Wendy,
Paraoxon(e) is an active metabolite of parathion, a rather potent organop
hosphate insecticide. You'll find a nice quick-'n'-dirty review in
HSDB (got to www.nlm.nih.gov, clic
k on Environmental etc. from the menu on the left, and choose HSDB from t
he database list). In the same place, you'll find 2,164 hits in
the TOXLINE bibliographic database. In PubMed, you'll find 1,8
23 hits.
Overall, when someone says "X is _____ times more toxic than Y", they a
re usually refering to LD50 or LC50 values ratio and it really isn't that X
is more "toxic" than Y if they have the same mechanism of action, it's t
hat X is more "potent" than Y. Whether paraoxon(e) is more potent t
han parathion may depend on the species exposed. Insects convert pa
rathion to the more potent paroxon(e) more rapidly than humans, and this
is part of the basis for parathion's use an an insecticide.
Paraoxon(e) would most likely be found in the lab as a liquid with often an
organic solvent base such as toluene, xylene, or kerosene, and it is
(as are all organophosphate insecticides), extremely well aborbed throug
h the skin. Proper skin PPE should be worn at all times. It
can also be aerosolized in certain circumstances and is very well a
bsorbed through the respiratory route as well, so consideration to respir
atory protection and exhaust ventilation should be given.
If a researcher were to be exposed and absorb a sufficient quantity
, the poisoning would be that of all of this class of agents: cho
linergic poisoning from inhibition of acetylcholinesterase in synapses with
both muscarinic effects (DUMBELS: Diarrhea, Urination,
Miosis [pinpoint pupils], Bradycardia, Bronchorrhea, Bronchospasm,
Emesis, Lacrimation, Salivation, Secretion, Sweating), nicotinic
effects (Days-of-the Week: Mydriasis (large pupils), Tachycardia
, Weakness, Hypertension, Hyperglycemia, Fasciculations), and the
"3-Cs" of Central Nervous System effects (Confusion, Convulsions
, Coma) as we teach it in the Advanced HAZMAT Life Support course (AHLS).
Hope this is useful.
Alan
Alan H. Hall, M.D.
Medical Toxicologist
AHLS Provider and Instructor
ahalltoxic**At_Symbol_Here**msn.com
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