DDT (2,2 bis (p-chlorophenyl) 1,1,1,-trichloroethane) was first synthesized in 1874 by Seidler in Switzerland, however, its effectiveness as an insecticide was not known until about 1942. The active principle was first known as G.H.B. (Gesarol-Neccid Base): but in 1943 DDT was suggested as an abbreviation for Dichlore Diphenyl Trichloroethane (Kaaegie, 1946). In fact DDT, as a powerful insecticide is one of the developments made during World War II. The importance of DDT in the control of the common insect enemies of mankind, such as mosquitoes, flies, moths, and many agricultural insect pests is realized more day by day. Many studies have been conducted to determine the uses, toxisity and residual effectiveness of DDT. However, the nutritive value of DDT dusted feedstuffs has not been investigated heretofore. During recent years, in the west, alfalfa seed and hay production has declined as a result of injuries caused by certain species of insects such as lygus bage and alfalfa weevil. DDT has been used successfully to control these insect pests. Because of this fact there is a need for more information on the chemical composition, digestibility and metabolisable energy content of DDT treated alfalfa hay.

This thesis describes a study undertaken between 1992 and 2001 to explore the possible health impacts of human exposure to pesticides. The study followed the health outcomes of approximately 4000 outdoor workers over a period of up to sixty-one years. These workers comprised two subcohorts of approximately even size, one composed of agricultural workers with high insecticide exposures, and the other made up of outdoor staff from local councils in the same area with little or no occupational exposure to insecticides. Mortality and morbidity were compared between the two groups, and with the general Australian community. The study identifies significantly increased mortality among both exposed and control subjects when compared to the Australian population. The major cause of this increase was mortality from smoking related diseases. The study also identifies significant increases in mortality among exposed subjects for a number of conditions that do not appear to be the result of smoking patterns, both when compared to the control group and the Australian population. These include pancreatic cancer in some DDT exposed subjects and asthma, diabetes, and leukaemia in subjects working with more modern chemicals. There was also an increase in self reported chronic illness and asthma, and lower neuropsychological functioning scores among surviving exposed subjects when compared to controls. Diabetes was also reported more commonly by subjects reporting occupational use of herbicides.

DDT, an extremely widely used organochlorine pesticide, was banned in most developed countries more than 30 years ago. However, DDT residues, including 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), still persist in the environment and have been identified as priority pollutants due to their toxicity and their ability to bioaccumulate and biomagnify in the food chain. In particular, DDE was long believed to be &quotenon-biodegradable&quote, however some microorganisms have now been isolated that are able to metabolise DDE in pure culture. Terrabacter sp. strain DDE-1 was enriched from a DDT-contaminated agricultural soil from the Canterbury plains and is able to metabolise DDE to 4-chlorobenzoic acid when induced with biphenyl. The primary objective of this study was to identify the gene(s) responsible for Terrabacter sp. strain DDE-1�s ability to metabolise DDE and, in particular, to investigate the hypothesis that DDE-1 degrades DDE cometabolically via a biphenyl degradation pathway. Catabolism of biphenyl by strain DDE-1 was demonstrated, and a biphenyl degradation (bph) gene cluster containing bphDA1A2A3A4BCST genes was identified. The bphDA1A2A3A4BC genes are predicted to encode a biphenyl degradation upper pathway for the degradation of biphenyl to benzoate and cis-2-hydroxypenta-2,4-dienoate and the bphST genes are predicted to encode a two-component signal transduction system involved in regulation of biphenyl catabolism. The bph gene cluster was found to be located on a linear plasmid, designated pBPH1. A plasmid-cured strain (MJ-2) was unable to catabolise both biphenyl and DDE, supporting the hypothesis that strain DDE-1 degrades DDE cometabolically via the biphenyl degradation pathway. Furthermore, preliminary evidence from DDE overlayer agar plate assays suggested that Pseudomonas aeruginosa carrying the strain DDE-1 bphA1A2A3A4BC genes is able to catabolise DDE when grown in the presence of biphenyl. A second objective of this study was to characterise pBPH1. The complete 84,054-bp sequence of the plasmid was determined. Annotation of the DNA sequence data revealed seventy-six ORFs predicted to encode proteins, four pseudogenes, and ten gene fragments. Putative functions were assigned to forty-two of the ORF and pseudogenes. Besides biphenyl catabolism, the major functional classes of the predicted proteins were transposition, regulation, heavy metal transport/resistance, and plasmid maintenance and replication. It was shown that pBPH1 has the terminal structural features of an actinomycete invertron, including terminal proteins and terminal inverted repeats (TIRs). This is the first report detailing the nucleotide sequence and characterisation of a (linear) plasmid from the genus Terrabacter.

Various premixed flame phenomena are studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics is essential for all premixed combustion problems where multidimensional effects cannot be disregarded.The present thesis consists of six parts. The first part deals with the fundamental problem of curved stationary flames propagation in free-slip tubes of different widths. It is shown that only simple "single-hump" slanted stationary flames are possible in tubes wider than some stability limit. The flame dynamics is shown to be governed by a large-scale stability mechanism resulting in a highly slanted flame front.The second part of the thesis is dedicated to studies of acceleration and fractal structure of outward freely propagating flames. It is shown that the development of Landau-Darrieus instability results in the formation of fractal-like flame front structure. Two-dimensional simulation of radially expanding flames displays a radial growth with 1.25 power law temporal behavior. It is shown that the fractal excess for 2D geometry obtained in thenumerical simulation is in good agreement with theoretical predictions.In third part the flame acceleration in tubes with non-slip at the walls is studied in the extremely wide range of flame front velocity. Flame accelerates from small initial velocity to supersonic speed in the laboratory reference frame. Flame acceleration undergoes three stages: 1) initial exponential acceleration in the quasi-isobaric regime, 2) almost linear increase of the flame speed to supersonic values, 3) saturation to a stationary high-speed deflagration velocity, which is correlated with the Chapman-Jouguet deflagration speed. The saturation velocity is in line with previous experimental results.In fourth part the role of viscous stress in heating of the fuel mixture in deflagration-to-detonation transition in tubes is studied both analytically and numerically. The developed analytical theory determines temperature distribution ahead of an accelerating flame. The heating effects of viscous stress and the compression wave become comparable at sufficiently high values of the Mach number. Viscous stress makes heating and explosion of the fuel mixture preferential at the walls.In fifth part we reveal the physical mechanism of ultra-fast flame acceleration in obstructed channels used in modern experiments on detonation triggering. It is demonstrated that delayed burning between the obstacles creates a powerful jet-flow, driving the acceleration. The flame front accelerates exponentially; theanalytical formula for the growth rate is obtained. The theory is validated by extensive direct numerical simulations and comparison to previous experiments.The last part of the thesis concerns the transition from deflagration to detonation. It is found that in sufficiently wide free-slip channels and for sufficiently fast flames Landau-Darrieus instability may invoke nucleation of hot spots within the wrinkled flame folds, triggering an abrupt transition from deflagrative to detonative combustion. Results on DDT in channels with non-slip at the walls are also presented. / QC 20100915

In the 1950s the otter started to decline in numbers and distribution in Sweden and other parts of Europe. In 1972 a game law came into force, listing otter as a species that if found dead should be reported and sent to the authorities. The numbers of dead otters reported from different areas indicate population status and distribution. Between 1970 and 2012, 832 otters were sent to the authorities, the majority (66%) during the last ten years. Most were killed in traffic accidents or drowned in fishing gear. However, the main cause of the decline is believed to be environmental contaminants. Experimental data show that a PCB residue level in muscle tissue of 12 mg/kg lw causes reproductive impairment in mink (Neovison vison), suggesting reproductive problems also in the highly PCB-exposed otters in Sweden. Since the bans of PCB and DDT in the mid-1970s, concentrations of these substances in otter and fish have decreased and the otter population is increasing. Few pathological changes in otters have been found that can be related to high contaminant concentrations. However, we found a correlation between elevated PCB concentrations and alterations in bone mineral density. No relationship was seen between DDE and bone parameters. The decline of the otter coincided with the decline of grey seals (Halichoerus grypus) and white-tailed sea eagles (Haliaeetus albicilla) in Sweden, all showing decreased reproductive outcome. Reproductive success started to increase for all of them around 1990 and during the same period concentrations of PCB and DDE have decreased in these species. The body condition among female otters has increased over the study period, indicating an improved health status. However, we found a high prevalence (71%) of cysts on the spermatic duct in otters collected between 1999 and 2012, possibly caused by endocrine disrupting chemicals. Although the organochlorine concentrations in otters have decreased, otters still face many problems. New threats to the otter population in Scandinavia are the perfluorinated chemicals, including PFOS and PFOA. Results in this thesis show an increasing trend for these compounds in otters up to 2011, including some extremely high concentrations of PFOS in otters from southern Sweden.

Organochlorine pesticides (OCPs) were used in agriculture throughout the world for a long time because they are very effective for pest control, but OCPs such as DDT and its metabolites can threaten human health and ecological systems. Although DDT has been banned for use in Canada since 1972, it still persists in Canadian farmland at detectable levels due to its chemical stability. The soils contaminated with DDT require economical remediation strategies because of the low land value and rural location. Although soil washing has been proposed as a possible economical technique to remove DDT, it has very low water solubility and so it is necessary to consider using surfactants to improve the soil-washing process. Building on previous research, we hypothesize that combinations of surfactants can be used to improve the performance of this remediation method. The surfactants Tween 80, Brij 35, and sodium dodecylbenzene sulfonate (SDBS) were selected based on environmental and reported performance criteria. Combinations of surfactants were tested in both batch and leaching column experiments. Experiments indicated that removal efficiency and flowrate in leaching columns were optimized when a mixture of 2% Brij 35 and 0.1% SDBS was employed. The presence of Tween 80 was found to be less effective, possibly due to its higher biodegradability in the soil. Since the measurement of surfactant concentration in the wash solution is important, several methods were tested before finally selecting a simple COD analysis as a surrogate parameter. Using the COD analysis, partitioning experiments were performed to measure the adsorption of surfactant on the soil. For economic reasons, it would be desirable to reuse the surfactant in a washing process. For this purpose, we employed activated carbon to selectively remove the more hydrophobic DDT from the surfactant solutions. Preliminary results have shown that carbon adsorption can remove some DDT, but additional work is required to understand and optimize the process.

Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 48-50). Also available via World Wide Web.

Kristina Taurozaitė Buvusių pesticidų sandėlių teritorijų užterštumo pesticidų likučiais vertinimas Santrauka Didžiausia tarša pesticidais stebima dirvožemyje ir požeminiuose gruntiniuose vandenyse, pesticidų kapinynų aplinkvietėse ir buvusių pesticidų sandėlių gaisravietėse, o pagrindiniai taršos pesticidais židiniai yra pesticidų sandelio gaisrai ir pesticidų kapinynai. Pesticidų sukeltas neigiamas poveikis aplinkai yra negrįžtamas, o tai pasireiškia įvairiais išsigimimais, nukrypimais ir ligomis žmonėms, gyvūnams bei augalijai. Iš atliktų dirvožemio bei grunto tyrimų Marijampolio ir Tryškių pesticidų sandeliuose 0,0 – 0,3 m gylyje nustatyta, kad kai kurių pesticidų koncentracijos viršija HN 60:2004 nustatytas DLK vertes nuo 1 iki 1460 kartų Marijampolio pesticidų sandelyje, o Tryškių pesticidų sandelyje nuo 1,5 iki 3600 kartų. Tuo tarpu tų pačių pesticidų koncentracijos grunto bandiniuose iš 0,9 – 1,0 m gylio sumažėja ir DLK viršijamos tik nuo 1 iki 38 kartų Marijampolio pesticidų sandelyje ir iki 144 kartų Tryškių pesticidų sandelyje. Iš atlikus gruntinio vandens tyrimų buvo nustatyta, kad Tryškių pesticidų sandėlio teritorijoje požeminis (gruntinis) vanduo yra smarkiai užterštas pesticidais. Jo tarša atskirais pesticidais skirtingais normatyviniais aktais nustatytas DLK viršija iki 96 kartų Tryškių ir iki tūkstančių kartų Marijampolio pesticidų sandelių teritorijose. Todėl galima teigti, kad Marijampolio pesticidų sandelio teritorijoje gruntinis vanduo užterštas labiau... [toliau žr. visą tekstą] / Kristina Taurozaitė The estimation of existed pesticides dumps contamination with pesticides residues Summary The biggest pollution of the pesticides is fixed in soil and ground water areas of the pesticides dumps and sites after a fire of the pesticides warehouses. The main sources of the pollution of the pesticides are fire of the warehouses of the pesticides and pesticides dumps. The negative impact on environment of pesticides is irreversible, causing various degenerations, aberrations and diseases to animals and plants. It was estimated that in Marijampolio and Tryškių pesticides dumps, concentration of some pesticides exceeds HN 60:2004 stated MCL (maximum concentration levels) values from 1 to 1460 times in Marijampolio pesticide dump while in Tryškių pesticides dump from 1,5 to 3600 times. Whereas the same concentration in ground samples in 0,9 -1.0 depth declines and MCL exceed just from 1 to 38 times in Marijampolio pesticides dumps, and to 144 times in Tryškių pesticides dumps. In Tryškių and Marijampolio pesticides dumps soil and ground analyses were made. It was estimted that ground water in Tryškių pesticide dump area is polluted deeply by pesticides. Its pollution of separate pesticides by different normative act stated MCL exeeds to 96 times in Tryškių and to 1000 times in Marijampolio pesticides dumps areas. That is why ground water of Marijampolio pesticides dumps areas is poluted more than in Tryškių pesticides dumps area. Analytically analyzed pesticides... [to full text]

Organochlorine pesticides (OCPs) were used in agriculture throughout the world for a long time because they are very effective for pest control, but OCPs such as DDT and its metabolites can threaten human health and ecological systems. Although DDT has been banned for use in Canada since 1972, it still persists in Canadian farmland at detectable levels due to its chemical stability. The soils contaminated with DDT require economical remediation strategies because of the low land value and rural location. Although soil washing has been proposed as a possible economical technique to remove DDT, it has very low water solubility and so it is necessary to consider using surfactants to improve the soil-washing process. Building on previous research, we hypothesize that combinations of surfactants can be used to improve the performance of this remediation method. The surfactants Tween 80, Brij 35, and sodium dodecylbenzene sulfonate (SDBS) were selected based on environmental and reported performance criteria. Combinations of surfactants were tested in both batch and leaching column experiments. Experiments indicated that removal efficiency and flowrate in leaching columns were optimized when a mixture of 2% Brij 35 and 0.1% SDBS was employed. The presence of Tween 80 was found to be less effective, possibly due to its higher biodegradability in the soil. Since the measurement of surfactant concentration in the wash solution is important, several methods were tested before finally selecting a simple COD analysis as a surrogate parameter. Using the COD analysis, partitioning experiments were performed to measure the adsorption of surfactant on the soil. For economic reasons, it would be desirable to reuse the surfactant in a washing process. For this purpose, we employed activated carbon to selectively remove the more hydrophobic DDT from the surfactant solutions. Preliminary results have shown that carbon adsorption can remove some DDT, but additional work is required to understand and optimize the process.

The debate regarding the advantages and disadvantages of using DDT for IRS has divided the scientific community. The health benefits of reducing malaria spreading are weighed against the potential health and environmental consequences of the chemical, and opinions also differ regarding the cost-effectiveness of the use of DDT. Global recommendations regarding use of DDT for IRS have been issued by the WHO, and the receipt of these on the local level is determined by the intended beneficiaries’ perception of legitimacy of the organisation. The WHO recommendations on DDT as well as interviews conducted with residents of a South African village and representatives for two South African NGOs have been reviewed using qualitative content analysis. This method was used to highlight different perceptions of and views on DDT use, as well as for examining the potential effect that the interviewees’ perception of international institutions’ legitimacy has on their views on DDT. This study shows that the controversy regarding DDT is not as prominent on the local level as on the global level, and that the perceptions of IRS with DDT differ between the WHO, the NGOs and the residents of the village. Further, this study shows that assessing legitimacy is dependent on a definition of “the people” in question, and that the accountability of authoritative actors on different levels needs to be evaluated further.