Heptachlor residues

Clark, D.R., Jr. R.K. LaVal, and A.J. Krynitsky. 1980. Dieldrin and heptachlor residues in dead gray bats, Franklin County, Missouri— 1976 versus 1977. Pestic. Monitor. Jour. 13 137-140. 

Shivankar VJ, Kavadia VS. 1989. Effects of temperature and humidity on the degradation of heptachlor residues in clay loam soil. Indian J Entomol 51(2) 205-210. 

Park, C.K., Yoo, J.Y., 1972. Studies on the residues of chlorinated organic insecticides I. Heptachlor residues in or on commercial vegetables. J. Korean Agric. Chem. Soc. (in... 

Lichtenstein and Schultz (7) found that the persistence of aldrin in soil depended largely on the presence of water in the soil. They concluded that once aldrin had been displaced by water from the soil particles, a major part of the insecticide was lost by volatilization. Unlike aldrin, DDT did not respond to displacement by water nor was it affected by enlargement of the surface onto which it had been deposited. Under field conditions, daily disking of a treated loam soil reduced 38% of the aldrin residue and 25% of the DDT residue after 3 months. In another study, Lichtenstein et al. (6) were able to recover aldrin and heptachlor residues ranging from 2.7 to 5.3% of the applied dosage 4 months after application to the soil surface. The persistence increased by a factor of 10 when the insecticides were mixed with the soil by rotatilling. One year after application 90% of the recovered insecticides was found in the upper 3 inches of the soil. Because two to three times more insecticide residues were recovered from crop-covered plots than from fallow ones, it was concluded that a dense... 

ASTM International (2003b). D 4947, Standard test method for chlordane and heptachlor residues in indoor air. Annual Book of ASTM Standards, Vol. 11.03, American Society for Testing and Materials, West Conshohoken, PA, USA (website http //www.astm.org). 

A variety of methods has been devised for the confirmation of heptachlor residues (Table II). The presence in the heptachlor molecule (Figure 1) of a reactive allylic chlorine atom has been the basis of three confirmatory tests based on its ease of replacement. Reaction with a silver acetate-glacial acetic acid mixture produced 1-acetoxychlordene which, with the GLC conditions used, had a retention time close to heptachlor epoxide 44). Of the common organochlorine pesticides, only heptachlor reacted quantitatively. Endrin reacts to a small extent with the glacial acetic acid to give a secondary endrin ketone peak. When the reaction of heptachlor with silver salts was extended to silver carbonate in aqueous alcohol, 1-hydroxychlordene was obtained which can easily be converted to the more volatile and GG-responsive silyl ether. Unfortunately, this silyl ether has a Rt identical to aldrin. With silver carbonate, hepta-... 

Few data are available on soil and airborne residues of chlordane and heptachlor from homes treated by commercial pest control firms. Thus, a study was undertaken to determine chlordane and heptachlor residues in clay and sand soils and in the air of selected houses. 

Chlordane and heptachlor residues from clay soils from houses constructed with crawl spaces are shown in Table I. Concentrations varied widely. The average level of chlordane in the first 10 cm of soil was 1405-ppm (15 samples) and the average concentration in soil from the 10 to 20 cm depth was 806 ppm (7 samples). In many instances) it was impossible to obtain a 10 to 20 cm depth sample, because of the hardness of the soil, interfering foundation footings, or construction debris which had been buried under many of the dwellings. The amount of heptachlor found in the soil samples averaged 386 ppm from the 0 to 10 cm (11 samples) and 261 ppm from the 10 to 20 cm depth (3 samples). 

Residues of chlordane and heptachlor in air from houses with crawl spaces constructed on clay soils are shown in Table II. The highest chlordane residues found were in the crawl space (8.7 pg/nP) compared to the kitchen (2.3 pg/m ) and bedroom (2.5 pg/m3), Heptachlor residues in air averaged 1.7 pg/m in crawl spaces compared to 0.6 pg/m3 in kitchens and bedrooms. 

Table I. Chlordane and Heptachlor Residues in Clay Soils from Houses...

D4947 Standard Test Method for Chlordane and Heptachlor Residues in Indoor Air... 

Report the concentration of heptachlor epoxide residue (in nanograms per gram) on the oranges. 

Heptachlor zero 0.0004 Liver damage risk of cancer Residue of banned termiticide... 

Musial CJ, Peach ME, Stiles DA. 1976. A simple procedure for the confirmation of residues of alpha-and beta-endosulfan, dieldrin, endrin, and heptachlor epoxide. Bull Environ Contam Toxicol 16 98-100. 

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. 

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 lethal effect of technical chlordane in birds is attributed primarily to chlordane metabolites, especially oxychlordane and, to a lesser extent, heptachlor epoxide (Shekel et al. 1983). Oxychlor-dane was the most persistent chlordane component in avian brain tissues. The half-time persistence of oxychlordane in brain was 63 days, and 95% loss was estimated in 280 days. The Tb 1/2 for heptachlor epoxide was 29 days, and for /ran.v-nonachlor it was 19 days (Shekel et al. 1979). Oxychlordane residues in brain tissue approaching 5 mg/kg FW were considered within the lethal hazard zone to birds (Shekel et al. 1979). 

Petterson, D.S., R.H. Casey, G.F. Ebell, and B.L. McIntyre. 1988. Residues in beef cattle accidentally exposed to commercial heptachlor. Austral. Veterin. Jour. 65 50-53. 

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