Toxaphene persistence

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... 

Adsorption and persistence in plants can be modified by other chemicals or by selected carriers, although mechanisms to account for these phenomena are unclear. The application mixture influences adsorption and persistence of fenvalerate. For example, interception and persistence in sugarcane were increased when fenvalerate was applied in a 25% water/75% soybean oil mixture vs. water or soybean oil alone (Smith et al. 1989). Also, biocidal properties of fenvalerate residues on cotton foliage were increased up to 100% due to enhanced persistence of fenvalerate in the presence of toxaphene (Brown et al. 1982). 

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,... 

Toxaphene elimination rates vary between species. In rats, the half-time persistence of toxaphene (time to 50% excretion = Tb 1/2) was 1 to 3 days (USEPA 1980a). If the trend persisted, virtually all toxaphene would be eliminated in five half-lives. Elevated blood toxaphene levels in a human subject who had eaten catfish fillets containing 52 mg of toxaphene/kg dropped 67% in 11 days. By 14 days after the initial measurement, toxaphene blood levels were below analytical detection limits (USEPA 1980a). Persistence seems to be longer in some fishes. Lake trout (Salvelinus namaycush) given a single intraperitoneal injection of 7 mg toxaphene/kg BW had a Tb 1/2 of 322 days for white suckers (Catostomus commersoni), this value was 524 days (Delorme et al. 1993). 

Toxaphene is persistent in soils, water, and other environmental compartments, with residence times measured in years. 

There is inadequate knowledge of interaction effects of toxaphene with other agricultural chemicals (especially when mixtures are applied simultaneously) and with other persistent compounds in aquatic ecosystems, such as PCBs, DDT and its isomers, and petroleum. 

Terrierre, L.C., U. Kiigemaki, A.R. Gerlach, and R.L. Borovicka. 1966. The persistence of toxaphene in lake water and its uptake in aquatic plants and animals. Jour. Agric. Food Chem. 14 66-69. 

Chlorinated micropoUutants are harmful for man and environment due to their toxicity, persistence, and bioaccumulation. Persistent compounds are very stable and difficult to get metabolized and mineralized by biological and chemical processes in the environment, and as a result, they have become ubiquitous in water, sediments, and the atmosphere bioaccumulation is the result of the lipophilicity of these compounds. Polychlorinated dibenzodioxins and -furans (PCDD/F) are not produced purposely like many of other chlorinated technical products, such as chlorinated biocides DDT, lindane, and toxaphene. The production and use of persistent organic pollutants (POPs), the dirty dozen has now been banned worldwide by the Stockholm protocol. It should be mentioned that about 3000 halogenated products have now been isolated as natural products in plants, microorganisms, and animals," but the total amount of these products is much smaller compared to xenobiotics. 

That some chemicals persist for long periods has been recognized for many years. Most of the pesticidal chemicals that came into wide use in the 1930s and 1940s were chlorinated organic compounds such as DDT, dieldrin, chlordane, kepone, toxaphene, and several others. 

Lindane (gamma-hexachlorocyclohexane) is one of the last of the old style organochlorine pesticides still in use. Use of organochlorines such as DDT, aldrin, dieldrin, heptachlor, and toxaphene is restricted or banned in many countries because of their persistence in the environment, bioaccumulation, and toxicity. Lindane was first isolated in 1825 along with other similar compounds, but its deadly effects on insects were not recognized until the 1940s. 

Toxaphene, or polychlorocamphene (CioHioCls), is a pesticide for cotton. It has no significant biodegradation or photolysis reactions in the environment, so it is a persistent chemical. Henry s law constant for toxaphene is Ht = 6.0 x 10 atm m /mole. The initial conditions are given in Figure E8.5.1. 

The Binational Toxics Strategy between the USA and Canada has identified 12 bioaccumulative substances (referred to as Level-1 substances) having significant persistency and toxicity to the Great Lakes system, with the goal of reducing the sources of these substances to achieve naturally occurring levels [23]. Six of the 12 Level-1 substances are OC pesticides aldrin/dieldrin, chlordane, DDT, HCB, mirex, and toxaphene. Several other OC pesticides, such as endrin, heptachlor/heptachlor epoxide, hexachloro-cyclohexanes, tetra- and penta-chlorobenzenes, and pentachlorophenol, have been identified as Level-2 substances. 

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