Toxaphene degradation

Williams, R.R. and T.R. Bidleman. 1978. Toxaphene degradation in estuarine sediments. Jour. Agric. Food Chem. 26 260-262. 

Khalifa, S., Holmstead, R.L., and Casida, J.E. Toxaphene degradation by iron(If) protoporphyrin systems, J. Agric. Food Chem., 24(2) 277-282, 1976. 

First, the effects of aerobic and anaerobic culture conditions on toxaphene degradation were studied with washed P. putida cells grown on camphor and incubated with no readily usable carbon source. The radioactivities remaining in water after extraction with n-hexane were used as an indicator of metabolic activity. This was further extracted with ethyl acetate after acidification to divide this "total polar metabolites" fraction into aqueous buffer phase and ethyl acetate phase, i.e., the total polar metabolites reported refer to summation of the aqueous buffer and ethyl acetate soluble phases (Table 4). All radioactivities have been corrected by zero time controls and autoclaved 8 hr controls are included in each experiment. 

In an incubation performed to test for possible toxaphene degradation in organic-rich lake sediments, a jar is filled with 2 kg of dry sediment 3 liters of water 0.1 g of nitrate 0.2 g of iron oxyhydroxides, Fe(OH)3 and 0.2 g of sulfate. The mixture is initially bubbled with air, toxaphene is incorporated at a concentration of 0.2 ppm, and the jar is sealed. Toxaphene is a mixture of compounds formed from the chlorination of camphene, and was once commonly employed as a pesticide. 

In soils, toxaphene can persist for lengthy periods, with microbial degradation occurring under aerobic and anaerobic conditions (Cohen etal. 1982). Pimentel (1971) reported that toxaphene,... 

As was thf case with dieldrin, photodecomposition of C-parathion and Cl-toxaphene was relatively extensive, and the addition of FMN has almost no effect on the enhancing or decreasing the rate of degradation to water-soluble products. Since the organic-soluble products were not analyzed in the case of parathion and toxaphene, it is difficult to speculate on the type of degradation products formed and the pathways involved on... 

Oscarson DW, Huang PM, Liaw WK, Hammer UT (1983) Kinetics of oxidation of arsenite by various manganese dioxides. Soil Sci Soc Am J 47 644-648 Pang LP, Close M, Flintoft M (2005) Degradation and sorption of atrazine, hexazinone and pro-cymidone in coastal sand aquifer media. Pest Man Sci 61 133-143 Paris DF, Lewis DL (1976) Accumulation of metoxychlor by microorganisms isolated from aqueous systems. BuU Environ Contam Toxicol 13 443-450 Parr JF, Smith S (1976) Degradation of toxaphene in selected anaerobic soil environments. Soil Science 121 52-57... 

Also in the C-toxaphene cultures (Table 4), the large proportion, if not all, of the radioactivities reported as total polar metabolites. were found as ethyl acetate soluble radioactivities in contrast to the C1-toxaphene cultures, where the radioactivities were partitioned between the aqueous buffer and ethyL acetate, phases in approximately a 2.5 1 ratio, respectively. When the and C1 percentage values in Table 4 from similarly incubated (aerobic or anaerobic) cultures were added, it became apparent that anaerobic cultures were slightly more active in degrading toxaphene than aerobic cultures. However, the above results clearly indicate that at least a portion of toxaphene metabolism by P. putida involves oxidative degradation. 

These observations suggest that the oxidative reactions occurring on toxaphene are similar in nature to the system described for camphor degradation (M). It is unfortunate that the above experiments could only be conducted with washed intact cells as cell-free preparations in all cases did not exhibit metabolic capabilities. The reason for this phenomenon has not been found, but to our knowledge no other research group has been able to demonstrate pesticide degrading activities of such oxygenase systems in cell-free preparations. 

Parr, J. F., and S. Smith, Degradation of toxaphene in selected anaerobic soil environments , Soil Sci., 121,52-57 (1976). 

Of the 5.34 x 1051 of toxaphene that were used in North America (includes the United States and Mexico), 1.541 (3%) was estimated to remain in active circulation as of the year 2000, 6.5 x 1041 (12%) had been removed from the continental environment by advection of air and water and burial in soils and sediments, and 4.54 x 1051 (85%) had been removed by degradation reactions. Most of the toxaphene in active circulation resides in the soils of the southern U.S. and Mexico (83%). The efficiency of toxaphene transfer to the Great Lakes from its usage within the basin was estimated to be 78 to 220 times greater than transfer from the southern United States. However, load-... 

Profiles of toxaphene in dated sediment cores have been used to infer historical deposition and degradation of toxaphene in Lake Superior and the nearby inland lakes [50,94,95], Michigan [94,96] and Ontario [94,97-99]. There is sufficient detail from these studies to infer the history of inputs of toxaphene... 

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