Dieldrin bioaccumulation

Jorgenson, J.L. (2001). Aldrin and Dieldrin A Review of Research on Their Production, Environmental Deposition and Fate, Bioaccumulation, Toxicology, and Epidemiology in the United States—A relatively recent, wide-ranging review of two of the most important cyclodienes. 

Turning now to indirect effects of neurotoxic pollutants, the status of predators and parasites can be affected by reductions in numbers of the species that they feed upon. Thus, the reduction in numbers of a prey species due to a behavioral effect can, if severe enough, cause a reduction in numbers of a predator. Also, as mentioned earlier, behavioral effects upon a prey species may lead to selective bioaccumulation of persistent neurotoxic pollutants such as DDT and dieldrin by predators thus, a behavioral effect may be hazardous for predator and prey alike ... 

Jorgenson, J.L. (2001). Aldrin and dieldrin A review of research on their production, environmental depositions and fate, bioaccumulation, toxicology and epidemiology in the United States. Environmental Health Perspectives 109, 113-139 (supplement). 

Lindane (gamma-hexachlorocyclohexane) is one of the last of the old style organochlorine pesticides still in use. Use of organochlorines such as DDT, aldrin, dieldrin, heptachlor, and toxaphene is restricted or banned in many countries because of their persistence in the environment, bioaccumulation, and toxicity. Lindane was first isolated in 1825 along with other similar compounds, but its deadly effects on insects were not recognized until the 1940s. 

Aldrin/dieldrin Pesticide - organochlorine - bioaccumulates - used to control mosquitoes and termites Importation and manufacture prohibited in the US in 1987... 

Diddrin [60-57-1] or l,2,3,4,10,10-hexachloro-l,4,4tf,5,8,8tf-hexahydro-6,7-epoxy-l,4- dvx< 5,8-dimethanonaphthalene (34) (mp 176°C, vp 0.4 mPa at 20°C) is formed from aldrin by epoxidation with peracetic or perbenzoic 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 bioaccumulation, registrations in the United States were canceled in 1974. 

Environmental. The high lipophilicity of the cydodienes and the prolonged persistence of dieldrin and heptachlor epoxide (soil half-lives 2—10 yr) have resulted in severe environmental contamination. These compounds are bioaccumulated from water to fish up to 100,000- to 300,000-fold and are ubiquitous in human fat and milk. Oxychlordane [26880-48-8], mirex, and chlordecone are also bioaccumulative. The cydodienes are extremely toxic to fish with LC5Qs (ppm) to trout and bluegill of endrin, 0.001-0.002 endosulfan, 0.001-0.003 diddrin, 0.003-0.015 aldrin, 0.006-0.01 heptachlor, 0.03-0.026 and chlordane, 0.022—0.095. The LD5Qs to pheasant and mallard are aldrin 16.8 and 520, dieldrin 79 and 381, and endrin 1.6 and 5.6 mg/kg. As indicated by their rat oral LD - s, they are also extremdy toxic to small mammals in fact, endrin has been used as a rodenticide (see Pesticides). Compounds, eg, aldrin and heptachlor, which have unsubstituted double bonds, readily add oxygen to form epoxides in plant and animal tissues and are preferentially concentrated and stored in animal fats. Aldrin epoxide (dieldrin) and heptachlor epoxide are more stable (half-lives on alfalfa of seven to eight days) than aldrin and heptachlor (half-lives on alfalfa of less than one day). 

The Binational Toxics Strategy between the USA and Canada has identified 12 bioaccumulative substances (referred to as Level-1 substances) having significant persistency and toxicity to the Great Lakes system, with the goal of reducing the sources of these substances to achieve naturally occurring levels [23]. Six of the 12 Level-1 substances are OC pesticides aldrin/dieldrin, chlordane, DDT, HCB, mirex, and toxaphene. Several other OC pesticides, such as endrin, heptachlor/heptachlor epoxide, hexachloro-cyclohexanes, tetra- and penta-chlorobenzenes, and pentachlorophenol, have been identified as Level-2 substances. 

Pesticides are also a major source of concern as water and soil pollutants. Because of their stability and persistence, the most hazardous pesticides are the organochlorine compounds such as DDT, aldrin, dieldrin, and chlordane. Persistent pesticides can accumulate in food chains for example, shrimp and fish can concentrate some pesticides as much as 1000- to 10,000-fold. This bioaccumulation has been well documented with the pesticide DDT, which is now banned in many parts of the world. In contrast to the persistent insecticides, the organophosphorus (OP) pesticides, such as malathion, and the carbamates, such as carbaryl, are short-lived and generally persist for only a few weeks to a few months. Thus these compounds do not usually present as serious a problem as the earlier insecticides. Herbicides, because of the large quantity used, are also of concern as potential toxic pollutants. Pesticides are discussed in more detail in Chapter 5. 

In response to the continuing discovery of the persistence, bioaccumulative properties, and toxicity of POPs, regional, national and international policies ban the intentional production of compounds, such as polychlorinated biphenyls (PCBs), several organochlo-rine pesticides, such as mirex and dieldrin, and the brominated flame retardants poly-brominated diphenyl ethers (penta-BDE and octa-BDE, and most recently, deca-BDE). Policies and programs have also targeted the unintentional production and release of POPs such as polychlorinated dibenzodioxins and furans (PCDD/Fs). Evidence of the success of these policies has been seen in immediate reductions of air concentrations, followed by declining concentrations in water bodies, soils, biota and our food supplies... 

Several terms have been used to describe this phenomenon, namely, biomagnification, bioconcentration, and bioaccumulation. However, the pesticide is not always concentrated or magnified as it moves up to the food chain, so the latter term is preferable (Nakatsugawa and Nelson, 1972). For example, dieldrin residue in cod at 0.009 ppm (whole fish bases) was less than in the sand eel, the major diet of the cod, at 0.016 ppm. Dieldrin residue in a macrozooplankton (crustacea) at 0.16 ppm was higher than in any of the fish examined... 

Cyclodienes (chlordane, aldrin, dieldrin, heptachlor, endrin, mirex, endosulfan, chlordecone). This new class of pesticides appeared on the scene following World War II. Most of them are very stable to sunlight and persistent in soil and they were used to control termites and other insects. Their effectiveness leads to insect resistance and bioaccumulation in the food chain and for these reasons their use was banned between 1984 and 1988. These compounds affect the CNS in the same way, causing tremors, convulsions, and prostration to the maximum extent, depending on the rate and time of exposure. 

It is well known that farmers use different types of insecticides to protect crops from insects. The more widely used insecticides are organophosphates, carbamates and organochlorides. Of these, organophosphates and carbamates are less persistent in the environment compared to the organochlorides (for example aldrin, dieldrin and DDT). Though the latter are definitely effective but they tend to bioaccumulate in many plant and animal species and incorporate into the food chain. Some of the insecticides are also responsible for the population decline" of beneficial insects and animals, such as honeybees, lacewings, mites, bald eagles etc. 

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