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quote:Malathion is an organophosphate parasympathomimetic which binds irreversibly to cholinesterase.Malathion is an insecticide of relatively low human toxicity.However, Malathion breaks down into Malaoxon, which is 60 times more toxic than Malathion. For this reason, if Malathion is used or somehow enters an indoor environment, as it breaks down into Malaoxon, it can seriously and chronically poison the occupants living or working in this environmnent.In 1976, numerous malaria workers in Pakistan were poisoned by isomalathion, a common impurity in malathion, which is capable of inhibiting carboxyesterase enzymes in those exposed to it; the original toxicity evaluation for malathion had not anticipated isomalathion coexposure.
quote:The potential of a single dose of malaoxon (26.2 or 39.2 mg/kg i.p.) to produce convulsions and to increase cerebral levels of inositol-1-phosphate (Ins1P), an intermediate in phosphoinositide (PI) cycle, was followed for 1, 4, or 72 hr. The lower dose of malaoxon did not produce convulsions whereas the higher dose induced convulsions in 60% of the exposed rats. Malaoxon caused a dose-dependent, at most 2-fold, increase in brain regional Ins1P levels in nonconvulsing rats as compared to controls. At the higher dose of malaoxon, in convulsing rats, the Ins1P-levels increased 4-fold above the control Ins1P-levels. In nonconvulsing rats, the Ins1P-levels reached their maximum 1-4 hr after the administration of malaoxon, whereas in convulsing rats the levels increased for 72 hr. The results suggest that PI-signalling is associated with convulsions produced by malaoxon.
quote:In trying to calm the fears of Tampa residents, representatives for the Florida Department of Agriculture have made public statements that after application, malathion "breaks-down" in a matter of hours. What they don't tell you is that malathion can actually break-down into compounds which are more poisonous than the malathion itself. This is, in fact, the conclusion of research from a graduate project by researcher N. E. Barlas at the Department of Biology, Hacetepe University, Turkey. Barlas went on to say, "The disappearance of pesticide residues at a given location does not mean the end of the problem. Pesticides can be translocated, bioconcentrated or converted into more dangerous chemicals." The breakdown fate of malathion was studied by adding malathion to soil samples containing 6 species of soil bacteria known to breakdown the pesticide. After 10 days the samples were analyzed. Malathion content had reduced from 100 down to 25 micrograms, so therefore, the Florida Department of Agriculture spokes people are correct when they say it "breaks down" relatively quickly (although in this case not in a matter of hours). However, even more important, Barlas found that new chemicals were formed in this breakdown process including 14 micrograms of monocarboxylic acid and about 8 micrograms of the highly toxic malaoxon. Barlas then exposed mice to the technical grade malathion and another group to the breakdown products just mentioned. Results showed even the mice exposed to the break-down products of malathion showed significant decreases in spleen weights and significant changes in liver blood tests which were suggestive of liver damage. Barlas summarized by stating, "It may be concluded that commercial malathion and it's degradation products together have detrimental effects on mice over a period of 15 weeks of treatment." Department of Biology, Faculty of Science, Hacettepe University, Turkey
quote:Almost 300 pupils and teachers of the Signal Hill Government Primary School had to be evacuated yesterday because of a chemical leak emanating from the nearby Public Health Department compound at Signal Hill. In addition, 80 employees of the Medical Transcription Centre and another 50 employees of the Public Health department had to abandon their jobs to seek refuge from the area. The offices were closed for the day. The drama started when two pupils and a teacher began vomiting during assembly around 8.30 a.m. An ambulance was summoned but by the time it arrived, ten other pupils complained of feeling unwell. They and the teacher were rushed to the Scarborough Regional Hospital where they were treated and discharged. Other teachers on staff were advised by the Trinidad and Tobago Unified Teachers' Association to also seek medical treatment. School teacher Anderson Charles said he was in charge of Morning Assembly when they began to get a scent of a chemical substance. "Soon pupils began complaining of feeling unwell and some began vomiting," he said. Units from the Scarborough Fire Station and the Police responded to the emergency around 9.15 a.m. and assisted in taking pupils in buses to safety at the Red Cross headquarters building, a half mile away. Fire Station Officer Carlston Edwards confirmed to the Express that the pupils had inhaled something that smelled like a chemical. Edwards said the chemical turned out to be Malathion used in spraying insects. It was stored in 45-gallon barrels on the eastern end of the compound.