Aldicarb toxicity

Channel catfish were shown to be more resistant to aldicarb toxicity compared to rainbow trout62. This species difference is partly explained by the differences in... 

El-Alfy, A. and D. Schlenk. Potential mechanisms of the enhancement of aldicarb toxicity to Japanese medaka, Oryzias latipes, at high salinity. Toxicol. Appl. Pharmacol. 152 175—183, 1998. 

Wang, J., S. Grisle and D. Schlenk. Effects of salinity on aldicarb toxicity in juvenile rainbow trout (Oncorhynchus mykiss) and striped bass (Morone saxatilis X chrysops). Toxicol. Sci. 64 200-207, 2001. 

Wang et al. (2001) investigated the effect of salinity of water on the toxicity of aldicarb in fishes. Their stndies indicated that salinity-mediated enhancement of aldicarb toxicity was species-dependent. In rainbow tront, salinity increased the toxicity of aldicarb, the effect attribnted to greater sulfoxidation to aldicarb snlfoxide cansed by increased flavin-containing monooxygenase and the catalytic activities in microsomes of liver, gill and kidney of rainbow trout. 

Perkins (Jr), E. and D. Schlenk. 2000. Role of biotransformation in determining aldicarb toxicity in fish. Marine Environ. Res. 50(1-5) 79. 

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. 

Since 1945 the use of synthetic pesticides in the United States has grown 33-fold. The amounts of herbicides, insecticides, and fungicides used have changed with time due, in large part, to changes in agricultural practices and cosmetic standards (14, 15). At the same time, the toxicity and biological effectiveness of these pesticides have increased at least 10-fold (15). For example, in 1945 DDT was applied at a rate of about 2 kg/ha. With the more potent insecticides available now, similar effective insect control is achieved with pyrethroids and aldicarb applied at 0.1 kg/ha and 0.05 kg/ha, respectively. 

EPA. 1981a. Acephate, aldicarb, carbophenothion, DBF, EPN, ethoprop, methyl parathion, and phorate Their acute and chronic toxicity, bioconcentration potential and persistence as related to marine environments. Gulf Breeze, FL U.S. Environmental Protection Agency, Environmental Research Laboratory. EPA-600/4-81/04L NTIS PB81-244477. 1-275. 

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. 

Oxime carbamates are generally applied either directly to the tilled soil or sprayed on crops. One of the advantages of oxime carbamates is their short persistence on plants. They are readily degraded into their metabolites shortly after application. However, some of these metabolites have insecticidal properties even more potent than those of the parent compound. For example, the oxidative product of aldicarb is aldicarb sulfoxide, which is observed to be 10-20 times more active as a cholinesterase inhibitor than aldicarb. Other oxime carbamates (e.g., methomyl) have degradates which show no insecticidal activity, have low to negligible ecotoxicity and mammalian toxicity relative to the parent, and are normally nondetectable in crops. Therefore, the residue definition may include the parent oxime carbamate (e.g., methomyl) or parent and metabolites (e.g., aldicarb and its sulfoxide and sulfone metabolites). The tolerance or maximum residue limit (MRL) of pesticides on any food commodity is based on the highest residue concentration detected on mature crops at harvest or the LOQ of the method submitted for enforcement purposes if no detectable residues are found. For example, the tolerances of methomyl in US food commodities range from 0.1 to 6 mg kg for food items and up to 40 mg kg for feed items. ... 

As Muller had prophesied and indeed hoped, DDT stimulated the discovery of more synthetic insecticides. DDT relatives included chlordane, toxaphene, aldrin, dieldrin, endrin, and heptachlor. Popular substitutes for DDT s family included organophosphates such as parathion, which is a powerful neurotoxin, and carbamates, which are also highly toxic to people. Unlike DDT, parathion and aldicarb have killed and injured many farm workers. Malathion was later developed to be several hundred times less toxic than parathion. 

The most toxic of the pesticides used in the USSR was the systemic insectoacaricide aldicarb (FD5o=0.93 mg/kg), which breaks down in the soil, forming the also highly toxic sulfoxide and sulfone. The herbicide propanile transforms in the soil into a dioxin-like substance [38]. 

Moore, M.T., D.B. Huggett, W.B. Gillespie Jr., J.H. Rodgers Jr., and C.M. Cooper. 1998. Comparative toxicity of chlordane, chlorpyrifos, and aldicarb to four aquatic testing organisms. Arch. Environ. Contam. Toxicol. 34 152-157. 

Information about exposure to infants, children, and other subgroups is then combined with toxicity information to determine the potential risks posed. If risks are unacceptable, the FDA and EPA will not approve the tolerances. Some of the EPA s recent important regulatory decisions, for example, were based on concerns about childhood or infant exposures, such as the elimination of the use of aldicarb on bananas and EBDCs on a number of fruits and vegetables. 

Goldman, L.R., Beller, M., and Jackson, R.J. (1990). Aldicarb food poisonings in California, 1985-1988 toxicity estimates for humans. Arch. Environ. Health, 45, 141-147. 

Edmiston, C.E., Jr., Goheen, M., Malaney, G.W., and Mills, W.E. Evaluation of carbamate toxicity acute toxicity in a culture of Paramecium multlmlcronucleatum upon exposure to aldicarb, carbaryl, and mexacarbate as measured by a Warburg respirometry and acute plate assay. Environ. Res., 36(2) 338-350, 1985. 

A third important carbamate is aldicarb or Temik , an insecticide and nematocide for potato and vegetable crops. This chemical has been foimd in water wells in 11 states above the 1 ppm EPA safety threshold, barring use in some locales in 1982. According to Union Carbide, one manufacturer, humans can safely ingest 500 ppb. But it is one of the most acutely toxic pesticides registered by the EPA. A fourth carbamate insecticide is methomyl. 

Carbamates act similar to organophosphates by interfering with nerve system enzymes. They are derived from carbamic acid, H NCOOH, and share many of the properties of organophosphates (Figure 18.9). The carbamate known as carbaryl (commercial trade name is Sevin) was synthesized in 1956 and has been used extensively since that time. Carbaryl s advantages are that its toxicity to mammals is low and it kills a broad spectrum of insects. It is widely used in a number of household lawn and garden products. Other common carbamates include aldicarb (Temik) and carbofuran (Furadan). 

DW Woodham, RG Reeves, RR Edwards. Total toxic aldicarb residues in weeds, grasses, and wildlife from the Texas high plains following a soil treatment with the insecticide. J Agric Food Chem 21 604-607, 1973. 

An example of an extremely toxic carbamate is aldicarb [2-methyl-2-(methylthio) propionaldehyde]. Both oral and dermal routes are the primary portals of entry, and it has an oral LD50 of 1.0 mg/kg (rat)and a dermal LD50 of 20 mg/kg (rabbit). For this reason it is recommended for application to soils on crops such as cotton, citrus, and sweet potatoes. This compound moves readily through soil profiles and has contaminated groundwater supplies. 

Perkins Jr, E.J. and Schlenk, D. (2000) In vivo acetylcholinesterase inhibition, metabolism, and toxicokinetics of aldicarb in channel catfish role of biotransformation in acute toxicity, Toxicological Sciences 53 (2), 308-315. 

Carbamate pesticides A salt or ester of carbamic acid used as a pesticide and known to cause death of animals at high concentrations. Aldicarb is effective against thrips, aphids, spider mites, lygus, fleahoppers, and leafminers but is mainly used against nematodes. Carbofuran is the most toxic of the carbamate pesticides used to control insects in potatoes, corn, and soybeans. Carbaryl kills beneficial insect and crustacean species along with the target pests. 2-(i-Methylpropyl)phenyl methylcarbamate is used as an insecticide on rice and cotton. 

Aldicarb Extremely toxic, even in very small concentrations... 

Uses Aldicarb is a white crystalline solid. It is formulated as a granular mix (10% to 15% active ingredient) because it is extremely toxic. It is not compatible with alkaline materials and is noncorrosive to metals and plastics. The systemic... 

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