Pesticides mirex

Rogers, J.M. 1982. The Perinatal Cataractogenicity of the Pesticide Mirex Lens Changes and Related Systemic Effects. Ph.D. thesis, Univ. Miami, Coral Gables. 100 pp. 

As a result of human health concerns, production of mirex ceased in 1976, at which time industrial releases of this chemical to surface waters were also curtailed. However, releases from waste disposal sites continue to add mirex to the environment. Virtually all industrial releases of mirex were to surface waters, principally Lake Ontario via contamination of the Niagara and Oswego Rivers. About 75% of the mirex produced was used as a fire retardant additive, while 25% was used as a pesticide. As a pesticide, mirex was widely dispersed throughout the southern United States where it was used in the fire ant eradication program for over 10 years. 

Grabowski CT. 1983a. Persistent cardiovascular problems in newborn rats prenatally exposed to subteratogenic doses of the pesticide, mirex. Dev Toxicol Environ Sci 11 (Dev Sci Pract Toxicol) 537-540. 

Grabowski CT, Payne DB. 1983a. The causes of perinatal death induced by prenatal exposure of rats to the pesticide mirex Part II. Postnatal observations. J Toxicol Environ Health 11 301-315. 

Moser GJ, Meyer SA, Smart RC. 1992. The chlorinated pesticide mirex is a novel nonphorbol ester-type tumor promoter in mouse skin. Cancer Res 52(3) 631-636. 

Simultaneous exposure of rats to Aroclor 1254 or 1260 and chemicals of environmental concern such as the pesticides mirex, photomirex, and/or kepone in the diet resulted in increased severity of the liver lesions attributed to exposure to chlorinated biphenyls alone (Chu et al. 1980). Induction of hepatic AHH activity by Aroclor 1254 in the diet of lactating rats was increased in an additive manner by simultaneous dietary exposure to polybrominated biphenyls such as Firemaster BP-6 (McCormack et al. 1979). 

The importance of binding was demonstrated for the photolysis of the hydro-phobic chlorocarbon pesticide mirex, which is predominantly bound to DOM in natural waters [55,56]. When humic acid solutions of mirex were irradiated, the mirex was photo-reduced by a humic-generated hydrated electron, which would... 

The facile dechlorination of the comer chlorines of the pesticide Mirex, 2, is of particular interest. These chlorines cannot be removed by nucleophilic substitution because nucleophiles cannot get inside the cage to approach carbon from the backside in Sn2 reactions. Elimination reactions are also in ossible since double bonds from these comer carbons can t be formed due to the constrained geometry. However, solvated electron solutions readily and conq>letely dechlorinate Mirex. ... 

Compounds that affect activities of hepatic microsomal enzymes can antagonize the effects of methyl parathion, presumably by decreasing metabolism of methyl parathion to methyl paraoxon or enhancing degradation to relatively nontoxic metabolites. For example, pretreatment with phenobarbital protected rats from methyl parathion s cholinergic effects (Murphy 1980) and reduced inhibition of acetylcholinesterase activity in the rat brain (Tvede et al. 1989). Phenobarbital pretreatment prevented lethality from methyl parathion in mice compared to saline-pretreated controls (Sultatos 1987). Pretreatment of rats with two other pesticides, chlordecone or mirex, also reduced inhibition of brain acetylcholinesterase activity in rats dosed with methyl parathion (2.5 mg/kg intraperitoneally), while pretreatment with the herbicide linuron decreased acetylcholine brain levels below those found with methyl parathion treatment alone (Tvede et al. 1989). 

Tvede KG, Loft S, Poulsen HE, et al. 1989. Methyl parathion toxicity in rats is changed by pretreatment with the pesticides chlordecone, mirex and linuron. Arch Toxicol Suppl 13 446-447. 

Results of volatilization and leaching estimations are reported for six pesticides that span a wide range of the physical/chemical properties that affect fate at the soil/air interface. The pesticides are Mirex, toxaphene, methoxychlor, lindane, malathion, and dibromochloropropane (DBCP). These particular pesticides were chosen for discussion here because they illustrate the methods for assessing the fate of organics at the... 

Table I shows the results of calculating a soil diffusion coefficient and soil diffusion half-lives for the pesticides. The 10% moisture level specified means that the soil is relatively dry and that 40% of the soil volume is air available for diffusion. Complete calculations were not made for methoxychlor, lindane, and malathion because, based on Goring s criteria for the Henry s law constant, they are not volatile enough to diffuse significantly in the gas phase. This lack of volatility is reflected in their low values of X. These materials would move upward in the soil only if carried "by water that was moving upward to replace the water lost through evapotranspiration at the surface. Mirex has a very high Henry s law constant. On the basis of Goring s criteria, Mirex should diffuse in the soil air but, because of its strong adsorption, it has a very large a and consequently a very small soil air diffusion coefficient. The behavior of Mirex shows that Goring s criteria must be applied carefully.

Wilson and co-workers [332, 333] have discussed the determination of aldrin, chlordane, dieldrin, endrin, lindane, o,p and p,p isomers of DDT and its metabolites, mirex, and toxaphene in seawater and molluscs. The US environmental Protection Agency has also published methods for organochlo-rine pesticides in water and wastewater. The Food and Drug Administration (USA) [334] has conducted a collaborative study of a method for multiple organochlorine insecticides in fish. Earlier work by Wilson et al. [333, 335] in 1968 indicated that organochlorine pesticides were not stable in seawater. 

Picer and Picer [357] investigated the recovery from fO litre samples of seawater of 0.1-1.0 xg/l chlorinated pesticides (DDT, DDE, TDE, and Dieldrin), and 1-2 xg/l PCB (Aroclor 1254). The recovery of Mirex during these steps varied between 80% and 90%. Losses of the investigated chlorinated hydrocarbons during these steps were 10-30% for about 10 ng pesticides. 

Mirex (dodecachlorooctahydro-l,3,4-metheno-2H-cyclobuta [tv/] pentalene) has been used extensively in pesticidal formulations to control the red imported fire ant (Solenopsis invicta), and as a flame retardant in electronic components, plastics, and fabrics. One environmental consequence of mirex was the severe damage recorded to fish and wildlife in nine southeastern states and the Great Lakes, especially Lake Ontario. In 1978, the U.S. Environmental Protection Agency banned all further use of mirex, partly because of the hazards it imposed on nontarget biota. These included ... 

Wiemeyer, S.N., T.G. Lamont, C.M. Bunck, C.R. Sindelar, FJ. Gramlich, J.D. Fraser, and M.A. Byrd. 1984. Organochlorine pesticide, polychlorobiphenyl, and mercury residues in bald eagle eggs — 1966-79 — and their relationships to shell thinning and reproduction. Arch. Environ. Contam. Toxicol. 13 529-549. Wolfe, J.L. and B.R. Norment. 1973. Accumulation of mirex residues in selected organisms after an aerial treatment, Mississippi, 1971-1972. Pestic. Monitor. Jour. 7 112-114. 

Terrence Collins is the Thomas Lord Professor of Chemistry at Carnegie Mellon University who contends that the dangers of chlorine chemistry are not adequately addressed by either academe or industry, and alternatives to chlorine and chlorine processors must be pursued. He notes, Many serious pollution episodes are attributable to chlorine products and processes. This information also belongs in chemistry courses to help avoid related mistakes. Examples include dioxin-contaminated 2,4,5-T, extensively used as a peacetime herbicide and as a component of the Vietnam War s agent orange chlorofluorocarbons (CFCs) polychlorinated biphenyls (PCBs the pesticides aldrin, chlordane, dieldrin, DDT, endrin, heptachlor, hexachlorobenzene, lindane, mirex, and toxaphene pentachlorophe-... 

Snyder et al. [20] have compared supercritical fluid extraction with classical sonication and Soxhlet extraction for the extraction of selected pesticides from soils. Samples extracted with supercritical carbon dioxide modified with 3% methanol at 350atm and 50°C gave a =85% recovery of organochlorine insecticides including Dichlorvos, Endrin, Endrin aldehyde, p,p -DDT mirex and decachlorobiphenyl (and organophosphorus insecticides). 

Mirex and chlordecone are no longer made or used in the United States. Mirex and chlordecone were most commonly used in the 1960s and 1970s. Mirex was used as a pesticide to control fire ants mostly in the southeastern part of the United States. It was also used extensively as a flame retardant additive under the trade name Dechlorane in plastics, rubber, paint, paper, and electrical goods from 1959 to 1972 because it does burn easily. Chlordecone was used to control insects that attacked bananas, citrus trees with no fruits, tobacco, and ornamental shrubs. It was also used in household products such as ant and roach traps. Chlordecone is also known by its trade name Kepone . All registered products containing mirex and chlordecone were canceled in the United States between 1977 and 1978. 

Like most halogenated hydrocarbon pesticides, very little of the chlordecone or its metabolites is excreted via the urine. Because of the apparent enterohepatic recirculation of chlordecone and chlordecone alcohol, most experimental approaches to chlordecone detoxification have focused on limiting reabsorption from the gastrointestinal tract using cholestyramine (Boylan et al. 1978 Cohn et al. 1978), liquid paraffin (Richter et al. 1979), and chlorella and chlorella- derived sporopollenin (Pore 1984). No information was found that indicated that mirex undergoes enterohepatic recirculation, so it is not known whether use of these therapies would be effective in reducing absorption of mirex. 

Mirex has been detected in air, surface water, soil and sediment, aquatic organisms, and foodstuffs. Historically, mirex was released to the environment primarily during its production or formulation for use as a fire retardant and as a pesticide. There are no known natural sources of mirex and production of the compound was terminated in 1976. Currently, hazardous waste disposal sites and contaminated sediment sinks in Lake Ontario are the major sources for mirex releases to the environment (Brower and Ramkrishnadas 1982 Comba et al. 1993). 

Chlordecone has been primarily released to surface waters in waste waters from a manufacturing plant in Hopewell, Virginia, and may be released in activities associated with the disposal of residual pesticide stocks, and as a result of the direct use of mirex. Chlordecone has been released directly as a contaminant of mirex and indirectly from the degradation of mirex. 

Mirex is not currently registered for use in the United States so release of mirex to soil from pesticide applications is no longer of concern. However, use of mirex as a pesticide for fire ant control required the spraying of this chemical on soils of an estimated 132 million acres in the southern United States (IARC 1979c). An estimated 226,000 kg (498,000 lb) of mirex was used in 9 states from 1962-1976 as part of the fire ant eradication program conducted by the Department of Agriculture (IARC 1979c). 

Less than 10% of the sediment samples taken from the San Joaquin River and its tributaries in California (an area of heavy organochloride pesticide use) in 1985 contained mirex residues all samples contained less than 0.1 pg/kg (ppb) (Gilliom and Clifton 1990). 

In general, because releases of mirex from its production and use as a pesticide were terminated almost 20 years ago, mirex residues in various biological organisms are much lower than those reported during or shortly after its peak years of production and use. This trend is supported by both regional and national studies. 

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