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Thimerosal - vedi anche:
Contenuto dei Vaccini
Il timerosal è un composto costituito da circa il 50% di
mercurio che è il secondo
elemento più velenoso che l'uomo conosca (accanto a uranio
ei suoi derivati.)
Quando qualcuno dice: "MERCURY!" Pensiamo subito delle
notizie del bambino a scuola che ha rotto un termometro in
classe di biologia e la ZTA- MAT squadra è stato chiamato e
tutti gli studenti erano in pericolo. Lo sapevate che fanno
grande di un affare (che significa portare nella ZTA-MAT
equipaggio) per meno di mercurio di quello che è contenuto
in 1 vaccino [http://www.epa.gov/mercury/spills/index.htm
] ?
Il timerosal è usato come conservante nei vaccini per
aiutare a prevenire la crescita dei batteri in multi-uso
vaccini. Inoltre, viene utilizzato nel processo di creazione
di un vaccino, e poi attraverso un processo di purificazione
è "rimosso" e solo "traccia" importi a sinistra. In primo
luogo, vi esorto a leggere questo articolo: C'è Thimerosal
nel vaccino antinfluenzale?
Quindi, cerchiamo di discutere
di ciò che di "tracce" si intende. (Se si nota nel
documento, sopra ed accanto a molti dei "Thimerosal" 's, c'è
un asterisco accanto ad essi. L'asterisco indica che "*Dove"
thimerosal" è contrassegnati con l'asterisco (*), cio'
indica che il prodotto dovrebbero essere considerati
equivalente a prodotti "privi di thimerosal".)
Prima di andare avanti, una piccola storia - ero al
supermercato a poco tempo fa guardando una grande borsa di "Stevia"
- la nuova moda in nessun contenuto calorico edulcoranti.
Stavo leggendo sul retro della borsa e sono arrivato a una
piccola macchia in basso che ha dichiarato: "Ogni dose
contiene meno di 2 calorie che la FDA considera
dieteticamente zero." Cosa ?!
Che non ha nemmeno senso! Se qualcosa è detto di essere
"senza calorie", dovrebbe essere privo di calorie, giusto ?
Se qualcosa è calorie in esso, ha calorie in esso. Non è
possibile inserire alcune carote sul bancone e mi dicono non
ci sono le carote sul bancone. Una porzione di Stevia è 1
cucchiaino, per cui supponiamo che 1 cucchiaino contiene 1,9
calorie.
Ricordate, dobbiamo presumere, perché in realtà non so. E
'la FDA che dice che le calorie in Stevia non esistono, ma
solo per il semplice fatto che ci sia questo disclaimer sul
sacchetto ci fa sapere che ci sono, infatti, le carote sul
bancone ... ehm, voglio dire calorie in borsa.
Ma tornando, stiamo andando a dire che ci sono 1,9 calorie
per porzione. Utilizzando Stevia è "tazza per tazza." In
altre parole, si utilizza la stessa quantità di Stevia come
si farebbe con zucchero normale. Così, ho intenzione di fare
qualche fantabulous "a basso contenuto calorico" biscotti al
cioccolato con il mio "no-calorie" Stevia. Sono su una dieta
rigorosa, in modo che tutti ho bisogno di aggiungere fino a
scoprire quante calorie sono nel mio gruppo di biscotti sono
tutti i miei ingredienti tranne lo zucchero, giusto ?
Ma aspetta ... sto aggiungendo 2 tazze di Stevia nel mio
gruppo di cookie. Ci sono 48 cucchiaini da tè in una tazza,
il che significa che sto aggiungendo 96 cucchiaini di Stevia
- che pure sarebbe pari a 182,4 calorie in eccesso. Non c'è
argomento che ha notevolmente ridotto il numero di calorie
nel mio lotto di biscotti rispetto all'utilizzo di zucchero
convenzionale, ma resta il fatto: NO-caloria non è privo di
calorie.
Quindi il fatto che questi
vaccini contenenti timerosal con l'asterisco accanto dice
praticamente la stessa cosa ed è estremamente fuorviante.
Essi dovrebbero essere "considerati equivalenti a prodotti
privi di thimerosal" dà l'illusione che non ci sia il
thimerosal nei vaccini, o almeno non abbastanza per avere di
cui preoccuparsi.
Ma ricordate, se mangio 8 lotti della mia cookie che si
suppone siano a basso contenuto calorico a causa del mio
"senza calorie" Stevia, sto consumando 1,459.2 calorie che
la FDA dice, non sono veramente lì.
Questo può essere applicata ai vaccini pure. Molti
"ben-bambino" check-up comprende fino a 8 vaccini in una
sola seduta.
Così quanto si "traccia"
significa? Secondo il CDC, si dice minore o uguale a 0.3mcg
per dose. Sailhome.org fa un bel lavoro di mettere questo in
prospettiva:
• 2 ppb di mercurio è il limite di mandato in acqua potabile
• 200 ppb mercurio nei rifiuti liquidi rende un pericolo
tossico
• 25.000 ppb si trova in vaccini contro l'influenza bambino
• 50.000 ppb si trova in scatti normale influenza -
consigliato per bambini, donne incinte, gli anziani ...
Anche la matematica ci conferma
su quanti ppb sono contenuti in un "thimerosal libero"
vaccino:
0,3 mcg / 0,5 ml = 0,3 mcg / L = 0,0005
3000 mcg / 5L = 600 mcg / L
1 mg / kg = 1 PPM (definizione formale di PPM)
1 L = 1 KG (densità di acqua o soluzione fisiologica)
1 mcg / L = 1 ppb (in quanto 1 kg e 1 L di acqua sono
equivalenti)
QUINDI:
600 mcg / L = 600 ppb di mercurio contenuto nel vaccino "thimerosal-free"
Vaccino contro l'influenza ha
"solo" 25 mcg di mercurio. Il tiro è 0,5 ml. Facciamo un po
'di matematica:
25 mcg / 0,5 ml =
25 mcg / L = 0,0005
250.000 mcg / 5L = 50.000 mcg / L
- 1 mcg / L = 1 ppb, quindi
In una vaccinazione un soggetto (bambino od adulto) ha
iniettato in se stesso 50.000 ppb di mercurio
Ricordate che 2 ppb di mercurio è il limite di mandato in
acqua potabile e normalmente 200 ppb dovrebbe esserci una
etichetta che dichiari il pericolo di
intossicazione.
Dopo tutte queste informazioni, dobbiamo chiederci: perché
il mercurio è pericoloso ?
Un video di ricerca presso l'Università di Calgary illustra
come il mercurio inibisce non solo la crescita stunt
neurologica, ma la inverte di fatto, o la distrugge.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Thiomersal
"I nostri peggior nemici arrivano a piccole dosi. Il 14
agosto 1996 Karen Wetterhahn, tossicologa e docente di
chimica presso il Dartmouth College si è versata una goccia,
una minuscola particella di dimetilmercurio sulla mano
sinistra. Wetterhahn, alta, magra, forte, era un esperta di
metalli tossici e di come sono in grado di provocare il
cancro, una volta penetrate nelle membrane delle cellule.
Quando si è versata la goccia di veleno lì, nel suo
laboratorio, non si aspettava nulla di quanto stava per
accadere, perché indossava i guanti di lattice. Ciò che
non conosceva l'ha uccisa.
Il dimetilmercurio è stato sufficientemente volatile da
penetrarle il guanto. Cinque mesi più tardi, Wetterhahn ha
cominciato a inciampare nelle porte e a strascicare le
parole. Dopo tre settimane in ospedale è entrata in coma.
"Sono andato a trovarla, ma non era il tipo di coma che mi
aspettavo," ricorda Diane Stearns. una dei suoi studenti
post-dottorato, ora anch'essa docente di chimica. "Si
dimenava, suo marito ha visto le lacrime rigarle il viso. Ho
chiesto se stesse male, ma i medici dicevano che non
risultava che il suo cervello fosse in grado anche solo di
registrare dolore."
Karen Wetterhahn è morta cinque mesi dopo. Aveva 48 anni,
era moglie e madre di due figli. Il mercurio aveva divorato
le sue cellule cerebrali "a poco a poco, come termiti, per
mesi," ha detto uno dei suoi medici."
Tratto da:
Dr. Sherri Tenpenny,
Challenging the Vaccine Dogma, LewRockwell.com, 5 Novembre
2011:
http://lewrockwell.com/orig12/tenpenny2.1.1.html
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
NEW YORK
(USA) VIETA I VACCINI AL MERCURIO
Il Senato di New York ha
vietato la somministrazione di vaccini contenenti “tracce
di mercurio” a bambini di meno di 3 anni e a donne
incinte.
La decisione prende di mira (senza nominarlo esplicitamente)
il thimerosal, un antibatterico al mercurio, prodotto dalla
Eli Lilly, che viene aggiunto da decenni ai più comuni
vaccini.
Esso è ritenuto responsabile di migliaia di casi di
autismo
infantile, essendo il mercurio un potente neurotossico.
La fonte della notizia –
In-Pharma, sito ufficiale delle
industrie farmaceutiche USA –
si premura di precisare che “dal 2000 [sic] i
vaccini per bambini sono disponibili in versioni che non
contengono mercurio (‘Thiomersal-free’) o che lo contengono
solo in tracce…eccettuate le fiale multidose destinate al
Terzo Mondo” [sospiro di sollievo].
La sostanza è già stata vietata
nello Iowa ed in California, ed il divieto sta per essere
sancito anche da Delaware, Florida, Maryland, Massachusettes,
Minnesota, Missouri, Nevada, North Carolina, Ohio, Oregon,
Pennsylvania, Rhode Island, Tennessee, Utah e Washington.
Questa notizia viene fornita a
beneficio speciale di una lettrice che, avendo letto a mia
firma la notizia sul Thimerosal e la sua pericolosità, mi ha
accusato di esagerare per “antiamericanismo”.
Evidentemente molti Stati in USA sono antiamericani.
By Maurizio Blondet
Da:
http://www.effedieffe.com/fdf/giornale/interventi.php?id=510¶metro=scienze
In:
http://www.effedieffe.com/fdf/giornale/giornale.php
vedi: Contenuto di
mercurio nei vaccini in Italia +
Vaccini al mercurio +
Autismo e Vaccini +
Falsita' della
medicina ufficiale +
1000 studi sui Danni dei Vaccini
+
Malassorbimento
+
Vaccini
sicuri ? NO !
+
Meningite dai vaccini
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Thimerosal -
mercurio contenuto nei
vaccini, un nemico che non vuole morire
Tratto dal libro "Le vaccinazioni pediatriche (revisione
delle conoscenze scientifiche" di Roberto Gava - Salus 2008
La Norvegia ha recentemente annunciato un divieto di impiego
del mercurio, comprese le
amalgami dentali,
che è entrato in vigore l'1 gennaio 2008. La Svezia ha
annunciato un analogo divieto ai dentisti e in Danimarca non
sarà più consentito utilizzare i mercurio nelle otturazioni
dopo il 1 aprile 2008. (Le Vaccinazioni Pediatriche - Dott.
Roberto Gava 2008)
Perchè si parla di autismo correlato alle
vaccinazioni ?
Molti autori sostengono che la capacità del mercurio di
causare varie patologie cerebrali, tra cui l'autismo,
risiede proprio nella sua azione neurotossica. Infatti in
questi ultimi anni c'è stata una vera e propria "epidemia"
di casi di autismo negli USA,
perchè si è passati da 1 caso ogni 1.333 bambini a metà
degli anni 80 (7,5 casi/10.000) a 1 caso ogni 323 bambini
alla fine degli anni 90 (31,2 casi/10.000), fino ad arrivare
a 1 caso ogni 166 bambini nel 2004. [1-2-3-4] e 1 ogni 85
nel 2010….
Questo aumento vertiginoso
è iniziato quando negli Stati Uniti sono aumentati
i
vaccini pediatrici
(nei bambini di 0-6 mesi e di 12-24 mesi vengono
iniettati rispettivamente un minimo di 13 e 10 vaccini, con
una dose totale di almeno 275 mcg di mercurio[5]) e la
corrispondente somministrazione di mercurio che è in media
38-129 volte superiore ai limiti di sicurezza stabiliti
dalle linee guida dell'EPA. [6]
Inoltre, uno studio americano ha dimostrato una correlazione
lineare tra l'aumento dell'assunzione pediatrica di mercurio
attraverso i vaccini e l'aumento dell'autismo... [7]
E' stato stimato che circa il 15% della popolazione può
mostrare una suscettibilità aumentata all'esposizione al
mercurio e in questi soggetti accade che i livelli di
etilmercurio trovati 8 giorni dopo le vaccinazioni conducono
all'inibizione del 50% dell'enzima metionina-sintetasi.
A causa di ciò i neuroni diventano incapaci di sintetizzare
la cisteina, che è l'aminoacido limitativo indispensabile
per la sintesi del
glutatione (un antiossidante prodotto sia dal cervello
che dal fegato).
Ne risulta che i neuroni sono più sensibili alla tossicità
al mercurio dal momento che il
glutatione è il maggior
agente intracellulare deputato alla
detossificazione dal
mercurio e da altri metalli
pesanti.
La sintesi della cisteina e del glutatione quindi, sono
cruciali per la detossificazione dal mercurio e questa
sintesi è ridotta nei bambini autistici., forse a causa
anche di un polimorfismo epigenetico [8][9].
Praticamente risulta che i bambini autistici hanno il 20% di
livelli più bassi di cisteina e il 54% di livelli più bassi
di glutatione e questo compromette la loro capacità di
detossificarsi e di espellere i metalli come il mercurio.
[10]
A ciò consegue una più alta concentrazione di mercurio
libero nel
sangue, che poi viene trasferito nei tessuti e
aumenta la vita media del mercurio nel corpo, rispetto a
quanto accade in bambini con livelli normali di cisteina e glutatione.
Come è stato dimostrato da Bradstreet et al [11] in uno
studio a cui hanno partecipato 221 bambini autistici, i
bambini vaccinati mostrano una elevazione
sei volte maggiore del mercurio
urinario rispetto al
gruppo di controllo normale dopo una appropriata
mobilizzazione con l'agente chelante DMSA. La
detossificazione ritardata del mercurio danneggia gravemente
le reazioni di metilazione (richieste per la corretta
espressione del DNA, dell'RNA e dei neurotrasmettitori
cerebrali), che a loro volta influiscono sui fattori di
crescita dello sviluppo del cervello e sulle abilità
attentive.
La metilazione fosfolipidica, che è cruciale per
l'attenzione, è danneggiata nei soggetti autistici, in
quelli con disordini da iperattività e in quelli con deficit
di attenzione.
Recentemente, un gruppo di ricercatori americani ha
esaminato la tossicità del Thimerosal nel corpo umano,
inclusi i neuroni cerebrali. [12] Sono stati esplorati i
meccanismi neurotossici e come il corpo si detossica dal
mercurio grazie anche al glutatione. Quando però questa
sostanza non è prodotta a sufficienza, il mercurio presente
può legarsi con alcune proteine cellulari causando:
- rottura dei filamenti del
DNA
- danni alle membrane
cellulari
- morte cellulare
I ricercatori hanno infatti scoperto che concentrazioni più
elevate di Thimerosal aumentano il numero delle cellule
uccise e che i primi segni di danno cellulare si notano già
tre ore dopo la somministrazione del vaccino
Negli ultimi due anni, gli studi che hanno dimostrato una
relazione stretta tra autismo e mercurio assunto dai bambini
attraverso le vaccinazioni si sono moltiplicati e i loro
autori non hanno avuto dubbi:
"Le evidenze consentono di affermare che i disordini
neurologici in seguito all'uso di vaccini con mercurio non
sono una coincidenza".[13]
"Lo studio dimostra che l'esposizione al mercurio contenuto
nei vaccini pediatrici è un rischio significativo e
consistente per l'aumento dei disordini neurologici".[14]
"Noi abbiamo prodotto evidenze per sostenere l'ipotesi
autismo-mercurio".[15]
Inoltre, nel marzo 2006 è uscito anche un libro che è subito
diventato famoso negli USA: è il libro di David Kirby, [16]
un giornalista medico-scientifico del New York Times che
raccoglie un gran numero di documenti, testimonianze e prove
che dimostrano quanto grande è la responsabilità del
mercurio contenuto nei vaccini pediatrici nel favorire e
scatenare l'autismo.
Il Dr. Mark Geier, presidente dei Genetic Centers of
America, nel 2003 ha pubblicato un interessante studio in
cui ha correlato l'aumento della dose di mercurio assunta
dai bambini attraverso le vaccinazioni pediatriche con la
prevalenza dell'autismo, dell'arresto cardiaco e dei
disordini del linguaggio [17]
Come è ben evidente da questi grafici, l'andamento delle due
funzioni è di tipo lineare, nel senso che quando aumenta la
dose di mercurio assunta aumenta anche la prevalenza del
danno e l'incremento è rispettivamente di:
- un caso di autismo ogni 100.000 bambini ogni microgrammo
di mercurio in più;
- un caso di disturbo del linguaggio ogni 100.000 bambini
ogni 3 microgrammi di mercurio in più.
E' vero che il Thimerosal ormai non è più presente nei
vaccini ?
Dal sito genitoricontroautismo.org
Il 1988 fu l'anno in cui, a cominciare dal vaccino
antiemofilo B, molti nuovi vaccini vennero aggiunti alla
tabella delle vaccinazioni americane.
Negli anni seguenti, il numero delle vaccinazioni
raccomandate per bambini sotto i due anni salì da 8 a 20. La
quantità di etilmercurio iniettata nel sangue di neonati e
bambini salì del 246%.
Solo nel 1999 l'American Academy of Pediatrics, i Center for
Disease Control and Prevention, la Food and Drug
Administration e l'Istituto Nazionale della Sanità americano
emisero un comunicato congiunto che "esortava" i produttori
di vaccini a rimuovere il thimerosal.
Nonostante l'esistenza di un accordo per eliminare il
thimerosal dai vaccini per bambini, si scoprì poi che le
scorte di vaccini contenenti thimerosal rimasero ancora in
circolazione a lungo: alcune ditte farmaceutiche
avevano solo cancellato il
suo nome dai foglietti
informativi.
Oggi, comunque, il thimerosal è ancora presente nella
maggior parte dei vaccini antinfluenzali, che vengono
consigliati ora anche ai bambini di più di 6 mesi di vita.
Viene usato nella fabbricazione di di una serie di prodotti
farmaceutici e i vaccini che in questo momento vengono
venduti fuori dagli USA contengono un'alta concentrazione di
thimerosal, specie quelli indirizzati verso il terzo mondo.
Il Dr. Neal Halsey era a capo del programma di vaccinazioni
dell'American Academy of Pediatrics dal 1995 al 1999 e
quando gli fu chiesto a proposito della quantità di mercurio
che i neonati americani avevano ricevuto durante il suo
incarico, rispose a un giornalista: "La mia prima reazione
fu di incredulità. Ciò che credevo, e ciò che tutti gli
altri credevano era che (il mercurio) fosse veramente solo
una piccola quantità, biologicamente insignificante.
Onestamente credo che se le etichette avessero riportato il
contenuto di mercurio in microgrammi, tutto ciò sarebbe
stato scoperto anni fa, ma il fatto è che nessuno fece i
calcoli."
...Per la maggior parte dei pediatri, il fatto che l'autismo
abbia più di 100 sintomi e caratteristiche in comune con
l'avvelenamento da mercurio...
...Il fatto che la sua incidenza sia aumentata tra i bambini
americani di pari passo con l'aumento del carico di mercurio
nei vaccini...
...E il fatto che non fosse mai stato diagnosticato negli
USA prima degli anni 30, quando il mercurio fu aggiunto per
la prima volta ai vaccini, sono tutte spiacevoli
coincidenze...
La Dott.ssa Elizabeth Mumper, Professore Associato di
pediatria e Medicina della famiglia all'Università della
Virginia e presidentessa di Advocates for Children, una
clinica pediatric di Lynchburg, dice:
"Ho visto una bibliografia contenente più di mille articoli
sul thimerosal che dimostra i vari modi in cui è nocivo...
Le prove ci sono, prove scientifiche buone e attendibili, ma
convincere i medici a guardarle è un'altra storia... Quello
che stiamo vedendo è una generazione di bimbi che sono stati
avvelenati a causa di negligenza e incompetenza. Non potrei
dirlo in modo più chiaro: tra vent' anni, il fatto stesso
che ci sia stato un dibattito sul legame tra autismo e
mercurio sarà considerato semplicemente ridicolo".
Dopo che dal 1999 il governo USA ha obbligato le ditte
farmaceutiche a "togliere" questo metallo, piano piano anche
le altre specialità vaccinali vendute negli altri Paesi
industrializzati hanno iniziato a sostituire il mercurio tra
gli eccipienti. Il problema però ora è:
E' vero che il mercurio non è contenuto nel vaccino quando
non è riportato nel foglietto informativo della confezione
oppure significa solo che le ditte farmaceutiche non
segnalano la sua presenza ?
Oltre al mercurio, cosa sta accadendo delle altre sostanze
tossiche associate ai vaccini, come alluminio, formaldeide e
nuovi composti recentemente impiegati anche se non ancora
sufficientemente sperimentati ?
Infatti per quanto riguarda questo ultimo punto, bisogna
ricordare, che anche l'idrossido di alluminio, altro
eccipiente contenuto in molti vaccini iniettabili e di
solito associato al mercurio, ha la capacità di danneggiare
i tessuti cerebrali.
(Per un approfondimento sulla tossicità e gli effetti
dell'alluminio e di tutte le altre sostanze contenute nei
vaccini rimandiamo al succitato testo)
By Federico Povoleri
NOTE
[1] California Department of Development Service: Autistic
Spectrum Disorders - Changes in the California Caseload - An
Update: 1999 to 2002.
Sacramento CA: State of California 2003
[2] Yazbak F. E. Autism in United States: a prospective. J
Am. Phys. Surg 8 (4); 2003
[3] Burd L. et al. Prevalence Study of pervasise
developmental disorders in North Dakota. J. Am. Acad. Child.
Adolesc. Psychiatry 26: 700; 1987
[4] Ritvo E. R. et al. Epidemiologic Survey of Autism:
Prevalence. Am. J. Psychiatry 146: 194; 1989
[5] Ball LK, Ball R, Pratt RD. An assessment of thimerosal
use in childhood vaccines. Pediatrics 2001; 107: 1147-54
[6] Geier MR, Geier DL. Thimesoral in childhood vaccines,
neurodevelopment disorders and heart disease in the United
States. J Am Phys Surg; 2003; 8 (1): 6-11
[7] Geier DA, Geier MR. A comparative evaluation of the
effects of MMR immunization and mercury doses from
thimerosal-containing childhood vaccines on the population
prevalence of autism. Med Sci Monit 2004; 10 (3): PI33-39.
[8] Deth R.C. Truth Revealed: New scientific discoveries
regarding mercury in medicine and autism. Congrssional
Testimony before the U.S. Of Representative. Subcommitee on
Human Rights and Wellness, Sept. 8. 2004.
[9] Waly M. et al. Activation of Methionine synthase by
insulin-like growth factor 1 and dopamine: a target for
neurodevelopmental toxins and thimerosal. Mol. Psyachiatry
9: 358; 2004
[10] James S.J. et al. Metabolic Biomarkers of increased
oxidativestress and impaired metilation capacity in children
with autism. Am. J. Clin. Nutr. 80: 1611; 2004.
[11] Bradstreet J. et al: A case control study of mercury
hurden in children with autistic spectrum disorders. J. Am.
Phys. Surg. 8: 76;2003
[12] James SJ, Slikker W 3rd, Melnyk S, New E, Pogribna M,
Jennigan S. Thimerosal neurotoxicity is associated with
glutathione depletion: protection with glutathione
precursors. Neurotoxicology. 2005 Jan; 26 (1): 1-8
[13] Geiser D. A, Geiser M. R. An assessment of the impact
of thimerosal on childhood neurodevelopmental disorders.
Pediatr. Rehabil. 6 (2): 97; 2003.
[14] Geiser D. A., Geiser M. R. A two-phased population
epidemiological study of the safety of thimerosal-containing
vaccines: a follow-up analysis. Med. Sci. Monit. 11 (4):
160; 2005.
[15] Blaxill M. F. et al. Thimerosal and autism? A plausible
hypotesis that should not be dismissed. Medical Hypotheses
62 (5): 788; 2004.
[16] Kirby D. Evidence of Harm: Mercury in vaccines and the
autism Epidemic: A Medical Controversy. St. Martin's Press,
2006
[17] Geier MR, Geier DL. Thimerosal in childhood vaccines,
neurodevelopment disorders and heart disease in the United
States. J Am Phys Surg; 2003; 8 (1): 6-11
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DANNI del TIMEROSAL o
THIOMERSAL
Il thimerosal o
thiomersal o mertiolato (sodio etilmercuriotiosalicilato), preservante impiegato nei
vaccini e a base di mercurio organico (quindi una potenziale neuro- e immunotossina),
provoca reazioni allergiche negli animali e potrebbe aumentare gli effetti collaterali
delle vaccinazioni nell'uomo ?
Nel
1994 questa ricerca si pronunciava affermativamente:
(1)
Int Arch Allergy Immunol 1994 Jul;104(3):296-301
Thimerosal
induces toxic reaction in non-sensitized animals. Uchida T, Naito S, Kato H, Hatano I,
Harashima A, Terada Y, Ohkawa T, Chino F, Eto K, Department of Safety Research on
Biologics, National Institute of Health, Tokyo, Japan.
The
effects of injection of thimerosal solution on nonsensitized animals was investigated.
Intrafootpad injection of thimerosal solution in nonsensitized mice resulted in a swelling
response which peaked 1 h after injection and lasted for more than 24 h. Histopathological
examination showed that there were severe edema and infiltration of polymorphonuclear
neutrophils at the site of injection. An increased vascular permeability was observed
after cutaneous injection of thimerosal solution on the back of nonsensitized rats.
Since
mercuric chloride and methyl mercury induced severer reactions, and thiosalicylic acid had
no effect, mercury contained in thimerosal would have caused the reactions observed in
this study.
These
results suggest that part of these hypersensitivity reactions against thimerosal
observed among patients were possibly induced by the toxic effect of thimerosal.
Therefore, thimerosal contained as a preservative in vaccine may augment the side-effects
of the vaccination. PMID: 7518269, UI: 94305382
Tale
effetto è stato riscontrato anche nell'uomo ? Si; e questo sin dal lontano
1980.
Già
allora venne suggerito che il thimerosal dovesse venire sostituito da qualche altro agente
antibatterico (senza mercurio), ma tale suggerimento all'epoca non venne preso in alcuna
considerazione:
(2)
Contact Dermatitis 1980 Jun;6(4):241-5 Merthiolate hypersensitivity and vaccination.
Forstrom
L, Hannuksela M, Kousa M, Lehmuskallio E Epicutaneous tests with 0.1% merthiolate in
petrolatum showed hypersensitivity in 96 of 4647 eczema patients (2.0%) and in seven of
105 healthy recruits (7%). There was a marked preponderance of young age classes in the
eczema group. Twelve of 41 merthiolate-positive patients tested reacted to mercury alone,
three to thiosalicylic acid alone and one to both. The remaining 25 patients reacted to
neither of the individual components although the merthiolate complex as a whole gave a
positive test result.
Forty-five
of the merthiolate-positive patients were tested subcutaneously with 0.5 ml of a 0.01%
merthiolate solution, i.e. a dose equal to that contained in one shot of tetanus toxoid,
for example.
Nine
patients developed a local reaction at the site of the injection, and the area became
eczematous in four cases. In one of the patients the eczema spread over the body, causing
fever. Since merthiolate-sensitive patients also react to merthiolate administered
intracutaneously, the vaccinator should avoid the use of a needle whose outer surface has
been contaminated when the vaccine was aspirated from the bottle. However, even when this
precautionary measure is taken, local reactions can be expected in such a high percentage
of merthiolate-sensitive persons that merthiolate in vaccines should be replaced by
another antibacterial agent. PMID: 6447032, UI: 80245112
Nel
1984 reazioni allergiche furono riscontrate con i vaccini contro tetano ed encefalite da
zecche, e anche allora venne suggerito il possibile ricorso ad alternative al thimerosal
nella preparazione di tali vaccini:
(3) Hautarzt 1984 Apr;35(4):192-6
[Reactions
to vaccinations against tetanus and tick-borne encephalitis caused by merthiolate].
Lindemayr H, Drobil M, Ebner H
Thirty
patients with suspected adverse reactions to tetanus- or tick-borne encephalitis-vaccines
were subjected to allergy tests. In 8 of 30 patients epicutaneous and/or intracutaneous
tests with merthiolate were positive.
Testing
anorganic mercury, formaldehyde, aluminium hydroxide, gentamycin and egg white (i.c. and
RAST), no positive reactions were found. After vaccination - prior to testing -
merthiolate - positive patients had suffered from local inflammatory reactions at the
injection site, fever and lymphadenopathy (four patients), urticarial (three patients) or
lichenoid exanthemas (one patient). Reviewing the literature it is suggested that
alternatively merthiolate-free vaccines be provided for sensitized individuals.PMID:
6724907, UI: 84211622
Nel
1990 simili reazioni allergiche furono riportate anche per il vaccino contro l'epatite B:
(4)
Dermatol Clin 1990 Jan;8(1):161-4
Reactions
to thimerosal in hepatitis B vaccines.
Rietschel
RL, Adams RM Department of Dermatology, Ochsner Clinic, New Orleans, Louisiana.
Hypersensitivity
to thimerosal in vaccines has been reported to induce persistent local reactions,
urticarial and generalized exanthematic eruptions, and, in the case of the hepatitis B
vaccine, urticaria with asthma. The authors describe two cases of extensive reactions, one
in a patient who did not form antibodies to the principal vaccine antigen.
Although
not all thimerosal-sensitive patients develop adverse reactions to vaccines containing
this material, there is a potential risk, and the reactions can be very long lasting.
PMID:
2137393, UI: 90150805
La
sensitizzazione allergica al thimerosal in Austria, che per frequenza è ormai diventata
seconda solo all'allergia da nichel, è dovuta alle vaccinazioni ?
Una
ricerca condotta nel 1991 diede risposta affermativa.
(5)
Contact Dermatitis 1991 Jan;24(1):6-10
Vaccination
despite thimerosal sensitivity. Aberer W Department of Dermatology I, University of
Vienna, Austria.
Thimerosal sensitivity is extremely common in Austria, being surpassed as a contact
allergen only by nickel. This high incidence is still rising and is probably due to the
frequent vaccinations which are performed in Austria.
Most of the patch-test-positive patients had recently been immunized with
thimerosal-containing vaccines, and no other obvious sources of exposure to thimerosal
could be found. On retrospective questioning, 48 out of 50 patients had had no problems
with their recent immunization; the 2 who reported massive local reactions had received
their injections, against the recommendation of the manufacturer, subcutaneously. In a
prospective study, 12 thimerosal-sensitized persons received their follow-up immunization
at our department, and no side effects occurred. This enables us to conclude that
sensitization had occurred through vaccines, but that those amounts of thimerosal
delivered i.m. are not sufficient to elicit clinical symptoms. Patch-test positivity to
thimerosal thus represents no contra-indication to i.m. immunization with
thimerosal-containing vaccines.
PMID:
2044374, UI: 91256734
Nel
1996 in Polonia venne riferita allergia al thimerosal in più del 5% di 685 pazienti
sottoposti a vaccinazioni o immunoterapia anti-pollinosi, tutte effettuate con
preparazioni contenenti thimerosal. Specialmente il personale sanitario (quasi il
14% di esso) ne risultava affetto:(6) Med Pr 1996;47(2):125-31
[Allergic
reaction to merthiolate (a disinfectant) based on material from the Occupational
Medicine Institute in Lodz]. Kiec-Swierczynska M. Przychodni Chorob Zawodowych Szpitala
Klinicznego, Instytutu Medycyny Pracy, Lodzi.
Incidence and causes of allergy to merthiolate (thimerosal) was studied in 685 patients,
examined in the Nofer Institute of Occupational Medicine, during the period from 1
September 1993 to 15 October 1995. Allergy to thimerosal was diagnosed in 39 persons
(5.7%) including 25 (6.3%) females and 14 (4.9%) males. Health service workers
predominated among those sensitized (13.8% of all medical personnel examined during that
period).
In
19 persons only allergy to mercury was observed. Among them 7 showed no skin changes, 6
manifested symptoms of hand dermatitis, in 4 patients atopic dermatitis and in 2
dermatitis diseminata were diagnosed.
Two patients suffered from allergic rhinitis. It was found that the general vaccination of
health service workers against viral hepatitis as well as immunotherapy with pollen
preparations containing thimerosal (Catalet, Biomed, Poland) were the main causes of
allergy to mertiolate.
Allergy
to thiosalicyclic acid was not observed and two persons reacted positively to mercuric
chloride.
PMID:
8656996, UI: 96252600
Ai
primi del 1999, ricercatori italiani hanno riscontrato che il thimerosal induce
sensitizzazione allergica in bambini affetti da dermatite atopica (e che quindi è un
possibile responsabile dell'insorgenza della stessa).
(7) Contact Dermatitis 1999 Feb;40(2):94-7
Sensitization
to thimerosal in atopic children.
Patrizi
A, Rizzoli L, Vincenzi C, Trevisi P, Tosti A
Department
of Clinical and Experimental Medicine, University of Bologna, Italy.
Thimerosal
is an organic mercurial compound widely used as a preservative in vaccines, eyedrops, and
contact lens cleaning and storage solutions. 5 infants, 2 female and 3 male, ranging in
age from 7 to 28 months and affected by atopic dermatitis (AD) diagnosed according to the
Hanifin and Rajka criteria, experienced an exacerbation of their clinical condition 2-10
days after mandatory vaccinations with vaccines containing thimerosal.
Cutaneous
lesions of nummular eczema appeared on the trunk, limbs and face.
All
patients were patch tested with serial dilutions of thimerosal in petrolatum. A positive
patch test reaction to thimerosal 0.1% pet. Was observed in all 5 children. 3 of them also
showed a positive reaction at 0. 01% and 0.05% pet. Despite their
thimerosal-hypersensitivity, all children completed the entire series of mandatory
vaccinations, care being taken to use different needles for injection and aspiration
of the vaccine.
The
2-year follow-up did not reveal other episodes of exacerbation of the AD after
vaccination.
The
present study confirms the high frequency of sensitization to thimerosal in atopic
children and suggests that vaccination can cause clinical symptoms in sensitized children.
Nevertheless,
sensitization to thimerosal does not prevent children from continuing with mandatory
vaccinations.
PMID:
10048654, UI: 99156441
Ma
alla fine, sulla base delle innegabili evidenze raggiunte fino ad oggi, e in
considerazione del sempre crescente numero di vaccinazioni che vengono fatte ai bambini e
purtroppo anche in considerazione ai danni che sono stati resi evidenti, recentemente è
stato ufficialmente richiesto da parte dei pediatri e della sanità pubblica americana di
eliminare il thimerosal dai vaccini:
(8)
MMWR Morb Mortal Wkly Rep 1999 Jul 9;48(26):563-5
Thimerosal
in vaccines: a joint statement of the American Academy of Pediatrics and the Public Health
Service.
The
Food and Drug Administration (FDA) Modernization Act of 1997 called for FDA to review and
assess the risk of all mercury-containing food and drugs.
In
line with this review, U.S. vaccine manufacturers responded to a December 1998 and April
1999 FDA request to provide more detailed information about the thimerosal
content of their preparations that include this compound as a preservative. Thimerosal has
been used as an additive to biologics and vaccines since the 1930s because it is very
effective in killing bacteria used in several vaccines and in preventing bacterial
contamination, parti cularly in opened multidose containers. Some but not all of the
vaccines recommended routinely for children in the United States contain thimerosal.
PMID:
10418806, UI: 99345147
(9)
MMWR Morb Mortal Wkly Rep 1999 Nov 5;48(43):996-8
Recommendations
regarding the use of vaccines that contain thimerosal as a preservative.
On October 20, 1999, the Advisory Committee on Immunization Practices (ACIP) reviewed
information about thimerosal in vaccines and received updates from CDC's National
Immunization Program and several vaccine manufacturers on the current and anticipated
availability of vaccines that do not contain thimerosal as a preservative. The review was
prompted by a joint statement about thimerosal issued July 8, 1999, by the American
Academy of Pediatrics (AAP) and the Public Health Service (PHS) (1) and a comparable
statement released by the American Academy of Family Physicians (2).
These
statements followed a Congressionally mandated Food and Drug Administration (FDA)
review of mercury in drugs and food, which included a reassessment of the use of
thimerosal in vaccines.
PMID:
10577494, UI: 20043426
Link
in Internet sull’argomento: http://www.aap.org/new/thimpublic.htm
Thimerosal
in Vaccines - an Interim Report to Clinicians
http://www.aap.org/advocacy/releases/jointvacc.htm
Joint Statement of the American Academy of Pediatrics (AAP) and the United States Public
Health Service (PHS)
http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/mm4843a4.htm
Recommendations Regarding the Use of Vaccines - That Contain Thimerosal as a Preservative
Esistono
oltre 500 pubblicazioni scientifiche che parlano dei gravi danni di questo prodotto.
Per
la Bibliografia inerente i danni del mercurio, vedere anche:
Amalgami.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
National
Immunization Program Thimerosal and Vaccine - Questions/Answers - July 15, 1999
Q 1. What is Thimerosal ?
A. Thimerosal is a very effective preservative that contains mercury and
has been used in some vaccines and other products since the 1930s.
Thimerosal is the most widely used preservative in vaccines. The FDA
estimates that it is used in more than 30 licensed vaccines and biologics.
Mercury is excreted from the body over time.
Q 2. Why is Thimerosal used
in vaccines ?
A. Thimerosal is used as an extra safeguard against contamination. It may
be used during processing or added to the final container to prevent
contamination when multi-dose vials are opened. Before Thimerosal was
marketed in the United States, a number of safety studies were conducted,
first on animals and then on humans. Thimerosal is an important
preservative that protects vaccine against bacterial contamination. It is
very effective in killing bacteria used in several vaccines
and in preventing bacterial contamination, particularly in opened
multi-dose containers. Some but not all of the vaccines recommended
routinely for children in the United States contain thimerosal. Disease
outbreaks have occurred following contamination of multi-dose vaccine
vials in the United States and from other countries. For example, in
April, 1995, three infants died in India from toxic shock syndrome after
administration of contaminated measles vaccine at one health center.
Q3. Can all vaccines be made
Thimerosal-free, or within accepted guidelines? If so, how quickly ?
A. All vaccines either do not contain thimerosal or contain thimerosal
within FDA guidelines. To further increase the margin of safety that
already exists, clinicians can use the inherent flexibility in the current
immunization schedule to fully vaccinate children and meet even the most
conservative guidelines for cumulative mercury exposure. Clinicians and
parents can take advantage of the flexibility within the existing schedule
for infants born to Hepatitis B surface antigen (HbsAg)-negative women to
postpone the first dose of hepatitis B vaccine from birth until two to six
months of age when the infant is considerably larger.
Pre-term infants
born to HBsAg-negative mothers should similarly receive hepatitis B
vaccine, but ideally not until they reach term gestational age and a
weight of at least 2.5 kilograms. Because of the substantial risk of
disease, there is no change in the recommendations for infants of
HbsAg-positive mothers or of mothers whose status is not known.
Also, in
populations where HbsAg screening of pregnant women is not routinely
performed, vaccination of all infants at birth should be maintained, as is
currently recommended. Public Health Service agencies are working with
private physician groups and vaccine manufacturers to expedite the process
to reduce or eliminate thimerosal from vaccines used in the United States.
Q4. What could happen if parents ignored recommendations to use
thimerosal-containing vaccines during this transition period ?
A. Children would be at very real risk from illnesses that can be
prevented with safe and effective vaccinations.
High rates of vaccination
led to declines of 95% to 100% in the occurrence of vaccine preventable
diseases in the United States. Despite this, the pathogens responsible
for most vaccine preventable diseases still circulate and rates of disease
would increase if vaccine coverage dropped. For example, if vaccination
coverage among infants dropped from 95% to 70%, an additional 2,500 cases
of pertussis would be expected to occur. Moreover, the risk of death from
pertussis is greatest in young children.
A second severe vaccine
preventable disease among young children is Haemophilus influenzae type b
(Hib). Before vaccine was introduced, this pathogen was the leading cause
of meningitis and other severe invasive infections among children; now
cases of invasive Hib disease have virtually disappeared. If vaccination
for Hib declined to 70%, 2,000 excess cases would occur with 1,200 cases
of meningitis, resulting in about 100 deaths and 180 children who would
suffer mental retardation and hearing loss.
Q5. Why isn&Mac226;t the federal government just recommending not
using vaccines with thimerosal in them if there is concern ?
A. Making vaccines safer and more effective is a constant goal for the
federal government; and, that is the purpose of the action
we&Mac226;re taking now. There is a significant safety margin
incorporated into all acceptable mercury exposure limits. Furthermore,
there are no data or evidence of any harm caused by the level of exposure
that some children may have encountered in following the existing
immunization schedule. Today, we&Mac226;re discussing a minimal, if
any, risk from minute levels of mercury-containing thimerosal versus the
large and devastating risk of childhood diseases like bacterial meningitis
and whooping cough if parents and physicians abandon vaccination during
this transition period. Any missed vaccinations puts children at risk from
disease.
Q6. How much mercury did my 6-month-old get in the last six months from
vaccines? How dangerous is that ?
A. Each dose of vaccine given your child met FDA requirements and should
not be a concern to you now--your choice to vaccinate your baby was a
sound one. The mercury levels being discussed are well within the safety
margins; however, we are working toward further increasing the margin of
safety that already exists. It is important that we limit the cumulative
amount of mercury children are exposed to, but parents should not abandon
vaccination as a means to do that.
Q7. If there are vaccines that are mercury-free, why shouldn't I just ask
for those ?
A. The American Academy of Pediatrics, the Advisory Committee on
Immunization Practices for CDC and the Surgeon General all recommend that
parents do not let their child miss a vaccination when safe and effective
vaccines are available.
Today, we are discussing a minimal, if any, risk
from cumulative levels of mercury from some vaccines versus the large and
devastating risk of childhood diseases like bacterial meningitis and
whooping cough if parents and physicians abandon vaccination during this
transition period. Clinicians and parents can take advantage of the
flexibility within the existing schedule for infants born to Hepatitis B
surface antigen (HbsAg)-negative women to postpone the first dose of
hepatitis B vaccine from birth until two to six months of age when the
infant is considerably larger.
Pre-term infants born to HBsAg-negative
mothers should similarly receive hepatitis B vaccine, but ideally not
until they reach term gestational age and a weight of at least 2.5
kilograms.
Because of the substantial risk of disease, there is no change
in the recommendations for infants of HbsAg-positive mothers or of mothers
whose status is not known. Also, in populations where HbsAg screening of
pregnant women is not routinely performed, vaccination of all infants at
birth should be maintained, as is currently recommended.
Public Health
Service agencies are working with private physician groups and vaccine
manufacturers to expedite the process to reduce or eliminate thimerosal
from vaccines used in the United States. The American Academy of
Pediatrics, the Advisory Committee on Immunization Practices for CDC and
the U.S. Surgeon General want parents to be fully informed about
children&Mac226;s vaccines and if you have questions or concerns, we
encourage you to speak to your child&Mac226;s trusted health care
provider.
Q8. I&Mac226;ve heard that children may be getting toxic levels of
mercury from vaccines. Is that true ?
A. Everyone is exposed to mercury, even in some foods and household
products. As part of an ongoing assessment of mercury in the environment
and in products, many agencies have developed guidelines for acceptable
levels of mercury--levels many times below any amount known to cause harm.
Some children, depending on which vaccines they receive and the timing of
those vaccines, are exposed to cumulative levels of mercury close to the
safety ranges of guidelines. To further increase this margin of safety,
clinicians and parents can take advantage of the flexibility within the
existing immunization schedule.
It&Mac226;s important to understand
that these highest acceptable levels include a "safety cushion" to take into account all the variables that people face in
their exposures to mercury. No children are getting toxic levels of mercury from vaccines.
Q9. Are there vaccines available to prevent childhood diseases without exposing them to mercury ?
A. Yes, although you may discover that these vaccines are not immediately available from your health care provider. The American
Academy of Pediatrics, the Advisory Committee on Immunization Practices for CDC and the Surgeon General all recommend that parents do not let
their child miss a vaccination when safe and effective vaccines are available. Today, we have a minimal, if any, risk from minute levels of
mercury-containing thimerosal in some vaccines versus the large and devastating risk of childhood diseases like bacterial meningitis and
whooping cough if parents and physicians abandon vaccination during this transition period. The American Academy of Pediatrics, the Advisory
Committee on Immunization Practices for CDC and the U.S. Surgeon General want parents to be fully informed about children&Mac226;s vaccines and if you
have questions or concerns, we encourage you to speak to your child&Mac226;s
trusted health care provider.
Q10. Why are the Public Health Service and AAP making these recommendations now ?
A. Although mercury is found in the environment, in food and in household products, exposure to mercury is of concern and, when
possible, should be avoided. The Public Health Service agencies, the American Academy of Pediatrics, and vaccine manufacturers agree that
thimerosal should be reduced or eliminated in vaccines to make already safety vaccines even safer and to allow for new vaccines to be added to
the schedule in the future. Some children, depending on which vaccines they receive and the timing of those vaccines, are exposed to cumulative
levels of mercury close to the safety ranges of guidelines.
The mercury levels being discussed are within the safety
margins; however, we are working toward further increasing the margin of safety that already
exists. It is important that we limit the cumulative amount of mercury children are exposed to, but parents should not abandon vaccination as a
means to do that.
Q11. Why are chemicals and other substances added to vaccines ?
A. Many things in today's world, including foods and medicines, have chemicals added to them to prevent the growth of germs and reduce
spoilage. Chemicals are added to vaccines for similar reasons, to inactivate a virus or bacteria and to stabilize it, helping to preserve
the vaccine and prevent it from losing its potency over time. Some additives are used in the production of vaccines. Vaccines may
include suspending fluid (e.g., sterile water, saline, or fluids containing protein); preservatives and stabilizers (e.g., albumin,
phenols, and glycine); and adjuvants or enhancers that help the vaccine
improve its immunogenicity (ability to protect against disease).
Q12. I understand some people are sensitive to thimerosal and must avoid it. Do they have problems with thimerosal-containing vaccines ?
A. Most patients do not develop reactions to thimerosal given as a component of vaccines even when they&Mac226;ve had a patch or intradermal tests
for thimerosal that indicated hypersensitivity. Hypersensitivity to thimerosal usually consists of local, delayed reactions.
Q13. How can I find out what chemical additives are in specific vaccines ?
A. Ask your health care provider or pharmacist for a copy of the vaccine package insert. The package insert lists ingredients in the vaccine and
discusses any known adverse reactions.
Q14. What is mercury ?
A. Mercury is a metal, a chemical element found everywhere. As such, it is neither created, nor destroyed -- the same amount of mercury has
existed since the earth was formed. Two major forms of mercury exist in nature, an inorganic form (the
mercury used in thermometers) and the organic form. Humans and wildlife are exposed to both, but the metallic mercury is quickly released from
the body. The organic form tends to accumulate in humans, and particularly in large predator fish.
Humans are usually exposed to
organic mercury from eating fish which have accumulated it in their muscle tissue.
Very high levels of mercury are toxic. Because mercury is
everywhere, it is not possible to prevent all exposure to mercury. Federal agencies, including the Agency for Toxic Substances and Disease
Registries and the Food Administration have established guidelines for levels of mercury exposure considered safe. In addition, uses and
releases of mercury have been reduced very substantially in recent decades in the U.S. and most other industrialized countries.
Q15. Who is most vulnerable to mercury ?
A. Two groups are most vulnerable to methyl mercury: the fetus and pregnant women. Premature babies are more vulnerable because they tend
to be very small and their brain is not as developed as a full term baby. Children may be at higher risk of mercury exposure than are adults
because they eat more per pound of body weight and because they may be inherently more sensitive than adults since their nervous systems are
still developing. The guidelines for mercury exposure are based on amount of mercury per weight. This helps estimate reference level of
exposure according to the person's weight.
Q16: What is the ATSDR level for mercury exposure ?
A: The minimal risk level, or MRL, is 0.3 micrograms per kilograms of body weight per day (ug/kg/d) for ingestion of methylmercury. Mercury
occurs in the environment in several forms: elemental, inorganic and organic mercury. Methylmercury is the most common form of
organic mercury. People can be exposed to methylmercury by eating fish or shellfish that come from mercury-contaminated waters.
MRLs are health guidance values established by ATSDR and are intended for use by health assessors as screening tools when determining whether
further evaluation of potential human exposure at hazardous waste sites is warranted. They are not intended for use in determining clean-up
levels or for other regulatory purposes.
Q17: Why is this level different from EPA&Mac226;s ?
A: Both agencies recognize Mercury as a neurotoxicant, a toxin which affects the nervous system of humans. Further, both agencies recognize
that fetuses and women of reproductive age are among the groups at high risk from Mercury exposure.
And, both agencies agree on the Minimal Risk
Levels for exposure to two of the three forms of Mercury&Mac246;Elemental
Mercury by inhalation, and Inorganic Mercury by oral means. The agencies do differ in the MRL for Methyl Mercury (Organic Mercury).
The difference between the two agencies is extremely small. In the Toxicological Profile for Mercury, ATSDR uses exposure to 0.3 micrograms
per kilogram of body weight per day as the Minimal Risk Level (the level at which scientists would not expect to see any adverse health effects,
but at which they would see the need for additional investigation). EPA considers the level to be 0.1 micrograms/kilogram/day. A microgram is
one millionth of a gram. A gram is 0.035 ounce.
Q18: What is the safety margin built into this level ?
A: The ATSDR value (mrl of 03 mcg/kg/d) has a significant safety margin
built into it. The value is approximately ten times below the highest exposure levels found in participants in the Seyschelles Study (a recent
study evaluating individuals who were exposed to methyl mercury). Even at the highest exposure levels recorded in the Seyschelles Study, no
participants experienced adverse health effects.
Q19: What happens if your exposure exceeds the recomended levels ?
A: The nervous system is very sensitive to all forms of mercury. Methylmercury and metal vapors are more harmful than other forms,
because more mercury in these forms reaches the brain. Exposure to high
levels of metallic, inorganic, or organic mercury can permanently damage
the brain, kidneys, and developing fetus. Effects on brain functioning may result in irritability, shyness, tremors, changes in vision or
hearing, and memory problems. Short-term exposure to high levels of metallic mercury vapors may cause
effects including lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation.
Q20: How can mercury affect children ?
A: Very young children are more sensitive to mercury than adults. Mercury in the mother's body passes to the fetus and can pass to a
nursing infant through breast milk. However, the benefits of breast feeding may be greater than the possible adverse effects of mercury in
breast milk. Mercury's harmful effects that may be passed from the mother to the
developing fetus include brain damage, mental retardation, and lack of coordination, blindness, seizures, and an inability to speak. Children
poisoned by mercury may develop problems of their nervous and digestive systems and kidney damage.
Q21. Which population groups have the highest levels of mercury ?
A. Groups that tend to have higher exposure include subsistence and frequent recreational fishers, people of Asian origin, and some Native
American groups. The typical U.S. consumer eating fish from restaurants and grocery stores are not in danger of consuming harmful levels of
mercury from fish and are not advised to limit fish consumption. Everyone is exposed to mercury, even in some foods and household
products.
Q22. How can parents learn more about children&Mac226;s immunizations ?
A. To learn more about children's immunizations, vaccinations, or baby shots from a CDC information specialist, please call CDC&Mac226;s National
Immunization Information Hotline: 1-800-232-2522, for English,
1-800-232-0233, for Spanish.
This page last reviewed July 15, 1999.
Centers for Disease Control and Prevention
National Immunization Program
(su "VIA" del 08.03.2000)
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Thimerosal
Toxicity
The various mercury guidelines are based on epidemiological
and laboratory studies of methyl mercury, whereas thimerosal
is a derivative of ethyl mercury. Because they are different
chemical entities - ethylversus methylmercury - different
toxicological profiles are expected. There is, therefore, an
uncertainty that arises in applying the methylmercury-based
guidelines to thimerosal. Lacking definitive data on the
comparative toxicities of ethyl- versus methylmercury, FDA
considered ethyl- and methyl-mercury as equivalent in its
risk evaluation . There are some data and studies bearing
directly on thimerosal toxicity and these are summarized in
this Section .
Allergic responses to thimerosal
are described in the clinical literature, with these
responses manifesting themselves primarily in the form of
delayed-type local hypersensitivity reactions, including
redness and swelling at the injection site (Cox and Forsyth
1988 ; Grabenstein 1996). Such reactions are usually mild
and last only a few days.
Some authors postulate that the thiosalicylate component is
the major determinant of allergic reactions (Goncalo et al.
1996) .
In a clinical setting, however, it is usually not possible
to determine whether local reactions are caused by
thimerosal or other vaccine components.
The earliest published report of thimerosal use in humans
was published in 1931 (Powell and Jamieson 1931) .
In this report, 22 individuals received 1% solution of
thimerosal intravenously for unspecified therapeutic reasons.
Subjects received up to 26 milligrams thimerosal/kg (1
milligrams equals 1,000 micrograms) with no reported toxic
effects, although 2 subjects demonstrated phlebitis or
sloughing of skin after local infiltration. Of note, this
study was not specifically designed to examine toxicity; 7
of 22 subjects were observed for only one day, the specific
clinical assessments were not described, and no laboratory
studies were reported.
Several cases of acute mercury
poisoning from thimerosal-containing products were found in
the medical literature with total doses of thimerosal
ranging from approximately 3 mg/kg to several hundred mg/kg.
These reports included the administration of immune globulin
(gamma globulin) (Matheson et al. 1980) and hepatitis B
immune globulin (Lowell et al . 1996), choramphenicol
formulated with 1000 times the proper dose of thimerosal as
a preservative (Axton 1972), thimerosal ear irrigation in a
child with tympanostomy tubes (Rohyans et al. 1994),
thimerosal treatment of omphaloceles in infants (Fagan et al
. 1977), and a suicide attempt with thimerosal (Pfab et al .
1996) .
These studies reported local necrosis, acute hemolysis,
disseminated intravascular coagulation, acute renal tubular
necrosis, and central nervous system injury including
obtundation, coma, and death. (IOM)
Several animal studies have
evaluated the toxicity of thimerosal. In 1931 Powell and
Jamieson reported acute toxicity studies in several animal
species. Maximum tolerated doses not associated with death
of the animals were 20 mg thimerosal/kg (rabbits) and 45
mg/kg (rats) . Blair evaluated the administration of
thimerosal intranasally for 190 days and observed no
histopathological changes in the brain or kidney (Blair et
al . 1975) .
Magos et al. directly compared the toxicity of ethyl- versus
methylmercury in adult male and female rats administered 5
daily doses of equimolar concentrations of ethyl- or
methylmercury by gavage (Magos et al 1985). Magos concluded
that ethylmercury, the mercury derivative found in
http://www.fda.gov/cber/vaccine/thimerosal.htm
- 9/27/2006
Thimerosal in Vaccines Page 6 of 15
thimerosal, is less neurotoxic than methylmercury, the
mercury derivative for which the various guidelines are
based .
One final piece of data
regarding thimerosal is worth noting . At the initial
National Vaccine Advisory Committee-sponsored meeting on
thimerosal in 1999, concerns were expressed that infants may
lack the ability to eliminate mercury.
More recent NIAID-supported studies at the University of
Rochester and National Naval Medical Center in Bethesda, MD
examined levels of mercury in blood and other samples from
infants who had received routine immunizations with
thimerosal-containing vaccines. [Pichichero ME, et al.
Lancet 360:1737-1741 (2002)] Blood levels of mercury did not
exceed safety guidelines for methyl mercury for all infants
in these studies.
Further, mercury was cleared from the blood in infants
exposed to thimerosal faster than would be predicted for
methyl mercury; infants excreted significant amounts of
mercury in stool after thimerosal exposure, thus removing
mercury from their bodies. These results suggest that there
are differences in the way that thimerosal and methyl
mercury are distributed, metabolized, and excreted .
Thimerosal appears to be removed from the blood and body
more rapidly than methyl mercury.
NIAID is sponsoring a follow-up study with larger numbers of
infants in Buenos Aires where thimerosal-containing vaccines
are still administered to children.
Tratto da:
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