Joseph G. Kunkel
joe at bio.umass.edu
Sun Nov 1 09:59:46 EST 1998
Another point to add is that concentrating on LD50s is not what we want
either. If we want to kill a population we might want to know the LD99
dose, i.e. what dose will kill 99% of the population. To spare a
population we would want to know the LD01 or LD001 dose, the doses at
which 99 of 100 or 999 of 1000 would survive. If then we go to 1/100 of
that dose I would start not to feel afraid for my life.
I cheer Neil's comment that LDs lethal doses are not what we want to
concentrate on for quality-of-life situations and the use of
insecticides/fumigants. While LD50s are often quoted, any good
toxicology study does present some extension up and down that scale
toward LD99 and LD01. As usual extrapolation from large dose studies
(lethality) do not insure that low dose effects (happiness quotient)
behave in a similar statistical way. Only careful studies on the
phenomenon of interest (i.e. happiness quotient) could establish the
facts. Thus when in doubt avoid the suggestion that a better life
through chemicals is valid. Rather a better life through avoiding
avoidable chemicals should be the rule.
Cheers to Neil.
Neil Jones wrote:
> In article <36286601.AB0 at concentric.net>
> paulcher at CONCENTRIC.NET "Paul Cherubini" writes:
> > Fulvio wrote:
> > > IARC : Group 3, not classifiable as to its carcinogenicity to humans
> > Thanks for pointing out that fairly recently Vapona was (due to the
> > results of new long term animal chronic toxicity studies) DOWNGRADED by
> > the EPA from a Group 2 "possible human carcinogen" to a Group 3 "not
> > classifiable as to it carcinogenicity to humans". In other words,Vapona
> > has not been found to reliably induce cancer in modern animal studies.
> > > SYMPTOM : Miosis, aching eyes; rhinorrhea; headaches; tight chest,
> > > wheezing,laryngeal spasms; salivation; cyanosis; anorexia, nausea,
> > > vomiting,diarrhea; sweating; muscle fasciculation, paralysis,
> > > giddiness, ataxia;convulsions;
> > > low blood pressure; cardiac irregularities; skin, eyeirritation
> > > HEALTH EFFECTS : Cholinesterase inhibition
> > > LD50 (oral,rat)
> > > 56-80 mg/kg
> > This LD 50 of 56-80 mg/kg is based on the 96% LIQUID MANUFACTURING
> > CONCENTRATE that chemical formulating companies use to make the much
> > more diluted consumer end use preparations like the 20% Vapona solid
> > resin strips, the 05% liquid sprays used in dairies and on horses and
> > the 5% liquid sprays used (in automatic fogging systems) to fog food
> > processing plants. If you measured the LD50 of a .05% end use spray it
> > would be well over 1000 mg/kg --more like the ingestion toxicity of
> > table salt.
> > Paul Cherubini, El Dorado, California
> Concentrating on the amount that it would take to kill misses one important
> point. Under health effects is listed Cholinesterase inhibition. This is
> interesting as it indicates that there are effects on brain function.
> The effects will of course differ from person to person and are difficult
> to measure. Everybody's levels of brain chemicals differs and their
> reponse to drugs that affect these varies widely. For example 1%
> of the population may become manic when treated with Prozac
> (an antidepressant).
> One possible effect of cholinesterase inhibition is depression.
> Of course happiness or the lack of it is a very difficult thing to measure.
> Consequently it would be difficult to establish if anyone subjected to
> lowish doses of Vapona were affected.
> It may well at these concentrations require a lot to kill someone but,
> using the table salt analogy, it may well require a lot less to show
> physiological changes, as anyone who has eaten salty food will know.
> It all comes down to a matter of individual choice. As for myself
> I prefer not to come into contact with chemicals which might make me depressed.
> Neil Jones- Neil at nwjones.demon.co.uk http://www.nwjones.demon.co.uk/
> "At some point I had to stand up and be counted. Who speaks for the
> butterflies?" Andrew Lees - The quotation on his memorial at Crymlyn Bog
> National Nature Reserve
Joseph G. Kunkel, Professor
Biology Department joe at bio.umass.edu
University of Massachusetts http://www.bio.umass.edu/biology/kunkel
Amherst MA 01003
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