils to growing plants. This phenomenon is caused by retention processes that modify volatile pesticide exchange between soil, air and plants. The aim of the study was to monitor organochlorine pesticide (HCB, alpha- and gamma-HCH, pp'DDE, op'DDT, pp'DDT) levels and compare these concentrations in soil, carrot roots and carrot leaves. Fifty soil samples, 50 carrot root and 50 carrot leaf samples were taken from the same fields and analyzed by GLC-ECD. The results reveal organochlorine pesticide diffusion from agricultural soils to growing carrot plants and their vapors adsorption by leaves. Within the carrot plant, organochlorine pesticides accumulate especially in carrot root peel, 3-7 times more than in root flesh.

  2. Trends, Long-range Transport and Lifetime of DDT in and over Central Europe

    NASA Astrophysics Data System (ADS)

    Lammel, G.; Dvorská, A.; Stohl, A.; Klánová, J.; Ries, L.

    2009-04-01

    Dichlorophenyltrichloroethane, DDT, and its major metabolites dichlorophenyldichloroethylene, DDE, and dichlorophenyldichloroethane, DDD, 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 is a multicompartmental substance with only a small mass fraction residing in air. Decreasing concentration trends are recorded in Europe, where the substance has not been used since ?1988 (Holoubek et al., 2007). Transport in the free troposphere is expected by models (Lammel & Semeena, 2005; Semeena et al., 2006), but no observations in the free troposphere had been reported in Europe. The degradation rates of DDT, DDE and DDD are uncertain. In particular, the hydroxyl radical reaction rate coefficients in air are unknown. DDT monitoring data in air at a central European continental background station, Kosetice, Czech Republic, were used in combination with back-trajectories (HYSPLIT model, NOAA) to localize DDT sources in central, western and northern Europe. The decreasing trend continued during recent years, 2004-06. During 2 campaigns at a high mountain site in the Alps (Zugspitze, 2650 m a.s.l.) mean concentrations of 0.23, 0.63 and 0.08 pg m-3 of DDT, DDE and DDD, respectively, were measured in summer and 0.73, 2.22, and 0.52 pg m-3, respectively, in winter. The levels were not lower in free tropospheric air than in boundary layer air. Transport and residence times in air were quantified using Lagrangian particle dispersion model retroplume analyses (FLEXPART model; Stohl et al., 1998). During a stable anti-cyclonic situation photochemical lifetimes corresponded to kOH < 1.5x10-12 cm3 molec-1 s-1 are found for p,p'-DDT, kOH < 0.75x10-12 cm3 molec-1 s-1 for p,p'-DDE and kOH < 1.0x10-12 cm3 molec-1 s-1 for p,p'-DDD. The kOH values for DDE and DDD are significantly lower than estimated (QSAR). References

  3. Long-term persistence of dieldrin, DDT, and heptachlor epoxide in earthworms

    USGS Publications Warehouse

    Beyer, W.N.; Krynitsky, A.J.

    1989-01-01

    Earthworms can accumulate persistent soilborne insecticides and are an important source of contamination of terrestrail wildlife. We treated experimental plots once with dieldrin, DDT, or heptachlor, and measured changes in insecticide concentrations in earthworms over a 20-year period. We estimated 'half-times,' defined as the time for a concentration in earthworms to be reduced by half. Deldrin had a half-time of 5.4 years. DDE, the metabolite of DDT most important to wildlife, increased until the third year and then decreased with a half-time of 5.7 years. Heptachlor epoxide, the metabolite of hepatachlor most important to wildlife, increased until the second year and then decreased with a half-time of 4.3 years. The declining parts of the curves of all three compounds fit exponential decay equations reasonably well. The estimates persistence are relevant to insecticides at low or moderate concentrations in relatively undistrubed soils in temperate climates.

  4. Studies on Dechlorination of DDT with Alkaline 2-propanol and Iron-Nickel (Fe-Ni) Catalyst.

    NASA Astrophysics Data System (ADS)

    Shareef, A.; Zaman, S. U.

    2009-05-01

    The Persistent Organic Pollutants (POPs) pesticides were previously extensively used in the cotton production and other agricultural activities in Pakistan and at least three thousand metric tons of obsolete pesticides have been stored under extreme hazardous conditions in more than thousand sites. Locally banned or severely restricted pesticides are easily available and DDT is continuously illegally imported and use in our country. Elimination of organochlorine pesticides (OCPs) waste has received considerable attention over the past two decades. Existing catalytic hydrodechlorinated techniques for disposing of OCPs are very costly due to the use of noble metals as catalysts. The aim of our study is to develop the cost effective and efficient method for the safe disposal of OCPs. This study is in continuation work on dechlorination of organochlorine pesticides with Fe-Ni catalyst in alkaline 2-propanol media. We turned our attention to the development of DDT disposal method for the third world countries. Herein, we report our first finding that in alkaline 2-propanol with Fe-Ni catalyst is an effective method for dechlorination of DDT. Catalytic dechlorination of DDT was carried out in an alkaline solution of NaOH and 2-propanol in the presence of catalyst at the temperature below 82 oC and end products were analyzed by using Gas Chromatography (GC-ECD) and Ion Chromatography (IC) techniques. Results obtained with initial concentration of DDT ranging between 10-100 μg/ml showed conversion of DDT to chlorine free product within 4 hrs.

  5. 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.

  6. 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.

  7. A report on the deflagration-to-detonation transition (DDT) in the high explosive LX-04

    SciTech Connect

    Hare, D E; Forbes, J W; Garcia, F; Granholm, R H; Tarver, C M; Vandersall, K S; Sandusky, H W

    2004-06-30

    The deflagration-to-detonation transition (DDT) was investigated for 1.874 g/cc (98.8 % of theoretical maximum density) LX-04 in moderate confinement (4340 steel tube at R{sub C} 32 with 1.020 inch inside diameter and 0.235 inch thick wall) at both ambient initial temperature (roughly 20 C) and at an initial temperature of 186 C. No transition to detonation was observed in a 295 mm column length for either case.

  8. Violent Reactions and DDT in Hot, Thermally Damaged HMX-Based PBXs

    SciTech Connect

    Parker, Gary R. Jr.; Holmes, Matthew D.; Dickson, Peter; Asay, Blaine W.; McAfee, John M.

    2012-07-03

    Conventional high explosives (e.g. PBX 9501, LX-07) have been observed to react violently following thermal insult: (1) Fast convective and compressive burns (HEVR); (2) Thermal explosions (HEVR); and (3) Deflagration-to-detonation transition (DDT). No models exist that sufficiently capture/predict these complex multiphase and multiscale behaviors. For now, research is focused on identifying vulnerabilities and factors that control this behavior.

  9. Impact of addition of amendments on the degradation of DDT and its residues partitioned on soil.

    PubMed

    Singh, Swatantra P; Bose, Purnendu; Guha, Saumyen; Gurjar, Suresh K; Bhalekar, Santosh

    2013-08-01

    Market-grade DDT used for mosquito control and other purposes is a mixture of 4,4-DDT, 2,4-DDT and smaller amounts of 4,4-DDD, 2,4-DDD, 4,4-DDE and 4,4-DDMU. All above components (together known as DDTr) are strongly hydrophobic and hence are present in the environment predominantly in the soil/sediment phases. The persistence of DDTr and the feasibility of attenuation of DDTr concentration in soil matrix through addition of amendments is a subject of ongoing interest. The objective of this study was to compare the decline of soil-partitioned DDTr concentration through, (1) the natural attenuation process, (2) enhanced aerobic and anaerobic biodegradation processes involving addition of acclimatized seed and co-metabolites and (3) Nanoscale Zero Valent Iron (NZVI) addition. The extent of decline in soil DDTr concentration in control experiments, where biodegradation and photolysis were excluded, was around 10-15% in ∼100d. Extent of DDTr decline in natural attenuation experiments was 25-30% and 15-20% under aerobic and anaerobic conditions respectively. In enhanced biodegradation experiments, addition of acclimatized seed and/or co-metabolites did not enhance the extent of DDTr attenuation over and above the natural attenuation rates both in aerobic and anaerobic conditions. It thus appeared that biodegradation of DDTr adsorbed on soil was severely limited and controlled by desorption and consequent bioavailability of DDTr in the aqueous phase. In case of NZVI addition, the rate of DDTr degradation was much faster, with 40% decrease in DDTr concentration within 28h of NZVI addition. Here, the faster DDTr degradation may be through direct electron transfer between NZVI particles and DDTr molecules adsorbed on soil. Increase in the concentration of 4,4-DDD and 2,4-DDD during NZVI addition suggest that these compounds are either intermediate or end products of DDT degradation process.

  10. Organochlorine insecticides DDT and chlordane in relation to survival following breast cancer

    PubMed Central

    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.

    2015-01-01

    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, 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; 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. PMID:26285160

  11. 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.

  12. Development and Execution of a Large-scale DDT Tube Test for IHE Material Qualification

    SciTech Connect

    Parker, Gary Robert; Broilo, Robert M.; Lopez-Pulliam, Ian Daniel; Vaughan, Larry Dean

    2016-10-24

    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. The 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

  13. 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.

  14. 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.

  15. Biodegradation of DDT by stimulation of indigenous microbial populations in soil with cosubstrates.

    PubMed

    Ortíz, Irmene; Velasco, Antonio; Le Borgne, Sylvie; Revah, Sergio

    2013-04-01

    Stimulation of native microbial populations in soil by the addition of small amounts of secondary carbon sources (cosubstrates) and its effect on the degradation and theoretical mineralization of DDT [l,l,l-trichloro-2,2-bis(p-chlorophenyl)ethane] and its main metabolites, DDD and DDE, were evaluated. Microbial activity in soil polluted with DDT, DDE and DDD was increased by the presence of phenol, hexane and toluene as cosubstrates. The consumption of DDT was increased from 23 % in a control (without cosubstrate) to 67, 59 and 56 % in the presence of phenol, hexane and toluene, respectively. DDE was completely removed in all cases, and DDD removal was enhanced from 67 % in the control to ~86 % with all substrates tested, except for acetic acid and glucose substrates. In the latter cases, DDD removal was either inhibited or unchanged from the control. The optimal amount of added cosubstrate was observed to be between 0.64 and 2.6 mg C [Formula: see text]. The CO2 produced was higher than the theoretical amount for complete cosubstrate mineralization indicating possible mineralization of DDT and its metabolites. Bacterial communities were evaluated by denaturing gradient gel electrophoresis, which indicated that native soil and the untreated control presented a low bacterial diversity. The detected bacteria were related to soil microorganisms and microorganisms with known biodegradative potential. In the presence of toluene a bacterium related to Azoarcus, a genus that includes species capable of growing at the expense of aromatic compounds such as toluene and halobenzoates under denitrifying conditions, was detected.

  16. DDT in Mytilus edulis: Spatio-temporal variations in the Punta Banda estuary, Baja California, Mexico

    SciTech Connect

    Galindo-Bect, M.S.; Flores-Baez, B.P. )

    1991-02-01

    The mussel Mytilus sp. has been widely used as a sentinel organism or biological indicator of organic pollutants in the marine environment. In studies recently carried out in Baja California, Mexico, it was found that the spatial and temporal variations of DDT in samples of the mussel Mytilus californianus collected from the area exposed to the ocean do not follow a defined pattern and that the highest values of DDT are found at the border with the US. The Maneadero Valley in Baja California, Mexico, is an agricultural area where important volumes of pesticides are applied, part of which are transported to the Punta Banda Estuary where they remain for an undetermined period of time during which they are consumed and bioaccumulated by organisms. The main objective of the present work is to determine the levels and temporal variation of DDT in the mussel Mytilus edulis in the Punta Banda Estuary, Baja California. With the results, the authors will define the dynamics of this pollutant in the estuary.

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

    SciTech Connect

    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 over 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.

  18. Computational evidence for the detoxifying mechanism of epsilon class glutathione transferase toward the insecticide DDT.

    PubMed

    Li, Yanwei; Shi, Xiangli; Zhang, Qingzhu; Hu, Jingtian; Chen, Jianmin; Wang, Wenxing

    2014-05-06

    A combined quantum mechanics/molecular mechanics (QM/MM) computation of the detoxifying mechanism of an epsilon class glutathione transferases (GSTs) toward organochlorine insecticide DDT, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, has been carried out. The exponential average barrier of the proton transfer mechanism is 15.2 kcal/mol, which is 27.6 kcal/mol lower than that of the GS-DDT conjugant mechanism. It suggests that the detoxifying reaction proceeds via a proton transfer mechanism where GSH acts as a cofactor rather than a conjugate. The study reveals that the protein environment has a strong effect on the reaction barrier. The experimentally proposed residues Arg112, Glu116 and Phe120 were found to have a strong influence on the detoxifying reaction. The influence of residues Pro13, Cys15, His53, Ile55, Glu67, Ser68, Phe115, and Leu119 was detected as well. It is worth noticing that Ile55 facilitates the detoxifying reaction most. On the basis of the structure of DDT, structure 2, (BrC6H4)2CHCCl3, is the best candidate among all the tested structures in resisting the detoxification of enzyme agGSTe2.

  19. Analysis of Compaction Shock Interactions During DDT of Low Density HMX

    NASA Astrophysics Data System (ADS)

    Rao, Pratap; Gonthier, Keith

    2015-06-01

    Deflagration-to-Detonation Transition (DDT) within low density HMX often occurs by a complex mechanism that involves compaction shock interactions. Piston driven DDT experiments indicate that detonation can be abruptly triggered by the interaction of a strong combustion driven shock and a lead piston supported shock, where the nature of the interaction depends on initial density and lead shock strength. These shocks induce dissipation and thermomechanical fluctuations at the meso-scale due to pore collapse resulting in hot-spots. 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 initial density, and lead and trailing shock strength. Emphasis is placed on interpreting solutions in a phase space expressed in terms of effective pressure and dissipative work because of their relevance to hot-spot formation. Meso-scale predictions are shown to compare favorably to those given by a macro-scale theory. This information is being used to formulate a dissipation-dependent reactive burn model to describe shock desensitization and DDT. Preliminary redictions will be presented that illustrate how initial density and input shock strength can affect the transition mechanism. This research is supported by the Defense Threat Reduction Agency (DTRA) under sponsor Award Number HDTRA1-10-1-0018, and the Air Force Research Laboratory (AFRL-RWME) under sponsor Award Number FA8651-09-0021.

  20. Joint toxicity of sediment-associated DDT and copper to a polychaete, Nereis succinea.

    PubMed

    Wang, Fei; Qi, Hong-Xue; You, Jing

    2015-03-01

    As major components in antifouling paints, both dichlorodiphenyltrichloroethane (DDT) and copper are ubiquitous in estuarine sediment and have been detected at high concentrations in the harbors in South China. In the present study joint toxicity between DDT and copper to an estuarine polychaete, Nereis succinea, was examined using bioaccumulation potential, growth impairment and change in lipid peroxidation contents as sub-lethal endpoints. In general, the toxicity of DDXs (DDT and its metabolites) and copper acted independently and copper was more toxic to the lugworms at environmentally relevant concentrations. Nevertheless, co-exposure to copper led to a significant reduction in the bioaccumulation of DDXs when the concentrations of DDXs in sediment were high. The inhibition of DDX bioaccumulation by copper may be partially explained by the decrease in the bioavailability of sediment-associated DDXs which were estimated by biomimetic gut fluid extraction. The saturation of the solubilization agents or the inhibition of protease activity in gut fluid of N. succinea by copper limited the DDX bioavailability and the subsequent bioaccumulation.

  1. PCDD/F formation during thermal desorption of p,p'-DDT contaminated soil.

    PubMed

    Zhao, Zhonghua; Ni, Mingjiang; Li, Xiaodong; Buekens, Alfons; Yan, Jianhua

    2017-04-10

    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.

  2. Pesticides and breast cancer risk: a review of DDT, DDE, and dieldrin.

    PubMed Central

    Snedeker, S M

    2001-01-01

    Established risk factors for breast cancer explain breast cancer risk only partially. Hence, there has been interest in evaluating what role environmental chemicals, especially those with evidence of being hormonally active agents, play in breast cancer risk. Organochlorine pesticides have received the most attention because of their persistence in the environment, ability to concentrate up the food chain, continued detection in the food supply and breast milk, and ability to be stored in the adipose tissue of animals and humans. Although several early descriptive studies and a cohort study identified a strong positive association with breast cancer risk and adipose or blood levels of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and/or its metabolite dichlorodiphenyldichloroethylene (DDE), most of the more recent case--control and nested case--control studies have not supported this association. In this review I discuss these findings and explore how exposure to different forms of DDT with varying estrogenicities may have affected the results of these studies. I also address how other factors influence the interpretation of the studies on DDT, DDE, and breast cancer risk. These include the effect of analytic methods, dietary factors, menopausal status, use of different types of control populations, lactation history, estrogen receptor status, ethnic/racial subgroups, breast tumor characteristics, and polymorphisms. I also discuss the emerging research on whether serum levels of the persistent organochlorine insecticide dieldrin are related to breast cancer risk in Danish and American women. Further research needs are also identified. PMID:11250804

  3. School Designed To Use 80 Percent Less Energy

    ERIC Educational Resources Information Center

    American School and University, 1975

    1975-01-01

    The new Terraset Elementary School in Reston, Virginia, uses earth as a cover for the roof area and for about 80 percent of the wall area. A heat recovery system will be used with solar collectors playing a primary role in heating and cooling. (Author/MLF)

  4. Tricky Times for the Top 10 Percent Program

    ERIC Educational Resources Information Center

    Roach, Ronald

    2007-01-01

    Both supporters and critics of Texas' Top 10 Percent law have been surprised at its popularity, but some UT officials and legislators would like to see the program scaled back. As a Texas state legislator, Jim McReynolds, D-Lufkin, knows a thing or two about influencing the voting positions of his colleagues. This past spring, when Texas House…

  5. Grieving: 22 to 30 Percent of All College Students

    ERIC Educational Resources Information Center

    Balk, David E.

    2008-01-01

    At any given time, 22 to 30 percent of college undergraduates are in the first twelve months of grieving the death of a family member or friend. This conclusion, startling to some but accepted by others, comes from a variety of sources at academic sites in the United States and Europe. Information about the prevalence rate resulted from clinical…

  6. 35 GHz integrated circuit rectifying antenna with 33 percent efficiency

    NASA Technical Reports Server (NTRS)

    Yoo, T.-W.; Chang, K.

    1991-01-01

    A 35 GHz integrated circuit rectifying antenna (rectenna) has been developed using a microstrip dipole antenna and beam-lead mixer diode. Greater than 33 percent conversion efficiency has been achieved. The circuit should have applications in microwave/millimeter-wave power transmission and detection.

  7. Evaluating Equating Results: Percent Relative Error for Chained Kernel Equating

    ERIC Educational Resources Information Center

    Jiang, Yanlin; von Davier, Alina A.; Chen, Haiwen

    2012-01-01

    This article presents a method for evaluating equating results. Within the kernel equating framework, the percent relative error (PRE) for chained equipercentile equating was computed under the nonequivalent groups with anchor test (NEAT) design. The method was applied to two data sets to obtain the PRE, which can be used to measure equating…

  8. Creatine monohydrate supplementation on body weight and percent body fat.

    PubMed

    Kutz, Matthew R; Gunter, Michael J

    2003-11-01

    Seventeen active males (age 22.9 +/- 4.9 year) participated in a study to examine the effects of creatine monohydrate supplementation on total body weight (TBW), percent body fat, body water content, and caloric intake. The TBW was measured in kilograms, percent body fat by hydrostatic weighing, body water content via bioelectrical impedance, and caloric intake by daily food log. Subjects were paired and assigned to a creatine or placebo group with a double-blind research design. Supplementation was given for 4 weeks (30 g a day for the initial 2 weeks and 15 g a day for the final 2 weeks). Subjects reported 2 days a week for supervised strength training of the lower extremity. Significant increases before and after the study were found in TBW (90.42 +/- 14.74 to 92.12 +/- 15.19 kg) and body water content (53.77 +/- 1.75 to 57.15 +/- 2.01 L) for the creatine group (p = 0.05). No significant changes were found in percent body fat or daily caloric intake in the creatine group. No significant changes were noted for the placebo group. These findings support previous research that creatine supplementation increases TBW. Mean percent body fat and caloric intake was not affected by creatine supplementation. Therefore weight gain in lieu of creatine supplementation may in part be due to water retention.

  9. Realities and Myths of the Top 10 Percent Rule

    ERIC Educational Resources Information Center

    Johnson, Troy

    2010-01-01

    Since its inception in Texas a baker's dozen years ago, educators look forward with every new legislative session to another round of discussion about the "top 10 percent rule," which guarantees admission to the state's public universities for these talented high school graduates. Originally passed as a way to increase enrollment of…

  10. 32 CFR 48.508 - Certain 100 percent disability retirement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 1 2012-07-01 2012-07-01 false Certain 100 percent disability retirement. 48.508 Section 48.508 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN RETIRED SERVICEMAN'S FAMILY PROTECTION PLAN Annuity § 48.508 Certain 100...

  11. 32 CFR 48.508 - Certain 100 percent disability retirement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Certain 100 percent disability retirement. 48.508 Section 48.508 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN RETIRED SERVICEMAN'S FAMILY PROTECTION PLAN Annuity § 48.508 Certain 100...

  12. 32 CFR 48.508 - Certain 100 percent disability retirement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Certain 100 percent disability retirement. 48.508 Section 48.508 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN RETIRED SERVICEMAN'S FAMILY PROTECTION PLAN Annuity § 48.508 Certain 100...

  13. 32 CFR 48.508 - Certain 100 percent disability retirement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Certain 100 percent disability retirement. 48.508 Section 48.508 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN RETIRED SERVICEMAN'S FAMILY PROTECTION PLAN Annuity § 48.508 Certain 100...

  14. 32 CFR 48.508 - Certain 100 percent disability retirement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Certain 100 percent disability retirement. 48.508 Section 48.508 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN RETIRED SERVICEMAN'S FAMILY PROTECTION PLAN Annuity § 48.508 Certain 100...

  15. Issues of Institutionalization: Five Percent Fallacies and Terminal Care.

    ERIC Educational Resources Information Center

    Rosenberg, Edwin; And Others

    1983-01-01

    Discusses the "5 percent fallacy," which refers to the number of older people living in institutions at a given time, and the likelihood of an older person dying in an institution. Three articles discuss research methodology, data interpretation, and measuring techniques. (JAC)

  16. Overview of Aerosol Distribution

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram

    2005-01-01

    Our knowledge of atmospheric aerosols (smoke, pollution, dust or sea salt particles, small enough to be suspended in the air), their evolution, composition, variability in space and time and interaction with clouds and precipitation is still lacking despite decades of research. Understanding the global aerosol system is fundamental for progress in climate change and hydrological cycle research. While a single instrument was used to demonstrate 50 years ago that the global CO2 levels are rising, posing threat of global warming, we need an array of satellites and field measurements coupled with chemical transport models to understand the global aerosol system. This complexity of the aerosol problem results from their short lifetime (1 week) and variable chemical composition. A new generation of satellites provides exciting opportunities to measure the global distribution of aerosols, distinguishing natural from anthropogenic aerosol and measuring their interaction with clouds and climate. I shall discuss these topics and application of the data to air quality monitoring.

  17. Serum Predictors of Percent Lean Mass in Young Adults.

    PubMed

    Lustgarten, Michael S; Price, Lori L; Phillips, Edward M; Kirn, Dylan R; Mills, John; Fielding, Roger A

    2016-08-01

    Lustgarten, MS, Price, LL, Phillips, EM, Kirn, DR, Mills, J, and Fielding, RA. Serum predictors of percent lean mass in young adults. J Strength Cond Res 30(8): 2194-2201, 2016-Elevated lean (skeletal muscle) mass is associated with increased muscle strength and anaerobic exercise performance, whereas low levels of lean mass are associated with insulin resistance and sarcopenia. Therefore, studies aimed at obtaining an improved understanding of mechanisms related to the quantity of lean mass are of interest. Percent lean mass (total lean mass/body weight × 100) in 77 young subjects (18-35 years) was measured with dual-energy x-ray absorptiometry. Twenty analytes and 296 metabolites were evaluated with the use of the standard chemistry screen and mass spectrometry-based metabolomic profiling, respectively. Sex-adjusted multivariable linear regression was used to determine serum analytes and metabolites significantly (p ≤ 0.05 and q ≤ 0.30) associated with the percent lean mass. Two enzymes (alkaline phosphatase and serum glutamate oxaloacetate aminotransferase) and 29 metabolites were found to be significantly associated with the percent lean mass, including metabolites related to microbial metabolism, uremia, inflammation, oxidative stress, branched-chain amino acid metabolism, insulin sensitivity, glycerolipid metabolism, and xenobiotics. Use of sex-adjusted stepwise regression to obtain a final covariate predictor model identified the combination of 5 analytes and metabolites as overall predictors of the percent lean mass (model R = 82.5%). Collectively, these data suggest that a complex interplay of various metabolic processes underlies the maintenance of lean mass in young healthy adults.

  18. Matter power spectrum and the challenge of percent accuracy

    NASA Astrophysics Data System (ADS)

    Schneider, Aurel; Teyssier, Romain; Potter, Doug; Stadel, Joachim; Onions, Julian; Reed, Darren S.; Smith, Robert E.; Springel, Volker; Pearce, Frazer R.; Scoccimarro, Roman

    2016-04-01

    Future galaxy surveys require one percent precision in the theoretical knowledge of the power spectrum over a large range including very nonlinear scales. While this level of accuracy is easily obtained in the linear regime with perturbation theory, it represents a serious challenge for small scales where numerical simulations are required. In this paper we quantify the precision of present-day N-body methods, identifying main potential error sources from the set-up of initial conditions to the measurement of the final power spectrum. We directly compare three widely used N-body codes, Ramses, Pkdgrav3, and Gadget3 which represent three main discretisation techniques: the particle-mesh method, the tree method, and a hybrid combination of the two. For standard run parameters, the codes agree to within one percent at k<=1 h Mpc-1 and to within three percent at k<=10 h Mpc-1. We also consider the bispectrum and show that the reduced bispectra agree at the sub-percent level for k<= 2 h Mpc-1. In a second step, we quantify potential errors due to initial conditions, box size, and resolution using an extended suite of simulations performed with our fastest code Pkdgrav3. We demonstrate that the simulation box size should not be smaller than L=0.5 h-1Gpc to avoid systematic finite-volume effects (while much larger boxes are required to beat down the statistical sample variance). Furthermore, a maximum particle mass of Mp=109 h-1Msolar is required to conservatively obtain one percent precision of the matter power spectrum. As a consequence, numerical simulations covering large survey volumes of upcoming missions such as DES, LSST, and Euclid will need more than a trillion particles to reproduce clustering properties at the targeted accuracy.

  19. Aerosol, radiation, and climate

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1983-01-01

    Airborne, spaceborne, and ground-based measurements are used to study the radiative and climatic effects of aerosols. The data, which are modelled with a hierarchy of radiation and climate models, and their implications are summarized. Consideration is given to volcanic aerosols, polar stratospheric clouds, and the Arctic haze. It is shown that several types of aerosols (volcanic particles and the Arctic haze) cause significant alterations to the radiation budget of the regions where they are located.

  20. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1997-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size resolved aerosol microphysics and chemistry. Both profiles included pollution haze layer from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core.

  1. 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

  2. Effects of DDT and dicofol on population growth of Brachionus calyciflorus under different algal (Scenedesmus obliquus) densities.

    PubMed

    Xu, Xiao-Ping; Xi, Yi-Long; Chu, Zhao-Xia; Xiang, Xian-Ling

    2014-09-01

    A number of organochlorine pesticides, including DDT and dicofol, used to be important in crop protection and management. Their residues may reach water bodies and eventually affect the non-target organisms such as rotifers. In the present study, we evaluated the effects of DDT (0.05, 0.1, 0.2 and 0.4 mg l(-1)) and dicofol (0.1, 0.2, 0.4 and 0.8 mg l(-1)) on the population growth of rotifer Brachionus calyciflorus under two levels of Scenedesmus obliquus (1.0 x 10(6) and 3.0 x 10(6) cell ml(-1)). Regardless of the food level, DDT was more toxic than dicofol to B. calyciflorus. Under low food level, DDT at 0.1 and 0.2 mg l(-1) decreased the population growth rate (r), and DDT at 0.05-0.4 mg l(-1) decreased the maximum population density (K). Dicofol at 0.4 and 0.8 mg l(-1) decreased r and K, but dicofol at 0.2 mg l(-1) increased K. Under high food level, DDT at 0.05-0.2 mg l(-1) increased K, whereas DDT at 0.4 mg l(-1) as well as dicofol at 0.4 and 0.8 mg l(-1) decreased r and K. Increase in food level increased r exposed to DDT at 0.05-0.2 mg l(-1) as well as dicofol at 0.8 mg l(-1), and Kexposed to DDTat 0.05-0.2 mg l(-1) as well as dicofol at 0.1 and 0.2 mg l(-1). DDT concentration, algal density and their interaction affected r and K of B. calyciflorus. Both dicofol concentration and algal density affected r. Dicofol concentration, algal density and their interaction affected K. Both r and K were suitable endpoints for assessing the effects of DDT and dicofol on the rotifers population dynamics under two algal densities, and the latter was more sensitive.

  3. Evaluation of AERONET Aerosol Retrievals

    NASA Astrophysics Data System (ADS)

    Schuster, G. L.; Dubovik, O.; Rutledge, C. K.

    2001-12-01

    The aerosol robotic network (AERONET) program provides aerosol retrievals at ground-based sunphotometer sites throughout the world. The aerosol size distributions and refractive index retrievals at two locations have been converted to phase functions and single-scattering albedo using Mie theory. These optical properties are incorporated into a discrete-ordinates radiative transfer model and calculations are compared to independent measurements obtained at the surface. The independent measurements include principle plane radiances from sunphotometer data and narrowband irradiances from multi-filter rotating shadowband radiometer (MFRSR) and rotating shadowband spectroradiometer (RSS) data. The two locations represent radically different environments. The Atmospheric Radiation Measurement (ARM) program Central Facility (CF) represents a rural continental environment, while the CERES (Clouds and the Earth's Radiant Energy System) Ocean Validation Experiment (COVE) site represents a coastal marine environment. Both sites exhibit good agreement between the model calculations and the principle plane radiances for the year 2000 (generally better than 15 percent at optical depths greater than 0.1). A comparison with RSS measurements in July 2000 at the ARM Central Facility shows an irradiance error of 12 percent or better at tested wavelenghs longer than 500 nm. Comparisons with MFRSR data fared less well, however, indicating a discrepancy between the instruments. Inspection of 28 whole-sky imager (WSI) files coincidental with all AERONET quality-controlled retrievals during 7 days reveals that no clouds were obstructing the almucantar field of view and that indeed the whole sky was clear during this period, indicating a degree of robustness in the AERONET cloud screening. Additionally, the size distributions were evaluated at COVE with hourly-averaged wind speed and direction. Linear regression indicates that the coarse mode column-integrated surface area increases from

  4. First compound-specific chlorine-isotope analysis of environmentally-bioaccumulated organochlorines indicates a degradation-relatable kinetic isotope effect for DDT.

    PubMed

    Holmstrand, Henry; Mandalakis, Manolis; Zencak, Zdenek; Andersson, Per; Gustafsson, Orjan

    2007-11-01

    Compound-specific chlorine-isotope analysis (CSIA-Cl) of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (p,p'-DDE) in blubber from Baltic Grey seal (Halichoerus grypus) was performed in order to investigate if a kinetic isotope effect (KIE) could be observed concomitant to environmental degradation of DDT. The delta(37)Cl of p,p'-DDT and p,p'-DDE were -0.69 +/- 0.21 per thousand and -2.98 +/- 0.57 per thousand (1s igma, n = 3), respectively. Both samples were enriched relative to the hypothesized initial isotope composition (-4.34 per thousand), thus indicating a composite KIE associated with the degradation mechanisms pertaining to DDT. An isotope fractionation factor for degradation of dichloromethane, from the literature, was adapted and modified for use in the calculation of DDT degradation. A subsequent simplified Rayleigh distillation model of the DDT chlorine-isotope composition yielded an estimated fraction (f) of 7 +/- 2% of released DDT presently remaining as undegraded compound in the environment. The consistency between the result of the Rayleigh model (f approximately 7%) and the use of the DDT/(DDT + DDE) ratio as a measure of DDT degradation ( approximately 10% undegraded DDT) suggests that the KIE of DDT degradation may be significant, and that the novel approach of CSIA-Cl may be a valuable tool for degradation/persistence studies of lipophilic organochlorines in the environment.

  5. The role of cyclooxygenase-2-dependent signaling via cyclic AMP response element activation on aromatase up-regulation by o,p'-DDT in human breast cancer cells.

    PubMed

    Han, Eun Hee; Kim, Hyung Gyun; Hwang, Yong Pil; Choi, Jae Ho; Im, Ji Hye; Park, Bonghwan; Yang, Ji Hye; Jeong, Tae Cheon; Jeong, Hye Gwang

    2010-10-20

    o,p'-Dichlorodiphenyltrichloroethane (o,p'-DDT) is a DDT isomer and xenoestrogen that can induce inflammation and cancer. However, the effect of o,p'-DDT on aromatase is unclear. Thus, we investigated the effects of o,p'-DDT on aromatase expression in human breast cancer cells. We also examined whether cyclooxygenase-2 (COX-2) is involved in o,p'-DDT-mediated aromatase expression. Treatment with o,p'-DDT-induced aromatase protein expression in MCF-7 and MDA-MB-231 human breast cancer cells; enhancing aromatase gene expression, and enzyme and promoter activity. Treatment with ICI 182.780, a estrogen receptor antagonist, did not affect the inductive effects of o,p'-DDT on aromatase expression. In addition, o,p'-DDT increased COX-2 protein levels markedly, increased COX-2 mRNA expression and promoter activity, enhanced the production of prostaglandin E(2) (PGE(2)), induced cyclic AMP response element (CRE) activation, and cAMP levels and binding of CREB. o,p'-DDT also increased the phosphorylation of PKA, Akt, ERK, and JNK in their signaling pathways in MCF-7 and MDA-MB-231 cells. Finally, o,p'-DDT induction of aromatase was inhibited by various inhibitors [COX-2 (by NS-398), PKA (H-89), PI3-K/Akt (LY 294002), EP2 (AH6809), and EP4 receptor (AH23848)]. Together, these results suggest that o,p'-DDT increases aromatase, and that o,p'-DDT-induced aromatase is correlated with COX-2 up-regulation, mediated via the CRE activation and PKA and PI3-kinase/Akt signaling pathways in breast cancer cells.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 28 percent efficient GaAs concentrator solar cells

    NASA Technical Reports Server (NTRS)

    Macmillan, H. F.; Hamaker, H. C.; Kaminar, N. R.; Kuryla, M. S.; Ladle Ristow, M.

    1988-01-01

    AlGaAs/GaAs heteroface solar concentrator cells which exhibit efficiencies in excess of 27 percent at high solar concentrations (over 400 suns, AM1.5D, 100 mW/sq cm) have been fabricated with both n/p and p/n configurations. The best n/p cell achieved an efficiency of 28.1 percent around 400 suns, and the best p/n cell achieved an efficiency of 27.5 percent around 1000 suns. The high performance of these GaAs concentrator cells compared to earlier high-efficiency cells was due to improved control of the metal-organic chemical vapor deposition growth conditions and improved cell fabrication procedures (gridline definition and edge passivation). The design parameters of the solar cell structures and optimized grid pattern were determined with a realistic computer modeling program. An evaluation of the device characteristics and a discussion of future GaAs concentrator cell development are presented.

  11. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  12. Global Aerosol Observations

    Atmospheric Science Data Center

    2013-04-19

    ... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column aerosol amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic aerosol exposure, ...

  13. Portable Aerosol Contaminant Extractor

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  14. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  15. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1996-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size-resolved aerosol microphysics and chemistry. Both profiles included a pollution haze from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate aerosol but had significantly less effect at higher humidities. A 3 km descent through a boundary layer air mass dominated by pollutant aerosol with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated aerosol optical depths (550 nm) of 0.160 (+/- 0.07) and 0. 157 (+/- 0.034) respectively. During descent the aerosol mass scattering coefficient per unit sulfate mass varied from about 5 to 16 m(exp 2)/g and primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4+/- 0.7 m(exp 2)/g. A subsequent descent through a Saharan dust layer located above the pollution aerosol layer revealed that both layers contributed similarly to aerosol optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(exp 2)/g. The large difference (50%) in measured and calculated optical depth for the dust layer exceeded measurements.

  16. Residues of polychlorinated biphenyls and DDT in water and sediment of the Indian River Lagoon, Florida - 1977 to 1978

    SciTech Connect

    Wang, T.C.; Johnson, R.S.; Bricker, J.L.

    1980-01-01

    Water and sediment samples collected during 1977 to 1978 from the Indian River lagoon between Vero Beach, Indian River County, and Fort Pierce, Saint Lucie County, Florida were analyzed for PCBs and DDT. Sample locations were chosen on the basis of proximity to major tributaries, sewage outfalls, or municipal area. Concentrations in water samples were below 0.01 ppB sigma DDT and 0.5 ppB PCBs. Small amounts of PCBs and DDT were found in most sediment samples, ranging from less than 1.0 ppB to 0.63 ppM Aroclor 1254 and from less than 0.1 ppB to 0.081 ppM sigma DDT. Samples from the Taylor Creek tributary and from the Fort Pierce power plant and municipal docking area contained higher PCB concentrations than did samples from other locations. DDT and PCB levels in most samples indicate little contamination by these compounds of the Indian River Waterway between Vero Beach and Fort Pierce.

  17. Aqueous aerosol SOA formation: impact on aerosol physical properties.

    PubMed

    Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

    2013-01-01

    Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions.

  18. Improvement of Aerosol Optical Depth Retrieval from MODIS Spectral Reflectance over the Global Ocean Using New Aerosol Models Archived from AERONET Inversion Data and Tri-axial Ellipsoidal Dust Database

    NASA Technical Reports Server (NTRS)

    Lee, J.; Kim, J.; Yang, P.; Hsu, N. C.

    2012-01-01

    New over-ocean aerosol models are developed by integrating the inversion data from the Aerosol Robotic Network (AERONET) sun/sky radiometers with a database for the optical properties of tri-axial ellipsoid particles. The new aerosol models allow more accurate retrieval of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) in the case of high AOD (AOD greater than 0.3). The aerosol models are categorized by using the fine-mode fraction (FMF) at 550 nm and the singlescattering albedo (SSA) at 440 nm from the AERONET inversion data to include a variety of aerosol types found around the globe. For each aerosol model, the changes in the aerosol optical properties (AOPs) as functions of AOD are considered to better represent aerosol characteristics. Comparisons of AODs between AERONET and MODIS for the period from 2003 to 2010 show that the use of the new aerosol models enhances the AOD accuracy with a Pearson coefficient of 0.93 and a regression slope of 0.99 compared to 0.92 and 0.85 calculated using the MODIS Collection 5 data. Moreover, the percentage of data within an expected error of +/-(0.03 + 0.05xAOD) is increased from 62 percent to 64 percent for overall data and from 39 percent to 51 percent for AOD greater than 0.3. Errors in the retrieved AOD are further characterized with respect to the Angstrom exponent (AE), scattering angle, SSA, and air mass factor (AMF). Due to more realistic AOPs assumptions, the new algorithm generally reduces systematic errors in the retrieved AODs compared with the current operational algorithm. In particular, the underestimation of fine-dominated AOD and the scattering angle dependence of dust-dominated AOD are significantly mitigated as results of the new algorithm's improved treatment of aerosol size distribution and dust particle nonsphericity.

  19. IET. Aerial view of project, 95 percent complete. Camera facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    IET. Aerial view of project, 95 percent complete. Camera facing east. Left to right: stack, duct, mobile test cell building (TAN-624), four-rail track, dolly. Retaining wall between mobile test building and shielded control building (TAN-620) just beyond. North of control building are tank building (TAN-627) and fuel-transfer pump building (TAN-625). Guard house at upper right along exclusion fence. Construction vehicles and temporary warehouse in view near guard house. Date: June 6, 1955. INEEL negative no. 55-1462 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  20. Percent Agricultural Land Cover on Steep Slopes (Future)

    EPA Pesticide Factsheets

    Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type. High amounts of agriculture on steep slopes can increase the amount of soil erosion leading to increased sediment in surface water. Agricultural land cover on steep slopes (AGSL) is the percent of agriculture on slopes greater than or equal to 9%. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  1. Congress approves 13 percent increase in AIDS spending.

    PubMed

    1996-10-18

    A Republican Congress voted for a significant increase in AIDS-related spending for the fiscal year 1996. Increases were granted in every major program, including the Ryan White CARE Act and the once-doomed Housing Opportunities for People with AIDS (HOPWA) program. Overall, discretionary spending for Federal AIDS programs rose by 13 percent. This increase includes an additional $94 million for AIDS-related research at the National Institute's of Health (NIH). Advocates call on policy-makers to develop a long-term strategy for providing drugs to those who lack private insurance and are not qualified for Medicaid.

  2. Creep behaviour of Cu-30 percent Zn at intermediate temperatures

    NASA Technical Reports Server (NTRS)

    Raj, S. V.

    1991-01-01

    The present, intermediate-temperature (573-823 K) range investigation of creep properties for single-phase Cu-30 percent Zn alpha-brass observed inverse, linear, and sigmoidal primary-creep transients above 573 K under stresses that yield minimum creep rates in the 10 to the -7th to 2 x 10 to the -4th range; normal primary creep occurred in all other conditions. In conjunction with a review of the pertinent literature, a detailed analysis of these data suggests that no clearly defined, classes M-to-A-to-M transition exists in this alloy notwithstanding the presence of both classes' characteristics under nominally similar stresses and temperatures.

  3. Association of DDT and heptachlor epoxide in human blood with diabetic nephropathy.

    PubMed

    Everett, Charles J; Thompson, Olivia M

    2015-01-01

    Six organochlorine pesticides and pesticide metabolites in human blood were tested to determine their relationships with diabetic nephropathy. The data were derived from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 (unweighted, n=2992, population estimate=133,088,752). The six chemicals were p,p'-DDT (dichlorodiphenyltrichloroethane), p,p'-DDE (dichlorodiphenyltrichloroethylene), beta-hexachlorocyclohexane, oxychlordane, trans-nonachlor and heptachlor epoxide. In this research, total diabetes included diagnosed and undiagnosed diabetes (glycohemoglobin, A1c ≥6.5%), and nephropathy was defined as a urinary albumin to creatinine ratio >30 mg/g, representing microalbuminuria and macroalbuminuria. The pesticide p,p'-DDT and pesticide metabolite heptachlor epoxide were significantly associated with total diabetes with nephropathy, with odds ratios of 2.08 (95% CI 1.06-4.11) and 1.75 (95% CI 1.05-2.93), respectively. Organochlorine pesticides are thought to act through the constitutive androstane receptor/pregnane X receptor disease pathway, but this is not well established. When p,p'-DDT and heptachlor epoxide were both elevated, the odds ratio for diabetic nephropathy was 2.76 (95% CI 1.31-5.81), and when six of six organochlorine pesticides and pesticide metabolites, were elevated, the odds ratio for diabetic nephropathy was 3.00 (95% CI 1.08-8.36). The differences in the odds ratios for these groups appear to be due to differences in the mean heptachlor epoxide concentration of each category. Organochlorine pesticides and pesticide metabolites are known to have estrogenic, antiestrogenic or antiandrogenic activity. The constitutive androstane receptor/pregnane X receptor pathway is thought to interact with the aryl hydrocarbon receptor pathway, and the associations noted may be due to that interaction.

  4. Ban of DDT and subsequent recovery of Reproduction in bald eagles

    SciTech Connect

    Grier, J.W.

    1982-12-17

    Reproduction of bald eagles in northwestern Ontario declined from 1.26 young per breeding area in 1966 to a low of 0.46 in 1974 and then increased to 1.12 in 1981. Residues of DDE in addled eggs showed a significant inverse relation, confirming the effects of this toxicant on bald eagle reproduction at the population level and the effectiveness of the ban on DDT. The recovery from DDE contamination in bald eagles appears to be occurring much more rapidly than predicted.

  5. Sugars in Antarctic aerosol

    NASA Astrophysics Data System (ADS)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

  6. Infrared spectroscopy of aerosols

    NASA Astrophysics Data System (ADS)

    Mentel, Th.; Sebald, H.

    2003-04-01

    In our large Aerosol Chamber at the FZ Jülich we apply HR FTIR absorption spectroscopy for the determination of trace gases. In the FTIR spectra we also observe broad absorptions of several 10 to a few 100 cm-1 widths that arise from species in the condensed aerosol phase: liquid H_2O, NO_3^-, SO_42-, HSO_4^-, or dicarboxylic acids. Moreover, the aerosol droplets caused extinctions over several 1000 cm-1 by IR scattering. This allows for in-situ observation of changes in the condensed aerosol phase e.g. on HNO_3 uptake, like the shift of the sulfate/bisulfate equilibrium or the growth by water condensation. The IR absorptions of the condensed aerosol phase provide useful extra information in process studies, if they can be quantified. Therefore the absorption cross section, respective, the absorption index which is the imaginary part of the complex refractive index is needed. We set up an aerosol flow tube in which IR spectroscopy on a 8 m light path and aerosol size distribution measurements in the range from 20 nm - 10 μm can be performed simultaneously. We measured sulfate aerosols at several relative humidities (dry, metastable, deliquescent). We will demonstrate an iterative procedure based on Mie calculations and Kramers Kronig transformation to retrieve the absorption index from the observed IR spectra and the corresponding size distribution (for dry ammonium sulfate). We will compare resulting absorption indices for aqueous sodium bisulfate aerosols at several relative humidties with thermodynamic model calculations for the Na^+/H^+/HSO_4^-/SO_42-/H_2O system.

  7. A 99 percent purity molecular sieve oxygen generator

    NASA Technical Reports Server (NTRS)

    Miller, G. W.

    1991-01-01

    Molecular sieve oxygen generating systems (MSOGS) have become the accepted method for the production of breathable oxygen on military aircraft. These systems separate oxygen for aircraft engine bleed air by application of pressure swing adsorption (PSA) technology. Oxygen is concentrated by preferential adsorption in nitrogen in a zeolite molecular sieve. However, the inability of current zeolite molecular sieves to discriminate between oxygen and argon results in an oxygen purity limitations of 93-95 percent (both oxygen and argon concentrate). The goal was to develop a new PSA process capable of exceeding the present oxygen purity limitations. A novel molecular sieve oxygen concentrator was developed which is capable of generating oxygen concentrations of up to 99.7 percent directly from air. The process is comprised of four absorbent beds, two containing a zeolite molecular sieve and two containing a carbon molecular sieve. This new process may find use in aircraft and medical breathing systems, and industrial air separation systems. The commercial potential of the process is currently being evaluated.

  8. DDT and its metabolites alter gene expression in human uterine cell lines through estrogen receptor-independent mechanisms.

    PubMed Central

    Frigo, Daniel E; Burow, Matthew E; Mitchell, Kamron A; Chiang, Tung-Chin; McLachlan, John A

    2002-01-01

    Endocrine-disrupting organochlorines, such as the pesticide dichlorodiphenyltrichloroethane (DDT), bind to and activate estrogen receptors (ERs), thereby eliciting estrogen-like effects. Although ERs function predominantly through activation of transcription via estrogen-responsive elements, both ERs, alpha and ss, can interact with various transcription factors such as activator protein-1 (AP-1). Additionally, estrogens may regulate early signaling events, suggesting that the biological effects of environmental estrogens may not be mediated through classic ER (alpha and ss) activity alone. We hypothesized that known environmental estrogens, such as DDT and its metabolites, activate AP-1-mediated gene transactivation through both ER-dependent and ER-independent means. Using two Ishikawa human endometrial adenocarcinoma cell line variants that we confirmed to be estrogen responsive [Ishikawa(+)] and estrogen unresponsive [Ishikawa(-)], we generated stably transfected AP-1 luciferase cell lines to identify the role of an estrogen-responsive mechanism in AP-1-mediated gene expression by various stimuli. Our results demonstrate that DDT and dichlorodiphenyldichloroethane (DDD) were the most potent activators of AP-1 activity; 2,2-bis(p-chlorophenyl) acetic acid failed to activate. Although stimulated in both Ishikawa(+) and Ishikawa(-) cells by DDT and its congeners, AP-1 activation was more pronounced in the estrogen-unresponsive Ishikawa(-) cells. In addition, DDT, DDD, and dichlorodiphenyldichloroethylene (DDE) could also stimulate AP-1 activity in the estrogen-unresponsive human embryonic kidney 293 cells using a different promoter context. Thus, our data demonstrate that DDT and its metabolites activate the AP-1 transcription factor independent of ER (alpha or ss) status. PMID:12460804

  9. 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.

  10. 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.

  11. 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

  12. Percutaneous absorption of ( sup 14 C)DDT and ( sup 14 C)benzo(a)pyrene from soil

    SciTech Connect

    Wester, R.C.; Maibach, H.I.; Bucks, D.A.; Sedik, L.; Melendres, J.; Liao, C.; DiZio, S. )

    1990-10-01

    The objective was to determine percutaneous absorption of DDT and benzo(a)pyrene in vitro and in vivo from soil into and through skin. Soil (Yolo County 65-California-57-8; 26% sand, 26% clay, 48% silt) was passed through 10-, 20-, and 48-mesh sieves. Soil then retained by 80-mesh was mixed with (14C)-labeled chemical at 10 ppm. Acetone solutions at 10 ppm were prepared for comparative analysis. Human cadaver skin was dermatomed to 500 microns and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 24-hr skin application time. With acetone vehicle, DDT (18.1 +/- 13.4%) readily penetrated into human skin. Significantly less DDT (1.0 +/- 0.7%) penetrated into human skin from soil. DDT would not partition from human skin into human plasma in the receptor phase (less than 0.1%). With acetone vehicle, benzo(a)pyrene (23.7 +/- 9.7%) readily penetrated into human skin. Significantly less benzo(a)pyrene (1.4 +/- 0.9%) penetrated into human skin from soil. Benzo(a)pyrene would not partition from human skin into human plasma in the receptor phase (less than 0.1%). Substantivity (skin retention) was investigated by applying 14C-labeled chemical to human skin in vitro for only 25 min. After soap and water wash, 16.7 +/- 13.2% of DDT applied in acetone remained absorbed to skin. With soil only 0.25 +/- 0.11% of DDT remained absorbed to skin. After soap and water wash 5.1 +/- 2.1% of benzo(a)pyrene applied in acetone remained absorbed to skin. With soil only 0.14 +/- 0.13% of benzo(a)pyrene remained absorbed to skin.

  13. Light extinction by aerosols during summer air pollution

    NASA Technical Reports Server (NTRS)

    Kaufman, Y. J.; Fraser, R. S.

    1983-01-01

    In order to utilize satellite measurements of optical thickness over land for estimating aerosol properties during air pollution episodes, the optical thickness was measured from the surface and investigated. Aerosol optical thicknesses have been derived from solar transmission measurements in eight spectral bands within the band lambda 440-870 nm during the summers of 1980 and 1981 near Washington, DC. The optical thicknesses for the eight bands are strongly correlated. It was found that first eigenvalue of the covariance matrix of all observations accounts for 99 percent of the trace of the matrix. Since the measured aerosol optical thickness was closely proportional to the wavelength raised to a power, the aerosol size distribution derived from it is proportional to the diameter (d) raised to a power for the range of diameters between 0.1 to 1.0 micron. This power is insensitive to the total optical thickness. Changes in the aerosol optical thickness depend on several aerosol parameters, but it is difficult to identify the dominant one. The effects of relative humidity and accumulation mode concentration on the optical thickness are analyzed theoretically, and compared with the measurements.

  14. Lightning flash density in relation to aerosol over Nanjing (China)

    NASA Astrophysics Data System (ADS)

    Tan, Y. B.; Peng, L.; Shi, Z.; Chen, H. R.

    2016-06-01

    Time series data of lightning flash density, aerosol optical depth (AOD), surface temperature, convective available potential energy (CAPE) and thunderstorm days for 10 years (2002-2011), cloud-to-ground lightning (CG), and AOD of 5 years for summer season, i.e., June, July, and August over Nanjing, China, have been analyzed, to investigate the impact of aerosols on lightning. The results indicate that the radiative effect of aerosol may be one of the main reason for the decrease of the lightning flash density in a long period, while the aerosol microphysical effect may be a major role in the increase of the percent of + CG flashes (P+ CG). The dependence of surface temperature, CAPE, and thunderstorm days on AOD (R = - 0.748, - 0.741, - 0.744), and the negative correlation (R = - 0.634) between lightning flash density and AOD may lend support for the radiative effect of aerosol on lightning. In addition, elevated aerosols may change the charge distribution in thundercloud, hence enhancing the positive cloud-to-ground lightning (+ CG) activity, as P+ CG is positively correlated with AOD.

  15. Activated carbon amendment as a treatment for residual DDT in sediment from a superfund site in San Francisco Bay, Richmond, California, USA.

    PubMed

    Tomaszewski, Jeanne E; Werner, David; Luthy, Richard G

    2007-10-01

    Pesticide formulators formerly operating at Lauritzen Channel, a portion of San Francisco Bay near Richmond (CA, USA), caused contamination of sediment with dichlorodiphenyltrichloroethane (DDT). The present study evaluated the distribution of residual DDT in channel sediment six years following extensive remedial dredging. High DDT concentrations (up to 252 mg/ kg) were found in Young Bay Mud sampled across the channel. Particle analyses showed most of the contamination is contained in the clay/silt sediment fraction, and desorption tests showed that availability is greater for DDT metabolites than parent DDT. The present study examined the feasibility of using activated carbon amendment to sequester DDT from sediment, including an evaluation of reactivated carbon as a less costly alternative to virgin activated carbons. Treatment success of activated carbon amendment to sediment collected from Lauritzen Channel was measured by reductions in aqueous equilibrium concentrations and uptake in semipermeable membrane devices (SPMDs). Four different activated carbons were tested and, after one month of treatment with 3.2 weight % carbon, DDT aqueous equilibrium concentrations were reduced up to 83% and SPMD uptake was reduced up to 91%. Reactivated carbon was comparable with virgin carbons in all tests. Reduction in SPMD uptake of DDT by treatment with 3.2% reactivated carbon increased to 99% after 26 months of treatment. The effectiveness of activated carbon was dependent on the type, size, dose, and contact time. The results show the potential usefulness of activated carbon amendment as a follow-up remedial technology for management of residuals after dredging contaminated sediment.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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...

  18. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  19. Palaeoclimate: Aerosols and rainfall

    NASA Astrophysics Data System (ADS)

    Partin, Jud

    2015-03-01

    Instrumental records have hinted that aerosol emissions may be shifting rainfall over Central America southwards. A 450-year-long precipitation reconstruction indicates that this shift began shortly after the Industrial Revolution.

  20. Effects of DDT on the calcium transport and thymidine uptake of bovine lymphocytes

    SciTech Connect

    McCabe, M.; Yin-Foo, D.

    1986-10-01

    It is known that organochlorine compounds in the environment present risks which may be related to an interference with calcium metabolism. The evidence in favor of a role for intracellular calcium levels as signals for the initiation of cell division is summarized by Metcalfe et al., and forms the basis for a calcium hypothesis for the control of cell growth. Lymphocytes undergoing transformation provide evidence for an involvement of calcium in the steps preceding mitogenic activation which occur within 20 hours of exposure to a mitogen. It has been suspected for some time that the incidence of lymphomas and leukemias may be higher in farming populations with significant past exposure to several organochlorine insecticides. It is also known that immune suppression can provoke an increase in the incidence of certain cancers, although whether this is an example of (lack of) immune surveillance for potential cancer cells or of some less direct mechanism such as a reduced resistance to a viral infection, is still unclear. For these reasons it is important to know whether DDT and other chemically related organochlorine compounds modulate calcium levels within lymphocytes, and if so whether this modulation relates to the observed effects of these compounds on lymphocyte mitogenesis. Such studies may also be of some value in providing a clue as to the relationship between chemically induced leukemias and DDT exposure.

  1. Differences in DDT and PCB residues between common and striped dolphins from the southwestern Mediterranean.

    PubMed

    Borrell, A; Aguilar, A

    2005-05-01

    Organochlorine concentrations (OCs) and stable isotopes were investigated in the blubber of common dolphins (Delphinus delphis) and striped dolphins (Stenella coeruleoalba) from the southwestern Mediterranean. Samples were obtained from dolphins entangled in fishing nets during the 1992-1994 fishing season and from biopsies taken in 1992. Intrapopulation variations were studied, but because most of the dolphins were juveniles or calves (90%), no significant differences were found on the basis of reproductive condition or sex. Only mature male common dolphins showed significantly higher levels of most of the compounds studied than immature individuals did. There were quantitative and qualitative interspecific differences in organochlorine compounds profile. As compared to common dolphins, striped dolphins carried higher concentrations of organochlorine concentrations (OCs), their %DDE/tDDT and PCB/tDDT ratios were significantly higher, and recalcitrant PCB congeners were more abundant. Distribution and information on composition of stomach contents would in principle support a higher exposure to OCs in common dolphins as compared to striped dolphins, thus apparently contradicting the observed results. However, stable isotopes showed that striped dolphins exploit a higher trophic level, thus explaining observed differences. Interspecific dissimilarities in metabolic capacity to handle OCs may be an added factor. Although in the two species OC concentrations exceeded levels considered to be ineffective in marine mammals, pollution-induced effects on populations could not be properly assessed.

  2. Development and qualification testing of a laser-ignited, all-secondary (DDT) detonator

    NASA Technical Reports Server (NTRS)

    Blachowski, Thomas J.; Krivitsky, Darrin Z.; Tipton, Stephen

    1994-01-01

    The Indian Head Division, Naval Surface Warfare Center (IHDIV, NSWC) is conducting a qualification program for a laser-ignited, all-secondary (DDT) explosive detonator. This detonator was developed jointly by IHDIV, NSWC and the Department of Energy's EG&G Mound Applied Technologies facility in Miamisburg, Ohio to accept a laser initiation signal and produce a fully developed shock wave output. The detonator performance requirements were established by the on-going IHDIV, NSWC Laser Initiated Transfer Energy Subsystem (LITES) advanced development program. Qualification of the detonator as a component utilizing existing military specifications is the selected approach for this program. The detonator is a deflagration-to-detonator transfer (DDT) device using a secondary explosive, HMX, to generate the required shock wave output. The prototype development and initial system integration tests for the LITES and for the detonator were reported at the 1992 International Pyrotechnics Society Symposium and at the 1992 Survival and Flight Equipment National Symposium. Recent results are presented for the all-fire sensitivity and qualification tests conducted at two different laser initiation pulses.

  3. Determination of DDT and related compounds in blood samples from agricultural workers.

    PubMed

    Guardino, X; Serra, C; Obiols, J; Rosell, M G; Berenguer, M J; López, F; Brosa, J

    1996-01-05

    An analytical method combining a solid-phase (C18) clean-up and GC-electron-capture detection using a capillary column, was implemented to determine p,p'-DDT and its metabolites (p,p'-DDD and p,p'-DDE), as well as other organochlorine pesticides in whole blood samples from 30 farmers and 24 non-occupationally exposed workers. The average concentrations for the quantified pesticides, p,p'-DDT, p,p'-DDD and p,p'-DDE, were 0.9, 1.5 and 8.0 micrograms/l whole blood for exposed workers and 0.3, 0.5 and 3.3 micrograms/l for unexposed workers, respectively. GC-MS was used to confirm the identity of the pesticides found. Solid-phase extraction and the protocol used give a cleaner analytical matrix, not only improving sensitivity and resolution, but also allowing analyses with smaller blood samples as compared to other methods.

  4. Biomarkers, PCBs, DDT, DDE, and plastic pollution in albatross of the north Pacific Ocean

    SciTech Connect

    Auman, H.J.; Giesy, J.P.; Ludwig, J.P.; Summer, C.L.; Verbrugge, D.A.

    1994-12-31

    The impacts of pollution in a remote area of the Pacific Ocean on seabirds were assessed. The amount and effects of accidentally ingested plastic on survival of Laysan albatross chicks were determined. Concentrations of synthetic organochlorine compounds and biomarkers of exposure to several classes of those compounds were measured in plasma of adults and chicks of both Laysan and Black-footed albatross of Sand Island, Midway Atoll. Concentrations of PCBs, DDT, DDE, and other chlorinated insecticides were measured in plasma and egg. Average, total PCB concentrations in the plasma of ten adult Laysan and five Black-footed albatross were 39 and 115 ng/g, respectively; DDE concentrations were 10.8 and 37.2 ng/mg respectively. Total pooled concentrations of PCBs in egg yolk of Laysan or Black-footed albatross were 1.06 or 3.84 {micro}g/g, respectively; DDE concentrations were 321.5 or 1,836.6 ng/g, respectively. Data will be presented on differences between chicks and adults, between species, and among sampling times throughout the nesting season. Serum retinol, T3 and T4 concentrations were quantified and correlated to concentrations of total PCBs, DDT, DDE, and other insecticides in the blood.

  5. 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

  6. Novel method for determining DDT in vapour and particulate phases within contaminated indoor air in a malaria area of South Africa.

    PubMed

    Naudé, Yvette; Rohwer, Egmont R

    2012-06-12

    The organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control in certain areas of South Africa. The strict Stockholm Convention on Persistent Organic Pollutants (POPs) allows spraying on the inside of traditional dwellings with DDT. In rural villages contaminated dust presents an additional pathway for exposure to DDT. We present a new method for the determination of DDT in indoor air where separate vapour and particulate samples are collected in a single step with a denuder configuration of a multi-channel open tubular silicone rubber (polydimethylsiloxane (PDMS)) trap combined with a micro quartz fibre filter. The multi-channel PDMS trap section of the denuder concentrates vapour phase insecticide whereas particle associated insecticide is transferred downstream where it is collected on a micro-fibre filter followed by a second multi-channel PDMS trap to capture the blow-off from the filter. The multi-channel PDMS trap and filter combination are designed to fit a commercial thermal desorber for direct introduction of samples into a GC-MS. The technique is solvent-free. Analyte extraction and sample clean-up is not required. Two fractions, vapour phase and particulate phase p,p'-DDT, o,p'-DDT; p,p'-DDD, o,p'-DDD; p,p'-DDE and o,p'-DDE in 4 L contaminated indoor air, were each quantitatively analysed by GC-MS using isotopically labelled ring substituted (13)C(12) -p,p'-DDT as an internal standard. Limits of detection were 0.07-0.35 ng m(-3) for p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE and o,p'-DDE. Ratios of airborne p,p'-DDD/p,p'-DDT and of o,p'-DDT/p,p'-DDT are unusual and do not match the ideal certified ingredient composition required of commercial DDT. Results suggest that the DDT products used for indoor residual spraying (IRS) prior to, and during 2007, may have been compromised with regards to insecticidal efficacy, demonstrating the power of this new environmental forensics tool.

  7. One Percent Strömvil Photometry in M 67

    NASA Astrophysics Data System (ADS)

    Philip, A. G. D.; Boyle, R. P.; Janusz, R.

    2005-05-01

    The Vatican Advanced Technology Telescope on Mt. Graham is being used in a program of CCD photometry of open and globular clusters. We are using the Ströomvil System (Straižys et al. 1996), a combination of the Strömgren and Vilnius Systems. This system allows stars to be classified as to temperature, surface gravity, metallicity and reddening from the photometric measures alone. However, to make accurate estimates of the stellar parameters the photometry should be accurate to 1 or 1.5 percent. In our initial runs on the VATT we did not achieve this accuracy. The problem turned out to be scattered light in the telescope and this has now been reduced so we can do accurate photometry. Boyle has written a routine in IRAF which allows us to correct the flats for any differences. We take rotated frames and also frames which are offset in position by one third of a frame, east-west and north-south. Measures of the offset stars give us the corrections that need to be made to the flat. Robert Janusz has written a program, the CommandLog, which allows us to paste IRAF commands in the correct order to reduce measures made on a given observing run. There is an automatic version where one can test various parameters and get a set of solutions. Now we have a set of Strömvil frames in the open cluster, M 67 and we compare our color-magnitude diagram with those of BATC (Fan et al. 1996) and Vilnius (Boyle et al. 1998). A preliminary report of the M 67 photometry will be found in Laugalys et al. (2004). Here we report on a selected set of stars in the M 67 frames, those with errors 1 percent or less.

  8. Emergency Protection from Aerosols

    SciTech Connect

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  9. Monodisperse aerosol generator

    DOEpatents

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  10. 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.

  11. Evaluation of foam surfactant for foam-flushing technique in remediation of DDT-contaminated soil using data envelopment analysis method.

    PubMed

    Wang, Xingwei; Chen, Jiajun; Lv, Ce

    2015-02-01

    With an aim to select the most appropriate foaming surfactant for remediation of DDT-contaminated soil by foam-flushing technique, the performances of nonionic and anionic surfactant in several aspects were observed in this study. SDS had the best foam static characteristic among the four experimental surfactants. The solubilizing ability for DDT followed the order of Tween80 > TX100 > SDS > Brij35. The adsorption loss of SDS onto soil was the lowest. The order of desorption efficiency for DDT followed as TX-100 > Tween80 > Brij35 > SDS. Based on these experimental investigations, the overall performances of foaming surfactants were evaluated by data envelopment analysis method. The results indicated that SDS was the optimal alternative for remediation of DDT-contaminated soil by foam-flushing technique. This conclusion was reached with the consideration of the cost, foam static characteristic, surfactant adsorption loss, solubilizing ability, and desorption efficiency of surfactant for DDT.

  12. Production and use of DDT containing antifouling paint resulted in high DDTs residue in three paint factory sites and two shipyard sites, China.

    PubMed

    Xin, Jia; Liu, Xiang; Liu, Wei; Jiang, Lu; Wang, Jihua; Niu, Jia

    2011-06-01

    This study provides the first intensive investigation of Dichlorodiphenyltrichloroethanes (DDT) distribution in typical paint factories and shipyards in China where DDT containing antifouling paint were mass produced and used respectively. DDTs were analyzed in soil, sludge and sediment samples collected from three major paint factories and two shipyards. The results showed that the total DDTs concentrations detected in paint factory and shipyard sites ranged from 0.06 to 8387.24 mg kg(-1). In comparison with paint factory sites, the shipyard sites were much more seriously contaminated. However, for both kinds of sites, the DDTs level was found to be largely affected by history and capacity of production and use of DDT containing antifouling paint. (DDE+DDD)/DDT ratios indicated that DDT containing antifouling paint could serve as important fresh input sources for DDTs. It can be seen that most samples in shipyards were in ranges where heavy contamination and potential ecological risk were identified.

  13. RACORO aerosol data processing

    SciTech Connect

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  14. 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.

  15. Flow tracing fidelity of scattering aerosol in laser Doppler velocimetry

    NASA Technical Reports Server (NTRS)

    Mazumder, M. K.; Kirsch, K. J.

    1974-01-01

    An experimental method for determinating the flow tracing fidelity of a scattering aerosol used in laser Doppler velocimeters was developed with particular reference to the subsonic turbulence measurements. The method employs the measurement of the dynamic response of a flow seeding aerosol excited by acoustic waves. The amplitude and frequency of excitation were controlled to simulate the corresponding values of fluid turbulence components. Experimental results are presented on the dynamic response of aerosols over the size range from 0.1 to 2.0 microns in diameter and over the frequency range 100 Hz to 100 kHz. It was observed that unit density spherical scatterers with diameters of 0.2 microns followed subsonic air turbulence frequency components up to 100 kHz with 98 percent fidelity.

  16. Enhancement of atmospheric radiation by an aerosol layer

    NASA Technical Reports Server (NTRS)

    Michelangeli, Diane V.; Yung, Yuk L.; Shia, Run-Lie; Eluszkiewicz, Janusz; Allen, Mark; Crisp, David

    1992-01-01

    The presence of a stratospheric haze layer may produce increases in both the actinic flux and the irradiance below this layer. Such haze layers result from the injection of aerosol-forming material into the stratosphere by volcanic eruptions. Simple heuristic arguments show that the increase in flux below the haze layer, relative to a clear sky case, is a consequence of 'photon trapping'. The magnitude of these flux perturbations, as a function of aerosol properties and illumination conditions, is explored with a new radiative transfer model that can accurately compute fluxes in an inhomogeneous atmosphere with nonconservative scatterers having arbitrary phase function. One calculated consequence of the El Chichon volcanic eruption is an increase in the midday surface actinic flux at 20 deg N latitude, summer, by as much as 45 percent at 2900 A. This increase in flux in the UV-B wavelength range was caused entirely by aerosol scattering, without any reduction in the overhead ozone column.

  17. Lidar measurements of ozone and aerosol distributions during the 1992 airborne Arctic stratospheric expedition

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.; Butler, Carolyn F.; Fenn, Marta A.; Grant, William B.; Ismail, Syed; Carter, Arlen F.

    1994-01-01

    The NASA Langley airborne differential absorption lidar system was operated from the NASA Ames DC-8 aircraft during the 1992 Airborne Arctic Stratospheric Expedition to investigate the distribution of stratospheric aerosols and ozone (O3) across the Arctic vortex from January to March 1992. Aerosols from the Mt. Pinatubo eruption were found outside and inside the Arctic vortex with distinctly different scattering characteristics and spatial distributions in the two regions. The aerosol and O3 distributions clearly identified the edge of the vortex and provided additional information on vortex dynamics and transport processes. Few polar stratospheric clouds were observed during the AASE-2; however, those that were found had enhanced scattering and depolarization over the background Pinatubo aerosols. The distribution of aerosols inside the vortex exhibited relatively minor changes during the AASE-2. Ozone depletion inside the vortex as limited to less than or equal to 20 percent in the altitude region from 15-20 km.

  18. Calculation of aerosol optical properties under different assumptions on mixing state, refractive index, density and hygroscopicity: uncertainties and importance of representation of aerosol mixing state

    NASA Astrophysics Data System (ADS)

    Curci, Gabriele

    2015-04-01

    The calculation of aerosol optical properties from aerosol mass is a process subject to uncertainty related to necessary assumptions on the treatment of the chemical species mixing state, density, refractive index, and hygroscopic growth. We used the FlexAOD post-processing tool to calculate the optical properties (aerosol optical depth (AOD), single scattering albedo (SSA) and asymmetry parameter (g)) from chemistry-transport model aerosol profiles, using a wide range of assumptions on aerosol chemical and physical properties. We calculated that the most important factor of uncertainty is the assumption about the mixing state, for which we estimate an uncertainty of 30-35% on the simulated aerosol optical depth (AOD) and single scattering albedo (SSA). The choice of the core composition in the core-shell representation is of minor importance for calculation of AOD, while it is critical for the SSA. Other factors of uncertainty tested here have a maximum average impact of 10% each on calculated AOD, and an impact of a few percent on SSA and g. We then tested simple parameterizations of the aerosol mixing state, expressed as a function of the aerosol aging, and verified that they may be helpful in reducing the uncertainty when comparing simulations with AERONET retrievals.

  19. Aerosolized amphotericin B-liposomes for treatment of systemic Candida infections in mice.

    PubMed

    Gilbert, B E; Wyde, P R; Lopez-Berestein, G; Wilson, S Z

    1994-02-01

    Mice lethally infected with Candida albicans were exposed to small-particle aerosols containing amphotericin B-liposomes. The drug, when administered twice daily for 2 h (0.58 mg/kg of body weight per day) on days 1, 2, and 3 postinoculation, significantly reduced the numbers of Candida organisms in the kidneys. Aerosol treatment increased the survival time of mice given 2 2-h treatments once a week for 4 weeks. A twice-weekly, 2-h small-particle aerosol administration of amphotericin B-liposomes for 1, 2, or 3 weeks significantly increased both the mean time of survival and percent survival.

  20. 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

  1. Effect of temperature on accumulation of methylmercuric chloride and p,p'DDT by rainbow trout (Salmo gairdneri)

    USGS Publications Warehouse

    Reinert, Robert E.; Stone, Linda J.; Willford, Wayne A.

    1974-01-01

    Amounts of mercury and DDT residues accumulated from water by yearling rainbow trout (Salmo gairdneri) in the laboratory increased as water temperature increased. Fish exposed to methylmercuric chloride at concentrations of 234–263 parts per trillion for 12 wk at 5, 10, and 15 C accumulated 1.19, 1.71, and 1.96 ppm; fish exposed to p,p′DDT at concentrations of 133–176 parts per trillion accumulated 3.76, 5.93, and 6.82 ppm. Concentrations of mercury accumulated by the fish were significantly different (P < 0.01) at each of the three temperatures, and the concentrations of DDT were significantly different at 5 and 10 and 5 and 15 C. Throughout the period of exposure, the concentration factors (concentration of contaminant in the fish/concentration in water) at each of the three temperatures were far higher for p,p′DDT than for methylmercuric chloride.

  2. 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.

  3. Morphofunctional Changes in the Thyroid Gland of Pubertal and Postpubertal Rats Exposed to Low Dose of DDT.

    PubMed

    Yaglova, N V; Sledneva, Yu P; Yaglov, V V

    2016-12-01

    Consumption of low dose DDT from birth until puberty suppressed functional activity of the thyroid gland in rats and leads to destructive changes in the organ during the postpubertal period with compensatory stimulation of secretory activity of thyrocytes aimed at normalization of thyroxin production.

  4. 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.

  5. Metabolism and distribution of p,p'-DDT during flight of the white-crowned sparrow, Zonotrichia leucophrys.

    PubMed

    Scollon, Edward J; Carr, James A; Rintoul, David A; McMurry, Scott T; Cobb, George P

    2012-02-01

    This study evaluated the interactions of flight, fasting, and 1,1,1-trichloro-bis(4-chlorophenyl)ethane (p,p'-DDT) loading on residue metabolism and distribution in recently exposed white-crowned sparrows (Zonotrichia leucophrys). Female sparrows were dosed with 5 mg p,p'-DDT per kg body weight over 3 d. Following 1 d of recovery, sparrows were flown in a wind tunnel for up to 140 min, in 15-min blocks. Food was withheld from the start of the flight period until birds were euthanized. DDT, 1,1-dichloro-2,2-bis(4 chlorophenyl)ethane (DDD), and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE) were present in all tissues examined. 1-Chloro-2,2-bis(4-chlorophenyl)ethene (DDµ), 1,1-bis(4-chlorophenyl)ethane (p,p'-DDη), and 2,2-bis(4-chlorophenyl)ethanol (p,p'-DDOH) were not found. Fasting did not significantly affect the rate of residue increase over time in any of the tissues examined. When sparrows flew and fasted simultaneously, fasting seldom contributed to an increase in tissue residues. However, the length of time flown was significantly correlated with increasing toxicant concentrations in the brain, kidney, and liver, effectively demonstrating the potential for brief flights to enhance mobilization of DDT and its metabolites. Dose, flight, and fasting also increased residues in brain tissue. These contaminant redistributions may have important ramifications on the stresses experienced by migratory birds.

  6. Violent cookoff reactions in HMX-based explosives in DDT tubes: tracking luminous waves with streak imaging

    NASA Astrophysics Data System (ADS)

    Parker, Gary; Dickson, Peter; Asay, Blaine; Smilowitz, Laura; Henson, Bryan; McAfee, John

    2011-06-01

    The authors present data from a series of high-temperature deflagration-to-detonation (DDT) tube experiments where the HMX-based high explosives PBX 9501 and LX-07 were heated above 180oC for various durations to impose damage (i.e. phase transitions and void generation) before being driven to cook off. These explosives have different polymeric binders, HMX mass fractions and cookoff responses and a comparison between the two offers revealing mechanistic insights on how thermal explosions evolve. From this series, results will be displayed indicating a wide range of violence from somewhat mild pressure bursts, to intermediate-power compressive burns, to high-violence DDT. Image data from high temperature DDT tube experiments, where the explosive was ignited on one end, were also collected and will be included for comparison. Analysis of the end-ignited streak images reveals characteristics that support established theories invoking a variety of burn modes in porous beds. Interestingly, from the cookoff experiments, the mechanism for build-up to DDT appears truncated. This analysis and its potential implications for modeling cookoff will be presented.

  7. A preliminary evaluation of the DDT contamination of sediments in lakes Natron and Bogoria (Eastern Rift Valley, Africa).

    PubMed

    Bettinetti, Roberta; Quadroni, Silvia; Crosa, Giuseppe; Harper, David; Dickie, Jennifer; Kyalo, Margaret; Mavuti, Kenneth; Galassi, Silvana

    2011-06-01

    Dichlorodiphenyltrichloroethane (DDT) is still used in Africa for the indoor control of malaria and it may represent a potential hazard for wildlife. The littoral sediments of two alkaline-saline lakes, Natron (Tanzania) and Bogoria (Kenya), in the Eastern Rift Valley, supporting large populations of lesser flamingos (Phoeniconaias minor), were analysed for DDT residues. Physical-chemical analyses (temperature, conductivity, pH and dissolved oxygen) were also performed on the water of the two lakes and in the tributaries of Lake Natron, to evaluate the influence of the environmental variables on pollutant occurrence. At Lake Natron, around 1 km from the sediment collection sites, tree leaves of Acacia tortilis were also collected. The main metabolite found in all sediment samples was pp'DDE, whilst equal concentrations of pp'DDT and pp'DDE were measured in acacia leaves. The levels of DDTs measured in the sediments were within 5.9-30.9 ng g(-1) d.w., reaching the maximum value in a tributary of Lake Natron. On the whole, the contamination of Lake Natron and Lake Bogoria basins seems to be quite moderate. Nevertheless, the pp'DDE/pp'DDT ratio equals 1 in the Acacia tortilis leaves, which makes one suppose that the input of the parent compound was rather recent and could have been from aerial transport or dust from relatively close-by old pesticides storage sites.

  8. Measuring and modeling reduction of DDT availability to the water column and mussels following activated carbon amendment of contaminated sediment.

    PubMed

    Tomaszewski, Jeanne E; McLeod, Pamela B; Luthy, Richard G

    2008-10-01

    A 28-day accumulation study demonstrated the use of mussel uptake, passive samplers, and biodynamic modeling to measure the reduction of dichlorodiphenyltrichloroethane (DDT) availability in the water column after the addition of activated carbon to contaminated sediment. Sediment collected from Lauritzen Channel, Richmond, California (16.5mg total DDT/kg) was mixed with either virgin activated carbon or a reactivated carbon for one month, after which a 28-day laboratory exposure study was completed. Mussels (Mytilus edulis) suspended above activated carbon-treated sediment accumulated significantly less total DDT in soft tissue, 91% and 84% for virgin and reactivated carbon, respectively, as compared to untreated sediment. Mussel tissue concentrations correlated to concentrations in semipermeable membrane devices (SPMDs) and polyethylene devices (PEDs) suspended over the same sediments. A biodynamic model that incorporated DDT water concentrations, either analytically measured or estimated from PED uptake, described mussel accumulation over time. Thus, passive samplers in combination with biodynamic modeling may provide an important screening tool for assessment of filter-feeding uptake and ecological risk to water-dwelling organisms exposed to aqueous phase hydrophobic organic contaminants.

  9. Distribution of DDT and other persistent organic contaminants in Canyons and on the continental shelf off the central California coast.

    PubMed

    Hartwell, S Ian

    2008-04-01

    Sediment samples were collected to delineate the distribution of contaminants along the central California coast. Sampling included a variety of Canyons and shelf/slope areas to evaluate contaminant transport patterns and potential delivery to Canyons and the continental slope to a depth of 1200 m. Sediments were collected and analyzed for organic contaminants using standard techniques of the NOAA National Status and Trends Program (NS&T). DDT is distributed on the shelf within a zone of fine-grained sediments between Half Moon and Monterey Bays. DDT was found at higher concentrations in Ascension, Año Nuevo, and Monterey/Soquel Canyons than in Pioneer and Carmel Canyons, the Gulf of the Farallones, or the continental slope. The Monterey Bay watershed appears to be the primary source of DDT. In contrast, PAHs and PCBs on the shelf appear to be derived primarily from San Francisco Bay. DDT appears to be delivered to the deep ocean via the Canyons more than from cross-shelf sediment transport. Sediment budget estimates for the continental shelf north of Monterey Bay need further refinement and more data to account for the movement of material from Monterey Bay onto the shelf.

  10. Concentration of PCBs,HCB,DDT, and HCH isomers in the ovaries, mammary gland, and liver of cows

    SciTech Connect

    Sitarska, E.; Klucinski, W.; Faundez, R. |

    1995-12-01

    Persistent organic chlorine compounds such as DDT and its metabolites, hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) play an important role in chronic poisoning and take part in a number of pathological processes. This study estimates the degree of accumulation of organic Chlorine compounds and polychlorinated biphynyls in the liver, ovaries, and mammary gland tissues of cows.12 refs., 1 fig., 1 tab.

  11. 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

    fragile and Chaetomorpha area and in isolated chloroplasts.’ŕ DDE is reported to be more toxic than DDT to the marine dinoflagellate Exuviella baltica...on Euglena gracilis . I. Growth Studies," Bull. Environ. Contam. Toxicol. 10:25-28 (1973). 171. Hicks, G.F., Jr. and T.R. Corner, "Location and

  12. The Effect of Ddt on the Polymorphism at the G6pd and Pgd Loci in DROSOPHILA MELANOGASTER

    PubMed Central

    Bijlsma, R.; Kerver, J. W. M.

    1983-01-01

    For the degradation of DDT and other chlorohydrocarbon insecticides energy in the form of NADPH is needed which for the greater part is supplied by the pentose phosphate shunt. Therefore the influence of DDT on the polymorphism at the G6pd and Pgd loci in Drosophila melanogaster was investigated by studying its effect on egg to adult survival and adult survival. The results show the existence of significant differences in fitness between the different genotypes of the two loci for both components. It is found that the effect of DDT supplementation differs significantly from the effect of sodium octanoate addition. DDT treatment also increases the activity of the pentose phosphate shunt as measured by the activity of G6PD and 6PGD. In larvae a 50% increase in activity is found and in adults a 100% increase. As there is little doubt that the activities of G6PD and 6PGD are somehow correlated with the fitness of flies, the data are discussed in relation to the in vitro and in vivo differences in activity between the different allozymes of both G6PD and 6PGD. PMID:6404694

  13. Evaluation of the global aerosol microphysical ModelE2-TOMAS model against satellite and ground-based observations

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Adams, P. J.; Shindell, D. T.

    2015-03-01

    The TwO-Moment Aerosol Sectional (TOMAS) microphysics model has been integrated into the state-of-the-art general circulation model, GISS ModelE2. This paper provides a detailed description of the ModelE2-TOMAS model and evaluates the model against various observations including aerosol precursor gas concentrations, aerosol mass and number concentrations, and aerosol optical depths. Additionally, global budgets in ModelE2-TOMAS are compared with those of other global aerosol models, and the ModelE2-TOMAS model is compared to the default aerosol model in ModelE2, which is a one-moment aerosol (OMA) model (i.e. no aerosol microphysics). Overall, the ModelE2-TOMAS predictions are within the range of other global aerosol model predictions, and the model has a reasonable agreement (mostly within a factor of 2) with observations of sulfur species and other aerosol components as well as aerosol optical depth. However, ModelE2-TOMAS (as well as ModelE2-OMA) cannot capture the observed vertical distribution of sulfur dioxide over the Pacific Ocean, possibly due to overly strong convective transport and overpredicted precipitation. The ModelE2-TOMAS model simulates observed aerosol number concentrations and cloud condensation nuclei concentrations roughly within a factor of 2. Anthropogenic aerosol burdens in ModelE2-OMA differ from ModelE2-TOMAS by a few percent to a factor of 2 regionally, mainly due to differences in aerosol processes including deposition, cloud processing, and emission parameterizations. We observed larger differences for naturally emitted aerosols such as sea salt and mineral dust, as those emission rates are quite different due to different upper size cutoff assumptions.

  14. 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.

  15. Atmospheric Chemistry: Nature's plasticized aerosols

    NASA Astrophysics Data System (ADS)

    Ziemann, Paul J.

    2016-01-01

    The structure of atmospheric aerosol particles affects their reactivity and growth rates. Measurements of aerosol properties over the Amazon rainforest indicate that organic particles above tropical rainforests are simple liquid drops.

  16. Palaeoclimate: Aerosols shift lake ecosystem

    NASA Astrophysics Data System (ADS)

    Dowsett, Harry J.

    2017-02-01

    Anthropogenic aerosols over the Chinese Loess Plateau have diminished monsoon precipitation and concomitant soil erosion that plagues the region. Now, a reconstruction documents the differences between historical warming events and the present, highlighting the paradoxical implications of decreasing atmospheric aerosols.

  17. Generation of aerosolized drugs.

    PubMed

    Wolff, R K; Niven, R W

    1994-01-01

    The expanding use of inhalation therapy has placed demands on current aerosol generation systems that are difficult to meet with current inhalers. The desire to deliver novel drug entities such as proteins and peptides, as well as complex formulations including liposomes and microspheres, requires delivery systems of improved efficiency that will target the lung in a reproducible manner. These efforts have also been spurred by the phase out of chlorofluorocarbons (CFCs) and this has included a directed search for alternative propellants. Consequently, a variety of new aerosol devices and methods of generating aerosols are being studied. This includes the use of freon replacement propellants, dry powder generation systems, aqueous unit spray systems and microprocessor controlled technologies. Each approach has advantages and disadvantages depending upon each principle of action and set of design variables. In addition, specific drugs may be better suited for one type of inhaler device vs. another. The extent to which aerosol generation systems achieve their goals is discussed together with a summary of selected papers presented at the recent International Congress of Aerosols in Medicine.

  18. Aerosol chemistry in GLOBE

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.

    1993-01-01

    This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).

  19. Extending "Deep Blue" Aerosol Retrieval Coverage to Cases of Absorbing Aerosols Above Clouds: Sensitivity Analysis and First Case Studies

    NASA Technical Reports Server (NTRS)

    Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Lee, J.; Redemann, J.; Schmid, B.; Shinozuka, Y.

    2016-01-01

    Cases of absorbing aerosols above clouds (AACs), such as smoke or mineral dust, are omitted from most routinely processed space-based aerosol optical depth (AOD) data products, including those from the Moderate Resolution Imaging Spectroradiometer (MODIS). This study presents a sensitivity analysis and preliminary algorithm to retrieve above-cloud AOD and liquid cloud optical depth (COD) for AAC cases from MODIS or similar sensors, for incorporation into a future version of the "Deep Blue" AOD data product. Detailed retrieval simulations suggest that these sensors should be able to determine AAC AOD with a typical level of uncertainty approximately 25-50 percent (with lower uncertainties for more strongly absorbing aerosol types) and COD with an uncertainty approximately10-20 percent, if an appropriate aerosol optical model is known beforehand. Errors are larger, particularly if the aerosols are only weakly absorbing, if the aerosol optical properties are not known, and the appropriate model to use must also be retrieved. Actual retrieval errors are also compared to uncertainty envelopes obtained through the optimal estimation (OE) technique; OE-based uncertainties are found to be generally reasonable for COD but larger than actual retrieval errors for AOD, due in part to difficulties in quantifying the degree of spectral correlation of forward model error. The algorithm is also applied to two MODIS scenes (one smoke and one dust) for which near-coincident NASA Ames Airborne Tracking Sun photometer (AATS) data were available to use as a ground truth AOD data source, and found to be in good agreement, demonstrating the validity of the technique with real observations.

  20. Dietary exposure of fathead minnows to the explosives TNT and RDX and to the pesticide DDT using contaminated invertebrates.

    PubMed

    Houston, Jerre G; Lotufo, Guilherme R

    2005-08-01

    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.

  1. A novel metabolic pathway for biodegradation of DDT by the white rot fungi, Phlebia lindtneri and Phlebia brevispora.

    PubMed

    Xiao, Pengfei; Mori, Toshio; Kamei, Ichiro; Kondo, Ryuichiro

    2011-09-01

    1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) was used as the substrate for a degradation experiment with the white rot fungi Phlebia lindtneri GB-1027 and Phlebia brevispora TMIC34596, which are capable of degrading polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated biphenyls (PCBs). Pure culture of P. lindtneri and P. brevispora with DDT (25 μmol l(-1)) showed that 70 and 30% of DDT, respectively, disappeared in a low-nitrogen medium after a 21-day incubation period. The metabolites were analyzed using gas chromatography/mass spectrometry (GC/MS). Both fungi metabolized DDT to 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD), 2,2-bis(4-chlorophenyl)acetic acid (DDA) and 4,4-dichlorobenzophenone (DBP). Additionally, DDD was converted to DDA and DBP. DDA was converted to DBP and 4,4-dichlorobenzhydrol (DBH). While DBP was treated as substrate, DBH and three hydroxylated metabolites, including one dihydroxylated DBP and two different isomers of monohydroxylated DBH, were produced from fungal cultures, and these hydroxylated metabolites were efficiently inhibited by the addition of a cytochrome P-450 inhibitor, piperonyl butoxide. These results indicate that the white rot fungi P. lindtneri and P. brevispora can degrade DBP/DBH through hydroxylation of the aromatic ring. Moreover, the single-ring aromatic metabolites, such as 4-chlorobenzaldehyde, 4-chlorobenzyl alcohol and 4-chlorobenzoic acid, were found as metabolic products of all substrate, demonstrating that the cleavage reaction of the aliphatic-aryl carbon bond occurs in the biodegradation process of DDT by white rot fungi.

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

    PubMed

    Hinck, Jo Ellen; Norstrom, Ross J; Orazio, Carl E; Schmitt, Christopher J; Tillitt, Donald E

    2009-02-01

    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.

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

    SciTech Connect

    Shabbir, Arsalan; DiStasio, Susan; Zhao, Jingbo; Cardozo, Christopher P.; Wolff, Mary S.; Caplan, Avrom J. . E-mail: avrom.caplan@mssm.edu

    2005-03-01

    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, 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.

  4. 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.

  5. 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.

  6. Care, food consumption, and behavior of bald eagles used in DDT tests

    USGS Publications Warehouse

    Chura, N.J.; Stewart, P.A.

    1967-01-01

    Twenty-seven Bald Eagles captured in southeastern Alaska were used in feeding tests to determine the effects of DDT in the diet.....Trapping and housing of eagles are discussed. Various aspects of eagle behavior and handling techniques are also presented. Recommendations are made for preventing injuries and increasing the comfort of captive birds.....The 1962 test birds consumed an average of 274 grams per bird day with a range of 109 to 401 grams per day between birds. Average food intake was 254 grams per bird day for the 1963 test birds with a range of 194 to 324 grams per day between birds.....Weight losses varied from 23 to 49 per cent of normal body weight for the 7 birds which died in the 1962 tests. Tremors and death occurred first for birds on the highest dosage and progressively later for birds on the lower dosages.

  7. Status of the development of 2-(5-cyanotetrazolato) pentaamminecobalt(III) perchlorate for DDT devices

    SciTech Connect

    Lieberman, M.L.; Fronabarger, J.W.

    1980-01-01

    The inorganic explosive 2-(5-cyanotetrazolato) pentaamminecobalt(III) perchlorate (CP) was synthesized by conventional coordination chemistry preparative methods. Its structure has been established via /sup 15/N NMR spectroscopy and x-ray diffraction techniques. Impurities have been identified and characterized. Procedures for qualification of the powder for detonator use have been established. Investigations of thermal properties are underway and no corrosion or compatibility problems have been determined under normal detonator environments. The physics of deflagration-to-detonation transition (DDT) of CP is being addressed. Studies are in progress to determine the shock characteristics of unreacted material, detonation parameters, equation of state of the reaction products, and characteristics of the transition to detonation. Engineering considerations have included measurements relating CP particle size, compaction behavior, spark sensitivity, shock sensitivity thermal ignition sensitivity, growth-to-detonation in device hardware, and output. 14 figures, 3 tables.

  8. Effects on wildlife of aerial applications of strobane, DDT, and BHC to tidal marshes in Delaware

    USGS Publications Warehouse

    George, J.L.; Darsie, R.F.; Springer, P.F.

    1957-01-01

    The principal purpose of this study was to ascertain what effect on wildlife, if any, would result from the use of the new insecticide, Strobane, for mosquito control on tideland areas. Comparisons were made with DDT and BHC (43 per cent gamma isomer) commonly used in control operations. The investigation was carried out on the tidal marshes of Bombay Hook National Wildlife Refuge near Smyrna, Delaware. Four areas, all similar in habitat, were chosen-three as test plots for Strobane, BHC, and DDT, respectively, and the fourth as an untreated check. The insecticides in oil solution were applied by airplane at the rates of 0.1, 0.2, and 0.3 pound per acre for gamma isomer of BHC, DDT, and Strobane, respectively. The first application was made on the morning of July 27; and the second, on the evening of August 23, 1955. To assay the results of spraying, 14 testing devices were set up in each area. They consisted of cages, traps, and microscope slides placed in the streams and ponds. The estuarine fishes, Fundulus heteroclitus, Cyprinodon variegatus, Leiostornus xanthurus, and Ailugil curemu; blue crabs, Callinectes sapidus; fiddler crabs, Uca pugnux, Uca minux, and Sesarma reticulaturn; and certain sessile organisms were included in the tests. Analyses of variance on fish and blue crabs showed no significant difference between deaths occurring in treated and control plots, nor among the three treatments. Differential mortalities were suffered by fish caged in streams and ponds. Greater numbers died in the BHC-treated streams and in the DDT-treated ponds. Local concentrations of insecticide appeared to be the cause, although the magnitude of kill was not significantly greater than in control areas. Field observations and crab-pot counts showed that both the fish and blue crabs avoided the sites of high insecticide concentration. Certainly the majority of the free-living individuals in the treated areas were able to survive the sprays, and at the level tested showed no

  9. Biphasic hormonal responses to the adrenocorticolytic DDT metabolite 3-methylsulfonyl-DDE in human cells

    SciTech Connect

    Asp, Vendela; Ulleras, Erik; Lindstroem, Veronica; Bergstroem, Ulrika; Oskarsson, Agneta; Brandt, Ingvar

    2010-02-01

    The DDT metabolite 3-methylsulfonyl-DDE (3-MeSO{sub 2}-DDE) has been proposed as a lead compound for an improved adrenocortical carcinoma (ACC) treatment. ACC is a rare malignant disorder with poor prognosis, and the current pharmacological therapy o,p'-DDD (mitotane) has limited efficacy and causes severe adverse effects. 3-MeSO{sub 2}-DDE is bioactivated by cytochrome P450 (CYP) 11B1 in mice and causes formation of irreversibly bound protein adducts, reduced glucocorticoid secretion, and cell death in the adrenal cortex of several animal species. The present study was carried out to assess similarities and differences between mice and humans concerning the adrenocorticolytic effects of 3-MeSO{sub 2}-DDE. The results support previous indications that humans are sensitive to the adrenocorticolytic actions of 3-MeSO{sub 2}-DDE by demonstrating protein adduct formation and cytotoxicity in the human adrenocortical cell line H295R. However, neither the irreversible binding nor the cytotoxicity of 3-MeSO{sub 2}-DDE in H295R cells was inhibited by the CYP11B1 inhibitor etomidate. We also report biphasic responses to 3-MeSO{sub 2}-DDE in cortisol and aldosterone secretion as well as in mRNA levels of the steroidogenic genes StAR, CYP11B1 and CYP11B2. Hormone levels and mRNA levels were increased at lower concentrations of 3-MeSO{sub 2}-DDE, while higher concentrations decreased hormone levels. These biphasic responses were not observed with o,p'-DDD or with the precursor DDT metabolite p,p'-DDE. Based on these results, 3-MeSO{sub 2}-DDE remains a viable lead compound for drug design, although the adrenocorticolytic effects of 3-MeSO{sub 2}-DDE in human cells seem more complex than in murine cells.

  10. Chemical aerosol Raman detector

    NASA Astrophysics Data System (ADS)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Amin, M.; Perkins, B. G.; Clark, M. L.; Jeys, T. H.; Sickenberger, D. W.; D'Amico, F. M.; Emmons, E. D.; Christesen, S. D.; Kreis, R. J.; Kilper, G. K.

    2017-03-01

    A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm3, which corresponds to 6.3 × 109 molecules/cm3 or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

  11. 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.

  12. Low concentrations of o,p'-DDT inhibit gene expression and prostaglandin synthesis by estrogen receptor-independent mechanism in rat ovarian cells.

    PubMed

    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.

  13. 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.

  14. 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.

  15. 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

  16. [Influence of the interaction between iron oxide and electron donor substances on 1,1,1-trichloro- 2, 2-bis (p-chlorophenyl) ethane ( DDT) reductive dechlorination in hydragric acrisols].

    PubMed

    Liu, Cui-Ying; Xu, Xiang-Hua; Wang, Zhuang; Yao, Tong-Yan

    2014-11-01

    The interaction between iron oxide and electron donor substance have significant influences on electron transfer and the growth of iron-reducing bacteria, which may affect the reductive dechlorination of polychlorinated organic compounds in soil. Anaerobic soil incubation experiment was conducted to study the effect and its mechanism of iron oxide (goethite), electron donor substances (butyrate and ethanol), and their interaction on DDT reductive dechlorination in Hydragric Acrisols. Results showed that after 6 weeks of anaerobic incubation, the extractable residues of DDT were between 1.29% and 2.01% of initial DDT amounts in soils, which was attributed to the dechlorinated degradation of DDT and formation of bound residues of DDT and its dechlorinated products. The main product of DDT anaerobic dechlorination was 1,1-dichloro-2,2-bis (p-chloro-phenyl) ethane (DDD). During the prophase of incubation, the application of butyrate or ethanol led to the decreased pH and increased Eh for reaction system, thus inhibited DDT dechlorination. The applications of only goethite or goethite and electron donor substances resulted in the increased soil pH, decreased soil Eh and increased Fe( II ) contents, thus accelerated DDT dechlorination. There was no significant interaction between butyrate and iron oxide on DDT dechlorination, whereas there was antagonistic action between ethanol and iron oxide on DDT dechlorination. The results will be of great significance for developing efficient and in-situ remediation technology of DDT contaminated soil.

  17. Measurement of total lung aerosol deposition as an index of lung abnormality.

    PubMed

    Kim, C S; Lewars, G A; Sackner, M A

    1988-04-01

    Total aerosol deposition in the lung was measured in 100 subjects with various lung conditions. The subjects consisted of 40 normals (N), 15 asymptomatic smokers (S), 10 smokers with small airway disease (SAD), 20 with chronic simple bronchitis (SB), and 15 with chronic obstructive bronchitis (COPD), and a relationship of total aerosol deposition to degree of lung abnormality was investigated. The subjects were categorized by medical history and a battery of pulmonary function tests, including spirometry, body plethysmography, and single and multiple N2 washout measurements. Subjects repeatedly breathed a monodisperse test aerosol (1.0 micron diam) from a collapsible rebreathing bag (0.5 liter volume) at a rate of 30 breaths/min, while inhaled and exhaled aerosol concentrations were continuously monitored by a laser aerosol photometer in situ and recorded on a strip-chart recorder. The number of rebreathing breaths resulting in 90% aerosol loss from the bag (N90) was determined, and percent predicted N90 values were then determined from the results of computer simulation and used as a deposition index. The percent predicted N90 values were 99.7 +/- 14, 86.5 +/- 15, 66.9 +/- 17, 51 +/- 12, and 30.9 +/- 9, respectively, for N, S, SAD, SB, and COPD. All of these values were significantly different from each other (P less than 0.05). There was no difference between male and female but percent predicted N90 values were slightly higher in young than in old normals. Percent predicted N90 values showed a strong linear correlation with spirometric measurements of forced expiratory volume in 1 s and maximum midexpiratory flow rate. However, many of the SAD and SB with normal spirometry showed abnormal N90. These results suggest that total lung aerosol deposition is a sensitive index of lung abnormality and may be of potential use for nonspecific general patient screening.

  18. Visibility-reducing organic aerosols in the vicinity of Grand Canyon National Park: Properties observed by high resolution gas chromatography

    SciTech Connect

    Mazurek, M. |; Masonjones, M.C.; Masonjones, H.D.; Salmon, L.G.; Cass, G.R.; Hallock, K.A.; Leach, M.

    1997-02-01

    Fine particle and total airborne particle samples were collected during August 1989 within the Grand Canyon [Indian Gardens (IG)] and on its south rim [Hopi Point (HP)] to define summertime organic aerosol concentration and composition as a function of elevation at Grand Canyon National Park. Inorganic chemical constituents were analyzed also to help place the relative importance of organics in perspective. Fine particle organic aerosols were approximately equal in concentration to sulfate aerosols at both sites. Monthly average mass concentrations for fine aerosol organics ranged from 1.1{mu}gm{sup {minus}3} (IG) to 1.3{mu}gm{sup {minus}3} (HP), while the organic aerosol concentration within total suspended particulate matter samples ranged from 1.9{mu}gm{sup {minus}3} (IG) to 2.1{mu}gm{sup {minus}3} (HP). Aerosol organics that could be evaluated by gas chromatography with flame ionization detection (GC-FID) (elutable organics) constituted 27{percent} to 53{percent} of the total organics mass collected as fine or total aerosol. At each site, roughly half of the elutable organics fine aerosol fraction was composed of highly polar organic compounds. Distributions of the elutable organics were compared to Los Angeles fine aerosol samples and to distributions of authentic sources of aerosol organics. It was found that the Grand Canyon organic aerosol during August 1989 did not resemble diluted aged Los Angeles organic aerosol, indicating that most of the organic particulate matter at the Grand Canyon at the time studied originated from other sources.{copyright} 1997 American Geophysical Union

  19. Highly stable aerosol generator

    SciTech Connect

    DeFord, Henry S.; Clark, Mark L.

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  20. Highly stable aerosol generator

    DOEpatents

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  1. [The effect of long-term exposure to low doses of endocrine disruptor ddt on serum levels of thyroid protein autoantigenes and antithyroid autoantibodies].

    PubMed

    Yaglova, N V; Yaglov, V V

    2016-01-01

    Changes in secretion of thyroid autoantigenes and production of antithyroid autoantibodies after long-term exposure to low doses of DDT were studied. Changes in serum levels of antithyroid peroxidase antibodies and thyroid peroxidase, attributed to disruption of thyroxine production by DDT were found. Long-term exposure of rats to low doses of DDT revealed no specific impact on serum autoantibodies to all thyroid autoantigenes studied. The increase of the ratio of autoantibody/autoantigen for thyroid peroxidase and thyroglobulin was rather small and thus could not be considered as a significant symptom of thyroid autoimmunity.

  2. Uncertainties of simulated aerosol optical properties induced by assumptions on aerosol physical and chemical properties: An AQMEII-2 perspective

    NASA Astrophysics Data System (ADS)

    Curci, G.; Hogrefe, C.; Bianconi, R.; Im, U.; Balzarini, A.; Baró, R.; Brunner, D.; Forkel, R.; Giordano, L.; Hirtl, M.; Honzak, L.; Jiménez-Guerrero, P.; Knote, C.; Langer, M.; Makar, P. A.; Pirovano, G.; Pérez, J. L.; San José, R.; Syrakov, D.; Tuccella, P.; Werhahn, J.; Wolke, R.; Žabkar, R.; Zhang, J.; Galmarini, S.

    2015-08-01

    The calculation of aerosol optical properties from aerosol mass is a process subject to uncertainty related to necessary assumptions on the treatment of the chemical species mixing state, density, refractive index, and hygroscopic growth. In the framework of the AQMEII-2 model intercomparison, we used the bulk mass profiles of aerosol chemical species sampled over the locations of AERONET stations across Europe and North America to calculate the aerosol optical properties under a range of common assumptions for all models. Several simulations with parameters perturbed within a range of observed values are carried out for July 2010 and compared in order to infer the assumptions that have the largest impact on the calculated aerosol optical properties. We calculate that the most important factor of uncertainty is the assumption about the mixing state, for which we estimate an uncertainty of 30-35% on the simulated aerosol optical depth (AOD) and single scattering albedo (SSA). The choice of the core composition in the core-shell representation is of minor importance for calculation of AOD, while it is critical for the SSA. The uncertainty introduced by the choice of mixing state choice on the calculation of the asymmetry parameter is the order of 10%. Other factors of uncertainty tested here have a maximum average impact of 10% each on calculated AOD, and an impact of a few percent on SSA and g. It is thus recommended to focus further research on a more accurate representation of the aerosol mixing state in models, in order to have a less uncertain simulation of the related optical properties.

  3. Local environmental pollution strongly influences culturable bacterial aerosols at an urban aquatic superfund site.

    PubMed

    Dueker, M Elias; O'Mullan, Gregory D; Juhl, Andrew R; Weathers, Kathleen C; Uriarte, Maria

    2012-10-16

    In polluted environments, when microbial aerosols originate locally, species composition of the aerosols should reflect the polluted source. To test the connection between local environmental pollution and microbial aerosols near an urban waterfront, we characterized bacterial aerosols at Newtown Creek (NTC), a public waterway and Superfund site in a densely populated area of New York, NY, USA. Culturable bacterial aerosol fallout rate and surface water bacterial concentrations were at least an order of magnitude greater at NTC than at a neighboring, less polluted waterfront and a nonurban coastal site in Maine. The NTC culturable bacterial aerosol community was significantly different in taxonomic structure from previous urban and coastal aerosol studies, particularly in relative abundances of Actinobacteria and Proteobacteria. Twenty-four percent of the operational taxonomic units in the NTC overall (air + water) bacterial isolate library were most similar to bacterial 16S rRNA gene sequences previously described in terrestrial or aquatic environments contaminated with sewage, hydrocarbons, heavy metals, and other industrial waste. This study is the first to examine the community composition and local deposition of bacterial aerosols from an aquatic Superfund site. The findings have important implications for the use of aeration remediation in polluted aquatic environments and suggest a novel pathway of microbial exposure in densely populated urban communities containing contaminated soil and water.

  4. Entomological and parasitological impacts of indoor residual spraying with DDT, alphacypermethrin and deltamethrin in the western foothill area of Madagascar

    PubMed Central

    2014-01-01

    Background In Madagascar, indoor residual spraying (IRS) with insecticide was part of the national malaria control programme since the middle of the twentieth century. It was mainly employed in the highlands and the foothill areas, which are prone to malaria epidemics. Prior to a policy change foreseeing a shift from DDT to pyrethroids, a study was carried out to assess the entomological and parasitological impacts of IRS in areas with DDT or pyrethroids and in areas without IRS. Methods The study was carried out from October 2002 to February 2005 in three communes of the western foothill area of Madagascar. Two communes received IRS with DDT in February 2003, then IRS with pyrethroids (alphacypermethrin or deltamethrin) in February 2004. The third commune remained untreated. Mosquitoes were collected at night using human landing catches and early in the morning in resting places. Blood smears were obtained from schoolchildren and microscopically examined for Plasmodium presence. Results In total, 18,168 human landing mosquitoes and 12,932 resting anophelines were collected. The Anopheles species caught comprised 10 species. The main and most abundant malaria vector was Anopheles funestus (72.3% of human-seeking malaria vectors caught indoors). After IRS had taken place, this species exhibited a lower human biting rate and a lower sporozoite index. Overall, 5,174 blood smears were examined with a mean plasmodic index of 19.9%. A total of four Plasmodium species were detected. Amongst tested school children the highest plasmodial index was 54.6% in the untreated commune, compared to 19.9% in the commune sprayed with DDT and 11.9% in the commune sprayed with pyrethroid. The highest prevalence of clinical malaria attacks in children present at school the day of the survey was 33% in the untreated commune compared to 8% in the areas which received IRS. Conclusion In terms of public health, the present study shows (1) a high efficacy of IRS with insecticide, (2) a

  5. 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

  6. Presence of DDT metabolites in water, sediment and fish muscle tissue from Lake Prespa, Republic of Macedonia.

    PubMed

    Veljanoska-Sarafiloska, Elizabeta M; Jordanoski, Momčula; Stafilov, Trajče

    2013-01-01

    Organochlorine pesticides were determined in water and sediment samples collected from the littoral zone of Lake Prespa, as well as from its three main tributaries (the rivers Golema, Brajcinska and Kranska), during the period 2004 to 2006. In addition, muscle tissue samples of barbus fish (Barbus prespensis Karaman, 1928) collected from the littoral zone of Lake Prespa were also analysed. The obtained results give an overview of the contamination levels of these problematic compounds at their potential sources in the river mouths, in the potentially affected, species-rich littoral section of the lake and in the muscle tissue of one selected fish species, collected near the rivers' deltas. Special attention was paid to the presence of some DDT metabolites (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE); (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDD) and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT). The extraction of pesticides from water samples was done by liquid-liquid partition in dichloromethane. For the sediment and fish tissue we used solid-liquid extraction. The extracted residues were analyzed on a gas chromatograph equipped with an electron capture detector (GC-ECD). The results of the respective studies indicated the presence of DDT metabolic forms in the samples of the three analysed matrixes. The highest levels of presence for these pollutants were found in the muscle tissue of the fish samples. The total DDTs content in the analysed muscle tissue samples range from 11.67 to 13.58 μg kg⁻¹ of fresh tissue. The average total DDTs content for the sediment samples were within the range of 2.32 to 4.17 μg kg⁻¹ of dry sediment. Higher DDT metabolites content were found in the sediments collected from the rivers than in the samples from the littoral zone. The lowest average total concentrations of DDTs, on the other hand, were recorded in the water samples and ranged between 0.036 and 0.057 μg L⁻¹. The obtained results

  7. Aerosol contributions to speleothem geochemistry

    NASA Astrophysics Data System (ADS)

    Dredge, J. A.; Fairchild, I. J.; Harrison, R.; Woodhead, J. D.; Hellstrom, J.

    2011-12-01

    The term "aerosols" encompasses the suspension of both fine solid or liquid particles within a gaseous medium. Aerosols become suspended into the earth's atmosphere through a multitude of processes both natural and anthropogenic. Atmospheric aerosols enter cave networks as a result of cave ventilation processes and are either deposited, or cycled and removed from the system. Speleothem offer a multiproxy palaeoclimate resource; many of the available proxies have been extensively investigated and utilised for palaeoclimatic reconstructions in a range of studies. The potential contribution of aerosols to speleothem chemistry and their applicability for palaeoenvironmental reconstructions remains untested and the extent of their value as an addition to palaeoclimate sciences unknown. Aerosols through incorporation into speleothem may provide a novel palaeoenvironmental resource. The aerosol component of interest is that which is transported into the cave atmosphere and deposited and are available for incorporation into precipitated calcite. Aerosol deposition and therefore distribution in the cave has shown to be a complex function of ventilation and changing environmental factors. Through detailed monitoring aerosols have been detected, identified, characterised and quantified to determine their prominence in the cave system. Investigations are on a case study basis, searching for suitable aerosol proxies of environmentally significant emission processes. Case studies include: Palaeofires at Yarrangobilly Caves, Australia; anthropogenic emissions at St Michaels Cave, Gibraltar and Cheddar gorge, UK; and drip water aerosol production and geochemical addition in Obir cave, Austria. Monitoring has allowed for the temporal and spatial determination of aerosols in karst networks. Speleothem samples will be analysed in combination with in-situ monitoring to determine incorporation factors and record preservation. By understanding how aerosols are transmitted within the

  8. Aerosolized liposome-based delivery of amphotericin B to alveolar macrophages.

    PubMed

    Vyas, Suresh P; Quraishi, Shama; Gupta, Swati; Jaganathan, K S

    2005-05-30

    The present study was aimed at preparation, characterization, and performance evaluation of amphotericin B (Amp B)-loaded aerosolized liposomes for their selective presentation to lungs (alveolar macrophages), that being the densest site of Aspergillosis infection. Egg phosphatidylcholine (PC)- and cholesterol (Chol)-based liposomes were modified by coating them with alveolar macrophage-specific ligands (O-palmitoyl mannan, OPM, and O-polmitoyl pullulan, OPP). The prepared formulations were characterized in vitro for vesicle morphology, mean vesicle size, vesicle size distribution and percent drug entrapment. Pressurized packed systems based on preformed liposomal formulations in chlorofluorocarbon aerosol propellants were prepared. In vitro airways penetration efficiency of the liposomal aerosols was determined by percent dose reaching the peripheral airways, it was recorded 1.4-1.6 times lower as compared to plain drug solution-based aerosol. In vivo tissue distribution studies on albino rats suggested the preferential accumulation of OPM- and OPP-coated formulations in the lung macrophages. Higher lung drug concentration was recorded in case of ligand-anchored liposomal aerosols as compared to plain drug solution and plain liposome-based aerosols. The drug was estimated in the lung in high concentration even after 24 h. The drug-localization index calculated after 6 h was nearly 1.42-, 4.47-, and 4.16-fold, respectively, for plain, OPM-, and OPP-coated liposomal aerosols as compared to plain drug solution-based aerosols. These results suggest that the ligand anchored liposomal aerosols are not only effective in rapid attainment of high-drug concentration in lungs with high population of alveolar macrophages but also maintain the same over prolonged period of time. The significance of targeting potential of the developed systems was established.

  9. 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. ...

  10. Near Zero Emissions at 50 Percent Thermal Efficiency

    SciTech Connect

    None, None

    2012-12-31

    Detroit Diesel Corporation (DDC) has successfully completed a 10 year DOE sponsored heavy-duty truck engine program, hereafter referred to as the NZ-50 program. This program was split into two major phases. The first phase was called Near-Zero Emission at 50 Percent Thermal Efficiency, and was completed in 2007. The second phase was initiated in 2006, and this phase was named Advancements in Engine Combustion Systems to Enable High-Efficiency Clean Combustion for Heavy-Duty Engines. This phase was completed in September, 2010. The key objectives of the NZ-50 program for this first phase were to: Quantify thermal efficiency degradation associated with reduction of engine-out NOx emissions to the 2007 regulated level of ~1.1 g/hp-hr. Implement an integrated analytical/experimental development plan for improving subsystem and component capabilities in support of emerging engine technologies for emissions and thermal efficiency goals of the program. Test prototype subsystem hardware featuring technology enhancements and demonstrate effective application on a multi-cylinder, production feasible heavy-duty engine test-bed. Optimize subsystem components and engine controls (calibration) to demonstrate thermal efficiency that is in compliance with the DOE 2005 Joule milestone, meaning greater than 45% thermal efficiency at 2007 emission levels. Develop technology roadmap for meeting emission regulations of 2010 and beyond while mitigating the associated degradation in engine fuel consumption. Ultimately, develop technical prime-path for meeting the overall goal of the NZ-50 program, i.e., 50% thermal efficiency at 2010 regulated emissions. These objectives were successfully met during the course of the NZ-50 program. The most noteworthy achievements in this program are summarized as follows: Demonstrated technologies through advanced integrated experiments and analysis to achieve the technical objectives of the NZ-50 program with 50.2% equivalent thermal efficiency under

  11. 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

  12. American Association for Aerosol Research (AAAR) `95

    SciTech Connect

    1995-12-31

    The Fourteenth annual meeting of the American Association for Aerosol Research was held October 9-13, 1995 at Westin William Penn Hotel in Pittsburgh, PA. This volume contains the abstracts of the papers and poster sessions presented at this meeting, grouped by the session in which they were presented as follows: Radiation Effects; Aerosol Deposition; Collision Simulations and Microphysical Behavior; Filtration Theory and Measurements; Materials Synthesis; Radioactive and Nuclear Aerosols; Aerosol Formation, Thermodynamic Properties, and Behavior; Particle Contamination Issues in the Computer Industry; Pharmaceutical Aerosol Technology; Modeling Global/Regional Aerosols; Visibility; Respiratory Deposition; Biomass and Biogenic Aerosols; Aerosol Dynamics; Atmospheric Aerosols.

  13. Engineering and Environmental Study of DDT Contamination of Huntsville Spring Branch, Indian Creek and Adjacent Lands and Waters, Wheeler Reservoir, Alabama. Revision,

    DTIC Science & Technology

    1984-04-01

    AD-A142 517 ENGINEERING AND ENVIRONMENTAL STUDY OF DDT CONTAMINATION OF HUNTSVILLE SP..(U) WATER AND AIR RESEARCH INC GAINESVILLE FL d H...DDT Con- tamination of Huntsville Spring Branch, Indian Creek and Adjacent Lands and Waters , Wheeler Reservoir, Alabama a. i irk ut iPOR...Pruitt and J. C. Nichols 8. CONTRACT OR GRANT NUMBER)» DACW01-79-C-0224 9. PERFORMING ORGANIZATION NAME AND ADDRESS Water and Air Research

  14. 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.

  15. Temporal and spatial variability of aerosol optical depth in the Sahel region in relation to vegetation remote sensing

    NASA Technical Reports Server (NTRS)

    Holben, B. N.; Fraser, R. S.; Eck, T. F.

    1991-01-01

    In order to monitor the aerosol characteristics needed for atmospheric correction of remotely sensed data, a network of sun photometers was established in the Sahel region of Senegal, Mali, and Niger. Data analysis suggests that there is a high spatial variability of the aerosol optical thickness tau(a) in the western Sahel region. At a 67 percent confidence level the instantaneous values of tau(a) can be extrapolated approximately 270-400 km with an error tolerance of 50 percent. Spatial variability in the dry season is found to be of a similar magnitude. The ranges of variations in the NDVI in the Sahel region are shown to be approximately 0.02 and 0.01, respectively, due to commonly observed fluctuations in the aerosol optical thickness and aerosol size distribution.

  16. Genotoxic effect of chronic exposure to DDT on lymphocytes, oral mucosa and breast cells of female rats.

    PubMed

    Canales-Aguirre, Alejandro; Padilla-Camberos, Eduardo; Gómez-Pinedo, Ulises; Salado-Ponce, Hugo; Feria-Velasco, Alfredo; De Celis, Ruth

    2011-02-01

    The genotoxicity of some environmental contaminants may affect human health directly by damaging genetic material and thus plays an important role in cancer development. Xenoestrogens are one kind of environmental pollutants that may alter hormonal routes or directly affect DNA. The number of available biomarkers used to assess genetic risk and cancer is very extensive. The present study evaluated genotoxicity produced by the pesticide DDT on systemic and mammary gland cells obtained from adult female Wistar rats. Oral mucosa cells micronuclei were assessed; the comet assay in peripheral blood-isolated lymphocytes and mammary epithelial cells was also carried out. Additionally, oxidative stress was studied in mammary tissue through a lipid peroxidation assay. Our data showed an increase in lipid peroxidation, product of an increase in free oxygen radical levels, which leads to an oxidative stress status. Our results suggest that DDT is genotoxic, not only for lymphocytes but also to mammary epithelial cells.

  17. Effects of DDT and permethrin on neurite growth in cultured neurons of chick embryo brain and Lymnaea stagnalis.

    PubMed

    Ferguson, C A; Audesirk, G

    1990-01-01

    The pesticides permethrin and 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT), dissolved in either ethanol (EtOH) or dimethylsulphoxide (DMSO), were studied to determine their effect on neurite growth from cultured neurons of Lymnaea stagnalis and embryonic chicks. Both of these toxins decreased the percentage of neurons growing neurites, mean neurite length, and number of neurites/cell in a dose-dependent manner. DMSO increased the toxicity of permethrin and DDT in L. stagnalis neurons. EtOH was not used as a solvent with the embryonic chick cultures. Pre-existing neurites of L. stagnalis neurons exposed to permethrin regressed in a dose- and time-dependent manner. These two toxins may affect neurite outgrowth through interference with intracellular calcium regulation.

  18. 30 CFR 57.22239 - Actions at 2.0 percent methane (IV mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... percent methane (IV mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from the mine until methane...

  19. 30 CFR 57.22240 - Actions at 2.0 percent methane (V-A mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... percent methane (V-A mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  20. 30 CFR 57.22239 - Actions at 2.0 percent methane (IV mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... percent methane (IV mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from the mine until methane...

  1. 30 CFR 57.22236 - Actions at 1.0 percent methane (VI mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... percent methane (VI mines). If methane reaches 1.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  2. 30 CFR 57.22240 - Actions at 2.0 percent methane (V-A mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... percent methane (V-A mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  3. 30 CFR 57.22236 - Actions at 1.0 percent methane (VI mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... percent methane (VI mines). If methane reaches 1.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  4. 30 CFR 57.22240 - Actions at 2.0 percent methane (V-A mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... percent methane (V-A mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  5. 30 CFR 57.22239 - Actions at 2.0 percent methane (IV mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... percent methane (IV mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from the mine until methane...

  6. 30 CFR 57.22236 - Actions at 1.0 percent methane (VI mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... percent methane (VI mines). If methane reaches 1.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until...

  7. Determination of aerosol ammonium using an aerodyne aerosol mass spectrometer

    NASA Astrophysics Data System (ADS)

    Delia, A. E.; Toohey, D. W.; Worsnop, D. R.

    2003-04-01

    The chemical composition of fine aerosols is a significant issue both because it influences the chemical and radiative properties of the aerosols, which in turn impact the regional and global climate and human health, and because it is difficult to measure accurately. The Aerosol Mass Spectrometer (AMS) developed by Aerodyne Research measures both chemical composition and aerodynamic size of submicron aerosols quantitatively. However, the measurement of aerosol ammonium is more difficult than that of the other major inorganic species, nitrate and sulfate, because of interferences in the mass spectrum from air and water. This presentation will describe the successful procedure developed for dealing with these interferences and accurately determining the ammonium mass. In addition, the application of this procedure to aerosols from a range of ambient conditions will be demonstrated using data from several field studies.

  8. Investigation of Effectiveness of a Wing Equipped with a 50-percent-chord Sliding Flap, a 30-percent-chord Slotted Flap, and a 30-percent-chord Slat in Deflecting Propeller Slipstreams Downward for Vertical Take-off

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E

    1957-01-01

    Results are presented of an investigation of the effectiveness of a wing equipped with a 50-percent-chord sliding flap and a 30-percent-chord slotted flap in deflecting a propeller slipstream downward for vertical take-off. Tests were conducted at zero forward speed in a large room and included the effects of flap deflection, proximity to the ground, a leading-edge slat, and end plates. A turning angle of about 70 degrees and a resultant force of about 100 percent of the thrust were achieved near the ground. Out of the ground-effect region, the turning angle was also about 70 degrees but the resultant force was reduced to about 86 percent of the thrust.

  9. 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

    SciTech Connect

    De Gregorio, Francesca; Pellegrino, Mario; Picchietti, Simona; Belardinelli, Maria C.; Taddei, Anna Rita; Fausto, Anna Maria; Rossi, Mario; Maggio, Roberto; Giorgi, Franco

    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 the 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

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

    SciTech Connect

    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 that 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.

  11. Enhancement effect of two ecological earthworm species (Eisenia foetida and Amynthas robustus E. Perrier) on removal and degradation processes of soil DDT.

    PubMed

    Lin, Zhong; Li, Xiao-min; Li, Yong-tao; Huang, De-yin; Dong, Jun; Li, Fang-bai

    2012-05-01

    Effects of two ecological earthworm species (epigeic Eisenia foetida and endogeic Amynthas robustus E. Perrier) with different densities (15 and 30 individuals per kg of soil) on the removal of soil 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) with two pollution levels (2 and 4 mg kg(-1)) were investigated. Concentrations of DDT and its metabolites, including 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), and 1-chloro-2,2-bis(4-chlorophenyl)ethylene (DDMU), were monitored after 60, 180, and 360 days of incubation. The results obtained showed that both earthworm species can significantly enhance degradation of soil DDT to its metabolites. For E. foetida, the higher earthworm density showed significantly higher rate of DDT degradation than the lower one. Anaerobic reductive dechlorination was the main degradation pathway over 180 days of incubation, while the aerobic dechlorination process was promoted between 180 and 360 days of incubation. Some earthworm amended treatments showed significantly higher microbial biomass carbon and nitrogen than the control, which suggested that earthworms might enhance the microbial degradation of DDT. Both earthworm species would have the potential to be applied to enhance the remediation of agricultural lands polluted by DDT.

  12. Insight into the metabolism of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) by biphenyl dioxygenases.

    PubMed

    L'Abbée, José-Bruno; Tu, Youbin; Barriault, Diane; Sylvestre, Michel

    2011-12-01

    In this work we have investigated the ability of the biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE(LB400)) and of Pandoraea pnomenusa B356 (BphAE(B356)) to metabolize DDT. Data show BphAE(LB400) is unable to metabolize this substrate but BphAE(B356) metabolizes DDT to produce two stereoisomers. Structural analysis of DDT-docked BphAE(LB400) and BphAE(B356) identified residue Phe336 of BphAE(LB400) as critical to prevent productive binding of DDT to BphAE(LB400). Furthermore, the fact that residue Gly319 of BphAE(B356) is less constrained than Gly321 of BphAE(LB400) most likely contributes to the ability of BphAE(B356) to bind DDT productively. This was confirmed by examining the ability of BphAE chimeras obtained by shuffling bphA genes from strain B356 and LB400. Chimeras where residues Thr335 (which modulates the constraints on Gly321) and Phe336 (which contacts the substrate) of BphAE(LB400) were replaced by Gly and Ile respectively were able to metabolize DDT. However their stereospecificities varied depending on the presence of other segments or residues from BphAE(B356). Structural analysis suggests that either one or both of residue 267 and a segments comprised of residue 247-260 are likely involved in stereospecificity.

  13. 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.

  14. Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

    PubMed Central

    Zhao, Yuechun; Yi, Xiaoyun

    2010-01-01

    High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5–4.5. PMID:20617049

  15. Acute toxicity of chromate, DDT, PCP, TPBS, and zinc to Daphnia magna cultured in hard and soft water

    SciTech Connect

    Berglind, R.; Dave, G.

    1984-07-01

    The aim of this study was to compare the toxicity of five chemicals to water fleas (Daphnia magna) cultured in either hard to soft water. The toxicity tests were made in reconstituted waters and the five chemicals to be tested were, p,p'-DDT, pentachlorophenol (PCP), tetrapropylenbenzyl sulfonate (TPBS), potassium bichromate (K/sub 2/Cr/sub 2/O/sub 7/) and zincsulfate (ZnSO/sub 4/ x 7H/sub 2/O).

  16. 24 CFR 266.305 - HFAs accepting less than 50 percent of risk.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false HFAs accepting less than 50 percent... PROJECT LOANS Processing, Development, and Approval § 266.305 HFAs accepting less than 50 percent of risk... electing to take less than 50 percent of the risk on certain projects are subject to review,...

  17. 30 CFR 57.22236 - Actions at 1.0 percent methane (VI mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Actions at 1.0 percent methane (VI mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22236 Actions at 1.0 percent methane (VI mines). If methane reaches 1.0 percent in the mine atmosphere, all persons other...

  18. 30 CFR 57.22239 - Actions at 2.0 percent methane (IV mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Actions at 2.0 percent methane (IV mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22239 Actions at 2.0 percent methane (IV mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other...

  19. 30 CFR 57.22233 - Actions at 0.5 percent methane (I-C mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Actions at 0.5 percent methane (I-C mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22233 Actions at 0.5 percent methane (I-C mines). If methane reaches 0.5 percent in the mine atmosphere, ventilation...

  20. 30 CFR 57.22236 - Actions at 1.0 percent methane (VI mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions at 1.0 percent methane (VI mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22236 Actions at 1.0 percent methane (VI mines). If methane reaches 1.0 percent in the mine atmosphere, all persons other...

  1. 30 CFR 57.22239 - Actions at 2.0 percent methane (IV mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions at 2.0 percent methane (IV mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22239 Actions at 2.0 percent methane (IV mines). If methane reaches 2.0 percent in the mine atmosphere, all persons other...

  2. 30 CFR 57.22233 - Actions at 0.5 percent methane (I-C mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions at 0.5 percent methane (I-C mines). 57... MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22233 Actions at 0.5 percent methane (I-C mines). If methane reaches 0.5 percent in the mine atmosphere, ventilation...

  3. Metabolism of carbaryl, chloropyrifos, DDT, and parathion in the European corn borer: effects of microsporidiosis on toxicity and detoxication

    SciTech Connect

    Tetreault, G.E.

    1985-01-01

    An investigation was conducted to examine the effects of microsporidiosis on an insect's response to insecticide intoxication. Healthy European corn borer, Ostrinia nubilalis, larvae and those heavily infected with the microsporidian pathogen, Nosema pyrausta, were bioassayed with ten insecticides. The compounds used were carbaryl, carbofuran, chlorophrifos, DDT, diazinon, fonofos, methomyl, parathion, permethrin, and terbufos. Third instar larvae were used for topical bioassays. The compounds carbaryl, carbofuran, chlorophrifos, methomyl and terbufos were found to be significantly more toxic to diseased insects than healthy insects at the 0.05 probability level. To examine the effect of Nosema pyrausta infection on the European corn borer's ability to detoxify insecticides, /sup 14/C ring-labeled carbaryl, chlorophrifos, DDT, and parathion were topically applied to fourth instar larvae. Qualitative differences between healthy and diseased insects were found in the metabolic pathways of carbaryl, DDT, and parathion. The degradative fate of chlorophrifos was the same in both groups. Quantitatively, each insecticide penetrated diseased larvae faster. This resulted in larger amounts of the applied dose of parent compound and metabolites being found in the feces from diseased insects. Conversely, healthy insects had more of these materials present in the body and associated with the cuticle.

  4. Relationship between kdr mutation and resistance to pyrethroid and DDT insecticides in natural populations of Anopheles gambiae.

    PubMed

    Reimer, Lisa; Fondjo, Etienne; Patchoké, Salomon; Diallo, Brehima; Lee, Yoosook; Ng, Arash; Ndjemai, Hamadou M; Atangana, Jean; Traore, Sekou F; Lanzaro, Gregory; Cornel, Anthony J

    2008-03-01

    The spread of insecticide resistance genes in Anopheles gambiae Giles sensu stricto threatens to compromise vector-based malaria control programs. Two mutations at the same locus in the voltage-gated sodium channel gene are known to confer knockdown resistance (kdr) to pyrethroids and DDT. Kdr-e involves a leucine-serine substitution, and it was until recently thought to be restricted to East Africa, whereas kdr-w, which involves a leucine-phenylalanine substitution, is associated with resistance in West Africa. In this study, we analyze the frequency and relationship between the kdr genotypes and resistance to type I and type II pyrethroids and DDT by using WHO test kits in both the Forest-M and S molecular forms of An. gambiae in Cameroon. Both kdr-w and kdr-e polymorphisms were found in sympatric An. gambiae, and in many cases in the same mosquito. Kdr-e and kdr-w were detected in both forms, but they were predominant in the S form. Both kdr-e and kdr-w were closely associated with resistance to DDT and weakly associated with resistance to type II pyrethroids. Kdr-w conferred greater resistance to permethrin than kdr-e. We also describe a modified diagnostic designed to detect both resistant alleles simultaneously.

  5. Violent cookoff reactions in HMX-based explosives in DDT tubes: Tracking luminous waves with streak imaging

    NASA Astrophysics Data System (ADS)

    Parker, Gary; Dickson, Peter; Asay, Blaine W.; Smilowitz, Laura; Henson, Bryan; McAfee, John

    2012-03-01

    Recent implementation of modern high-speed video cameras has permitted the experimental flexibility needed to revisit classic deflagration-to-detonation (DDT) tube experiments and capture novel and valuable results displaying the progression of luminous reaction from a cookoff event. The authors present select data from a series of experiments where the HMX-based high explosives PBX 9501 and LX-07 were heated above 180°C for various durations to impose damage (i.e. phase transitions and void generation) before being driven to cook off. These two explosives have different polymeric binders, HMX mass fractions and cook off responses and a comparison between the two offers mechanistic insights on how thermal explosions evolve. From this series, results will be displayed indicating a wide range of violence from somewhat mild pressure bursts, to intermediate power compressive burns, to high-violence DDT. Image data from high temperature DDT tube experiments, where the explosive was ignited on one end, were also collected and will be included for comparison.

  6. Charicteristics of Aerosol indices distribution followed by Aerosol types

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, J.; Lee, J.; Kim, M.; Lee, S.; Song, C.

    2010-12-01

    Transboundary transport of aerosol has been a hot issue in East Asia and with various aerosol types from different source region. To detect signals from aerosols, OMI provides aerosol indices. Aerosol Indices (AI) represent the change of spectral contrast between two wavelengths and these indices are derived in UV and Visible regions. These indices also can get not only in ocean but also in land region so that AI is good to observe the source region and transport of aerosols. In UV region, AI (UV-AI) can classify the absorbing and non-absorbing aerosols (Torres et al., 1998) so that this value is frequently used for dust detection. Additionally, visible AI (VIS-AI) uses to differentiate the absorbing and non-absorbing aerosol types. If we combine two types of indices at the coordinate system of two types of AI, distribution of indices contains different signals if aerosol types change theoretically. In this study, we want to find out classification results based by the observation data to see the theoretical distribution in two AI values. For the observation data, aerosol types are obtained from the results of MODIS-OMI algorithm and 4-channel algorithm classify four types of aerosols, i.e. dust, carbonaceous, sea-salt and Non-Absorbing (NA). These algorithms classify aerosol by using the characteristics of aerosol optical properties in visible and near IR regions. MODIS-OMI algorithm uses the MODIS AOD and UV-AI in OMI values. For UV-AI case, dust and carbonaceous types have larger UV-AI values than non-absorbing aerosols because of absorbing characteristics. However, dust and carbonaceous types cannot classify if UV-AI values use only. For VIS-AI case, dust has larger proportion, but carbonaceous aerosol has smaller proportion in high AI value. However, VIS-AI cannot clearly classify between dust and carbonaceous types except for the case of extremely high AI cases. In NA type, VIS-AI has almost positive values, but the distribution has smaller than the absorbing

  7. Air Quality Monitoring and Forecasting Applications of Suomi NPP VIIRS Aerosol Products

    NASA Astrophysics Data System (ADS)

    Kondragunta, Shobha

    The Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched on October 28, 2011. It provides Aerosol Optical Thickness (AOT) at two different spatial resolutions: a pixel level (~750 m at nadir) product called the Intermediate Product (IP) and an aggregated (~6 km at nadir) product called the Environmental Data Record (EDR), and a Suspended Matter (SM) EDR that provides aerosol type (dust, smoke, sea salt, and volcanic ash) information. An extensive validation of VIIRS best quality aerosol products with ground based L1.5 Aerosol Robotic NETwork (AERONET) data shows that the AOT EDR product has an accuracy/precision of -0.01/0.11 and 0.01/0.08 over land and ocean respectively. Globally, VIIRS mean AOT EDR (0.20) is similar to Aqua MODIS (0.16) with some important regional and seasonal differences. The accuracy of the SM product, however, is found to be very low (20 percent) when compared to Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) and AERONET. Several algorithm updates which include a better approach to retrieve surface reflectance have been developed for AOT retrieval. For dust aerosol type retrieval, a new approach that takes advantage of spectral dependence of Rayleigh scattering, surface reflectance, dust absorption in the deep blue (412 nm), blue (440 nm), and mid-IR (2.2 um) has been developed that detects dust with an accuracy of ~80 percent. For smoke plume identification, a source apportionment algorithm that combines fire hot spots with AOT imagery has been developed that provides smoke plume extent with an accuracy of ~70 percent. The VIIRS aerosol products will provide continuity to the current operational use of aerosol products from Aqua and Terra MODIS. These include aerosol data assimilation in Naval Research Laboratory (NRL) global aerosol model, verification of National Weather Service (NWS) dust and smoke forecasts, exceptional events monitoring by different states

  8. Aerosol Dynamics Laboratory

    SciTech Connect

    Rader, D.J.; Mondy, L.A.

    1990-04-01

    In past five years, Department 1510 has developed a state-of-the-art Aerosol Dynamics Laboratory (ADL). This report documents the current instrumentation and capabilities that exist in this laboratory. The ADL was developed from a variety of sources, with a primary contribution from Department 1510's Independent Research and Development program in aerosol dynamics. Current capabilities of the ADL include: (1) generation of calibration-quality monodisperse particles with diameters between 0.005 to 100 {mu}m, (2) real-time measurement of particle size distributions for particle diameters between 0.01 and 100 {mu}m, (3) in situ, real-time measurement of particle size distributions for particle diameters between 0.3 and 100 {mu}m, and (4) real-time measurement of particle charge distributions for particle diameters between 0.01 and 1.0 {mu}m. 14 refs., 5 figs.

  9. On COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback

    NASA Astrophysics Data System (ADS)

    Kulmala, Markku

    2016-04-01

    Anthropogenic emissions of GHGs have increased substantially during the past century. Elevated concentrations of CO2 and methane are the most important forcing agents causing global warming. However, it is not straightforward to attribute or predict the climate change in detail, as the internal variability of climate is only partially understood, aerosol forcings are still highly uncertain, and there are many feedback mechanisms that are difficult to quantify. It has been recognized for decades that the biosphere plays an important role in climate. For example, Kulmala et al. (2004) suggested a negative climate feedback mechanism whereby higher temperatures and CO2-levels boost continental biomass production, leading to increased biogenic secondary organic aerosol (BSOA) and cloud condensation nuclei (CCN) concentrations, tending to cause cooling. This COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback is similar to the so-called CLAW-hypothesis by Charlson et al. (1987) which connects the ocean biochemistry and climate via a negative feedback loop involving CCN production due to sulphur emissions from plankton. The first quantification of the COBACC feedback loop (Kulmala et al. 2014) was based on continuous comprehensive observations at SMEAR II (Station for Measuring Forest Ecosystem-Atmosphere Relations) station in Hyytiälä, Finland, and showed that a 10 ppm increase in atmospheric CO2 concentration leads to a significant (several percent) increase in both carbon sink and aerosol source. These effects operate through changes in gross primary production, volatile organic compound (VOC) emissions and secondary aerosol formation associated with atmospheric oxidation of VOCs. Here we will describe the present knowledge from processes level understanding to whole COBACC feedback including some hints on biogenic and anthropogenic contributions to global aerosol number load. References: Charlson, R. J. et al. Nature 326, 655 1987 Kulmala, M. et al. Atmos

  10. Atmospheric aerosols: Their Optical Properties and Effects

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Measured properties of atmospheric aerosol particles are presented. These include aerosol size frequency distribution and complex retractive index. The optical properties of aerosols are computed based on the presuppositions of thermodynamic equilibrium and of Mie-theory.

  11. Study of the dehydrochlorination of DDT in basic media in sulfobetaine aqueous micellar solutions

    SciTech Connect

    Rodriguez, A.; Mar Graciani, M. del; Guinda, A.; Munoz, M.; Moya, M.L.

    2000-04-04

    The reaction of dehydrochlorination of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, DDT, with hydroxide ions has been studied in aqueous micellar solutions of N-tetradecyl-N,N-dimethyl-3-ammino-1-propane-sulfonate, SB3-14, and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, SB3-16. A simple expression for the observed rate constant, k{sub obs}, based on the pseudophase model, could explain the influence of changes in the surfactant concentration on k{sub obs}. The kinetic effects of added electrolytes (NaF, NaCl, NaBr, and NaNO{sub 3}) on the reaction rate in SB3-14 micellar media have also been studied. They were rationalized by considering the binding of the anions, which come from the added salt, to the sulfobetaine micelles and their competition with the reactive hydroxide ions for the micellar surface. Conductivity measurements have been a helpful tool in the discussion of the kinetic effects of added salts and permitted the estimation of equilibrium constants for the distribution of the anions between the zwitterionic micelles and the aqueous phase.

  12. Breast milk excretion Kinetic of b-HCH, pp'DDE and pp'DDT.

    PubMed

    Waliszewski, S M; Melo-Santiesteban, G; Villalobos-Pietrini, R; Gómez-Arroyo, S; Amador-Muñoz, O; Herrero-Mercado, M; Carvajal, O

    2009-12-01

    Breast milk is considered the most important route in the elimination of deposited organochlorine pesticides in a mother’s body. The equilibrium of organochlorine pesticides in the human body considers the elements of internal transport processes, the equilibrium pattern between pesticides and tissue fat contents, and the mobilization of lipids and lipoproteins among body parts. The aim of this study was to determine organochlorine pesticide levels in breast milk samples from the 4th to the 30th day of lactation and the trend in their concentration time so as to forecast the time tendency of residue levels and the pesticide excretion pattern. Milk samples were taken from forty participants and analyzed by GLC-ECD. The organochlorine pesticide residues determined in the breast milk samples during lactation decreased: β-HCH from 0.095 to 0.066 mg/kg, pp′DDE from 1.807 to 1.423 mg/kg and pp′DDT from 0.528 to 0.405 mg/kg, at the characteristic rate for each compound. The obtained results compared with the calculated fits of forecasts were parallel and did not exhibit significant differences. The newborn baby exposed during lactation had organochlorine pesticide residues whose levels decreased permanently. The levels depended not only on the breast milk nutrition, but also on the total environmental exposures which included air pollution as a significant contamination source.

  13. Observation and modeling of deflagration-to-detonation transition (DDT) in low-density HMX

    NASA Astrophysics Data System (ADS)

    Tringe, Joseph W.; Vandersall, Kevin S.; Reaugh, John E.; Levie, Harold W.; Henson, Bryan F.; Smilowitz, Laura B.; Parker, Gary R.

    2017-01-01

    We employ simultaneous flash x-ray radiography and streak imaging, together with a multi-phase finite element model, to understand deflagration-to-detonation transition (DDT) phenomena in low-density (˜1.2 gm/cm3) powder of the explosive cyclotetramethylene-tetranitramine (HMX). HMX powder was lightly hand-tamped in a 12.7 mm diameter column, relatively lightly-confined in an optically-transparent polycarbonate cylinder with wall thickness 25.4 mm. We observe apparent compaction of the powder in advance of the detonation transition by the motion of small steel spheres pre-emplaced throughout the length of explosive. High-speed imaging along the explosive cylinder length provides a more temporally continuous record of the transition that is correlated with the high-resolution x-ray image record. Preliminary simulation of these experiments with the HERMES model implemented in the ALE3D code enables improved understanding of the explosive particle burning, compaction and detonation phenomena which are implied by the observed reaction rate and transition location within the cylinder.

  14. Observation and modeling of deflagration-to-detonation (DDT) transition in low-density HMX

    NASA Astrophysics Data System (ADS)

    Tringe, Joseph; Vandersall, Kevin; Reaugh, Jack; Levie, Harold; Henson, Bryan; Smilowitz, Laura; Parker, Gary

    2015-06-01

    We employ simultaneous flash x-ray radiography and streak imaging, together with a multi-phase finite element model, to understand deflagration-to-detonation transition (DDT) phenomena in low-density (~ 1.2 gm/cm3) powder of the explosive cyclotetramethylene-tetranitramine (HMX). HMX powder was lightly hand-tamped in a 12.7 mm diameter column, relatively lightly-confined in an optically-transparent polycarbonate cylinder with wall thickness 25.4 mm. We observe apparent compaction of the powder in advance of the detonation transition, both by x-ray contrast and by the motion of small steel spheres pre-emplaced throughout the length of explosive. High-speed imaging along the explosive cylinder length provides a temporally continuous record of the transition that is correlated with the high-resolution x-ray image record. Preliminary simulation of these experiments with the HERMES model implemented in the ALE3D code enables improved understanding of the explosive particle burning, compaction and detonation phenomena which are implied by the observed reaction rate and transition location within the cylinder. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. Shock induced ignition and DDT in the presence of mechanically driven fluctuations

    NASA Astrophysics Data System (ADS)

    Wang, Wentian; McDonald, James G.; Radulescu, Matei I.

    2015-11-01

    The present study addresses the problem of shock induced ignition and transition to detonation in the presence of mechanical and thermal fluctuations. These departures from a homogeneous medium are of significant importance in practical situations, where such fluctuations may promote hot-spot ignition and favor the flame transition to detonation. The problem is studied in 1D, where a piston-induced shock ignites the gas. The fluctuations in the shock-compressed medium are controlled by allowing the piston's speed to oscillate around a mean, with controllable frequency and amplitude. A Lagrangian numerical formulation is used, which allows to treat exactly the transient boundary condition at the piston head. The hydrodynamic solver is coupled with the reactive dynamics of the gas using Cantera. The code was verified by comparison with steady state ZND solutions and previous shock induced ignition results in homogeneous media. Results obtained for different fuels illustrate the strong relation of the DDT amplification length to mechanical fluctuations in systems with a high effective activation energy and fast rate of energy deposition, consistent with experiments performed on fast flame acceleration in the presence of strong mechanical perturbations. Financial support from NSERC and Shell, with A. Pekalski and M. Levin as technical monitors, are greatly acknowledged.

  16. Allantoinase in lake trout (Salvelinus namaycush): in vitro effects of PCBs, DDT and metals

    USGS Publications Warehouse

    Passino, Dora R. May; Cotant, Carol A.

    1979-01-01

    1. Allantoinase, an enzyme in the purine-urea cycle, was found in livers of Salvelinus namaycush (Osteichthyes: Salmoniformes). 2. The enzyme was active from pH 6.6 to 8.2 at 37°C and from pH 7.4 to 9.0 at 10°C and had an Arrhenius energy of activation of 11.0 kcal/mol and a temperature quotient of 2.0. The Km of the enzyme homogenate was 8.4 mM allantoin. 3. The concentration of inorganic metals at which 50% inhibition occurred during in vitro exposure were 6.0 mg/l Cu2+, 6.7 mg/l Cd2+, 34 mg/l Hg2+ and 52 mg/l Pb2+. The in vitro sensitivity to PCBs, DDT and DDE and kinetics in the presence of metals were determined. 4. Allantoinase activity was negatively correlated with body length for fish from Lake Michigan but not from Lake Superior or the laboratory.

  17. DDT modeling and shock compression experiments of porous or damaged energetic materials

    SciTech Connect

    Baer, M.R.; Anderson, M.U.; Graham, R.A.

    1994-05-01

    In this presentation, we present modeling of DDT in porous energetic materials and experimental studies of a time-resolved, shock compression of highly porous inert and reactive materials. This combined theoretical and experimental studies explore the nature of the microscale processes of consolidation, deformation and reaction which are key features of the shock response of porous or damaged energetic materials. The theoretical modeling is based on the theory of mixtures in which multiphase mixtures are treated in complete nonequilibrium allowing for internal boundary effects associated mass/momentum and energy exchange between phases, relative flow, rate-dependent compaction behavior, multistage chemistry and interphase boundary effects. Numerous studies of low-velocity impacts using a high resolution adaptive finite element method are presented which replicate experimental observations. The incorporation of this model into multi-material hydrocode analysis will be discussed to address the effects of confinement and its influence on accelerated combustion behavior. The experimental studies will focus on the use of PVDF piezoelectric polymer stress-rate gauge to precisely measure the input and propagating shock stress response of porous materials. In addition to single constituent porous materials, such as granular HMX, we have resolved shock waves in porous composite intermetallic powders that confirm a dispersive wave nature which is highly morphologically and material dependent. This document consists of viewgraphs from the poster session.

  18. Improvement of Aerosol Prediction Capability

    DTIC Science & Technology

    2001-09-30

    by dust storms in the past.) The operational aerosol products will be used for initialization or specification of aerosols in COAMPS when new cloud...Figure 2. SeaWiFS visible imagery for May 18, 2001, showing a dust storm originating at dry lakes along the Iran-Afghanistan border and then...versions of the Navy Aerosol Analysis and Prediction System (NAAPS) for analysis of airborne dust loads (Westphal/NRL). B: Modify existing radiative

  19. Unified Aerosol Microphysics for NWP

    DTIC Science & Technology

    2011-09-30

    Specifically, the goal is to develop a COAMPS that is capable of simulating the full range of interactions between aerosol particles, clouds , and radiative...aerosol species that are responsible for degradation of Electro- Optical (EO) propagation or that modify cloud behavior and lifetime. Report...enabling new development of more complex cloud -aerosol interactions. The work on this project has been divided into two phases, an investigation phase

  20. Photothermal spectroscopy of aerosols

    SciTech Connect

    Campillo, A.J.; Lin, H.B.

    1981-04-01

    In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 ..mu..m were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO/sub 2/ laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m/sup 2//g at 1087 cm/sup -1/. The absorption coefficient sensitivity of this scheme was less than or equal to 10/sup -8/ cm/sup -1/. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations.

  1. Ozone and aerosol changes during the 1991-1992 airborne Arctic stratospheric expedition

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.; Buller, Carolyn F.; Fenn, Marta A.; Grant, William B.; Ismail, Syed; Schoeberl, Mark R.; Toon, Owen B.; Loewenstein, Max; Podolske, James R.

    1993-01-01

    Stratospheric ozone and aerosol distributions were measured across the wintertime Arctic vortex from January to March 1992 with an airborne lidar system as part of the 1992 Airborne Arctic Stratospheric Expedition (AASE II). Aerosols from the Mount Pinatubo eruption were found outside and inside the vortex with distinctly different distributions that clearly identified the dynamics of the vortex. Changes in aerosols inside the vortex indicated advection of air from outside to inside the vortex below 16 kilometers. No polar stratospheric clouds were observed and no evidence was found for frozen volcanic aerosols inside the vortex. Between January and March, ozone depletion was observed inside the vortex from 14 to 20 kilometers with a maximum average loss of about 23 percent near 18 kilometers.

  2. Ozone and aerosol changes during the 1991-1992 Airborne Arctic Stratospheric Expedition

    SciTech Connect

    Browell, E.V.; Grant, W.B.; Ismail, S. ); Butler, C.F.; Fenn, M.A. ); Schoeberl, M.R. ); Toon, O.B.; Loewenstein, M.; Podolske, J.R. )

    1993-08-27

    Stratospheric ozone and aerosol distributions were measured across the wintertime Arctic vortex from January to March 1992 with an airborne lidar system as part of the 1992 Airborne Arctic Stratospheric Expedition (AASE II). Aerosols from the Mount Pinatubo eruption were found outside and inside the vortex with distinctly different distributions that clearly identified the dynamics of the vortex. Changes in aerosols inside the vortex indicated advection of air from outside to inside the vortex below 16 kilometers. No polar stratospheric clouds were observed and no evidence was found for frozen volcanic aerosols inside the vortex. Between January and March, ozone depletion was observed inside the vortex from 14 to 20 kilometers with a maximum average loss of about 23 percent near 18 kilometers.

  3. Development of the RAQM2 aerosol chemical transport model and predictions of the Northeast Asian aerosol mass, size, chemistry, and mixing type

    NASA Astrophysics Data System (ADS)

    Kajino, M.; Inomata, Y.; Sato, K.; Ueda, H.; Han, Z.; An, J.; Katata, G.; Deushi, M.; Maki, T.; Oshima, N.; Kurokawa, J.; Ohara, T.; Takami, A.; Hatakeyama, S.

    2012-12-01

    A new aerosol chemical transport model, the Regional Air Quality Model 2 (RAQM2), was developed to simulate the Asian air quality. We implemented a simple version of a triple-moment modal aerosol dynamics model (MADMS) and achieved a completely dynamic (non-equilibrium) solution of a gas-to-particle mass transfer over a wide range of aerosol diameters from 1 nm to super-μm. To consider a variety of atmospheric aerosol properties, a category approach was utilized in which the aerosols were distributed into four categories: particles in the Aitken mode (ATK), soot-free particles in the accumulation mode (ACM), soot aggregates (AGR), and particles in the coarse mode (COR). The aerosol size distribution in each category is characterized by a single mode. The condensation, evaporation, and Brownian coagulations for each mode were solved dynamically. A regional-scale simulation (Δx = 60 km) was performed for the entire year of 2006 covering the Northeast Asian region. The modeled PM1/bulk ratios of the chemical components were consistent with observations, indicating that the simulated aerosol mixing types were consistent with those in nature. The non-sea-salt SO42- mixed with ATK + ACM was the largest at Hedo in summer, whereas the SOSO42- was substantially mixed with AGR in the cold seasons. Ninety-eight percent of the modeled NO3- was mixed with sea salt at Hedo, whereas 53.7% of the NO3- was mixed with sea salt at Gosan, which is located upwind toward the Asian continent. The condensation of HNO3 onto sea salt particles during transport over the ocean accounts for the difference in the NO3- mixing type at the two sites. Because the aerosol mixing type alters the optical properties and cloud condensation nuclei activity, its accurate prediction and evaluation are indispensable for aerosol-cloud-radiation interaction studies.

  4. Volcanic aerosols and lunar eclipses.

    PubMed

    Keen, R A

    1983-12-02

    The moon is visible during total lunar eclipses due to sunlight refracted into the earth's shadow by the atmosphere. Stratospheric aerosols can profoundly affect the brightness of the eclipsed moon. Observed brightnesses of 21 lunar eclipses during 1960-1982 are compared with theoretical calculations based on refraction by an aerosol-free atmosphere to yield globally averaged aerosol optical depths. Results indicate the global aerosol loading from the 1982 eruption of El Chichón is similar in magnitude to that from the 1963 Agung eruption.

  5. 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.

  6. 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

  7. The role of coastal fog in increased viability of marine microbial aerosols

    NASA Astrophysics Data System (ADS)

    Dueker, M.; O'Mullan, G. D.; Weathers, K. C.; Juhl, A. R.; Uriarte, M.

    2011-12-01

    Microbes in the atmosphere (microbial aerosols) play an important role in climate and provide an ecological and biogeochemical connection between oceanic, atmospheric, and terrestrial environments. Despite the ubiquity of these bacteria (concentration estimates range from 1 x 10^4 to 6 x 10^5 cells m-3), much is still being learned about their source, viability, and interactions with climatic controls. They can be attached to ambient aerosol particles or exist singly in the air. They affect climate by serving as ice, cloud, and fog nucleators, and have the metabolic potential to alter atmospheric chemistry. Fog presence in particular has been shown to greatly increase the deposition of viable microbial aerosols in both urban and coastal environments, but the mechanisms behind this are not fully understood. To address this gap, we examined the diversity of culturable microbial aerosols from a relatively pristine coastal environment in Maine (USA) and determined the effect of fog presence on viability and community composition of microbial aerosols. 16S rRNA sequencing of culturable ocean surface bacteria and depositing microbial aerosols (under clear and foggy conditions) resulted in the detection of 31 bacterial genera, with 5 dominant genera (Vibrio, Bacillus, Pseudoalteromonas, Psychrobacter, Salinibacterium) making up 66% of all sequences. Seventy-five percent of the viable microbial aerosols falling out under foggy conditions were most similar to GenBank-published sequences detected in marine environments. The fog and ocean surface sequence libraries were significantly more similar in microbial community composition than clear (non-foggy) and ocean surface libraries. These findings support a dual role for fog in enhancing the fallout of viable marine microbial aerosols via increased gravitational settling rates and decreased aerosolization stress on the organisms. The dominant presence of marine bacteria in coastal microbial aerosols provides a strong case for

  8. Nano-sized aerosol classification, collection and analysis--method development using dental composite materials.

    PubMed

    Bogdan, Axel; Buckett, Mary I; Japuntich, Daniel A

    2014-01-01

    This article presents a methodical approach for generating, collecting, and analyzing nano-size (1-100 nm) aerosol from abraded dental composite materials. Existing aerosol sampling instruments were combined with a custom-made sampling chamber to create and sample a fresh, steady-state aerosol size distribution before significant Brownian coagulation. Morphological, size, and compositional information was obtained by Transmission Electron Microscopy (TEM). To create samples sizes suitable for TEM analysis, aerosol concentrations in the test chamber had to be much higher than one would typically expect in a dental office, and therefore, these results do not represent patient or dental personnel exposures. Results show that nano-size aerosol was produced by the dental drill alone, with and without cooling water drip, prior to abrasion of dental composite. During abrasion, aerosol generation seemed independent of the percent filler load of the restorative material and the operator who generated the test aerosol. TEM investigation showed that "chunks" of filler and resin were generated in the nano-size range; however, free nano-size filler particles were not observed. The majority of observed particles consisted of oil droplets, ash, and graphitic structures.

  9. Impact of wet scavenging of natural and anthropogenic aerosol components on the columnar aerosol optical depth over a tropical rural atmosphere

    NASA Astrophysics Data System (ADS)

    Chatterjee, Abhijit; Jayaraman, Achuthan

    distinctly different types of cases were observed. Firstly, the rain events with the higher intensities (about 6 mm/hr) were found to scavenge the coarse mode or larger sea-salt and dust aerosol components with higher reduction in AOD at higher wavelength (1020 nm). The higher concentrations of sea-salt (Na+ and Cl-) and dust aerosol (Ca2+ and Mg2+) components were observed in rainwater samples in this case. Secondly, the rain events with lower intensities (about 2 mm/hr) were found to scavenge more anthropogenic components (NH4+, NO3-, SO42-and K+) with higher reduction in AOD at lower wavelength (400 nm). The concentrations of NH4+, NO3-, SO42-and K+ were found to be higher in rainwater samples in this case. On an average, the AOD at lower wavelength (400 nm) was found to be reduced by 40 percent and at higher wavelength (1020 nm) by 54 percent. Conclusively we observed that, when anthropogenic aerosol components were scavenged more compared to natural aerosol components, AOD at lower wavelength (400 nm) was found to be reduced more compared to higher wavelength (1020 nm). On the other hand, AOD at higher wavelength was found to be reduced more compared to lower wavelength when scavenging of natural aerosol components took over the anthropogenic aerosol components.

  10. 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.

  11. Common Pesticide, Dichlorodiphenyltrichloroethane (DDT), Increases Amyloid-β Levels by Impairing the Function of ABCA1 and IDE: Implication for Alzheimer's Disease.

    PubMed

    Li, Gongbo; Kim, Chaeyoung; Kim, Jaekwang; Yoon, Hyejin; Zhou, Huadong; Kim, Jungsu

    2015-01-01

    While early-onset familial Alzheimer's disease (AD) is caused by a genetic mutation, the vast majority of late-onset AD is likely caused by the combination of genetic and environmental factors. Unlike genetic studies, potential environmental factors affecting AD pathogenesis have not yet been thoroughly investigated. Among environmental factors, pesticides seem to be one of critical environmental contributors to late-onset AD. Recent studies reported that the serum and brains of AD patients have dramatically higher levels of a metabolite of dichlorodiphenyltrichloroethane (DDT). While these epidemiological studies provided initial clues to the environmental risks potentially contributing to disease pathogenesis, a functional approach is required to determine whether they actually have a causal role in disease development. In our study, we addressed this critical knowledge gap by investigating possible mechanisms by which DDT affects amyloid-β (Aβ) levels. We treated H4-AβPPswe or H4 cells with DDT to analyze its effect on Aβ metabolism using Aβ production, clearance, and degradation assays. We found that DDT significantly increased the levels of amyloid-β protein precursor (AβPP) and β-site AβPP-cleaving enzyme1 (BACE1), affecting Aβ synthesis pathway in H4-AβPPswe cells. Additionally, DDT impaired the clearance and extracellular degradation of Aβ peptides. Most importantly, we identified for the first time that ATP-binding cassette transporter A1 (ABCA1) and insulin-degrading enzyme (IDE) are the downstream target genes adversely affected by DDT. Our findings provide insight into the molecular mechanisms by which DDT exposure may increase the risk of AD, and it further supports that ABCA1 and IDE may be potential therapeutic targets.

  12. 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

    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.

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

    SciTech Connect

    Kwekel, Joshua C.; Forgacs, Agnes L.; Williams, Kurt J.; Zacharewski, Timothy R.

    2013-12-15

    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. 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.

  14. Application of GOES-12 Aerosol Optical Depths and OMI Aerosol Indices to Evaluate NOAA/NESDIS Hazard Mapping System Smoke Analysis

    NASA Astrophysics Data System (ADS)

    Zeng, J.; Kondragunta, S.

    2006-05-01

    NOAA/NESDIS Hazard Mapping System (HMS) provides biomass burning fires and smoke analysis products to users. The smoke analysis is done by human analysts by inspecting visible imagery and fire locations. Analysts have difficulty in drawing plumes once the plumes are removed from the source (fires) and mixed with clouds and other types of aerosols. NOAA/NESDIS also provides GOES Aerosol Optical Depth (AOD) product to the users. The AOD product is derived from visible radiance measurements using a look-up table which is created assuming a continental aerosol model. In this study we examine the usefulness of Aura Ozone Monitoring Instrument (OMI) Aerosol Index (AI) in evaluating the analyst drawn smoke plumes and GOES AODs corresponding to smoke plumes. OMI AI in the near UV and visible bands is capable of distinguishing between absorbing aerosols and non-absorbing aerosols. We will present analysis of GOES AODs, OMI AI, and HMS smoke analysis product for several prescribed and natural fires observed during 2005. This analysis is expected to provide information on average percent area overlap between GOES AOD and HMS smoke plumes, OMI AI and HMS smoke plumes, and GOES AOD and OMI AI that will lead to an assessment of HMS smoke analysis.

  15. Recent Studies Investigating Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Weber, R. J.

    2009-05-01

    The metropolitan areas of Mexico City and Atlanta have very different emissions and meteorology, yet in both cities secondary organic aerosol (SOA) comprises a significant fraction of fine particle mass. SOA in Mexico City is predominately from anthropogenic emissions and a number of studies have investigated the role of dicarbonyl partitioning to aerosol liquid water as a SOA formation route [Volkamer et al., 2006; 2007]. Hennigan et al. [2008] noted a high correlation between SOA (measured as water-soluble organic carbon) and fine particle nitrate in Mexico City and used this to estimate the volatility of both species during periods of rapidly decreasing RH in late morning. Secondary aerosol may also form when particles are much drier. In Mexico City, both nitrate and SOA were also frequently observed and highly correlated in late afternoon when RH was below 30 percent. A thermodynamic model could reproduce the observed morning nitrate under high RH when equilibrium was between nitric acid and dissolved nitrate, whereas equilibrium between vapor and crystalline ammonium nitrate was predicted in the afternoon [Fountoukis et al., 2007]. By analogy, these results may suggest two different SOA partitioning mechanisms in Mexico City, occurring at different times of the day. In contrast, measurements suggest that SOA in the southeastern United States is largely from biogenic precursors, and there is evidence that liquid water also plays a role. The stability of dissolved organic aerosol in response to loss of liquid water is currently being investigated and preliminary data suggest that like Mexico City, there is some degree of volatility. Recent experiments comparing data from rural-urban sites shows that there are periods when anthropogenic emissions also substantially contribute to SOA in the Atlanta metropolitan region. However, the mechanisms, or organic precursors involved, are yet to be determined. Results from these various ongoing studies will be presented

  16. Mount Saint Helens aerosol evolution

    NASA Technical Reports Server (NTRS)

    Oberbeck, V. R.; Farlow, N. H.; Snetsinger, K. G.; Ferry, G. V.; Fong, W.; Hayes, D. M.

    1982-01-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  17. INDOOR AEROSOLS AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    This chapter provides an overview of both indoor aerosol concentration measurements, and the considerations for assessment of exposure to aerosols in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...

  18. Aerosol Variability Observed with Rpas

    NASA Astrophysics Data System (ADS)

    Altstädter, B.; Lampert, A.; Scholtz, A.; Bange, J.; Platis, A.; Hermann, M.; Wehner, B.

    2013-08-01

    To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS) Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter). Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  19. Aerosol in the Pacific troposphere

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.

    1989-01-01

    The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric aerosol over the Central Pacific. The primary focus is on measurement of the aerosol size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser Aerosol Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of aerosol size distributions. A thermal preheater system (Thermo Optic Aerosol Descriminator (TOAD) conditions the aerosol in a manner that allows the discrimination of the size distribution of individual aerosol components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these aerosol components from ground based and aircraft platforms.

  20. Mount St. Helens aerosol evolution

    SciTech Connect

    Oberbeck, V.R.; Farlow, N.H.

    1982-08-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.