Mirex

Eisler, R. 1985. Mirex hazards to fish, wildhfe, and invertebrates a synoptic review. U.S. Fish Wildl. Serv. Biol. Rep. 85(1.1), 42 pp. 

Eisler, R. 2000. Mirex. Pages 1133—1157 in Handbook of Chemical Risk Assessment Health Hazards to Humans, Plants, and Animals. Volume 2, Organics. Lewis Publishers, Boca Raton, Florida. 

Synonyms l,l -(2,2-dichloroethylidene)bis [4-ethylbenzene] 2,2-dichloro-1,1 -bis( -ethylphenyl)ethane 1,1 -bis(p-ethylphe- 

Crystalline solid mp 56°C (132.8°F) insoluble in water soluble in acetone, kerosene, and diesel fuel. 

Mildly toxic by ingestion the oral median lethal doses in all experimental animals were 5000 mg/kg however, produced moderate to severe effects when administered intravenously toxic properties are somewhat similar to those of DDT susceptible to storage in fat also bioaccumulative a teratogenic substance sufficient evidence of carcinogenicity in mice, but inadequate evidence in other animals cancer-causing effects in human unknown. 

LD50 oral (rat) 6600 mg/kg LD50 oral (wild bird) 9000 mg/kg LD50 intravenous (rat) 73 mg/kg 

Synonyms ethyl 2-hydroxy-2,2-bis(4-chloro-phenyl)acetate 4,4 -dichlorobenzilic acid ethyl ester 4-chloro-a-(4-chlorophenyl)-a-hydroxybenzeneacetic acid ethyl ester 4,4 -dichlorobenzilate 

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Mitex [2385-85-5] is l,2,3,4,5,5,6,7,8,9,10,10-dodecachloro-octahydro-l,3,4-metheno-2JT-cyclobuta-p,<7 -pentalene (37) (mp 485°C). The rat LD s are 306, 600 (oral) and >2000 (dermal) mg/kg. Mirex is extremely resistant to biodegradation and was once considered the perfect stomach poison iasecticide for use ia baits to control imported fire ants. However, even at doses of a few milligrams per 10 m it was found to bioaccumulate ia birds and fish and its registrations were canceled ia the United States ia 1976. 

Aldrin, chlordecone (Kepone), 2,4-D, DDT and metabolites, dieldrin, endosulfan, endrin, f]- and y-HCH (lindane), linuron, methoxychlor, mirex... 

Concentrations of PCBs in fish from each of the Great Lakes currently exceed the GLWQA objectives for the protection of aquatic life. Similarly, concentrations of some substances (e.g., PCBs, Hg, mirex, toxaphene) in Great Lakes fish continue to exceed acceptable guidelines for human consumption. Documented effects in the Great Lakes include reproductive failure, congenital abnormalities and induction of tumours in various aquatic, terrestrial and avian species (23). 

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. 

It is well established that important photochemical reactions are mediated by humic material in the aquatic environment (Zepp et al. 1981a,b), and that these are particularly signihcant for hydrophobic contaminants. Partial reductive dechlorination of the persistent insecticide mirex associated with... 

Burns SE, JP Hassett, MV Rossi (1996) Binding effects on humic-mediated photoreaction intrahumic dechlorination of mirex in water. Environ Sci Technol 30 2934-2941. 

Holmstead RL (1976) Studies of the degradation of mirex with an iron (II) porphyrin model system. J Agric Food Chem 24 620-624. 

Lambrych KL, JP Hassett (2006) Wavelength-dependent photoreactivity of mirex in Lake Ontario. Environ Sci Technol 40 858-863. 

The insecticide heptachlor oxidizes in the soil, and becomes a more toxic epoxide, capable of remaining for a long time. The insecticide aldrin transforms in the soil into dieldrin, maintaining its toxicity [15, 30]. Mirex (FDso=300-600 mg/kg), used to fight ants, just like kelevan (FDS0=255-325 mg/kg), used to fight the Colorado beetle, transform in the soil into the more toxic chlordekon (FD50 decreases to 95-140 mg/kg) [30]. 

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.

Table III illustrates the impact of adsorption on the leaching of organic chemicals in the soil. A water input of 305 cm was used, which is equivalent to a full year of precipitation in the eastern United States. In a soil with a field capacity of 30%, the water would penetrate 1017 cm. Mirex with a very large Kqc is practically immobile after a full year of precipitation, it is still on the surface. It is likely that any compound adsorbed this strongly would be carried off the land surface by soil erosion instead of being leached into the soil. In contrast, DBCP, which is very weakly adsorbed, penetrates the soil profile almost as far as the water does.

Mlrex. Mirex does not leach into the soil profile and is predicted to volatilize only slowly. There Is no evidence for any rapid transformation so it should be considered persistent. Because It is so strongly adsorbed to the soil and stays on the surface, a major loss from terrestrial systems would probably be erosion and transport Into surface waters. 

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. 

Aspila et al. [338] reported the results of an interlaboratory quality control study in five laboratories on the electron capture gas chromatographic determination of ten chlorinated insecticides in standards and spiked and unspiked seawater samples (lindane, heptachlor, aldrin, 5-chlordane, a-chlordane, dield-rin, endrin, p, p -DDT, methoxychlor, and mirex). The methods of analyses used by these workers were not discussed, although it is mentioned that the methods were quite similar to those described in the water quality Branch Analytical Methods Manual [339]. Both hexane and benzene were used for the initial extraction of the water samples. 

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. 

Ritter L, Solomon KR (1995) A review of the persistent organic pollutants DDT, aldrin, dieldrin, endrin, chlordane, heptachlor, hexachlorobenzene, mirex, toxaphene, polychlorinated biphenyls, dioxins and furans. In T.I.P.o.C.S. (IPCS) (ed) Geneve, Suisse... 

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