In article ,
Phisherman wrote:

Malathion
http://en.wikipedia.org/wiki/Malathion

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
environment. Malathion present in untreated water is converted to
malaoxon during the chlorination phase of water treatment, so malathion
should not be used in waters that may be used as a source for drinking
water, or any upstream waters.

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.
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FB - FFF

Billy
http://angryarab.blogspot.com/