Insecticides accidental poisoning

These compounds are mainly used as agricultural and household insecticides. The poisoning may be occupational (for those who are involved professionally with these agents), accidental (accidental consumption) or suicidal due to intentional ingestion of these compounds. 

The amount of the pesticides present in different autopsled tissues received from fatal cases of poisoning have been estimated quantitatively in our laboratory. In accidental poisoning cases where vapors of insecticides are inhaled, no insecticide is likely to be detected in the stomach or intestine but considerable amounts may be detected in the lungs, brain, and blood. 

There are many different cholinesterase inhibitors which find use, particularly as insecticides but also as nerve gases for use in chemical warfare. Organophosphorus insecticides are the most widely used and the most frequently involved in fatal human poisonings. They may be absorbed through the skin and there have been accidental poisoning cases arising from such exposure. Accidental contamination of food with insecticides such as parathion has led to a significant number of deaths. There are two types of toxic effects inhibition of cholinesterases and delayed neuropathy. 

The phosphorothioates and phosphorodithioates, shown in Table 1 of Chapter 2, were developed when the nerve agents were found to be too toxic and volatile for use in agriculture. These OP insecticides contain a P-S-alkyl and/ or a P=S group in their structure. The best known member of this class is parathion, the most widely used insecticide at one time and responsible for more cases of accidental poisoning and death than any other OP compound. The activation and conversion of this weak AChEI (parathion) to the more active and potent form (paraoxon) was demonstrated to lake place in the liver (Diggle and Gage, 1951 Gage, 1953). 

The toxicides of organophosphate insecticides vary a great deal. Their major toxic effect is inhibition of acetylcholinesterase, an enzyme essential for nerve function. For example, as little as 120 mg of parathion has been known to kill an adult human and a dose of 2 mg has killed a child. Most accidental poisonings have occurred by absorption through the skin. Since its use began, several hundred people have been killed by parathion. 

Heavy metals on or in vegetation and water have been and continue to be toxic to animals and fish. Arsenic and lead from smelters, molybdenum from steel plants, and mercury from chlorine-caustic plants are major offenders. Poisoning of aquatic life by mercury is relatively new, whereas the toxic effects of the other metals have been largely eliminated by proper control of industrial emissions. Gaseous (and particulate) fluorides have caused injury and damage to a wide variety of animals—domestic and wild—as well as to fish. Accidental effects resulting from insecticides and nerve gas have been reported. 

Data recorded in Tables III and IV shows the amount of the insecticide in the unchanged form. However, most of the tissues also contain the metabolite of the insecticide. From the above discussion it is evident that the study of the distribution of pesticides in different tissues and body fluids can help in resolving the questions of how and when the pesticide was administered. Furthermore, the clue regarding the nature of poisoning whether suicidal, homicidal or accidental can also be obtained by careful study of the distribution pattern of the insecticides in body tissues and fluids derived by quantitative TLC. 

The commercial applications of thallium are limited, and at present there are no bulk consumers. Consumption of thallium in the United States has fallen steadily from 1.4 tons in 1987 to 0.3 tons in 1998. Previously, though, over a period from 1920 to 1970, several tons of thallium were used each year in the form of insecticides and rodenticides. However, many countries have terminated its use because of accidental or secondary poisoning of wild animals and birds even children have been known to be severely poisoned as a result of ingesting thallium-containing bait. 

Fluoride poisoning can occur after chronic ingestion of excessive amounts of fluoride, causing osteosclerosis and dental fluorosis (mottled enamel), due to accidental ingestion of fluoride mixtures during dental treatment (7,8), or after ingestion of insecticides or rodenticides containing fluoride salts. 

Ingestion is the most frequent route of exposure. Exposure can also occur following instillation of eye solutions and via subcutaneous, intramuscular, intravenous, and inhalation routes. Accidental overdosage may occur when atropine is administered for the treatment of organophosphate or carbamate insecticide poisoning. 

The chlorinated hydrocarbons were among the first synthetic insecticide compounds to be used but have fallen into disfavor because of their persistence in the environment. Typical examples of chlorinated hydrocarbon insecticides are DDT, lindane, and to-xaphene. The toxicity of these compounds in small animals is characterized by severe CNS effects, including ataxia and convulsions. Small animals usually get poisoned by being accidentally sprayed or by... 

Estimates of the number of people injured by pesticides vary widely but may be 100-times the accidental death rate on a worldwide basis (j5, 6). In 1985, 2500 occupationally-related accidental pesticide poisonings were officially reported in California and the real number of injuries may be considerably higher. Neither is the record of safety in pesticide manufacturing in the USA unblemished. Serious injuries to workers involved in manufacturing the insecticide chlordecone, the nematicide dibromochloropropane (DBCP), and, possibly, the insecticide leptophos have been reported in the last 15 years (4, ). There is preliminary but disquieting epidemiological evidence that frequent users of some herbicides may have an elevated risk of contracting cancer, particularly if standard safety precautions are not observed (e.g. 7.,8). 

There are a lot of examples of fatal accidental massive poisonings, such as the Bhopal catastrophe caused by a leak of 4,000 tons of methylisocyanate, used in manufacturing of the insecticide carbaryl, from the Union Carbide facility in... 

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