Aquatic fate and effect of Carbofuran

Abstract

Carbofuran is an insecticide widely used in North America. Its relatively short halflife in the environment has been a major factor in its increased use and substitution for insecticides known to persist in the environment for long periods of time and accumulate in animal tissues. The relatively high water solubility of carbofuran coupled with its relatively low adsorption on soils and sediments permits natural surface waters to become a repository for excessive amounts of the insecticide escaping treated areas or being accidentally introduced hito aquatic environments. Carbofuran's persistence is directly related to the pH of the water. The compound is stable in acid waters, but subject to increasing chemical hydrolysis as the water becomes more alkaline. Microbial populations in water, sediments, and flooded soils also reduce the persistence of carbofuran. Carbofuran is very toxic to fish. Generally, fish LC 50 S for carbofuran are below 1 mg/l. While accidental spraying of carbofuran poses a threat to the aquatic environment, a more serious threat is the carbofuran in runoff water from fields or orchards immediately after treatment. Localized fish kills have been reported in such instances.

Light effects on Carbofuran and Fluometuron: Impact on natural waters. Spectrophotometric study

“…Many studies have been conducted to evaluate the degradation of pesticides and to determine their future in the environment (Trotter Kent and Wong, 1991;Kim, In Seon, et al, 2004;Otieno, Lalah, Virani, Jondiko and Schramm, 2010;Hernandez-Moreno, Perez-Lopez, Solera, Gravato and Guilhermino, 2011;H'meidy O. I. et al, 2012;Benicha, Mrabet and Azmani, 2013). These results showed that carbamates are stable in acidic or neutral media.…”

“…Those done on Carbofuran with several experimental animals showed that it is an inhibitor of acetyl cholinesterase (AChE), (National Research Council of Canada, 1979;FAO/OMS, 1981;Trotter Kent and Wong, 1991;Haubruge, Amichot, 1998;Bretaud Saglio and Toutant, 2001;EPA., 2006;Otieno, Lalah, Virani, Jondiko, and Schramm, 2010;Health Canada, 2013;Salman, 2013;Santé Canada, 2013. On the contrary, the results of the toxicity study on Fluometuron has shown that this product is not toxic, neither by oral ingestion, with a DL50 for the rat included between 6416-8900 mg/kg, (WSSA, 1994;Halladja, 2008), nor by dermal way with a DL50 superior to 200 mg/kg for the rat and superior to 100 mg/kg for the rabbit.…”

Physiological Responses of Fathead Minnow Larvae to Rice Pesticides

“…Carbofuran is a neurotoxin (Trotter et al, 1991) as are the organochlorine insecticides. The latter have been shown to increase sensitivity of fish to external stimuli (reviewed by Heath, 1995).…”

Effets de l'exposition à un insecticide carbamate, le carbofuran, sur les performances de jeunes stades de brochet (Esox lucius L., 1758) : résultats préliminaires

“…Cependant, dans le contexte particulier de la contamination des eaux superficielles par des pesticides en Bretagne, le risque d'observer chez le brochet les altérations décrites ci-dessus paraît faible, compte tenu du niveau modéré des concentrations maximales enregistrées (0,2-0,3 pg.L 1 ; GUIHO, 1995) et du caractère fugace de la présence du carbofuran dans ces eaux. L'éventualité d'une accumulation de carbofuran dans certains tissus des jeunes stades de brochet et d'une toxicité à des stades ultérieurs du cycle vital est peu vraisemblable, plusieurs études ayant montré l'absence d'une bioconcentration significative de ce composé chez les poissons et l'élimination rapide des metabolites du carbofuran par les poissons, après arrêt de l'exposition (revue par TROTTER et al, 1991).…”