3- Chlordene

Technical chlordane is stable under ultraviolet (UV) light, although some components, such as chlordene, heptachlor, cis-chlordane, and /ram-chlordanc, will form photoisomers under high-intensity UV light in the presence of sensitizers, such as ketones (NRCC 1975 Menzie 1978). Several compounds were measured in alfalfa grown on soils treated with chlordane, including 1,2-... 

Figure 13.1 Chemical structure of chlordane-related compounds 1, chlordene (4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro-4, 7-methanoindene) 2, c/ s-chlordane, also known as alpha-chlordane (1-exo, 2-exo, 4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene) 3, trans-chlordane, also known as gamma-chlordane (1-exo, 2-endo, 4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene) 4, heptachlor (1,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methanoindene) — technical heptachlor contains about 15% c/s-chlordane and 2.5% trans-chlordane 5, heptachlor epoxide (1,4,5,6,7,8,8-heptachloro-2,3-epoxy-3a,4,7,7a-tetrahydro-4,7-methanoindene) and 6, oxychlordane, also known as octachlor epoxide (1-exo, 2-endo, 4,5,6,7,8,8-octachloro,2,3-exo-epoxy-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene). 

Microorganisms such as Nocardiopsis sp., an actinomycete, can metabolize cis- and trans-chlo-rdane to at least eight solvent-soluble substances, including dichlorochlordene, oxychlordane, hep-tachlor, heptachlor endo-epoxide, chlordene chlorohydrin, and 3-hydroxy-trans-chlordane (Beeman and Matsumura 1981). Based on studies of chlordane metabolism in animals, four metabolic pathways are proposed (Feroz and Khan 1979a WHO 1984 Nomeir and Hajjar 1987 USEPA 1988) ... 

Residues of dv-chlordanc were preferentially stored and magnified over tran.v-chlordane by freshwater fish and invertebrates in ponds treated with technical chlordane at concentrations up to 1.14 pg/L. The di-isomer, with an estimated Tb 1/2 of 46 days, persisted longer than did the trans-isomer (Johnson and Finley 1980). Tissue concentrations of 106,000 pg total chlordanes/kg, on a lipid weight basis, were associated with reduced survival of estuarine invertebrates (Zitko 1978). Moribund amphipods (Hyallela azteca), for example, contained 137,000 to 2,180,000 pg/kg lipid of various chlordanes, heptachlors, and chlordenes (Zitko 1978). In fish, chlordane concentrations of 300,000 to 4,000,000 pg/kg lipid weight in tissues were lethal (Zitko 1978). 

The analyses involved the exposure of developed chromatograms to x-ray films followed by scraping of radioactive spots and quantifying them. Relative amounts of various compounds in the fractions are indicated on the righthand side against numbered spots. Spots A-6, B-4, and C-5 represent unchanged cis-chlordane A-7 was a mixture of dichloro-chlordene and oxychlordane. A-3, B-3, C-4, and D-4 represent chlordene chlorohydrin. A-2, B-2, C-2, and D-2 were complex spots with the heptachlor diol as the major compound. A-l, B-l, C-l, and D-l were polyhydroxy derivatives or conjugates. Identities of other spots are not known. Recoveries in fractions A, B, C, and D were, respectively, 60.1%, 0.6%, 2.2%, and 2.9% of the applied radiocarbon. 

Only 6% of the radioactivity from radiolabeled ( "C) heptachlor was found in the urine while 60% was found in the feces of male rats 10 days after a single oral dose indicating that most of the radioactive material was not absorbed and was excreted in the feces (Tashiro and Matsumura 1978). These data strongly suggest that a large percentage of heptachlor is absorbed from the gastrointestinal tract and eliminated via the bile into the feces. More than 72% of the radioactivity eliminated in the feces was present as metabolites of heptachlor (heptachlor epoxide, 13.1% H-2, < 0.1% 1-OH-chlordene, 19.5% 1-OH-chlordene epoxide, 17.5% 1,2-OH-chlordene, 3.5% H-6, 19.0%). 

Heptachlor is produced commercially by the free-radical chlorination of chlordene in benzene containing from 0.5% to 5.0% of fuller s earth. The reaction is run for up to 8 hours. The chlordene starting material is prepared by the Diels-Alder condensation of hexachlorocyclopentadiene with cyclopentadiene (Sittig 1980). Technical-grade heptachlor usually consists of 72% heptachlor and 28% impurities such as trans-chlordane, cis-chlordane, and nonachlor (HSDB 1990a). 

Incubations of heptachlor with a mixed culture of soil microorganisms for 12 weeks showed conversion of heptachlor to chlordene, 1-exohydroxychlordene, heptachlor epoxide, and chlordene epoxide. A mixed culture of soil microorganisms, obtained from a sandy loamy soil, degraded heptachlor epoxide to the less toxic 1-exohydroxychlordene. Conversion was about 1% per week during the 12-week test period (Miles et al. 1971). 

Lu PY, Metcalf RL, Hirwe AS, et al. 1975. Evaluation of environmental distribution and fate of hexachlorocyclopentadiene, chlordene, heptachlor, and heptachlor epoxide in a laboratory model ecosystem. J Agric Food Chem 23(5) 967-973. 

Note Chlordane is a mixture of cis- and tra/rs-chlordane and other complex chlorinated hydrocarbons including heptachlor (<7%) and nonachlor. According to Brooks (1974), technical chlordane has the approximate composition fra/rs-chlordane (24%), four chlordene isomers (CioHeCls) (21.5%), cA-chlordane (19%), heptachlor (10%), nonachlor (7%), pentachloro-cyclopentadiene (2%), hexachlorocyclopentadiene (>1%), octachlorocyclopentene (1%), C10H7. sCle- (8.5%), and unidentified compounds (6%). 

Soil The actinomycete Nocardiopsis sp. isolated from soil extensively degraded pure cis- and /ra/3s-chlordane to dichlorochlordene, oxychlordane, heptachlor, heptachlor e/ c/o-epoxide, chlordene chlorohydrin, and 3-hydroxy-traas-chlordane. Oxychlordane slowly degraded to 1-hydroxy-2-chlorochlordene (Beeman and Matsumura, 1981). In Hudson River, NY sediments, the presence of adsorbed chlordane suggests it is very persistent in this environment (Bopp et al., 1982). The reported half-life in soil is approximately 1 yr (Hartley and Kidd, 1987). 

Heptachlor rapidly degraded when incubated with acclimated, mixed microbial cultures under aerobic conditions. After 4 wk, 95.3% of the applied dosage was removed (Leigh, 1969). In a mixed bacterial culture under aerobic conditions, heptachlor was transformed to chlordene, 1-hydroxychlordene, heptachlor epoxide, and chlordene epoxide in low yields (Miles et al, 1971). Heptachlor rapidly degraded when incubated with acclimated, mixed microbial cultures under aerobic conditions. After 4 wk, 95.3% of the applied dosage was removed (Leigh, 1969). 

Chloranil, see Pentachlorophenol p-Choranil, see Pentachlorophenol Cis-Chlordan, see cfs-Chlordane a-Chlordan, see cfs-Chlordane p-Chlordane, frans-Chlordane y-Chlordane, see Heptachlor cfs-Chlordane, see Photo-cfs-chlordane frans-Chlordane, see Photo-frans-chlordane Chlordene, see Heptachlor... 

Chlordene chlorohydrin, see Chlordane Chlordene epoxide, see Heptachlor Chlorinated dibenzo-p-dioxin, see Pentachlorophenol Chlorinated dibenzo-p-dioxins, see PCB-1242, PCB-1254... 

Gab, S Saravanja, V., and Korte, F. Irradiation studies of aldrin and chlordene adsorbed on a silica gel surface. Bull. Environ. 

Chiral sulfides, dioxirane oxidation, 1156-7 Chlamydomonas reinhardtii, hydrogen peroxide determination, 646 y-Chlordene, isomers, 728 Chlorellajusca, hydrogen peroxide determination, 646... 

Isolimonene, artemisinin synthesis, 277 Isoluminol, lipid hydroperoxide determination, 680, 681 Isomerization aUyhc alcohols, 789-90 y-chlordene, 728... 

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