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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. Lethal mobilization of DDT by cowbirds

    USGS Publications Warehouse

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

    1972-01-01

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

  4. DDT contamination from indoor residual spraying for malaria control.

    PubMed

    Van Dyk, J C; Bouwman, H; Barnhoorn, I E J; Bornman, M S

    2010-06-01

    The insecticide DDT is still used in specific areas of South Africa for indoor residual spray (IRS) to control malaria vectors. Local residents could be exposed to residues of DDT through various pathways including indoor air, dust, soil, food and water. The aims of this study were to determine the levels of DDT contamination, as a result of IRS, in representative homesteads, and to evaluate the possible routes of human exposure. Two villages, exposed (DV) and reference (TV) were selected. Sampling was done two months after the IRS process was completed. Twelve homesteads were selected in DV and nine in TV. Human serum, indoor air, floor dust, outside soil, potable water, leafy vegetables, and chicken samples (muscle, fat and liver) were collected and analyzed for both the o,p'- and p,p'-isomers of DDT, DDD and DDE. DDT was detected in all the media analyzed indicating a combination of potential dietary and non-dietary pathways of uptake. DV had the most samples with detectable levels of DDT and its metabolites, and with the exception of chicken muscle samples, DV also had higher mean levels for all the components analyzed compared to TV. Seventy-nine percent of participants from DV had serum levels of DDT (mean [summation operator]DDT 7.3microg g(-1) lipid). These residues constituted mainly of p,p'-DDD and p,p'-DDE. [summation operator]DDT levels were detected in all indoor air (mean [summation operator]DDT 3900.0 ng m(-3)) and floor dust (mean [summation operator]DDT 1200.0 microg m(-2)) samples. Levels were also detected in outside soil (mean [summation operator]DDT 25.0 microg kg(-1)) and potable water (mean [summation operator]DDT 2.0 microg L(-1)). Vegetable sample composition (mean [summation operator]DDT 43.0 microg kg(-1)) constituted mainly p,p'-DDT and p,p'-DDD. Chicken samples were highly contaminated with DDT (muscle mean [summation operator]DDT 700.0 microg kg(-1), fat mean [summation operator]DDT 240,000.0 microg kg(-1), liver mean [summation

  5. 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)

  6. 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)

  7. 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

  8. 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…

  9. 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…

  10. DDT residues and declining reproduction in the Bermuda petrel.

    PubMed

    Wurster, C F; Wingate, D B

    1968-03-01

    Residues of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] averaging 6.44 parts per million in eggs and chicks of the carnivorous Bermuda petrel indicate widespread contamination of an oceanic food chain that is remote from applications of DDT. Reproduction by the petrel has declined during the last 10 years at the annual rate of 3.25 percent; if the decline continues, reproduction will fail completely by 1978. Concentrations of residues are similar to those in certain terrestrial carnivorous birds whose productivity is also declining. Various considerations implicate contamination by insecticides as a probable major cause of the decline.

  11. 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

  12. 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.

  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. 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....

  15. 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....

  16. 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....

  17. 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....

  18. Dechlorination of DDT by Aerobacter aerogenes

    USGS Publications Warehouse

    1966-01-01

    Dechlorination of DDT to DDD in higher animals requires the presence of molecular oxygen, but in microorganisms the presence of oxygen hinders dechlorination. In cell-free preparations of Aerobacter aerogenes, the use of selected metabolic inhibitors indicated that reduced Fe(II) cytochrome oxidase was responsible for DDT dechlorination. This finding may possibly explain. the persistence of DDT residues in soils and sediments.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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)

  7. 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

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

    PubMed

    Turusov, Vladimir; Rakitsky, Valery; Tomatis, Lorenzo

    2002-02-01

    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.

  9. 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.

  10. 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.

  11. 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.

  12. Percent Wetland Cover

    EPA Pesticide Factsheets

    Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be indicate cleaner surface water. 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.

  13. 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

  14. Dichlorodiphenyltrichloroethane (DDT) and risk of hepatocellular carcinoma

    PubMed Central

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

    2014-01-01

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

  15. 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

  16. Optical device for continuous monitoring of DDT residues

    NASA Astrophysics Data System (ADS)

    Sharma, Ashutosh; Sheikh, Sohail H.

    1997-05-01

    A two step filtration based fluorometric device for continuous measurement of DDT residues is developed. The device which exploits the native fluorescence of DDT can be easily adopted to a commercial spectrofluorometer. The device was tested for its use in measuring DDT contamination in soil, potato peel and orange juice extracts and provides a detection limit approximately 1 (mu) M.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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...

  2. 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.

  3. 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.

  4. DDT in human milk. What determines the levels?

    PubMed

    Bradt, P T; Herrenkohl, R C

    1976-09-01

    In a study of fifty-five human milk samples from eastern Pennsylvania, the total DDT derived products exceeded the DDT content of cows milk and canned infant formula. Total DDT in human milk exceeded the U.S. Food and Drug Administration's tolerance for total DDT in cows milk in 47% of the samples. Four factors were identified statistically as accounting for 54% of the variance on total DDT levels in human milk. These factors are: (1) number of children nursed; (2) number of cigarettes smoked per day; (3) use of non-persistent pesticides; and (4) diet in calories.

  5. 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.

  6. Serum DDT, age at menarche, and abnormal menstrual cycle length

    PubMed Central

    Ouyang, F; Perry, M; Venners, S; Chen, C; Wang, B; Yang, F; Fang, Z; Zang, T; Wang, L; Xu, X; Wang, X

    2005-01-01

    Background: Although dichlorodiphenyl trichloroethane (DDT) exposure is known to affect human endocrine function, few previous studies have investigated the effects of DDT exposure on age at menarche or menstrual cycle length. Methods: A cross sectional study was conducted to study the effects of DDT exposure on age at menarche and menstrual cycle length among 466 newly married, nulliparous female Chinese textile workers aged 20–34 years enrolled between 1996 and 1998. Serum was analysed for DDT and its major metabolites. Multivariate linear regression was used to estimate DDT exposure effects on age at menarche and multivariate logistic regression was used to estimate DDT exposure effects on odds of experiencing short or long cycles. Results: Relative to those in the lowest DDT quartile, the adjusted mean age at menarche was younger in those in the fourth quartile (–1.11 years). Modeled as a continuous variable, a 10 ng/g increase in serum DDT concentration was associated with an adjusted reduction in age at menarche of 0.20 years. Relative to those in the lowest DDT quartile, odds of any short cycle (<21 days) in the previous year were higher for those in the fourth quartile (odds ratio = 2.78; 95% CI 1.07 to 7.14). There were no associations between serum DDT concentrations and odds of experiencing a long cycle (>40 days). Conclusion: Results suggest that DDT exposure was associated with earlier age at menarche and increased risk of experiencing a shortened menstrual cycle. PMID:16299097

  7. Physiological effects of polychlorinated biphenyls or a combination of DDT, DDD, and DDE in penned white pelicans.

    PubMed

    Greichus, Y A; Call, D J; Ammann, B M

    1975-01-01

    The effects of PCBs (polychlorinated biphenyls) or a combination of DDT (1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane), DDD (1,1-dichloro-2,2-bis (p-chlorophenyl) ethane) and DDE (1,1-dichloro-2,2,-bis (p-chlorophenyl ethylene) on organ weights, liver storage of vitamin A and carotene, selected blood chemistry parameters, and serum protein fractions were determined in penned white pelicans (Pelecanus erythrorhynchos) receiving a daily dosage of these compounds. Birds received 100 mg of PCBs or a combination of DDT (20 mg), DDD (15 mg), and DDE (15 mg) injected into the first fish fed each day for ten weeks. A greater percentage of PCB treatment was retained in brain, liver, carcass and feathers than the percentage of DDT + DDD + DDE treatment. Liver weight as percent of body weight decreased (p less than 0.01) in DDT + DDD + DDE-treated birds and increased (p less than 0.01) as a total weight in PCB-treated birds. Spleen weight as percent of body weight was greater (p less than 0.05) in PCB-treated birds. Neither treatment had a significant effect on the weight of the brain, heart, or kidney. Liver vitamin A levels were greater (p less than 0.01) on a mug/g of liver basis in the DDT-treated birds than in controls. Significant lowering of serum potassium and protein values was noted in both the PCB- and the combination of DDT, DDD, DDE-treated birds, while serum calcium values were lowered (p less than 0.01) only in PCB-treated birds. Vaues of serum inorganic phosphorus, uric acid and magnesium were not significantly changed by either treatment. Globulin fractions were unaltered by either treatment, but albumin fractions were lowered (p less than 0.01) in the PCB-treated pelicans.

  8. 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

  9. 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).

  10. 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)

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. Former DDT factory in Pakistan revisited for remediation: severe DDT concentrations in soils and plants from within the area.

    PubMed

    Younas, Asma; Hilber, Isabel; ur Rehman, Shafique; Khwaja, Mahmood; Bucheli, Thomas D

    2013-04-01

    A factory in Amman Garh near Nowshera, Khyber Pakhtunkhwa, Pakistan, produced dichlorodiphenyltrichloroethane (DDT) from 1963-1994. Consequently, earlier papers reported a soil contamination in the per mille range inside the former factory wall (88 m × 106 m) and up to 10 mg/kg of DDT in the surroundings in 2005-2007. The site within the factory wall was remonitored systematically in 2011 to complement the earlier data as a prerequisite for remediation, to put them in exposure context in a population developing area, and to suggest and evaluate the optimal remediation technique for the site. The contamination was drastically higher than the earlier published data, and the sum of DDT and its metabolites (ΣDDT) was up to 65% in the soil. Grasses, shrubs, and trees growing in this severely contaminated site had 50-450 mg/kgdw of ΣDDT. Thus, people living nearby and husbandry as well as wild animals are heavily exposed to DDT. The semiarid climate favors wind drift and deposition of the pollutant. Additionally, DDT from products of herbivore animals feeding on the contaminated plants will enter the food web. To overcome the exposure and distribution of the DDT, the site within the factory wall was capped with 1.5 m of soil. This remediation technique represents the easiest and least expensive solution. Nevertheless, DDT can still evaporate or leach, and groundwater can rise in this flood-prone area and thereby become contaminated, especially because a binding layer is missing.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  17. 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

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 22 2014-07-01 2013-07-01 true DDT, DDD and DDE. 129.101 Section 129.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 23 2012-07-01 2012-07-01 false DDT, DDD and DDE. 129.101 Section 129.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE...

  20. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  1. 40 CFR 129.101 - DDT, DDD and DDE.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 23 2013-07-01 2013-07-01 false DDT, DDD and DDE. 129.101 Section 129.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE...

  2. 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 129.101 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE...

  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. 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.

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  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. 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.

  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. Variability in DDT-induced apoptosis in Mexican indigenous populations.

    PubMed

    Pérez-Maldonado, Iván N; Pérez-Vázquez, Francisco J; Gaspar-Ramírez, Octavio; González-Amaro, Roberto; Díaz-Barriga, Fernando

    2011-11-01

    In previous studies, we showed that DDT and its metabolites are able to induce apoptosis of peripheral blood mononuclear cells (PBMC) "in vitro" and "in vivo", by a mechanism involving oxidative stress. The objective of this study was to evaluate the mechanism by which DDT induces apoptosis in PBMC in children exposed to DDT and its metabolites. Eligibility criteria included children who: (1) have lived in the selected community since birth, (2) were between 6 and 14 years of age at the time of the study, (3) had not been exposed to medicaments or tobacco smoke, and (4) had had no infectious diseases in the month prior to the study. DDT and its metabolites were quantified using gas chromatography with an electron capture detector, PBMC apoptosis was measured using the TUNEL assay, DNA damage and oxidative damage were studied using the comet assay. Apoptosis correlated to DDE exposure (p=0.040), as previously found. DNA damage also correlated to DDT (p=0.005) and DDE (p=0.004) levels. However, neither exposure to DDT or DDE and oxidative damage, nor oxidative damage and apoptosis, were significantly correlated. Children living in Lacanja, Chiapas, one of the communities studied in this work, had the highest levels of exposure to DDT and its metabolites, yet had the lowest percentage of apoptosis. Resistance to DDE-induced apoptosis was found in children from one community. Further studies are needed in order to understand the mechanism involved in this apoptosis resistance.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Percent Agriculture Adjacent to Streams

    EPA Pesticide Factsheets

    The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept pollutants before they reach the stream. High percentages of agriculture along streams increase the likelihood of elevated nutrient, pesticide and sediment levels in the stream. Agricultural land cover along streams (RIPAG) is the percent of total stream length adjacent to agriculture. 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. 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.

  2. Effects of DDT on the growth of crop plants.

    PubMed

    Mitra, J; Raghu, K

    1989-01-01

    The effects of DDT on the germination and growth of plants were studied using many crop species. Of the species tested, oil-rich seeds of plants, such as peanut (Arachis hypogaea) and mustard (Brassica juncea), were more prone to DDT induced inhibition of germination and subsequent plant growth than cereals, pulses and fibre crops, like rice (Oryza sativa), barley (Hordeum vulgare), mung bean Vigna radiata), pigeon pea (Cajanus cajan) and cotton (Gossypium hirsutum). Studies with (14)C labelled DDT showed that insecticide uptake by seeds was directly proportional to seed size. However, there was no direct relationship between DDT uptake by the seeds and its subsequent translocation to the growing regions or the degree of growth inhibition. Data suggest that oil content of the seeds per se has a bearing on the susceptibility or tolerance of a plant to DDT. It is suggested that lipids of the plant cell solubilize and disperse DDT in the cytoplasm, which, in turn, affects normal metabolism within the cell.

  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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. ROE Fish Faunal Percent Loss

    EPA Pesticide Factsheets

    Percent reduction is based on the number of native species determined to be present as of 2015, compared with historical numbers documented prior to 1970. Data are displayed by 6-digit hydrologic unit code (HUC-6) watershed. A species is considered present if there is at least one record of its presence in any 8-digit HUC within the 6-digit HUC. This indicator presents a summary of data available from the NatureServe Explorer database (http://www.natureserve.org/conservation-tools/data-maps-tools/natureserve-explorer). The identity and status (current vs. historical) of all native fish species recorded in each 8-digit HUC are available from this database, along with species-by-species distribution maps at the 8-digit HUC level. Analyses based on these data have previously been reported in Master et al. (1998, 2003) and Stein et al. (2000). Data were provided by NatureServe.

  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. 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.

  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. 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.

  13. Review on DDT and its residues in Turkey's wetlands.

    PubMed

    Ayas, Zafer

    2007-10-01

    Turkey is a country rich in wetlands (250 wetlands, approximately one million hectares). As it is in many countries, the wetlands in Turkey are threatened by the agricultural activities, loss of habitats due to these activities and by pesticide contamination. After 1940, large quantities of pesticides, especially DDT were used intensively against mosquitoes and pests in most of the wetlands in Turkey causing considerable contamination. In the beginning of 1980's, production, import and use of DDT was forbidden due to its toxicity on non-target organisms, environmental persistence, and accumulation in food chains. The scientific studies made in Turkey on the level of contamination in various environs and organisms by DDTand its metabolites, are limited These limited studies, especially the ones made after 1990's, have shown that we still observe DDT contamination in many wetlands (including internationally important ones like Goksu Delta and Meric Delta) and in organisms like birds and fishes. The data on the concentrations of DDTand its metabolites in the organisms and the biological magnification levels are not adequate since in most of the studies only water and sediment samples were analyzed. Besides, in the few studies made on the organisms, standard methods and suitable indicator organisms were not used. Because of these reasons, it is very difficult to make reliable evaluations on the DDT levels and its effects in the wetlands of Turkey. It is interesting that DDTlevels are higher than its metabolites in water sediment and organism samples in some wetlands which imply the possible use of DDT recently The aim of this review is to summarize the studies made so far on DDT and its residues in the wetlands of Turkey and to shed light on the possible hazardous effects and to propose approaches for future studies.

  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

    USDA-ARS?s Scientific Manuscript database

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

  16. The comparative toxicity of DDT and analogues to susceptible and resistant houseflies and mosquitos*

    PubMed Central

    Metcalf, R. L.; Fukuto, T. R.

    1968-01-01

    Studies of the comparative toxicity of more than 120 DDT analogues to susceptible and insecticide-resistant houseflies (Musca domestica L.) and mosquitos (Culex fatigans Wiedemann and Anopheles albimanus Wiedemann) have shown that the relative effectiveness of these compounds against DDT-resistant insects is correlated with the susceptibility of the molecule to attack by DDT-ase at the benzylic hydrogen. Compounds highly effective against DDT-resistant flies and mosquitos are produced by blocking this detoxication mechanism by o-chlorination, α-fluorination, and by altering the aliphatic portion of the molecule as in the nitropropyl, neopentyl, dichlorocyclopropyl, and trichlorobenzanilide derivatives. These compounds offer practical possibilities for the control of DDT-resistant insects. The correlation of structure, DDT-like activity, and resistance ratios gives new insight into the mode of action of DDT and the nature of DDT resistance. PMID:4386201

  17. 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.

  18. DDT-resistance and dieldrin-resistance in Anopheles quadrimaculatus*

    PubMed Central

    Davidson, G.

    1963-01-01

    The nature and mode of inheritance of both DDT-resistance and dieldrin-resistance in Anopheles quadrimaculatus from the United States of America have been studied. Dieldrin-resistance is shown to be dependent on a single, semi-dominant, genetic factor, and DDT-resistance on a single, recessive one, though the expression of this latter factor is to some extent dependent on the genetic background. Both resistances can occur in the same mosquito but can be separated, thus indicating the independent nature of the two genetic factors involved. PMID:14056269

  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. 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.…

  1. DDT and detonation waves in dust-air mixtures

    NASA Astrophysics Data System (ADS)

    Zhang, F.; Grönig, H.; van de Ven, A.

    This paper summarizes the studies of DDT and stable detonation waves in dust-air mixtures at the Stosswellenlabor of RWTH Aachen. The DDT process and propagation mechanism for stable heterogeneous dust detonations in air are essentially the same as in the oxygen environment studied previously. The dust DDT process in tubes is composed of a reaction compression stage followed by a reaction shock stage as the pre-detonation process. The transverse waves that couple the shock wave and the chemical energy release are responsible for the propagation of a stable dust-air detonation. However, the transverse wave spacing of dust-air mixtures is much larger. Therefore, DDT and propagation of a stable detonation in most industrial and agricultural, combustible dust-air mixtures require a tube that has a large diameter between 0.1 m and 1 m and a sufficient length-diameter ratio beyond 100, when an appropriately strong initiation energy is used. Two dust detonation tubes, 0.14 m and 0.3 m in diameter, were used for observation of the above-mentioned results in cornstarch, anthraquinone and aluminum dust suspended in air. Smoked-foil technique was also used to measure the cellular structure of dust detonations in the 0.3 m detonation tube.

  2. 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.}

  3. 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.…

  4. 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)

  5. Alzheimer's Deaths Jump 55 Percent: CDC

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_165941.html Alzheimer's Deaths Jump 55 Percent: CDC More patients also ... News) -- As more baby boomers age, deaths from Alzheimer's disease have jumped 55 percent, and in a ...

  6. A Conceptual Model for Solving Percent Problems.

    ERIC Educational Resources Information Center

    Bennett, Albert B., Jr.; Nelson, L. Ted

    1994-01-01

    Presents an alternative method to teaching percent problems which uses a 10x10 grid to help students visualize percents. Offers a means of representing information and suggests different approaches for finding solutions. Includes reproducible student worksheet. (MKR)

  7. 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.

  8. 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.

  9. Effects on wildlife of DDT used for control of Dutch elm disease

    USGS Publications Warehouse

    Benton, A.H.

    1951-01-01

    During the summer of 1949 studies were conducted at Princeton, New Jersey, to determine the effects on wildlife of DDT used in the control of Dutch elm disease. Direct mortality was determined by intensive search for dead birds after spraying. Twenty-six songbirds, one bat, and one gray squirrel were found. Of 11 dead birds from a study area of approximately 20 acres only one was an adult. Songbird populations were determined by censuses before and after spraying on a study area and on a similar unsprayed check area. The number of all breeding birds showed a 19.6 percent decrease on both the study and check areas during the week immediately following spraying. About two weeks after spraying the population in the treated area began to increase and within another week was back to prespray level. When only those species common to both sprayed and unsprayed areas are considered a population decline of 22 percent was measured in the sprayed area while the check area showed a 6 percent increase in numbers over the same period. Nestling mortality was studied in both areas. Among 18 young found on the study area during and following spraying 8 (44%) survived. Death of two broods of catbirds occurred four days after spraying. Of 21 young found on the check area 15 (71%) survived.

  10. 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…

  11. 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…

  12. Persistence and Bioavailability of DDT in a Coastal Salt Marsh

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  13. 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.

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

    PubMed

    Gautam, Sumit Kumar; Suresh, Sumathi

    2006-12-01

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

  15. Wood mouse and box turtle populations in an area treated annually with DDT for five years

    USGS Publications Warehouse

    Stickel, L.F.

    1951-01-01

    A 117-acre area of dense woodland on the Patuxent Research Refuge received an aerial application of DDT in oil at the rate of 2 pounds per acre gnnually for five years. DDT reached ground level in a much smaller amount (thousandths to hundredths of a pound per acre). Treatment was made during the first week of June of each year from 1945 through 1949. Field studies of the wood mouse population in DDT and check areas showed no significant differences in the two areas before and after the 1949 DDT treatment. There was no significant difference between trapping samples taken in DDT and check areas in 1945 and those taken in 1949. Field studies of the box turtles in DDT and check areas in 1945 and 1949 showed no significant difference in population size. Growth of the four young turtles taken in the DDT area in both 1945 and 1949 appeared to be normal in comparison with growth of check area turtles.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. PCB, DDT, Benzo(a)phrene in raw and pan-fried white croaker (Genyonemus lineatus)

    SciTech Connect

    Puffer, H.W.; Gossett, R.W.

    1983-01-01

    Contaminated white croaker (GENYONEMUS LINEATUS) were caught from waters of Santa Monica Bay and Orange County, California, in 1981. Samples were panfried and analyzed for PCBs, DDT, and benzo(a)pyrene (BaP). Pan-frying of Orange County samples reduced total DDT by 39% and total PCBs by 28%; Santa Monica Bay samples had a 74% reduction of DDT and a 65% reduction of PCBs. BaP was below detectable limits in all cases. (JMT)

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. In utero exposure to dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) and neurodevelopment among young Mexican American children.

    PubMed

    Eskenazi, Brenda; Marks, Amy R; Bradman, Asa; Fenster, Laura; Johnson, Caroline; Barr, Dana B; Jewell, Nicholas P

    2006-07-01

    We investigated the relationship between prenatal exposure to dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) and neurodevelopment of Mexican farm-workers' children in California. Participants from the Center for the Health Assessment of Mothers and Children of Salinas study, a birth cohort study, included 360 singletons with maternal serum measures of p,p'-DDT, o,p'-DDT, and p,p'-DDE. Psychomotor development and mental development were assessed with the Bayley Scales of Infant Development at 6, 12, and 24 months. We found a approximately 2-point decrease in Psychomotor Developmental Index scores with each 10-fold increase in p,p'-DDT levels at 6 and 12 months (but not 24 months) and p,p'-DDE levels at 6 months only. We found no association with mental development at 6 months but a 2- to 3-point decrease in Mental Developmental Index scores for p,p'-DDT and o,p'-DDT at 12 and 24 months, corresponding to 7- to 10-point decreases across the exposure range. Even when mothers had substantial exposure, breastfeeding was usually associated positively with Bayley scale scores. Prenatal exposure to DDT, and to a lesser extent DDE, was associated with neurodevelopmental delays during early childhood, although breastfeeding was found to be beneficial even among women with high levels of exposure. Countries considering the use of DDT should weigh its benefit in eradicating malaria against the negative associations found in this first report on DDT and human neurodevelopment.

  7. 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.

  8. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. 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.

  10. DDT environmental persistence from its use in a vector control program: a case study.

    PubMed

    Vieira, E D; Torres, J P; Malm, O

    2001-06-01

    DDT contamination was investigated in soil, sediment, and chicken eggs from an endemic leishmaniasis area located in Rio de Janeiro City, Brazil. The last DDT application in this area was in 1990, for sand-fly vector control. Sampling campaigns were conducted in 1997 and 1999. DDT was extracted by use of a modified soxhlet apparatus and analysis was performed by gas chromatography with electron capture detector. The results show that, in 1997, soil samples contained up to 351 microg x kg(-1) x d x w. of summation operator DDT near the insecticide-sprayed sites. In 1999, the soil concentration decreased to 112 microg x kg(-1) x d x w. of summation operator DDT. Sediments from small creeks also showed low concentrations (up to 32.9 microg x kg(-1) x d x w. of summation operator DDT). Chicken eggs had, on average, 1.98 mg x kg(-1) summation operator DDT (twice FAO's maximum residue limit), comprising 82% of p,p'-DDE. Taking into account the egg results, DDT bioaccumulation is a question of concern. Considering just the egg consumption, it was estimated that DDT intake in the study area is 0.38x10(-4) mg x kg(-1) body weight x day(-1) whereas the reference maximum dose (US EPA) is 5x10(-4) mg x kg(-1) body weight x day(-1). This approach can be used to estimate DDT exposure in other places where DDT contamination may be of concern, especially in places where locally produced animals and eggs are a significant portion of the diet. Copyright 2001 Academic Press.

  11. DDT Behavior of Waxed Mixtures of RDX, HMX, and Tetryl

    DTIC Science & Technology

    1977-10-18

    NSWC/WOL TR 77-96 O DDT BEHAVIOR OF WAXED MIXTURES OF " RDX, HMX, AND TETRYL BY DONNA PRICE and RICHARD R. BERNECKER RESEARCH AND TECHNOLOGY...50.95 mm OD) with heavy end closures was used. A B/ KNO3 ignitor (1) was used to ignite one end of the 295.4 mm explosive column. Charge loading, tube...data reduction are also as in reference 1 with the modification for strain gages given in reference 2. I. R. R. Bernecker and D. Price , "Transition

  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. 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

  14. Genome-Wide Sequencing and an Open Reading Frame Analysis of Dichlorodiphenyltrichloroethane (DDT) Susceptible (91-C) and Resistant (91-R) Drosophila melanogaster Laboratory Populations

    PubMed Central

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

    2014-01-01

    The Drosophila melanogaster 91-R and 91-C strains are of common origin, however, 91-R has been intensely selected for dichlorodiphenyltrichloroethane (DDT) resistance over six decades while 91-C has been maintained as the non-selected control strain. These fly strains represent a unique genetic resource to understand the accumulation and fixation of mutations under laboratory conditions over decades of pesticide selection. Considerable research has been done to investigate the differential expression of genes associated with the highly DDT resistant strain 91-R, however, with the advent of whole genome sequencing we can now begin to develop an in depth understanding of the genomic changes associated with this intense decades-long xenobiotic selection pressure. Here we present the first whole genome sequencing analysis of the 91-R and 91-C fly strains to identify genome-wide structural changes within the open reading frames. Between-strain changes in allele frequencies revealed a higher percent of new alleles going to fixation for the 91-R strain, as compared to 91-C (P<0.0001). These results suggest that resistance to DDT in the 91-R laboratory strain could potentially be due primarily to new mutations, as well as being polygenic rather than the result of a few major mutations, two hypotheses that remain to be tested. PMID:24915415

  15. 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

  16. 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

  17. 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...

  18. 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

  19. Ultrastructural Alterations in the Eggshell Gland Epithelium of the Mallard Duck After Chronic Exposure to DDT.

    DTIC Science & Technology

    1978-03-01

    This study was conducted to determine what effects the chronic ingestion of DDT would have on the ultrastructure of the eggshell gland of the mallard...endoplasmic reticulum. Since the type II cells are responsible for the transport of calcium, alterations in these cells indicate that decreased calcium transport may be responsible for DDT-induced eggshell thinning. (Author)

  20. 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...

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

    PubMed

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

    2010-03-01

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

  2. 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.

  3. 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.

  4. 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.

  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 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

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

    PubMed

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

    2014-11-01

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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  8. 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

  9. 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.

  10. 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.

  11. Auxiliary Gas Loading of Explosives and Their Sensitivity to DDT (Deflagration to Detonation Transition),

    DTIC Science & Technology

    1984-06-25

    RD-R147 659 AUXILIARY GAS LORDING OF EXPLOSIVES AND THEIR1/ SENSITIVITY TO DDT (DEFLARR (U) NAVAL SURFACE WEAPONS CENTER SILVER SPRING MD D PRICE ET...3 7.. AND THEIR11 SENITVITY TO DDT LnL Ll BY D. PRICE R. BERNECKER RESEARCH AND TECHNOLOGY DEPARTMENT ( 25JUNE 1984 C1 * Approved for public releass...AUXILIARY GAS LOADING OF EXPLOSIVES AND THEIR SENSITIVITY TO DDT S. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(e) S. CONTRACT OR GRANT NUMMER(a) Donna Price

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

    PubMed

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

    2014-01-01

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

  13. 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.

  14. 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

  15. 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.

  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. 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.

  18. 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...

  19. 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.

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

    Treesearch

    Robert E. Stevens

    1965-01-01

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

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. Abuse of Rachel Carson and Misuse of DDT Science in the Service of Environmental Deregulation.

    PubMed

    Yang, Jingxiang; Ward, Michael D; Kahr, Bart

    2017-08-14

    Fake news?? The contact insecticide DDT has been reappraised as a safe, life-saving compound by special interest groups committed to repealing environmental regulations. It is shown in this essay how some specific toxicological data has been misused by those aiming to disingenuously influence public policy. Graphic: Pestroy, a DDT-laced coating marketed in 1946 by Sherwin-Williams Research Laboratories. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. 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.

  10. 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.

  11. [The DDT and malathion resistance of malarial mosquitoes in the Mariupol area].

    PubMed

    Severin, N V

    1989-01-01

    The paper presents results of comparative studies of the level of sensitivity of endophilic malarial mosquito species to DDT and malathion. The sensitivity of the vectors was shown to remain at the same level in spite of cessation of DDT use in medical practice. It may be probably due to the use of organochlorines as pesticides within the city area. Wide use of organophosphorous preparations in medical and agricultural practices has not still led to malathion resistance.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

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

    PubMed Central

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

    2004-01-01

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

  19. 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.

  20. 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.

  1. 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.

  2. Serum DDT and DDE Levels in Pregnant Women of Chiapas, Mexico

    PubMed Central

    KOEPKE, RUTH; WARNER, MARCELLA; PETREAS, MYRTO; CABRIA, ANGELES; DANIS, ROGELIO; HERNANDEZ-AVILA, MAURICIO; ESKENAZI, BRENDA

    2007-01-01

    The authors measured the main ingredients of technical DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl [p,p′-DDT]) and its principal metabolite, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene [p,p′-DDE]) in serum collected from 52 pregnant women in Tapachula, Chiapas, Mexico in 1998. The median lipid-adjusted serum levels for the women were 676 ng/g p,p′-DDT (range: 56–23,169 ng/g) and 4,843 ng/g p,p′-DDE (range: 113–41,964 ng/g). In regression analysis, serum DDT and DDE increased with age (test for trend, p = .022) but decreased with total lactation (test for trend, p < .001). Residence in a house that had ever been sprayed for malaria control was also related to serum DDT and DDE. This study provides evidence of high-level exposure to DDT and DDE among pregnant women living in Chiapas, Mexico, despite countrywide restrictions on its use at the time. PMID:16599003

  3. Serum DDT and DDE levels in pregnant women of Chiapas, Mexico.

    PubMed

    Koepke, Ruth; Warner, Marcella; Petreas, Myrto; Cabria, Angeles; Danis, Rogelio; Hernandez-Avila, Mauricio; Eskenazi, Brenda

    2004-11-01

    The authors measured the main ingredients of technical DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl [p,p'-DDT]) and its principal metabolite, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene [p,p'-DDE]) in serum collected from 52 pregnant women in Tapachula, Chiapas, Mexico in 1998. The median lipid-adjusted serum levels for the women were 676 ng/g p,p'-DDT (range: 56-23,169 ng/g) and 4,843 ng/g p,p'-DDE (range: 113-41,964 ng/g). In regression analysis, serum DDT and DDE increased with age (test for trend, p = .022) but decreased with total lactation (test for trend, p < .001). Residence in a house that had ever been sprayed for malaria control was also related to serum DDT and DDE. This study provides evidence of high-level exposure to DDT and DDE among pregnant women living in Chiapas, Mexico, despite countrywide restrictions on its use at the time.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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 ...

  9. 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 ...

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

    USDA-ARS?s Scientific Manuscript database

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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

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

    PubMed

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

    2016-03-01

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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. [Study on the Resistance of Culex tritaeniorhynchus to DDT and Deltamethrin in Yunnan Province].

    PubMed

    Jiang, Jin-yong; Zhou, Hong-ning; Zheng, Yu-ting; Wang, Jian; Yang, Rui; Ma, Ya-jun

    2015-04-01

    To investigate the resistance level of Culex tritaeniorhynchus to DDT and deltamethrin in Yunnan Province. Adult Culex tritaeniorhynchus samples were collected in Zhaoyang District of Zhaotong City, Mangshi County of Dehong Prefecture, Yuanjiang County of Yuxi City, Jiangcheng and Menglian County of Puer City. The susceptibility of Cx. tritaeniorhynchus to DDT and deltamethrin were tested by bioassay method. The resistance level was judged by adjusted mortality. Culex tritaeniorhynchus collected from Zhaoyang, Mangshi, Jiangcheng, Menglian, and Yuanjiang, and exposed to DDT for 1 h, the mortality after 24 hours was 51.1%, 86.8%, 35.4%, 21.0%, and 4.6%, respectively; the resistant grade in Mangshi was maybe resistance(M), and the others 4 sites were resistance (R). The range of KT, to DDT was from 18.76 min to 395.65 min. The mortality of the mosquitoes from the five sites to deltamethrin was 36.9%, 59.2%, 43.1%, 34.1%, and 3.3%, respectively; the resistant grade was R in all sites, and the range of KT50 was 8.69-715.37 min. Culex tritaeniorhynchus in Yunnan Province shows simultaneously resistant to DDT and deltamethrin, and therefore the insecticiding strategy should be adjusted.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Application of DDT, BHC, and Cyanogas in the control of plague in India

    PubMed Central

    Wagle, P. M.; Seal, S. C.

    1953-01-01

    A comparison is made of the results obtained in various parts of India since 1945 with DDT, BHC, and Cyanogas in the control of plague. Antiplague campaigns involving the use of Cyanogas (calcium cyanide) have shown this pulicide to be effective in many cases in keeping down the flea index and in restricting the spread of the disease, although Cyanogas fumigation alone will not stop the annual recrudescence of epidemics. Comparative trials in Madras State showed that insufflation of rat-holes and harbourages with 10% DDT dusting-powder was effective in keeping the flea index below 1 in several villages, while repeated Cyanogas fumigation in the town of Coonoor did not greatly reduce the index there. In another series of experiments, the toxic action of both DDT and BHC (Gammexane) was still evident 84-90 days after dusting, but the DDT was the more powerful pulicide. Cyanogas dusting had no effect in reducing the flea index in these experiments. In their conclusions, the authors consider that DDT, despite a number of instances of its failure, is the most valuable pulicide, followed by BHC and Cyanogas, in that order. A successful antiplague operation, however, depends on the methods used, the dosage of pulicide, and the time and intensity of its application. In addition, to eradicate plague in endemic areas, it is, of course, necessary to continue control efforts during the interepidemic periods. PMID:13115981

  13. 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.

  14. 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)

  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. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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%.

  5. D-dopachrome tautomerase (D-DT or MIF-2): doubling the MIF cytokine family.

    PubMed

    Merk, Melanie; Mitchell, Robert A; Endres, Stefan; Bucala, Richard

    2012-07-01

    D-dopachrome tautomerase (D-DT) is a newly described cytokine and a member of the macrophage migration inhibitory factor (MIF) protein superfamily. MIF is a broadly expressed pro-inflammatory cytokine that regulates both the innate and the adaptive immune response. MIF activates the MAP kinase cascade, modulates cell migration, and counter-acts the immunosuppressive effects of glucocorticoids. For many cell types, MIF also acts as an important survival or anti-apoptotic factor. Circulating MIF levels are elevated in the serum in different infectious and autoimmune diseases, and neutralization of the MIF protein via antibodies or small molecule antagonists improves the outcome in numerous animal models of human disease. Recently, a detailed investigation of the biological role of the closely homologous protein D-DT, which is encoded by a gene adjacent to MIF, revealed an overlapping functional spectrum with MIF. The D-DT protein also is present in most tissues and circulates in serum at similar concentrations as MIF. D-DT binds the MIF cell surface receptor complex, CD74/CD44, with high affinity and induces similar cell signaling and effector functions. Furthermore, an analysis of the signaling properties of the two proteins showed that they work cooperatively, and that neutralization of D-DT in vivo significantly decreases inflammation. In this review, we highlight the similarities and differences between MIF and D-DT, which we propose to designate "MIF-2", and discuss the implication of D-DT/MIF-2 expression for MIF-based therapies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. Impact of DDT spraying on malaria transmission in Bareilly District, Uttar Pradesh, India.

    PubMed

    Sharma, S N; Shukla, R P; Raghavendra, K; Subbarao, Sarala K

    2005-06-01

    Impact of indoor residual spraying of DDT on malaria transmission and vector density was evaluated in six villages of Shergarh PHC, Bareilly district, Uttar Pradesh under the operational condition of National Vector Borne Disease Control Programme (NVBDCP) from July 2001 to March 2002 (one transmission season only). Two rounds of DDT (50% WDP) spraying @ 1 g/m2 were done both in the experimental and control villages by the state health authorities. The spraying in experimental villages was supervised by Malaria Research Centre (MRC) whereas the district health authorities supervised the operation in control villages. Mass blood surveys were made three times--before the first round, in between the first and second rounds and after the second round of spraying. The blood smears were examined by the trained microscopists of MRC, Haldwani. From the above examinations epidemiological indicators such as slide positivity rate (SPR), slide falciparum rate (SFR) and infant parasite rate (IPR) were calculated. All malaria positive cases were given radical treatment as per NVBDCP schedule. Entomological parameters such as per man hour mosquito density, parity rate, gonotrophic condition and adult susceptibility status of Anopheles culicifacies to diagnostic dosages of DDT (4%) were monitored as per the standard techniques. A total of 988.5 kg of DDT was consumed during two rounds of spray. The house coverage varied from 87 to 95.3%. Parasitological evaluation revealed significant reduction in malaria cases (p < 0.0005) and infant parasite rate declined from 2.9 to 0%. Entomological observations revealed considerable reduction in the density of malaria vector An. culicifacies despite of its 21.4% mortality against DDT test papers. The overall results of the study revealed that DDT is still a viable insecticide in indoor residual spraying owing to its effectivity in well supervised spray operation and high excito-repellency factor.

  9. DDT & deltamethrin resistance status of known Japanese encephalitis vectors in Assam, India.

    PubMed

    Dhiman, Sunil; Rabha, Bipul; Talukdar, P K; Das, N G; Yadav, Kavita; Baruah, Indra; Singh, Lokendra; Veer, Vijay

    2013-12-01

    Japanese encephalitis (JE) outbreaks are common in Assam, northeastern State of India. Information on resistance in known JE vectors in the affected area is important for effective control measures. This study was undertaken to determine the species abundance of JE vectors endemic to Sibsagar district of Assam, and their susceptibility against DDT and deltamethrin. Adult mosquitoes were collected using CDC light trap and aspirators from human dwellings from 13 endemic villages falling under three Primary Health Centres. Collected mosquitoes were identified and unfed female mosquitoes were used for DDT and deltamethrin sensitivity bioassay. The bioassay was performed following WHO protocol using standard susceptibility test kit. Knockdown time (KDT) was monitored at every 10 minutes intervals, whereas mortalities were recorded 24 h post-exposure. Vector density and resistance status were mapped using geographic information system (GIS) technique. A total of 7655 mosquitoes were sampled under three genera, i.e. Anopheles, Culex and Mansonia, and nine species, the JE vector Cx. vishnui group (31.78%) was the most predominant species, followed by Ma. uniformis (16.81%) and Ma. indiana (16.45%). All vector species were suspected to be resistant to DDT and sensitive to deltamethrin, except Ma. indiana, which was suspected to deltamethrin resistant. The KDT50 and KDT95 values of vector mosquitoes for DDT were significantly higher as compared to deltamethrin. The probit model used to estimate KDT50 and KDT95 values did not display normal distribution of percentage knockdown with time for all the vectors tested for DDT and deltamethrin, except for Ma. indiana for deltamethrin assay and Cx. gelidus for the DDT assay. Differences in insecticide resistance status were observed between insecticides and vector species. The results of this study provided baseline data on insecticide resistance in known JE vectors of Sibsagar, Assam. The maps generated may allow better

  10. Association of hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) with in vitro fertilization (IVF) outcomes.

    PubMed

    Mahalingaiah, Shruthi; Missmer, Stacey A; Maity, Arnab; Williams, Paige L; Meeker, John D; Berry, Katharine; Ehrlich, Shelley; Perry, Melissa J; Cramer, Daniel W; Hauser, Russ

    2012-02-01

    Hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) are persistent chlorinated pesticides with endocrine activity that may adversely affect the early stages of human reproduction. Our goal was to determine the association of serum levels of HCB, DDT, and DDE with implantation failure, chemical pregnancy, and spontaneous abortion in women undergoing in vitro fertilization (IVF) from 1994 to 2003. Levels of HCB and congeners of DDT and DDE were measured in serum collected during the follicular phase. Multivariable-adjusted statistical models accommodating multiple outcomes and multiple cycles per woman were used to estimate the relation between serum pesticide levels and IVF outcomes. A total of 720 women with a mean ± SD age 35.4 ± 4.2 years at enrollment contributed 774 IVF cycles. All samples had detectable levels of HCB, DDT, and DDE, with median levels of 0.087 ng/g serum for HCB, 1.12 ng/g serum for total DDT, and 1.04 ng/g serum for p,p´-DDE. Compared with the lowest quartile (Q1) of HCB, the lipid- and multivariable-adjusted odds ratio (OR) for failed implantation was significantly elevated for those with higher HCB quartiles [Q2-Q4; adjusted ORs: for Q2, 1.71; 95% confidence interval (CI): 1.03, 2.82; for Q3, 2.30; 95% CI: 1.39, 3.81; for Q4, 2.32; 95% CI: 1.38, 3.90] and showed a significantly increasing trend (p = 0.001). No statistically significant associations were observed between DDT/DDE and IVF outcomes or between HCB and chemical pregnancy or spontaneous abortion. Serum HCB concentrations were on average lower than that of the general U.S. population and associated with failed implantation among women undergoing IVF.

  11. Association of Hexachlorobenzene (HCB), Dichlorodiphenyltrichloroethane (DDT), and Dichlorodiphenyldichloroethylene (DDE) with in Vitro Fertilization (IVF) Outcomes

    PubMed Central

    Missmer, Stacey A.; Maity, Arnab; Williams, Paige L.; Meeker, John D.; Berry, Katharine; Ehrlich, Shelley; Perry, Melissa J.; Cramer, Daniel W.; Hauser, Russ

    2011-01-01

    Background: Hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) are persistent chlorinated pesticides with endocrine activity that may adversely affect the early stages of human reproduction. Objective: Our goal was to determine the association of serum levels of HCB, DDT, and DDE with implantation failure, chemical pregnancy, and spontaneous abortion in women undergoing in vitro fertilization (IVF) from 1994 to 2003. Methods: Levels of HCB and congeners of DDT and DDE were measured in serum collected during the follicular phase. Multivariable-adjusted statistical models accommodating multiple outcomes and multiple cycles per woman were used to estimate the relation between serum pesticide levels and IVF outcomes. Results: A total of 720 women with a mean ± SD age 35.4 ± 4.2 years at enrollment contributed 774 IVF cycles. All samples had detectable levels of HCB, DDT, and DDE, with median levels of 0.087 ng/g serum for HCB, 1.12 ng/g serum for total DDT, and 1.04 ng/g serum for p,p´-DDE. Compared with the lowest quartile (Q1) of HCB, the lipid- and multivariable-adjusted odds ratio (OR) for failed implantation was significantly elevated for those with higher HCB quartiles [Q2–Q4; adjusted ORs: for Q2, 1.71; 95% confidence interval (CI): 1.03, 2.82; for Q3, 2.30; 95% CI: 1.39, 3.81; for Q4, 2.32; 95% CI: 1.38, 3.90] and showed a significantly increasing trend (p = 0.001). No statistically significant associations were observed between DDT/DDE and IVF outcomes or between HCB and chemical pregnancy or spontaneous abortion. Conclusions: Serum HCB concentrations were on average lower than that of the general U.S. population and associated with failed implantation among women undergoing IVF. PMID:22204795

  12. 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.

  13. Nearly 4 Percent of Americans Suffer from Food Allergies

    MedlinePlus

    ... html Nearly 4 Percent of Americans Suffer From Food Allergies Study finds most common allergy is to shellfish, ... shows. Approximately 4 percent of Americans have a food allergy, with women and Asians the most affected, the ...

  14. 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.

  15. 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.

  16. Assessment of DDT, DDE, and 1-hydroxypyrene levels in blood and urine samples in children from Chiapas Mexico.

    PubMed

    Martínez-salinas, Rebeca I; Pérez-Maldonado, Iván N; Batres-Esquivel, Lilia E; Flores-Ramírez, Rogelio; Díaz-Barriga, Fernando

    2011-08-01

    The aim of this study was assess co-exposure to DDT, DDE (main DDT metabolite), and PAHs (1-hydroxypyrene) in areas where biomass is used to cook and to heat homes and where DDT was used to combat malaria transmission. During 2009, we analyzed a total of 190 blood and urine samples from children living in six communities in Mexico. Quantitative analyses of DDT and DDE were performed using gas chromatography coupled with mass spectrometry. Analyses of 1-hydroxypyrene were performed by HPLC using a fluorescence detector. In this work, we found high levels of DDT and its principal metabolite (DDE) in the blood of children living in four communities in Chiapas located in the southeastern region of Mexico (range, DDT and DDE, respectively). Moreover, high levels of 1-hydroxypyrene (a PAH biomarker) were found in urine samples (range, 0.02 to 4.82 μmol/mol creatinine). An important finding was that around one third of the children studied in these areas were co-exposed to the three compounds. This study demonstrates that children in these communities were exposed to DDT and its metabolites, and to other contaminants generated by the combustion of firewood. Therefore, the complex mixture studied in this study (PAHs and DDT/DDE) requires further research.

  17. SELECTIVE IN VITRO HORMONE ACTIVITY OF O,P'-DDT AND O,P'-METHOXYCHLOR OPTICAL ISOMERS

    EPA Science Inventory

    Components and metabolites of the pesticides DDT and Methoxychlor have been described as endocrine disrupting chemicals with estrogen and/or antiandrogen activity. We account the estrogen and antiandrogen activity of the individual enantiomers of o,p'-DDT and o,p'-Methoxychlor. O...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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 is...

  4. 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 is...

  5. 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 is...

  6. 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 is...

  7. 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 is...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  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. 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.

  15. Electron Donor Substances and Iron Oxides Stimulate Anaerobic Dechlorination of DDT in a Slurry System with Hydragric Acrisols.

    PubMed

    Liu, Cui-Ying; Cade-Menun, Barbara J; Xu, Xiang-Hua; Fan, Jian-Ling

    2016-01-01

    The interactive effects between electron donor substances and iron (Fe) oxides have significant influence on electron transfer and the growth of Fe-reducing bacteria, which may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in soils. To evaluate the roles of volatile fatty acids and Fe(III) oxide in accelerating the reductive dechlorination of DDT in Hydragric Acrisols, a batch anaerobic incubation experiment was conducted in a slurry system with the following seven treatments: sterile soil, control (DDT-contaminated soil), lactic acid, propionic acid, goethite, lactic acid + goethite, and propionic acid + goethite. Results showed that after 20 d of incubation, DDT residues for these treatments decreased by 34, 65, 77, 81, 77, 90, and 92% of the initial quantities, respectively, with 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane as the dominant metabolite. The application of lactic acid had no significant effect on DDT dechlorination in the first 8 d while the methanogenesis rate increased quickly but accelerated DDT dechlorination after Day 8 while the methanogenesis rate decreased and Fe(II) contents increased. The application of propionic acid enhanced DDT dechlorination rates throughout the incubation. The amendment by goethite stimulated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus accelerating DDT dechlorination significantly in the early incubation period. A synergetic interaction that accelerated DDT dechlorination, either between lactic acid and goethite or between propionic acid and goethite, was obtained. The results will be of great significance to develop efficient in situ remediation technology of DDT-contaminated soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. 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.

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

    PubMed

    Sereda, Barbara; Bouwman, Henk; Kylin, Henrik

    2009-01-01

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

  18. 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.

  19. 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...

  20. 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...

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. [Using instantaneous spectra to determine dominant species in the DDT process of epoxypropane].

    PubMed

    Li, Ping; Hu, Dong; Yuan, Chang-Ying; Dai, Song-Hui; Xiao, Hai-Bo

    2006-09-01

    After solving problems of weak light detection, the calibration of the spectral sensitivity of the measuring system, and the synchronization of the measuring system, instantaneous emission spectra of epoxypropane in the process of deflagration to detonation transition (DDT) with the exposure time of 2-8 micros and the resolution of 0. 2 nm were acquired from six different side windows of an explosion shock tube. Using the corrected spectral data, curves of the optical radiant intensity of main reaction products versus the DDT distance from the ignition point were obtained. These curves provided information about the evolution of the reaction and the products during the DDT process. Results indicate that the chemical reaction rate of the gaseous fuel and the corresponding concentrations of intermediate products increased gradually at the deflagration stage, but at the moment of deflagration to detonation transition, the reaction rate increased rapidly and the concentrations! of products increased sharply. Among these main products, concentration increments of molecule CO, and radicals CHO and OH were greater than other products, which means that CO, CHO and OH are the dominant species that affect the DDT process greatly.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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

  14. 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...

  15. Studies of DDT enhancement approaches for kerosene-fueled small-scale pulse detonation engines applications

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Tang, H.; Li, J.; Zhang, C.

    2012-11-01

    Two-phase small-scale pulse detonation engine (SPDE) offers a competitive alternative for small-scale propulsion systems from a high cycle efficiency and structural simplicity standpoint. SPDE models are designed with the aero-valve, and three different cases of obstacle combinations are used as deflagration-to-detonation transition (DDT) devices. The inner diameters of detonation tubes are 29 mm, and the lengths of three SPDEs are 995, 1,100, and 1,175 mm. Using kerosene-air as the fuel-oxidizer, a series of high-frequency detonation tests is conducted to seek efficient DDT enhancement approaches that reduce DDT distance and time and increase the frequency of kerosene-fueled SPDE. The results show that the fully developed detonation wave can be achieved at a distance of 3.4 times the minimum characteristic distance for gaseous detonation formation from the igniter and that the SPDE can steadily operate at a maximal frequency of 62.5 Hz. By adopting these DDT enhancement approaches, the detonability of kerosene is significantly improved. In addition, experiments are performed to study the effects of firing frequencies on detonation transitions. The results clearly indicate that the values of detonation wave pressures and velocities, the degree of overdriven wave, the ignition delay times, and detonation initiation times vary with frequencies. In terms of the performance, the optimal frequencies of three SPDE models are 20, 42.5, and 50 Hz, respectively.

  16. 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.

  17. 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

  18. 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).

  19. 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.

  20. Association of DDT with spontaneous abortion: a case-control study.

    PubMed

    Korrick, S A; Chen, C; Damokosh, A I; Ni, J; Liu, X; Cho, S I; Altshul, L; Ryan, L; Xu, X

    2001-10-01

    Spontaneous abortion (SAB), the most common adverse pregnancy outcome, affects approximately 15% of clinically recognized pregnancies. Except for advanced maternal age and smoking, there are not well-established risk factors for SAB. Animal models associate increased fetal resorption or abortion with exposure to the pesticide dichlorodiphenyl trichloroethane (DDT), but epidemiologic investigations of DDT and SAB are inconsistent. We undertook a pilot investigation of the hypothesized association of DDT with SAB. Participants in this case-control study were selected from a longitudinal study of reproductive effects of rotating shifts among female Chinese textile workers who were married, ages 22-34, nulliparous without history of SAB or infertility, and planning pregnancy. From 412 pregnancies, 42 of which ended in SAB, 15 SAB cases and 15 full-term controls were randomly selected and phlebotomized. Serum was analyzed for p,p'-DDT, o,p'-DDT, their metabolites (DDE and DDD), and other organochlorines including polychlorinated biphenyls. Cases and controls were nonsmokers and did not differ in age (mean 25 years), body mass index (BMI), passive smoke exposure, or workplace exposures. Cases had significantly (p < 0.05) higher serum levels of p,p'-DDE (22 vs.12 ng/g) and o,p'-DDE (0.09 vs. 0.05 ng/g) than controls. After adjustment for age and BMI, each ng/g serum increase in p,p'-DDE was associated with a 1.13 (CI, 1.02-1.26) increased odds of SAB. With adjustment of serum DDE levels for excretion via breastfeeding, DDE-associated increased odds of SAB remained significant with up to 7% declines in maternal serum DDE levels for each month of breastfeeding. A potential increased risk of SAB is associated with maternal serum DDE levels.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Remediation of DDT-contaminated water and soil by using pretreated iron byproducts from the automotive industry.

    PubMed

    Satapanajaru, Tunlawit; Anurakpongsatorn, Patana; Pengthamkeerati, Patthra

    2006-01-01

    The objective of this study was to quantify the effectiveness of different pretreated iron byproducts from the automotive industry to degrade DDT [(1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane] in aqueous solutions and soil slurry. Iron byproducts from automotive manufacturing were pretreated by three different methods (heating, solvent and 0.5N HCl acid washing) prior to experimentation. All pretreated irons were used at 5% (wt v-1) to treat 0.014 mM (5 mgL-1) of DDT in aqueous solution. Among the pretreated irons, acid pretreated iron results in the fastest destruction rates, with a pseudo first-order degradation rate of 0.364 d-1. By lowering the pH of the DDT aqueous solution from 9 to 3, destruction kinetic rates increase more than 20%. In addition, when DDT-contaminated soil slurry (3.54 mg kg-1) was incubated with 5% (wt v-1) acid-pretreated iron, more than 90% destruction of DDT was observed within 8 weeks. Moreover, DDT destruction kinetics were enhanced when Fe(II), Fe(III) or Al(III) sulfate salts were added to the soil slurry, with the following order of destruction kinetics: Al(III) sulfate > Fe(III) sulfate > Fe(II) sulfate. These results provide proof-of concept that inexpensive iron byproducts of the automotive industry can be used to remediate DDT-contaminated water and soil.

  6. The Reaction of CIONO_2 with Submicrometer Sulfuric Acid Aerosol

    NASA Astrophysics Data System (ADS)

    Hanson, D. R.; Lovejoy, E. R.

    1995-03-01

    The measured reaction probability, γ, for the reaction of chlorine nitrate (CIONO_2) with 60 percent (by weight) sulfuric acid aerosol increases monotonically with particle size at 250 kelvin. The reacto-diffusive length (l, the effective liquid depth over which reaction occurs) derived from these experiments is 0.037 ± 0.007 micrometer (95 percent confidence level for precision). The reaction probability for the reaction of CIONO_2 with 60 percent sulfuric acid aerosol doped with ~7 x 10-4 M hydrochloric acid at 250 kelvin is larger by about a factor of 4 than in the absence of hydrochloric acid and varies less with particle size (l = 0.009 ± 0.005 micrometer). These results provide a test of the theory for gas-particle reactions and further insight into the reactivity of atmospheric aerosol.

  7. The Reaction of CIONO2 with Submicrometer Sulfuric Acid Aerosol.

    PubMed

    Hanson, D R; Lovejoy, E R

    1995-03-03

    The measured reaction probability, gamma for the reaction of chlorine nitrate (CIONa(2)) with 60 percent (by weight) sulfuric acid aerosol increases monotonically with particle size at 250 kelvin. The reacto-diffusive length (l, the effective liquid depth over which reaction occurs) derived from these experiments is 0.037 +/- 0.007 micrometer (95 percent confidence level for precision). The reaction probability for the reaction of CIONO(2) with 60 percent sulfuric acid aerosol doped with approximately 7 x 10(-4) M hydrochloric acid at 250 kelvin is larger by about a factor of 4 than in the absence of hydrochloric acid and varies less with particle size (l = 0.009 +/- 0.005 micrometer). These results provide a test of the theory for gas-particle reactions and further insight into the reactivity of atmospheric aerosol.

  8. Targeting distinct tautomerase sites of D-DT and MIF with a single molecule for inhibition of neutrophil lung recruitment

    PubMed Central

    Rajasekaran, Deepa; Zierow, Swen; Syed, Mansoor; Bucala, Richard; Bhandari, Vineet; Lolis, Elias J.

    2014-01-01

    We report a new inflammatory activity for extracellular d-dopachrome tautomerase (D-DT), the recruitment of neutrophils to the lung on D-DT intratracheal installation of C57BL/6J mice with an EC50 of 5.6 μg. We also find that D-DT and macrophage migration inhibitory factor (MIF) have additive effects in neutrophil recruitment. Although the tautomerase site of D-DT and its homologue MIF are biophysically very different, 4-iodo-6-phenylpyrimidine (4-IPP) forms a covalent bond with Pro-1 of both proteins, resulting in a 6-phenylpyrimidine (6-PP) adduct. Recruitment of neutrophils to the lung for the 6-PP adducts of D-DT and MIF are reduced by ∼50% relative to the apo proteins, demonstrating that an unmodified Pro-1 is important for this activity, but there is no cooperativity in inhibition of the proteins together. The differences in the binding mode of the 6-PP adduct for D-DT was determined by crystallographic studies at 1.13 Å resolution and compared to the structure of the MIF–6-PP complex. There are major differences in the location of the 6-PP adduct to the D-DT and MIF active sites that provide insight into the lack of cooperativity by 4-IPP and into tuning the properties of the covalent inhibitors of D-DT and MIF that are necessary for the development of therapeutic small molecules against neutrophil damage from lung infections such as Pseudomonas aeruginosa in cystic fibrosis and immunocompromised patients.—Rajasekaran, D., Zierow, S., Syed, M., Bucala, R., Bhandari, V., Lolis, E. J. Targeting distinct tautomerase sites of D-DT and MIF with a single molecule for inhibition of neutrophil lung recruitment. PMID:25016026

  9. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  10. 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.

  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

    respectively.11@ No information was retrieved for m,p-DDE. Reptiles . No quantitative toxicity data were recovered, but Stickel has stated that the box...against loss of reptiles through land application of DDT is summarized by McKee and Wolfe." * Direct treatment of ponds at DDT concentrations of 2 ppm or...34 Spermatogenesis in Bald Eagles Experimentally Fed a Diet Containing DDT," Condor 68:497-502 (1966). 94. Hickey, J.J. and D.W. Anderson, "Chlorinated

  12. Impact of DDT indoor residual spraying on Phlebotomus argentipes in a kala-azar endemic village in eastern Uttar Pradesh.

    PubMed Central

    Kaul, S. M.; Sharma, R. S.; Dey, K. P.; Rai, R. N.; Verghese, T.

    1994-01-01

    Data on the operational efficacy of DDT indoor residual spraying against Phlebotomus argentipes, the vector of kala-azar in India, are scarce. We therefore undertook a study of the impact on kala-azar and its vector of DDT indoor residual spraying in the Varanasi district of eastern Uttar Pradesh. Preliminary results indicate that after two rounds of DDT spraying in one village no P. argentipes were found during the peak vector season; in contrast, a large number of these sandfies were collected in the unsprayed comparison village. PMID:8131254

  13. Genetical studies on dieldrin-resistance in Aëdes aegypti and its cross-resistance to DDT

    PubMed Central

    Khan, N. H.; Brown, A. W. A.

    1961-01-01

    A strain of Aëdes aegypti was recently found in Puerto Rico which proved to be resistant to both DDT and dieldrin. This paper reports on genetical studies of this strain to determine whether a single entity is involved or two distinct resistances. Tests carried out by repeated back-crossing combined with selection pressure from DDT and dieldrin and by crossing with a strain with marker genes indicate that a single entity is responsible (dieldrin-resistance with cross-resistance to DDT) and that its genetic factor is located on chromosome 2 at a distance of 25 from locus ”yellow”. PMID:13755610

  14. Assessment of the levels of DDT and its metabolites in soil and dust samples from Chiapas, Mexico.

    PubMed

    Martínez-Salinas, Rebeca I; Díaz-Barriga, Fernando; Batres-Esquivel, Lilia E; Pérez-Maldonado, Iván N

    2011-01-01

    The aim of this study was to assess the levels of DDT and its metabolites in two environmental matrices (soil and dust) in five communities in Chiapas, Mexico. DDT and its metabolites were analyzed by gas chromatography/mass spectrometry. The soil levels of total DDT ranged from non detectable (

  15. Nitrosyl sulfuric acid and stratospheric aerosols

    NASA Astrophysics Data System (ADS)

    Burley, Joel D.; Johnston, H. S.

    1992-07-01

    It is proposed on the basis of information found in the atmospheric and chemical literature that nitrosyl sulfuric acid (NSA), NOHSO4 may play an important role in stratospheric chemistry. If the reaction probability of forming NSA per collision of NO with a sulfuric acid aerosol is 0.001, 1 percent of the sulfuric acid would be converted to NSA within 1 d at 20 km altitude. If NSA in the sulfate aerosols is 1 percent of the sulfuric acid and if the second order rate constant for (HCl + NOHSO4 = H2SO4 + ClNO) in sulfuric acid solution is greater than 10 exp -18 cu cm/molecule s under conditions at 20 km altitude, the rate of HCl + NSA is faster than the rate of HO + HCl. In this case, this heterogeneous catalysis is expected to affect the balance of No sub y, Cl sub y, and the ozone in the lower stratosphere.

  16. 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...

  17. 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...

  18. 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.

  19. The Texas Ten Percent Plan's Impact on College Enrollment

    ERIC Educational Resources Information Center

    Daugherty, Lindsay; Martorell, Paco; McFarlin, Isaac, Jr.

    2014-01-01

    The Texas Ten Percent Plan (TTP) provides students in the top 10 percent of their high-school class with automatic admission to any public university in the state, including the two flagship schools, the University of Texas at Austin and Texas A&M. Texas created the policy in 1997 after a federal appellate court ruled that the state's previous…

  20. 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…

  1. 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.

  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. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  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. [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.

  10. Stratospheric Aerosol and Gas Experiment (SAGE 3)

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.

    1993-01-01

    The proposed SAGE III instrument would be the principal source of data for global changes of stratospheric aerosols, stratospheric water vapor, and ozone profiles, and a contributing source of data for upper tropospheric water vapor, aerosols, and clouds. The ability to obtain such data has been demonstrated by the predecessor instrument, SAGE II, but SAGE III will be substantially more capable, as discussed below. The capabilities for monitoring the profiles of atmospheric constituents have been verified in detail, including ground-based validations, for aerosol, ozone, and water vapor. Indeed, because of its self-calibrating characteristics, SAGE II was an essential component of the international ozone trend assessments, and SAGE II is now proving to be invaluable in tracking the aerosols from Mt. Pinatubo. Although SAGE profiles generally terminate at the height of the first tropospheric cloud layer, it has been found that the measurements extend down to 3 km altitude more than 40 percent of the time at most latitudes. Thus, useful information can also be obtained on upper tropospheric aerosols, water vapor, and ozone.

  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. 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.

  13. 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.

  14. Targeting distinct tautomerase sites of D-DT and MIF with a single molecule for inhibition of neutrophil lung recruitment.

    PubMed

    Rajasekaran, Deepa; Zierow, Swen; Syed, Mansoor; Bucala, Richard; Bhandari, Vineet; Lolis, Elias J

    2014-11-01

    We report a new inflammatory activity for extracellular d-dopachrome tautomerase (D-DT), the recruitment of neutrophils to the lung on D-DT intratracheal installation of C57BL/6J mice with an EC50 of 5.6 μg. We also find that D-DT and macrophage migration inhibitory factor (MIF) have additive effects in neutrophil recruitment. Although the tautomerase site of D-DT and its homologue MIF are biophysically very different, 4-iodo-6-phenylpyrimidine (4-IPP) forms a covalent bond with Pro-1 of both proteins, resulting in a 6-phenylpyrimidine (6-PP) adduct. Recruitment of neutrophils to the lung for the 6-PP adducts of D-DT and MIF are reduced by ∼ 50% relative to the apo proteins, demonstrating that an unmodified Pro-1 is important for this activity, but there is no cooperativity in inhibition of the proteins together. The differences in the binding mode of the 6-PP adduct for D-DT was determined by crystallographic studies at 1.13 Å resolution and compared to the structure of the MIF-6-PP complex. There are major differences in the location of the 6-PP adduct to the D-DT and MIF active sites that provide insight into the lack of cooperativity by 4-IPP and into tuning the properties of the covalent inhibitors of D-DT and MIF that are necessary for the development of therapeutic small molecules against neutrophil damage from lung infections such as Pseudomonas aeruginosa in cystic fibrosis and immunocompromised patients. © FASEB.

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

    PubMed

    Liu, Cuiying; Xu, Xianghua; Fan, Jianling

    2015-12-01

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

  16. 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.

  17. 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

  18. Effects of phenobarbital and p,p'-DDT on carboxylesterase activity and hydrolysis of propanidid in rat liver.

    PubMed

    Nousiainen, U

    1985-01-01

    Time-dependent responses of microsomal and cytosolic carboxylesterases (EC 3.1.1.1) to administration of phenobarbital or p,p'-DDT were studied in rat liver using p-nitrophenylacetate and propanidid as substrates. In vitro and in vivo studies indicate that the hepatic carboxylesterases are induced by phenobarbital and p,p'-DDT. The induced metabolism of propanidid does not appear to be due to the microsomal polysubstrate monooxygenase system of the liver.

  19. 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.

  20. Developmental and Environmental Origins of Breast Cancer DDT as a Case Study

    PubMed Central

    2012-01-01

    More than 20 studies of serum “DDT” and breast cancer have found little support for the hypothesis that exposure influences risk of breast cancer. However, studies share common limitations including the inability to account for exposure in early life when the breast may be most vulnerable and the inability to measure exposure to the primary components of commercial DDT. This paper 1) Summarizes evidence regarding critical windows of exposure for breast cancer 2) Summarizes lessons learned from initial efforts to study DDT and breast cancer 3) Reviews evidence from the Child Health and Development Studies (CHDS) where exposure was measured in young women using blood samples obtained during active exposure, 1- 3 days after delivery. 4) Suggests approaches for human studies that might advance understanding of environmental stressors in the developmental origins of disease. PMID:20965245

  1. 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

  2. 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.

  3. Relation between smoking and levels of DDT and dieldrin in human fat.

    PubMed

    Domanski, J J; Nelson, L A; Guthrie, F E; Domanski, R E; Mark, R; Postlethwait, R W

    1977-01-01

    The adipose tissue of humans with known patterns of cigarette smoking was collected during 1973-74 and analyzed for DDT components and dieldrin. Although smokers are exposed to high levels of insecticides from smoke of cigarettes and some of these compounds can be stored in adipose tissue, it could not be demonstrated that a relationship exists between smoking habit and residual levels of DDT found in fat. Smokers seem able, through induction of enzymes by substances in tobacco smoke, to metabolize these insecticides at a rate approximately equal to the rate of their intake in the smoke. Dieldrin residues in black male subjects were found to be linearly related to the number of cigarettes smoked, but the factors governing this relationship were not obvious.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Fenton (H2O2/Fe) reaction involved in Penicillium sp. culture for DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane)] degradation.

    PubMed

    Izcapa-Treviño, Cecilia; Loera, Octavio; Tomasini-Campocosio, Araceli; Esparza-García, Fernando; Salazar-Montoya, Juan A; Díaz-Cervantes, María D; Rodríguez-Vázquez, Refugio

    2009-11-01

    The purpose of this work was to demonstrate that a Fenton (H(2)O(2)/Fe) reaction was involved in DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane)] degradation in a culture of Penicillium sp. spiked with FeSO(4). A commercial DDT mixture (10% DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], 30% o,p-DDT and 60% of p,p' -DDT) of 10 mg L(-1) was used. Hydrogen peroxide (H(2)O(2)), tartaric acid and oxalic acid were identified at 18 h in culture media, with and without added DDT; this correlated positively with lowering of pH from 5.8 to 2.7. Lower concentrations of oxalic acid and H(2)O(2) (7.9 and 52.6 mg L(-1), respectively) occurred in media with DDT at 30 h, in comparison to that one without DDT mixture (27.9 and 65.3 mg L(-1), respectively), at this time there was maximum degradation (87.7, 91.7 and 94.2%) for DDE, o,p-DDT and p,p'-DDT, respectively. We propose that the degradation of the DDT mixture by Penicillium sp. was through a Fenton reaction (H(2)O(2)/Fe) under acidic conditions produced in situ during the fungal culture amended with FeSO(4).

  9. 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.

  10. 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.

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

    PubMed

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

    2017-09-01

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

  12. 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.

  13. 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

  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. 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

  16. DDE residues in young wood ducks (Aix sponsa) near a former DDT manufacturing plant.

    PubMed

    Fleming, W J; Cromartie, E

    1981-03-01

    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.

  17. 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.

  18. 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.

  19. Black Carbon Facilitated Dechlorination of DDT and its Metabolites by Sulfide.

    PubMed

    Ding, Kai; Xu, Wenqing

    2016-12-06

    1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) and its metabolites 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), are often detected in soils and sediments containing high concentrations of black carbon. Sulfide (∼5 mM) from biological sulfate reduction often coexists with black carbon and serves as both a strong reductant and a nucleophile for the abiotic transformation of contaminants. In this study, we found that the abiotic transformation of DDT, DDD, and DDE (collectively referred to as DDX) require both sulfide and black carbon. 89.3 ± 1.8% of DDT, 63.2 ± 1.9% of DDD, and 50.9 ± 1.6% of DDE were degraded by sulfide (5 mM) in the presence of graphite powder (21 g/L) after 28 days at pH 7. Chloride was a product of DDX degradation. To better understand the reaction pathways, electrochemical cells and batch reactor experiments with sulfide-pretreated graphite powder were used to differentiate the involvement of black carbon materials in DDX transformation by sulfide. Our results suggest that DDT and DDD are transformed by surface intermediates formed from the reaction between sulfide and black carbon, while DDE degradation involves reductive dechlorination. This research lays the groundwork for developing an alternative in situ remediation technique for rapidly decontaminating soils and sediments to lower toxic products under environmentally relevant conditions.

  20. 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.

  1. 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.

  2. Hepatoprotective activity of Rhus oxyacantha root cortex extract against DDT-induced liver injury in rats.

    PubMed

    Ben Miled, Hanène; Barka, Zaineb Ben; Hallègue, Dorsaf; Lahbib, Karima; Ladjimi, Mohamed; Tlili, Mounira; Sakly, Mohsen; Rhouma, Khémais Ben; Ksouri, Riadh; Tebourbi, Olfa

    2017-06-01

    The present investigation aimed to study the antioxidant activity and hepatoprotective effects of ethyl acetate extract of R. oxyacantha root cortex (RE) against DDT-induced liver injury in male rats. The RE exhibited high total phenolic, flavonoid and condensed tannins contents. The antioxidant activity in vitro systems showed a significant potent free radical scavenging activity of the extract. The HPLC finger print of R. oxyacantha active extract showed the presence of five phenolic compounds with higher amounts of catechol and gallic acid. The in vivo results showed that a single intraperitoneal administration of DDT enhanced levels of hepatic markers (ALT, AST and LDH) in serum of experimental animals. It also increased the oxidative stress markers resulting in increased levels of the lipid peroxidation with a significant induction of SOD and GPx, metallothioneins (MTs) and a concomitant decrease of non protein thiols (NPSH) in liver. However, pretreatment of rats with RE at a dose of 150 and 300mg/kg body weight significantly lowered serum transaminases and LDH in treated rats. A significant reduction in hepatic thiobarbituric reactive substances and a decrease in antioxidant enzymes activities and hepatic MTs levels by treatment with plant extract against DDT, were observed. These biochemical changes were consistent with histopathological observations, suggesting marked hepatoprotective effect of RE with the two doses used. These results strongly suggest that treatment with ethyl acetate extract normalizes various biochemical parameters and protects the liver against DDT-induced oxidative damage in rats and thus help in evaluation of traditional claim on this plant. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. 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.

  4. 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.

  5. 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.

  6. Is DDT exposure during fetal period and breast-feeding associated with neurological impairment?

    PubMed

    Hardell, Lennart; Lindström, Gunilla; Van Bavel, Bert

    2002-03-01

    The concentration of certain persistent organic pollutants was determined in a family including both parents and one son with neurological impairment suggested to be Attention Deficit-Hyperactivity Disorder (ADHD). For comparison control subjects from other ongoing studies were used. They were of the same sex and age group as the respective family member. For polychlorinated biphenyls, hexachlorobenzene, and chlordanes similar results were found in the study groups. The concentration of DDE, the main metabolite of DDT, was increased in the mother, 782 ng/g lipid, compared with mean 403, median 259 (range 51-1354) for the female controls. Also, the son had an increased concentration of 259 ng/g lipid, compared with mean 104, median 72 (range 46-349) for controls. A low concentration was found in the father, 127 ng/g lipid. As a child and as a teenager to the age of 17, the mother was exposed to DDT in her home environment. We discuss the potential of fetal and breast-feeding exposure of the son. Neurodevelopmental impairment has been reported for dioxins and PCBs, but DDT seems to have been less investigated in this respect. (c) 2002 Elsevier Science (USA).

  7. 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.

  8. 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.

  9. 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

  10. Mechanism and kinetic properties of NO3-initiated atmospheric degradation of DDT.

    PubMed

    Liu, Cai; Li, Shanqing; Gao, Rui; Dang, Juan; Wang, Wenxing; Zhang, Qingzhu

    2014-03-01

    In this article, the NO3 radical-initiated atmospheric oxidation degradation of DDT was theoretically investigated using molecular orbital theory calculations. All the calculations of intermediates, transition states and products were performed at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level of theory. Several energetically favorable reaction pathways were revealed. The formation mechanisms of secondary pollutants were presented and discussed. The rate constants were deduced over the temperature range of 273-333 K using canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) method. Our study shows that H abstraction from the alkyl group and NO3 addition to the C3 atom of the benzene ring are the dominant reaction pathways. The rate-temperature formula of the overall rate constants is k(T)(DDT+NO3) = (7.21 × 10(-15))exp(-153.81/T) cm(3)/(molsec) over the possible atmospheric temperature range of 273-333 K. The atmospheric lifetime of DDT determined by NO3 radical is about 52.5 days, which indicates that it can be degraded in the gas phase within several months. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  11. 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.

  12. 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.

  13. Polychlorinated biphenyls and DDT in swordfish (Xiphias gladius) and blue shark (Prionace glauca) from Brazilian coast.

    PubMed

    de Azevedo e Silva, Claudio Eduardo; Azeredo, Antonio; Lailson-Brito, José; Torres, João Paulo Machado; Malm, Olaf

    2007-04-01

    The polychlorinated biphenyls (PCBs) and DDT may bioaccumulate in the aquatic food web and have been of great concern due to their toxic effects on wildlife and human health. There is evidence showing that fish in the human diet contributes at a significant proportion to the total intake of PCBs and other organochlorine compounds, particularly fish with higher fat levels. This study investigated the concentration of PCBs and DDTs in muscle tissues of samples of the blue shark (Prionace glauca) and a swordfish (Xiphias gladius) from east Brazilian coast and estimate the human exposure to total DDTs through the consumption of both the species. Samples of the each species were caught between August and September 2001. The mean concentration for summation operator PCBs in P. glauca was 3.15 ng/g w.w. and the summation operator DDTs was 0.93 ng/g w.w. The mean concentration of summation operator PCBs in X. gladius was 6.50 ng/g and the mean of summation operator DDTs was 2.47 ng/g. The estimated daily intake of summation operator DDT through X. gladius or P. glauca consumption can be considered safe since it contributes to less than 0.1% of the limit of acceptable daily intake (ADI) of summation operator DDT proposed by WHO.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Imaging aerosol viscosity

    NASA Astrophysics Data System (ADS)

    Pope, Francis; Athanasiadis, Thanos; Botchway, Stan; Davdison, Nicholas; Fitzgerald, Clare; Gallimore, Peter; Hosny, Neveen; Kalberer, Markus; Kuimova, Marina; Vysniauskas, Aurimas; Ward, Andy

    2017-04-01

    Organic aerosol particles play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states; however, diffusion rates of small molecules such as water appear not to be limited by these high viscosities. We have developed a technique for measuring viscosity that allows for the imaging of aerosol viscosity in micron sized aerosols through use of fluorescence lifetime imaging of viscosity sensitive dyes which are also known as 'molecular rotors'. These rotors can be introduced into laboratory generated aerosol by adding minute quantities of the rotor to aerosol precursor prior to aerosolization. Real world aerosols can also be studied by doping them in situ with the rotors. The doping is achieved through generation of ultrafine aerosol particles that contain the rotors; the ultrafine aerosol particles deliver the rotors to the aerosol of interest via impaction and coagulation. This work has been conducted both on aerosols deposited on microscope coverslips and on particles that are levitated in their true aerosol phase through the use of a bespoke optical trap developed at the Central Laser Facility. The technique allows for the direct observation of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles. The technique is non-destructive thereby allowing for multiple experiments to be carried out on the same sample. It can dynamically quantify and track viscosity changes during atmospherically relevant processes such oxidation and hygroscopic growth (1). This presentation will focus on the oxidation of aerosol particles composed of unsaturated and saturated organic species. It will discuss how the type of oxidant, oxidation rate and the composition of the oxidized products affect the time

  20. Percent body fat, fractures and risk of osteoporosis in women.

    PubMed

    Wyshak, G

    2010-06-01

    Globally, in an aging population, osteoporosis and fractures are emerging as major public health problems; accessible and affordable recognition, prevention and treatment strategies are needed. Percent body fat is known to be associated with bone mineral density and fractures. This paper uses an innovative, virtually cost-free method to estimate percent body fat from age, height and weight, and assesses its validity by examining the association between percent body fat and fractures among women 39 and older. An epidemiologic study. 3940 college alumnae, median age 53.6, participated by responding to a mailed questionnaire covering medical history, behavioral factors, birth date, weight and height. T-tests, chi-square and multivariable logistic regression. Percent body fat estimated from age, weight, height and gender. Associations of fractures with percent body fat are expressed as odds ratios: for osteoporotic (wrist, hip and/or x-ray confirmed vertebral), the adjusted OR = 2.41, 95% CI (1.65, 3.54), P < 0.0001; for wrist fractures, the adjusted OR = 2.56, 95% CI (1.65, 3.96), P < 0.0001; for x-ray confirmed vertebral fractures the adjusted OR = 4.69, 95% CI (2.05, 10.77), P=0.0003).; and for non-osteoporotic, he adjusted OR= 1.00, 95% CI (0.76 1.32), P=0.999. The findings are consistent with methods using DXA and/or other technologies that show percent body fat is associated with fractures of the wrist and vertebrae. Identification of risk factors is necessary for the prevention and treatment of osteoporosis and osteoporotic fractures. Estimation of percent body fat from age, height and weight may be a valid, cost-saving, and cost-effective alternative tool for screening and assessing risk of osteoporosis in settings where Dual x-ray absorptiometry (DXA) or other radiological techniques are too costly or unavailable.

  1. 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.

  2. 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.

  3. 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.

  4. 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…

  5. 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…

  6. 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.

  7. 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.

  8. MIF-2/D-DT enhances proximal tubular cell regeneration through SLPI- and ATF4-dependent mechanisms.

    PubMed

    Ochi, Akinobu; Chen, Dong; Schulte, Wibke; Leng, Lin; Moeckel, Nickolas; Piecychna, Marta; Averdunk, Luisa; Stoppe, Christian; Bucala, Richard; Moeckel, Gilbert

    2017-09-01

    Macrophage migration inhibitory factor (MIF) is a cytokine with pleiotropic actions that is produced by several organs and cell types. Depending on the target cell and the inflammatory context, MIF can engage its two component receptor complex CD74 and CD44 and the chemokine receptors CXCR2/4. MIF is constitutively expressed in renal proximal tubular cells, stored in intracellular preformed pools, and released at a low rate. Recently, a second MIF-like protein (i.e., MIF-2/D-DT) has been characterized in mammals. Our study was aimed at examining the role of MIF-2/D-DT, which mediates tissue protection in the heart, in tubular cell regeneration from ischemia-reperfusion injury. We found that Mif-/-, Mif-2-/-, and Cd74-/- mice had significantly worse tubular injury compared with wild-type (WT) control mice and that treatment with MIF-2/D-DT significantly improved recovery of injured epithelial cells. RNAseq analysis of kidney tissue from the ischemia-reperfusion injury model revealed that MIF-2/D-DT treatment stimulates secretory leukocyte proteinase inhibitor (SLPI) and cyclin D1 expression. MIF-2/D-DT additionally activates of eukaryotic initiation factor (eIF) 2α and activating transcription factor (ATF) 4, two transcription factors involved in the integrated stress response (ISR), which is a cellular stress response activated by hypoxia, nutrient deprivation, and oxygen radicals. MIF-2/D-DT also inhibited apoptosis and induced autophagy in hypoxia-treated mouse proximal tubular (MPT) cells. These results indicate that MIF-2/D-DT is an important factor in tubular cell regeneration and may be of therapeutic utility as a regenerative agent in the clinical setting of ischemic acute kidney injury. Copyright © 2017 the American Physiological Society.

  9. 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.

  10. 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.

  11. 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

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

    PubMed

    Ogoma, Sheila B; Lorenz, Lena M; Ngonyani, Hassan; Sangusangu, Robert; Kitumbukile, Mohammed; Kilalangongono, Masoudi; Simfukwe, Emmanuel T; Mseka, Anton; Mbeyela, Edgar; Roman, Deogratius; Moore, Jason; Kreppel, Katharina; Maia, Marta F; Moore, Sarah J

    2014-04-01

    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. 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. 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. This study highlights that airborne pyrethroids and DDT affect a range of anopheline mosquito behaviours that are important parameters in malaria transmission, namely deterrence, irritancy/excito-repellency and blood-feeding inhibition. These effects are in addition to significant toxicity and reduced mosquito fecundity that affect mosquito densities and, therefore, provide community protection against diseases for both users and non-users. Airborne insecticides and freshly applied DDT had similar effects on deterrence, irritancy and feeding inhibition. Therefore, it is suggested that airborne pyrethroids, if delivered in suitable

  13. 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.

  14. 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.

  15. 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.

  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. Field validation of anaerobic degradation pathways for dichlorodiphenyltrichloroethane (DDT) and 13 metabolites in marine sediment cores from China.

    PubMed

    Yu, Huan-Yun; Bao, Lian-Jun; Liang, Yan; Zeng, Eddy Y

    2011-06-15

    Although the production and use of dichlorodiphenyltrichloroethane (DDT), a legacy component of persistent organic pollutants, have been highly restricted worldwide, the environmental fate of DDT has remained a great concern as it is not only ubiquitous and bioaccumulative but can also be degraded to a series of metabolites that may be more hazardous ecologically. The present study, taking advantage of the abundant levels of DDT and its metabolites in a subtropical coastal region of China, investigated into the degradation pathways of DDT in natural coastal sediment. Sediment profiles indicated that degradation of 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDT) to 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDD) mainly occurred in sediment of the top 20 cm layer. 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDE), aerobically transformed from p,p'-DDT prior to sedimentation, was likely to degrade to 1-chloro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDMU) which was further converted to 2,2-bis(p-chlorophenyl)ethylene (p,p'-DDNU). In addition, p,p'-DDNU could be transformed to 2,2-bis(p-chlorophenyl)ethane (p,p'-DDNS) and other high-order metabolites. On the other hand, the conversions of p,p'-DDD to p,p'-DDMU and 1-chloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDMS) to p,p'-DDNU were deemed slow in anaerobic sediment. Therefore, the present study confirmed all the degradation pathways involving reductive dechlorination and p,p'-DDE being a more important precursor for p,p'-DDMU than p,p'-DDD in anaerobic sediment, as proposed previously. On the other hand, the present study suggested that p,p'-DDMU instead of p,p'-DDMS was more likely the precursor for formation of high-order metabolites. Based on the current assessments, use of (DDD+DDE)/DDTs to indicate whether there is fresh DDT input may lead to large uncertainties if the concentrations of high-order metabolites are not negligible. Similarly, ecological risk assessment associated with DDT

  18. 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.

  19. Titan aerosols - Optical properties and vertical distribution

    NASA Technical Reports Server (NTRS)

    Rages, K.; Pollack, J. B.

    1980-01-01

    An analysis of Titan's solar phase variation as a function of wavelength together with the continuum geometric albedo makes it possible to set limits on the real part of the refractive index and on the average particle size of the aerosol component of Titan's atmosphere of between about 1.5 and 2.0 and between 0.20 microns and about 0.35 microns, respectively. If the real part of the refractive index is known the average particle size can be determined to within a few percent, and varies inversely with the real part of the refractive index. Using this information in a two-layer model of a methane-aerosol atmosphere and comparing the result with Titan's visible and near-infrared methane spectrum leads to the conclusion that the top layer of Titan's atmosphere contains 0.01 km atm of methane and 2.5 extinction optical depths of aerosol, while the data are consistent with a bottom layer containing 2.2 km atm of methane and about 7.5 aerosol optical depths for a real part of the refractive index equal to 1.7 and an average particle size of 0.25 microns.

  20. 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

  1. 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)

  2. 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…

  3. 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.

  4. 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... disability retirement. An election filed on or after August 13, 1968 is not effective if the member dies within 30 days following retirement from a disability of 100 per centum (under the standard schedule of...

  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. 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…

  7. Assessment of 2001 NLCD percent tree and impervious cover estimates

    Treesearch

    Eric Greenfield; David J. Nowak; Jeffrey T. Walton

    2009-01-01

    The 2001 National Land Cover Database (NLCD) tree and impervious cover maps provide an opportunity to extract basic land-cover information helpful for natural resource assessments. To determine the potential utility and limitations of the 2001 NLCD data, this exploratory study compared 2001 NLCD-derived values of overall percent tree and impervious cover within...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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…

  13. 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)

  14. Modeling percent tree canopy cover: a pilot study

    Treesearch

    John W. Coulston; Gretchen G. Moisen; Barry T. Wilson; Mark V. Finco; Warren B. Cohen; C. Kenneth Brewer

    2012-01-01

    Tree canopy cover is a fundamental component of the landscape, and the amount of cover influences fire behavior, air pollution mitigation, and carbon storage. As such, efforts to empirically model percent tree canopy cover across the United States are a critical area of research. The 2001 national-scale canopy cover modeling and mapping effort was completed in 2006,...

  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. Electronic ampere-hour integrator is accurate to one percent

    NASA Technical Reports Server (NTRS)

    Paulkovich, J.

    1965-01-01

    Electronic ampere-hour integrator is based on current-to-frequency conversion. It operates on low power and is accurate to one percent. This device can measure the ampere-hour capacity of batteries and can be adapted for other functions.

  17. 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.

  18. 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…

  19. 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.

  20. HCH and DDT Residues in Bivalves Anodonta woodiana from the Taihu Lake, China.

    PubMed

    Bian, Xuesen; Liu, Hongbo; Gan, Juli; Li, Rong; Yang, Jian

    2009-01-01

    The present article attempts to use freshwater bivalves Anodonta woodiana for monitoring the pollution of hexachlorocyclohexane isomers (alpha-, beta-, gamma-, delta-HCH), dichlorodiphenyltrichloroethanes (o, p', p, p'-DDT) and metabolites (p, p'-DDE, p, p'-DDD) in the Taihu Lake, China. A total of 36 bivalves were sampled from 4 sites of Huzhou city, Dapu of Yixing city, Xueyan of Changzhou city, and Wulihu of Wuxi city around the lake in August-October 2004. The organochlorines were detected in all bivalves, and the mean concentration of SigmaDDTs (7.07 ng/g wet weight) was significantly higher than that of SigmaHCHs (2.37 ng/g wet weight). Overall, SigmaHCHs are at the highest concentrations in the bivalves from the Dapu and Huzhou site, whereas SigmaDDTs are at highest concentrations in the bivalves from the Wulihu site. Compositions of SigmaHCHs were predominated by alpha- and gamma-HCH isomers in the bivalves from all four study sites. Among these sampling sites, p, p'-DDT exhibited the highest percentage in the bivalves from Huzhou site. Furthermore, significant regional variations in compositions of both SigmaDDTs and SigmaHCHs had been identified. The residue levels of SigmaDDTs and SigmaHCHs in the bivalves of the present study were much lower than the corresponding residue limits for aquatic products of Ministry of Agriculture of China, FDA, and FAO/WHO. These findings suggest that Anodonta woodiana could serve as a unique bioindicator to monitor the HCH and DDT pollutions in the freshwater environment.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Toxicity, dioxin-like activities, and endocrine effects of DDT metabolites--DDA, DDMU, DDMS, and DDCN.

    PubMed

    Wetterauer, Bernhard; Ricking, Mathias; Otte, Jens C; Hallare, Arnold V; Rastall, Andrew; Erdinger, Lothar; Schwarzbauer, Jan; Braunbeck, Thomas; Hollert, Henner

    2012-02-01

    2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) metabolites, other than those routinely measured [i.e., 2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE) and 2,2-bis(chlorophenyl)-1,1-dichloroethane (DDD)], have recently been detected in elevated concentrations not only in the surface water of Teltow Canal, Berlin, but also in sediment samples from Elbe tributaries (e.g., Mulde and Havel/Spree). This was paralleled by recent reports that multiple other metabolites could emerge from the degradation of parent DDT by naturally occurring organisms or by interaction with some heavy metals. Nevertheless, only very few data on the biological activities of these metabolites are available to date. The objective of this communication is to evaluate, for the first time, the cytotoxicity, dioxin-like activity, and estrogenicity of the least-studied DDT metabolites. Four DDT metabolites, p,p'-2,2-bis(chlorophenyl)-1-chloroethylene (DDMU), p,p'-2,2-bis(chlorophenyl)-1-chloroethane (DDMS), p,p'-2,2-bis(4-ch1oropheny1)acetonitrile (DDCN), and p,p'-2,2-bis(chlorophenyl)acetic acid (DDA), were selected based on their presence in environmental samples in Germany such as in sediments from the Mulde River and Teltow Canal. O,p'-DDT was used as reference in all assays. Cytotoxicity was measured by neutral red retention with the permanent cell line RTG-2 of rainbow trout (Oncorhynchus mykiss). Dioxin-like activity was determined using the 7-ethoxyresorufin-O-deetylase assay. The estrogenic potential was tested in a dot blot/RNAse protection-assay with primary hepatocytes from male rainbow trout (O. mykiss) and in a yeast estrogen screen (YES) assay. All DDT metabolites tested revealed a clear dose-response relationship for cytotoxicity in RTG-2 cells, but no dioxin-like activities with RTL-W1 cells. The dot blot/RNAse protection-assay demonstrated that the highest non-toxic concentrations of these DDT metabolites (50 μM) had vitellogenin-induction potentials comparable to the positive

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Influence of Glutathione S-Transferase Polymorphisms on Cognitive Functioning Effects Induced by p,p′-DDT among Preschoolers

    PubMed Central

    Morales, Eva; Sunyer, Jordi; Castro-Giner, Francesc; Estivill, Xavier; Julvez, Jordi; Ribas-Fitó, Nuria; Torrent, Maties; Grimalt, Joan O.; de Cid, Rafael

    2008-01-01

    Background Early-life exposure to p,p′-DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] is associated with a decrease in cognitive skills among preschoolers at 4 years of age. We hypothesized that genetic variability in glutathione S-transferase (GST) genes (GSTP1, GSTM1, and GSTT1) could influence the effects of prenatal exposure to p,p′-DDT. Methods We used data from 326 children assessed in a prospective population-based birth cohort at the age of 4 years. In that study, the McCarthy Scales of Children’s Abilities were administrated by psychologists, organochlorine compounds were measured in cord serum, and genotyping was conducted for the coding variant Ile105Val from GSTP1 and for null alleles from GSTM1 and GSTT1. We used linear regression models to measure the association between organochlorines and neurodevelopmental scores by GST polymorphisms. Results p,p′-DDT cord serum concentration was inversely associated with general cognitive, memory, quantitative, and verbal skills, as well as executive function and working memory, in children who had any GSTP1 Val-105 allele. GSTP1 polymorphisms and prenatal p,p′-DDT exposure showed a statistically significant interaction for general cognitive skills (p = 0.05), quantitative skills (p = 0.02), executive function (p = 0.01), and working memory (p = 0.02). There were no significant associations between p,p′-DDT and cognitive functioning at 4 years of age according to GSTM1 and GSTT1 polymorphisms. Conclusions Results indicate that children with GSTP1 Val-105 allele were at higher risk of the adverse cognitive functioning effects of prenatal p,p′-DDT exposure. PMID:19057715

  13. 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

  14. 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

  15. 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.

  16. Atmosphere aerosol satellite project Aerosol-UA

    NASA Astrophysics Data System (ADS)

    Milinevsky, Gennadi; Yatskiv, Yaroslav; Syniavskyi, Ivan; Bovchaliuk, Andrii; Degtyaryov, Oleksandr; Sosonkin, Mikhail; Mishchenko, Michael; Danylevsky, Vassyl; Ivanov, Yury; Oberemok, Yevgeny; Masley, Volodymyr; Rosenbush, Vera; Moskalev, Sergii

    2017-04-01

    The experiment Aerosol-UA is Ukrainian space mission aimed to the terrestrial atmospheric aerosol spatial distribution and microphysics investigations. The experiment concept is based on idea of Glory/APS mission of precise orbital measurements of polarization and intensity of the sunlight scattered by the atmosphere, aerosol and the surface the multichannel Scanning Polarimeter (ScanPol) with narrow field-of-view. ScanPol measurements will be accompanied by the wide-angle MultiSpectral Imager-Polarimeter (MSIP). The ScanPol is designed to measure Stokes parameters I, Q, U within the spectral range from the UV to the SWIR in a wide range of phase angles along satellite ground path. Expected ScanPol polarimetric accuracy is 0.15%. A high accuracy measurement of the degree of linear polarization is provided by on-board calibration of the ScanPol polarimeter. On-board calibration is performed for each scan of the mirror scanning system. A set of calibrators is viewed during the part of the scan range when the ScanPol polarimeter looks in the direction opposite to the Earth's surface. These reference assemblies provide calibration of the zero of the polarimetric scale (unpolarized reference assembly) and the scale factor for the polarimetric scale (polarized reference assembly). The zero of the radiometric scale is provided by the dark reference assembly.The spectral channels of the ScanPol are used to estimate the tropospheric aerosol absorption, the aerosol over the ocean and the land surface, the signals from cirrus clouds, stratospheric aerosols caused by major volcanic eruptions, and the contribution of the Earth's surface. The imager-polarimeter MSIP will collect 60°x60° field-of-view images on the state of the atmosphere and surface in the area, where the ScanPol polarimeter will measure, to retrieve aerosol optical depth and polarization properties of aerosol by registration of three Stokes parameters simultaneously in three spectral channels. The two more

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

    USDA-ARS?s Scientific Manuscript database

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

  19. 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...

  20. 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.

  1. Percent Errors in the Estimation of Demand for Secondary Items.

    DTIC Science & Technology

    1985-11-01

    percent errors, and the program change factor (PCF) to predict item demana during the procurement *’ leadtime (PROLT) ior the item. The PCF accounts for...type of demand it was. It may"-- have been demanded over two years ago or it may nave been a non-recurring demana . Since CC b only retains two years of...observed distributions could be compared with negative binomial distributions. For each item the computed ratio of actual demana to expected demand was

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

    PubMed

    Kucher, S; Schwarzbauer, J

    2017-10-01

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

  3. 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.

  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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Promoting and anticarcinogenic effects of phenobarbital and DDT in the rat hepatocarcinogenesis.

    PubMed

    Kitagawa, T

    1986-01-01

    The possible discrepancy between the dose level required for promoting action (when given after the initiation process, and that needed to exert an anticarcinogenic effect when given simultaneously with a carcinogen) of hepatic promoters were investigated in an attempt to obtain a "practical" threshold dose of promoters. Phenobarbital (PB) and dichlorophenyltrichlorethane (DDT) were used as promoters and 3'-methyl-4-(dimethylamino)-azobenzene (3'-Me-DAB) was used as the carcinogen. Male weanling rats were treated with either 600 ppm 3'-Me-DAB for 3 weeks followed by a diet containing a promoter at various dose levels (5-500 ppm), or the animals were treated with a low dose (100 ppm) of 3'-Me-DAB plus a promoter at various dose levels (20-500 ppm). The effects of promoters were measured by scoring size and number of enzyme-altered islands (EAIs) at 12 and 24 weeks of age. The promoting effect of PB and DDT was demonstrated in dose-dependent fashion, in the dose range of 10-500 ppm and 20-500 ppm, respectively. On the other hand, promoters given simultaneously with a low dose of carcinogen enhanced carcinogenesis at all the dose levels tested, in contrast with the inhibitory effect on carcinogenesis when given together with relatively high doses of carcinogens.

  10. 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.

  11. Aerosol: a novel vehicle in pharmacotherapy in neonates.

    PubMed

    MacLoughlin, Ronan; Telfer, Colin; Clark, Andy; Fink, James

    2017-09-18

    Local delivery of drugs to the lungs of newborn infant represents an unmet need as no drugs have been approved. Potential benefits could be large. Development of aerosol for delivery of drugs to infants and newborn offers huge potential for better therapy. Newborn infants present unique challenges with regard to aerosol therapy. Efficient deposition of aerosolized medications on the neonate airway surface is hampered by anatomical features such as small airway geometries and physiological features such as exquisitely small tidal volumes, rapid breathing and unfavorable inhalation:exhalation ratios. The selection of aerosol generators capable of delivering any more than a few percent of the nominal drug dose to the airways remains extremely limited with nebulizers and pressurized metered dose inhalers being predominantly used. Further hampering the development of bespoke high performance aerosol therapy for neonates is the as yet unknown ideal droplet size. Droplet size is a critical determinant of the amount of aerosol that escapes the patient circuit, becoming available to the patient, and subsequently the location of deposition within the lung. It is assumed that smaller is better at traversing the tortuous path from aerosol generator to airway surface. To date, patient interface has been shown to have little effect with respect to delivered dose, but some may provide advantage with respect to ease of use and patient acceptance. The present review iteratively describes the difficulties in achieving optimized aerosol drug delivery in neonates. We suggest possible technical solutions aimed at improving delivery and developing a platform for increased reliability and reproducibility of dosing such that new and existing medications may exploit the potential advantages of aerosol therapy in the neonate population. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. 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.

  13. 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.

  14. 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

  15. Aerosol mass spectrometer measurements of organic aerosol

    NASA Astrophysics Data System (ADS)

    Worsnop, D.; Canagaratna, M.; Jayne, J.; Boudries, H.; Onasch, T.; Jimenez, J.; Slowik, J.; Coe, H.

    2003-12-01

    Organic species are known to be ubiquitous and comprise a significant component of ambient aerosols. Identifying the sources, chemical compositions, and loadings of particulate organics remains a difficult, yet important problem as organic components may affect the formation, hygroscopicity, growth, reactivity, and radiative effects of ambient particles. Unraveling this complexity inherently must rely on chemical information (such as off-line filter analyses and collector/concentrator techniques), but also on real-time instruments that are capable of combining particle physical measurements (size, density) with chemical speciation information. The Aerodyne Aerosol Mass Spectrometer (AMS) has been deployed on many different measurement platforms around the world and is generating a rich data set capable of providing insight into the complexity of particulate organics. Highlights of the aerosol measurements will be presented. Although the AMS cannot uniquely classify individual organic compounds, it has been become evident that classes of organic compounds can be identified. These include the identification of a size-resolved chemical signature for fresh diesel and gasoline particulate emissions. Electron impact ionization mass spectral signatures of oxidized organic components and the temporal and spatial relationships between the signatures for fresh organic emissions and aged/oxidized organic components. Laboratory studies on soot and other organic aerosols will also be presented within this context.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Observations of aerosol light scattering, absorption, and particle morphology changes as a function of relative humidity

    NASA Astrophysics Data System (ADS)

    Arnott, W. P.; Lewis, K.; Paredes-Miranda, G.; Winter, S.; Day, D.; Chakrabarty, R.; Moosmuller, H.; Jimenez, J. L.; Ulbrich, I.; Huffman, A.; Onasch, T.; Trimborn, A.; Kreidenweis, S.; Carrico, C.; Wold, C.; Lincoln, E.; Freeborn, P.; Hao, W.; McMeeking, G.

    2006-12-01

    A very interesting case of smoke aerosol with very low single scattering albedo, yet very large hygroscopic growth for scattering is presented. Several samples of chamise (Adenostoma fasciculatum), a common and often dominant species in California chaparral, were recently burned at the USFS Fire Science Laboratory in Missoula Montana, and aerosol optics and chemistry were observed, along with humidity-dependent light scattering, absorption, and particle morphology. Photoacoustic measurements of light absorption by two instruments at 870 nm, one on the dry channel, one on the humidified channel, showed strong reduction of aerosol light absorption with RH above 65 percent, and yet a strong increase in light scattering was observed both at 870 nm and 550 nm with nephelometers. Multispectral measurements of aerosol light absorption indicated an Angstrom coefficient for absorption near unity for the aerosols from chamise combustion. It is argued that the hygroscopic growth of scattering is due to uptake of water by the sulfur bearing aerosol. Furthermore, the reduction of aerosol light absorption is argued to be due to the collapse of chain aggregate aerosol as the RH increases wherein the interior of aerosol does no longer contribute to absorption. Implications for biomass burning in general are that humidity processing of aerosols from this source and others like it tends to substantially increase its single scattering albedo, probably in a non-reversible manner. The chemical pathway to hygroscopicity will be addressed.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. In Situ Aerosol Detector

    NASA Technical Reports Server (NTRS)

    Vakhtin, Andrei; Krasnoperov, Lev

    2011-01-01

    An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes. This technology is based on detection of light scattered by aerosol particles where an optical layout is used to enhance the performance of the laboratory prototype instrument, which allows detection of smaller aerosol particles and improves the accuracy of aerosol particle size measurement. It has been determined that using focused illumination geometry without any apertures is advantageous over using the originally proposed collimated beam/slit geometry (that is supposed to produce uniform illumination over the beam cross-section). The illumination source is used more efficiently, which allows detection of smaller aerosol particles. Second, the obtained integral scattered light intensity measured for the particle can be corrected for the beam intensity profile inhomogeneity based on the measured beam intensity profile and measured particle location. The particle location (coordinates) in the illuminated sample volume is determined based on the information contained in the image frame. The procedure considerably improves the accuracy of determination of the aerosol particle size.

  17. 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.

  18. 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.

  19. 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.

  20. 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.