Carbofuran toxicity

Gupta RC and Kadel WL (1989) Concerted role of car-boxylesterases in the potentiation of carbofuran toxicity by iso-OMPA pretreatment. Journal of Toxicology and Environmental Health 26 447-457. 

Gupta. R. C. (1994a). Carbofuran toxicity. J. Toxicol. Emimn. 

Gupta, R. C., and Kadel, W. L. 0989a). Concerted role of carboxylc.sicrases in the potcnfialion of carbofuran toxicity by iso-OMPA preireatmeni. J. Toxicol. Environ. Health 26. 447-457. 

Environmental. The A/-methylcarbamates generally are biodegradable and of low soil persistence with half-Hves for carbaryl and aldicarb of 1—2 weeks and of carbofuran of 1—4 months. Certain carbamates are highly toxic to birds with oral LD qS for mallard, eg, pheasant, in mg/kg carbofuran, 0.40, 4.2 mexacarbate, 3.0, 4.5 and methomyl, 16, 15 compared to carbaryl >2000. Fish toxicity of carbamates is generally low, but these compounds are extremely toxic to bees. In cases of human poisoning, atropine is a specific antidote. 

CBs have been widely used in agriculture as insecticides, molluskicides, and aca-ricides. They have been applied as sprays and as granules or pellets. Highly toxic compounds, such as aldicarb and carbofuran, are usually only available as granules. 

Acute oral toxicities of carbofuran to birds and mammals... 

Acute aerosol inhalation toxicity of carbofuran to warm-blooded animals... 

Pharmacologically, carbofuran inhibits cholinesterase, resulting in stimulation of the central, parasympathetic, and somatic motor systems. Sensitive biochemical tests have been developed to measure cholinesterase inhibition in avian and mammalian brain and plasma samples and are useful in the forensic assessment of carbamate exposure in human and wildlife pesticide incidents (Bal-lantyne and Marrs Hunt and Hooper 1993). Acute toxic clinical effects resulting from carbofuran exposure in animals and humans appear to be completely reversible and have been successfully treated with atropine sulfate. However, treatment should occur as soon as possible after exposure because acute carbofuran toxicosis can be fatal younger age groups of various species are more susceptible than adults (Finlayson et al. 1979). Carbofuran labels indicate that application is forbidden to streams, lakes, or ponds. In addition, manufacturers have stated that carbofuran is poisonous if swallowed, inhaled, or absorbed through the skin. Users are cautioned not to breathe carbofuran dust, fumes, or spray mist and treated areas should be avoided for at least 2 days (Anonymous 1971). Three points are emphasized at this juncture. First, some carbofuran degradation... 

Table 12.3 Acute Toxicities of Carbofuran to Aquatic Organisms... 

Acute oral toxicities of carbofuran to various species of mammals ranged from 2000 pg/kg BW in mice to 34,500 pg/kg BW in rats (Table 12.4). Mammals were generally more resistant than birds to acute biocidal properties of carbofuran. 

Table 12.4 Acute Oral Toxicities of Carbofuran to Birds and Mammals (Concentrations shown are in micrograms carbofuran administered per kilogram body weight [ g/kg] in a single dose fatal to 50% within 14 days.)...

Table 12.5 Toxicity of Dietary Carbofuran to Birds and Mammals... 

Table 12.6 Acute Aerosol Inhalation Toxicity of Carbofuran to Warm-Blooded Animals...

Modified from Zakour, H.R. 1980. Toxicity, Uptake and Metabolism of the /V-methyl-carbamate Pesticide Carbofuran by the Freshwater Bivalve Mollusc Glebula rotundata (Lamarck). Ph.D. Thesis, Rice University, Houston. 148 pp. 

Carbamate pesticides can easily be converted to A-nitroso derivatives in the presence of sodium nitrite under acidic conditions. The A-nitroso form of carbofuran could possibly be formed in the human stomach (Nelson et al. 1981). Since carbofuran is used routinely on a variety of crops and nitrite is a common component of the human diet and present in human saliva, nitrosation of carbamates under conditions simulating those in the human stomach is possible. Lijinsky and Schmal (1978) tested nitrosocarbofuran and five other nitrosated carbamate pesticides for carcinogenicity in rats. Nitrosocarbofuran, at 16.5 mg/kg BW administered orally once weekly for 23 weeks, was the most toxic compound tested and caused the death of several animals by liver damage early in the experiment. Among survivors, nitrosocarbofuran was the most carcinogenic,... 

Anton, F.A., E. Laborda, P. Laborda, and E. Ramos. 1993a. Carbofuran acute toxicity to freshwater algae and fish. Bull. Environ. Contam. Toxicol. 50 400-406. 

Forsythe, D.J., C.F. Hinks, and N.D. Westcott. 1994. Feeding by clay-colored sparrows on grasshoppers and toxicity of carbofuran residues. Environ. Toxicol. Chem. 13 781-788. 

Gilman, A.P and A. Vardanis. 1974. Carbofuran. Comparative toxicity and metabolism in the worms Lumbricus terrestris L. and Eisenia foetida S. Jour. Agric. Food Chem. 22 625-628. 

Jash, N.B. and S. Bhattacharya. 1983. Delayed toxicity of carbofuran in freshwater teleosts, Channapunctatas (Bloch) and Anabas testudineus (Bloch). Water Air Soil Pollut. 19 209-213. 

Kar, S. and P.K. Singh. 1978. Effect of pH, light intensity and population on the toxicity of the pesticide carbofuran to the blue-green alga Nostoc muscorum. Microbios 21 177-184. 

Nelson, J., E.A. MacKinnon, H.F. Mower, and L. Wong. 1981. Mutagenicity of V-nitroso derivatives of carbofuran and its toxic metabolites. Jour. Toxicol. Environ. Health 7 519-531. 

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