Dato:  Lør Nov 1, 2003  10:21  
Emne: 
SV: Review article on the toxicology of mercury

"Perhaps side effects at "very low doses" of mercury cannot be
studied in a non-clinical setting, but only where real patients turn
up with their unsolved problems. Side effects are more or less
exceptional reactions, and will easily be overlooked if the patients
are not followed for long enough to see what happens when exposure
has been reduced or eliminated."

Slik sluttet du kommentaren din.

Det ser ut til at vi kan bli enige om en veitrase.

Litt om egen erfaring:
Min bratte vestlandsgård er dramatisk og spennende, som en munn
med sølv og gull. (Bilder på snowboat.no) Men den og nabobrukene
manglet vei. Vi trengte ni km til sammen. Grunneierne (les:
pasientene) slo seg sammen. Jeg valgte å gå som spiss i
ledertroikaen. Det var lærerikt, også som et slags
psykologistudium.
Noen gikk i mot å få vei over sin eiendom (les: EMF/Hg kan
umulig stå bak mine helseproblemer).

Et tjuetall høringsinstanser skulle først uttale seg (les:
bivirkningsnemnd, legeforening, tannlegeforening,
universitetsklinikker osv.) Nesten samtlige stilte seg negative til
den nødvendige reguleringsplanen og veifremføringen.

Men de avgjørende myndigheter (les: statlige helsemyndigheter)
valgte å støtte vår argumentering og våre valg av
veitraseer.

Vi bygget veinettet. For mitt vedkommende med stor egeninnsats.

Hva holder vi på med her og nå?
Hvem er våre samarbeidspartnere?
Hvem er våre motstandere?

Mvh
Tor Johnsen

P.S.
Beklager at jeg ikke har lyst til å være mer konkret akkurat
nå.

--- I nordbiomed@y...
, Per Dalen <pdalen@s...>
> This week's issue of the New England Journal of Medicine carries a
review
> article entitled "Current Concepts: The Toxicology of Mercury --
Current
> Exposures and Clinical Manifestations" by Thomas W. Clarkson,
Ph.D., Laszlo
> Magos, M.D., and Gary J. Myers, M.D. (Vol 349:1731-1737)
> (<
http://content.nejm.org/cgi/content/short/349/18/1731?query=TOC>)
>
> The second paragraph of the article starts on a promising note, but
ends in
> uncertainty:
>
> "Today, however, exposure of the general population comes from
three major
> sources: fish consumption, dental amalgams, and vaccines. Each has
its own
> characteristic form of mercury and distinctive toxicologic profile
and
> clinical symptoms. Dental amalgams emit mercury vapor that is
inhaled and
> absorbed into the bloodstream. Dentists and anyone with an amalgam
filling
> are exposed to this form of mercury. <snip> Humans are also exposed
to two
> distinct but related organic forms, methyl mercury (CH3Hg+) and
ethyl
> mercury (CH3CH2Hg+). Fish are the main if not the only source of
methyl
> mercury, since it is no longer used as a fungicide. In many
countries,
> babies are exposed to ethyl mercury through vaccination, since this
form is
> the active ingredient of the preservative thimerosal used in
vaccines.
> Whereas removal of certain forms of mercury, such as that in blood-
pressure
> cuffs, will not cause increased health risks, removal of each of
the three
> major sources described in this article entails health risks and
thus poses
> a dilemma to the health professional."
>
> And further:
>
> "Nevertheless, amalgam fillings are the chief source of exposure to
mercury
> vapor in the general population. Brain, blood, and urinary
concentrations
> correlate with the number of amalgam surfaces present. It has been
> estimated that 10 amalgam surfaces would raise urinary
concentrations by 1
> µg of mercury per liter, roughly doubling the background
concentrations.
> Higher urinary concentrations are found in persons who chew a great
deal.
> For example, the long-term use of nicotine chewing gum will raise
urinary
> concentrations close to occupational health limits. The removal of
amalgam
> fillings can also cause temporary elevations in blood
concentrations, since
> the process transiently increases the amount of mercury vapor
inhaled."
>
> The authors seem to be firmly grounded in the tradition of
occupational
> health limits, and concentrations in blood and urine. From a
clinical point
> of view this is somewhat sterile. Side effects of *drugs* usually
occur at
> ordinary (non-toxic) dosage levels in a minority of patients who
are
> abnormally sensitive. There is no reason whatever that mercury
should be
> different in this respect. (The authors mention the concept of
sensitivity
> only once, when dealing with acrodynia: "It is believed to be a
> hypersensitivity reaction.")
>
> "Current concern arises from claims that long-term exposure to low
> concentrations of mercury vapor from amalgams either causes or
exacerbates
> degenerative diseases such as amyotrophic lateral sclerosis,
Alzheimer's
> disease, multiple sclerosis, and Parkinson's disease. Speculation
has been
> most intense with respect to Alzheimer's disease after a report
that the
> brains of patients with Alzheimer's disease had elevated mercury
> concentrations. However, several epidemiologic investigations
failed to
> provide evidence of a role of amalgam in these degenerative
diseases,
> including a long-term study of 1462 women in Sweden
> [<
http://shorl.com/bobaprufosofu>], an ongoing Swedish twin study
involving
> 587 subjects [<
http://shorl.com/gygremujyposa>], and a study of 129
nuns 75
> to 102 years of age, which included eight tests of cognitive
function
> [<
http://shorl.com/hiruvutolabe>]. Nevertheless, in vitro studies
have
> indicated that mercury can affect the biochemical processes
believed to be
> involved in Alzheimer's disease. The problem is that mercury can
inhibit
> various biochemical processes in vitro without having the same
effect in vivo."
>
> The three epidemiologic studies mentioned here were all designed
with the
> tacit but unwarranted assumption that any side effects of dental
amalgam
> must be dose-dependent -- "the dose makes the poison". It is
interesting,
> by the way, that Paracelsus (1493-1541) seems to have coined this
still
> popular phrase when defending himself against reproaches for
introducing
> mercury in therapeutics in spite of this metal's notorious toxicity.
>
> The epidemiologic studies cited above each include less than 1000
subjects.
> (A large proportion of the 1462 women in the first-mentioned study
were
> younger than 75 at their last follow-up). If those had been studies
of the
> side effects of a drug, the detection threshold would have
corresponded to
> an incidence of at least several percent. Less common side effects
than
> that would have been missed completely!
>
> "Patients who have questions about the potential relation between
mercury
> and degenerative diseases can be assured that the available
evidence shows
> no connection. Some will ask whether their mercury fillings should
be
> removed. They should be reminded that the process of removal
generates
> mercury vapor and that blood concentrations will subsequently rise
> substantially before they eventually decline. There is no clear
evidence
> supporting the removal of amalgams."
>
> This is the conservative conclusion as far as amalgam is concerned.
>
> Then to thimerosal, and the general conclusion:
>
> "Given the short half-life of ethyl mercury, any risks of its
damaging
> either the brain or kidneys would seem remote. A World Health
Organization
> advisory committee recently concluded that it is safe to continue
using
> thimerosal in vaccines. This is especially important in developing
> countries, where the use of a preservative is essential in
multidose vials.
> The known risk of infectious diseases far exceeds that of the
hypothetical
> risk of thimerosal. Claims have been made that thimerosal in
vaccines may
> be a cause of autism and related disorders, but studies testing
that theory
> have yet to be performed."
>
> "All forms of mercury have adverse effects on health at high doses.
> However, the evidence that exposure to very low doses of mercury
from fish
> consumption, the receipt of dental amalgams, or thimerosal in
vaccines has
> adverse effects is open to wide interpretation. Moreover, attempts
to
> reduce such exposure may pose greater health risks than those
hypothesized
> to occur from mercury."
> <end of article>
>
> Perhaps side effects at "very low doses" of mercury cannot be
studied in a
> non-clinical setting, but only where real patients turn up with
their
> unsolved problems. Side effects are more or less exceptional
reactions, and
> will easily be overlooked if the patients are not followed for long
enough
> to see what happens when exposure has been reduced or eliminated.
>
> Per
>
> Per Dalen <pdalen@s...>
> Per Dalen <pdalen@s...>



 

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