Insecticides dieldrin

Much controversy has arisen regarding the ability of mixtures of weakly estrogenic compounds to act synergistically, notably the synergistic potential of mixtures of PCBs or of the insecticides dieldrin and toxaphene. " Recent studies suggest that the action of mixtures is at least additive. "... 

Human mutation data reported. An insecticide. Dieldrin is considerably more toxic than DDT by ingestion and skin contact. Dieldrin or its derivatives may accumulate in the body from chronic low dosages. When heated to decomposition it emits toxic fumes of CL. See also ALDRIN. 

Chlorinated ring systems, such as cyclodiene insecticides dieldrin and aldrin react to CO2 and HCl during irradiation with UVdight (X > 290 nm). By using... 

CABA receptors - antagonists Active plant alkaloids, mainly convulsants, include bicuculline and picrotoxin (active principle is picrotoxinin). Important synthetic agents include the synthetic chlorinated hydrocarbon (cyclodiene) insecticide dieldrin, which is similar to many other insecticides, including aldrin, heptachlor and chlordane. In mammals they cause central stimulation and convulsions. 

Water as Reaction Medium. Being transparent to the near-ultraviolet spectrum of sunlight, pure water can serve as an inert medium in which pesticide transformations take place. For example, Henderson and Crosby (28) have shown that suspensions of the chlorinated hydrocarbon insecticide dieldrin (I), although essentially insoluble in water, undergo a photocondensation reaction to give photodieldrin (II) (Equation 2). 

The insecticide dieldrin contains carbon, hydrogen, oxygen, and chlorine. When burned in an excess of oxygen, a 1.510 g sample yields 2.094 g CO2 and 0.286 g H2O. The compound has a molecular mass of 381 u and has half as many chlorine atoms as carbon atoms. What is the molecular formula of dieldrin ... 

Dieldrin [60-57-1] or l,2,3,4,10,10-hexachloro-l,4,4t ,5,8,8t -hexahydro-6,7-epoxy-l,4- <7o, Aro-5,8-dimethanonaphthalene (34) (mp 176°C, vp 0.4 mPa at 20°C) is formed from aldrin by epoxidation with peracetic or perben2oic acids. It is soluble in water to 27 / g/L. Aldrin and dieldrin have had extensive use as soil insecticides and for seed treatments. Dieldrin, which is very persistent, has had wide use to control migratory locusts, as a residual spray to control the Anopheles vectors of malaria, and to control tsetse flies. Because of environmental persistence and propensity for bio accumulation, registrations in the United States were canceled in 1974. 

Endrin [72-20-8] is l,2,3,4,10,10-hexachloro-l,4,4t ,5,8,8t -hexahydro-6,7-epoxy-l,4- <7o, <7o-5,8-dimethanonaphthalene (35) (mp 245 dec, vp 0.022 mPa at 25°C) and is soluble in water to 23 / g/L. It is produced by a Diels-Alder reaction of hexachloronorbomadiene with cyclopentadiene, followed by epoxidation. This reaction produces the endo,endo isomer of dieldrin, which is less stable and more toxic with rat LD q values of 17.8 and 7.5 (oral) and 15 (dermal) mg/kg. It is used as a cotton insecticide but because of its high toxicity to fish it has been restricted. 

The concentration of the residues of isomers of HCH, DDT, Eindane, Aldrine, Dieldrine, Heptachlorine and Heptachloroepoxide and Endosulphanes in investigated samples ai e within norms of currently applied Standards while concentration of organochlorine insecticides are greatly below the MAC in range of 0.00-23.53T0 mg/dm . 

The reagent sequence is specific for endosulfan and phosphamidon. Other insecticides, e.g. organochlorine insecticides, such as endrin, aldrin, dieldrin, DDT and BHC, organophosphorus insecticides, such as malathion, parathion, dimethoate, quinalphos, phorate and fenitrothion, or carbamate insecticides, such as baygon, car-baryl and carbofuran do not react. Neither is there interference from amino acids, peptides or proteins which might be extracted from the biological material together with the pesticides. 

Halogen-containing substances e. g. chlorine-containing insecticides [1, 7] such as aldrin, dieldrin, DDT, perthane,... 

The cyclodiene insecticides aldrin, dieldrin, endrin, heptachlor, endosulfan, and others were introduced in the early 1950s. They were used to control a variety of pests, parasites, and, in developing countries, certain vectors of disease such as the tsetse fly. However, some of them (e.g., dieldrin) combined high toxicity to vertebrates with marked persistence and were soon found to have serious side effects in the field, notably in Western European countries where they were extensively used. During the 1960s, severe restrictions were placed on cyclodienes so that few uses remained by the 1980s. 

Apart from the oxidations just mentioned, cyclodienes are rather stable chemically. It should, however, be noted that dieldrin can undergo photochemical rearrangement under the influence of sunlight to the persistent and toxic molecule photo dieldrin, which occurs as a residue following the application of this insecticide in the field. 

As mentioned earlier (Figure 5.5), aldrin and heptachlor are rapidly metabolized to their respective epoxides (i.e., dieldrin and heptachlor epoxide) by most vertebrate species. These two stable toxic compounds are the most important residues of the three insecticides found in terrestrial or aquatic food chains. In soils and sediments, aldrin and heptachlor are epoxidized relatively slowly and, in contrast to the situation in biota, may reach significant levels (note, however, the difference between aldrin and dieldrin half-lives in soil shown in Table 5.8). The important point is that, after entering the food chain, they are quickly converted to their epoxides, which become the dominant residues. 

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