Lindane insecticides

Other chemicals are agonists such as those that directly affect the y-butyric acid receptor (GABAa) receptor in neurons. Drugs such as barbiturates and benzodiazepines are agonists (activators) for this receptor and cause neuronal inhibition and sedation at therapeutic doses but coma and depression at higher doses. Conversely, antagonists (inhibitors) for this receptor such as the insecticides lindane and cyclodienes and picrotoxin inhibit neurons and may cause tremor and convulsions at toxic doses. 

The most fundamental properties of a chemical substance are those of the substance in pure form, in most cases as a solid or liquid. Molecular mass can be deduced readily from the chemical formula or structure, although a range of values may exist for commercial mixtures. In some cases, the substance may adopt different structural (e.g., cis-trans) or enantiomeric forms, usually with relatively small physical property differences but with potentially substantial differences in ability to induce toxicity or other biological responses. The hexachlorocyclohexane isomers and enantiomers are examples, the insecticide lindane or y HCH being the most active form. 

Practical use of pheromones started in 1978. That year we used 110.000 trap-trees sprayed with an insecticide (Lindane). The first year we used one dispenser with an initial loading of 70 mg cis-verbenol and 10 mg ipsdienol. A second dispenser was loaded with 100 mg methylbutenol. In 1979 we adjusted the loading and used only one dispenser containing all 3... 

The amounts volatilized in 10 days were extremely low in most cases. Dicamba was the only herbicide exhibiting significant volatilization and that only in the presence of high water evaporation. Apparently the insecticide carbaryl, has the potential to volatilize significantly from the soil with or without water evaporation, particularly when it is present near the soil surface. The reference insecticide, lindane, will appreciably volatilize when it is present near the soil surface, but its volatility decreases markedly when present within the entire 0 - 10 cm depth. Volatilization of the other insecticides will be essentially insignificant due either to their rapid degradation rate or low Kh-... 

Hexachlorocyclohexane, once confusingly called benzene hexachloride (BHC), consists of several stereoisomers with different orientations of H and Cl atoms. The gamma isomer is shown in Figure 16.5. It is an effective insecticide, constituting at least 99% of the commercial insecticide lindane. 

The addition of chlorine to benzene, believed to involve a free-radical mechanism, is normally impossible to stop at an intermediate stage. The first addition destroys the ring s aromaticity, and the next 2 moles of Cl2 add very rapidly. All eight possible stereoisomers are produced in various amounts. The most important isomer for commercial purposes is the insecticide lindane, which is used in a shampoo to kill head lice. 

Solid-Phase Microextraction (SPME). Coupled with GC/ MS, SPME was proposed for analysis of the insecticides lindane, para-thion, carbaryl, malathion, endosulfan, methoxychlor, and methida-thion, procymidone, vinclozoline, folpet, and captan (fungicides), and the herbicides terbuthylazine, trifluralin, and phosalone in wine (Vitali... 

Moody. R. P.. and Ritter, L. (1989). Dermal absorption of the insecticide lindane (la, 2a. 3b. 4a. 5a. 6b-hexachlorocyclo-hexane) in rats and rhesus monkeys Effect of anatomical. site, J. Toxicol. Environ. Health 28, 161-169. 

Like PCP, the insecticide lindane found a broad spectrum of application in wood preservation and for the treatment of pests affecting soil and forests. Because of the relatively high volatility and slow rate of decomposition of lindane in the environment, this substance, like PCP, also occurs ubiquitously. Table 9-2 gives toxicity data and levels of occurrence of lindane in the environment. 

Seaweeds contain hxmdreds of organohalogens (see Figure 4). Telfairine, like the synthetic insecticide lindane, is a powerful insecticide. These organohalogens are used by marine fife in chemical defense (natural pesticides). The smell of the ocean is fikely due to the myriad volatile... 

The addition of calcium and EDTA at these concentrations had no effect on the apparent toxicity of 1,4-dinitrobenzene, the herbicide 2,4-D, 2,4-dinitrotoluene, 4-chloro-benzo-ate, carbon tetrachloride, chloroform, cynazine, hexachlorophene, isonicotinic acid the insecticide Lindane, o-nitrophenol, p-toluidine, the antibiotic Streptomycin, tetrachloroethylene and trichlorophenol. 

The insecticide Lindan (y-hexachloro cyclohexane) is not adsorbed by TMA montmorillonite. However, illites modified with TMA ions adsorb certain amounts of Lindan [98]. The saturated hydrocarbon overloaded with... 

The concentration of the insecticide lindane in subsurface soil at an abandoned pesticide manufacturing plant is 88 ppm. Assuming continuous contact of contaminated soil with an unconsolidated aquifer, estimate the concentration of lindane in groundwater, assuming standard conditions. (Hint See Table 2.2 for the log value for lindane.)... 

Classify the carbon centers containing chlorine in the insecticide lindane. 

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