Infants' bodies expel thimerosal mercury much faster than originally thought

[Guest guest]

Must be alright then, mustn't it? How could we ever think that it might be

harmful! And it is such a relief to these people that they haven't got to

remove it after all for all the third world countries.

This article makes me fume....not that you'd ever know!!!

Sue

http://www.news-medical.net/?id=34855

Infants' bodies expel thimerosal mercury much faster than originally thought

Child Health News

Published: Monday, 4-Feb-2008

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February's issue of Pediatrics offers another reason to rethink blaming the

spike in autism diagnoses on thimerosal, a mercury-containing preservative

routinely used in several childhood vaccines until the late '90s.

New research from the University of Rochester suggests that infants' bodies

expel the thimerosal mercury much faster than originally thought - thereby

leaving little chance for a progressive building up of the toxic metal. This

debunks the great myth, believed by both parents and some pediatricians,

that the gauntlet of thimerosal-containing shots many infants received in

the 1990s - when the average number of vaccines kids received increased

sharply - had put them at risk for developmental disorders.

" Thimerosal has been used for decades, but the surge in vaccinations caused

fear that possible accumulations of ethyl mercury, the kind in thimerosal,

might exceed safe levels - at least, when based on the stringent risk

guidelines applied to its better-understood chemical cousin, methyl mercury,

which is associated with eating fish, " said Pichichero, M.D.,

professor of Microbiology/Immunology, Pediatrics and Medicine at the

University of Rochester and the study's main author.

But scientists are learning that the two mercury species actually behave

quite differently; in fact, the body rids the kind found in thimerosal more

that 10 times faster than it removes the kind one might encounter in a

Friday night fish fry.

In the Rochester study, 216 infants from R. Gutierrez Children's Hospital

(in Buenos Aires, Argentina, where thimerosal is still routinely used in

vaccines) were divided into three age groups to have their blood-mercury

levels tested both before and after shots were administered at either their

newborn, 2- or 6-month checkup. Researchers learned that, in all three age

groups, the half-life of ethyl mercury in the blood - or, the time it takes

for the body to dispose of half the mercury, and then another half, and so

on - was measured to be 3.7 days. That's a far cry from the blood half-life

of methyl mercury, which is 44 days.

" Until recently, that longer half-life was assumed to be the rule for both

types of mercury. Now it's obvious that ethyl mercury's short half-life

prevents toxic build-up from occurring. It's just gone too fast, " Pichichero

said.

To illustrate, researchers cite that infants in the 6-month-old group - who,

in their lifetimes, had encountered more total ethyl mercury that any other

group studied - still had the same pre-vaccination blood-mercury levels

before their checkups as most 2-month-olds had before theirs. This suggests

that, before each round of shots, the mercury has plenty of time to be

cleared.

The study also showed that ethyl mercury was nearly undetectable in urine

samples; instead, it seemed that most of it was eliminated via stools. That

s good, because mercury in large amounts is toxic to kidneys - yet in the

study sample, there was no evidence of any harm to renal tissues.

These findings come in the wake of recent news from the California

Department of Health, which reported last month that autism rates continue

to mushroom in spite of the widespread removal of thimerosal from most U.S.

Childhood vaccines in 2001, though it continues to be used in vaccines used

elsewhere in the world.

Thimerosal, hailed for its bacteria-killing properties, has been a vaccine

staple ingredient since the 1930s. But when the Environmental Protection

Agency announced in 1999 that the cumulative exposure children typically

received in vaccines might exceed a safe level for intake based on methyl

mercury statistics (even this " safe level " was placed ten times lower than

the amount held to pose real risk), public health officials, together with

the American Academy of Pediatrics, recommended its removal - though still

without concrete evidence of harm. The decision demanded a new formulation

be created and administered - at a higher cost.

" Though it's reassuring to affirm that these immunizations have always been

safe, our findings really have greater implications for world health, "

Pichichero said. " Replacing the thimerosal in vaccines globally would put

these vaccines beyond what the world community could afford for its children

It's a relief we haven't cause to do that. "

http://www.urmc.rochester.edu/