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mill effluent chloro-xanthene as toxic as tcdd; great lakes; cardiovascular
some may have seen janet ralloff's newest, fascinating as always, dioxin
research update in _science news_ ('those old dioxin blues', 151:306-7, 17
after reviewing blue sac syndrome in fish fry, and the acute
sensitivity--LC50 of 60 ppt--of tcdd to lake trout fry (a top predator and
a key species to great lakes ecosystem balance; 400 ppt for rainbow trout),
she goes on to say that a recently identified paper mill effluent compound,
2,3,6,7-tetrachloroxanthene is as toxic (not quantified here) in inducing
blue sac syndrome as 2,3,7,8-tcdd (work of good old richard peterson, and
erik zabel, @ u. wi/madison).
the brominated 2,3,7,8-tbdd is more potent than it chlorinated analog at
inducing blue sac. source is largely the increasing testing of brominated
fire retardants; and, various brominated biphenyls are 10 times as potent
as their pcb analogues. (peterson et al., october '96 _tox & appl.
present in an unamed compound used to kill lamprey eel is a fluorine
substituted--3F, 1 Cl--dioxin (Environment Canada scientist mark servos).
john geisy et al. of mich. state u. have evidence that some pcb damage
immune T cells, which may have contributed to 1989 great lakes fish
die-offs from bacterial kidney disease [inter alia, presumably].
regarding the mechanism of blue sac syndrome:
consistent w/ finding the Ah receptor in fish, whales, mussels and lobsters
by mark hahn @ woods hole, don tillitt of usgs & mark hannink of u.
missouri find that the blood vessels of tcdd exposed fry are induced into
inappropriate programmed cell death [a key defence against cancer, btw, &
n.b. because of tcdd's cancer associations], which maybe due to tcdd's
ability to express genes that produce oxidative enzymes (john stegeman and
jenifer schlesinger @ woods hole). meanwhile peterson in collaboration w/
unmaned cornell u. scientists have discovered their pollutants slow both
the blood flow & heart rate of zebra fish, and "prune back" the number of
blood vessels and the ability to maintain new ones.
sounds like excellent work on the mechanistic end of things.
epidemeologicly, tcdd & pcdd/f are already associated w/ cardiovascular
disease. let's see: mechanistic .. epidemeologic .. and lab animal
evidence ... hmmn ... dr. lynn goldman, head of epa's oppt, needs to stick
this in her pipe, and smoke it!