I started on this quest to find what the heck a “safe dose” statement was based on. Because ingesting and injecting a substance isn’t the same thing (I can’t think of anything that is 100% absorbed into the blood from ingestion).

See alcohol.

But here’s a question. There is a safe level of mercury per L of blood. Would it be reasonable to compare the dose of mercury to the presumed blood volume of an infant/child weighing X. Of course as the body excreted it the levels would drop back down but the vaccine could cause it to be temporarily over the limit.

It may seem reasonable to compare dose to presumed blood volume, but it isn’t necessary, as actual measurements have been taken in relevant age groups.

http://www.ncbi.nlm.nih.gov/pubmed/18245396

Note: ng/mL is equivalent to µg/L

Of course that still leaves the question of “what’s the mercury been replaced with and is it safe”. Which of course is a debate for another day.

No, it doesn’t leave that question, and there is little debate about the elimination/reduction of Thimerosal from vaccines in the U.S. Thimerosal was primarily used as an anti-microbial in multi-dose vials. Use of single dose vials for childhood vaccines, and changes in manufacturing processes mean it’s not always necessary anymore.

But here’s a question. There is a safe level of mercury per L of blood. Would it be reasonable to compare the dose of mercury to the presumed blood volume of an infant/child weighing X. Of course as the body excreted it the levels would drop back down but the vaccine could cause it to be temporarily over the limit.

Of course that still leaves the question of “what’s the mercury been replaced with and is it safe”. Which of course is a debate for another day.

However its wrong to characterize the anti-vaccine crowd as being paranoid/obsessed with autism. Most anti-vaccine people I know don’t even list autism in their top 10 concerns.

As indicated by most of your comments in this thread, I’m not sure you understood what was communicated by this post, the linked reference materials, or my comments. Conclude whatever you like.

I’m sorry, but I’m not terribly interested in discussing maternal seafood consumption guidance further than noting its existence and documentation (by the EPA).

Well, my friend, you’ve been making some pretty big claims about your understanding of the EPA seafood consumption guidance, and now you back down from applying your own logic? If you refuse to answer, I cannot accept that its because you are “not interested.” I can only conclude that it is because you **cannot** apply your sloppy logic to EPA guidance without getting tangled in the mess of your own flawed thinking.

My explanation is not intended to “fit with EPA guidance”. What I’ve offered is the explanation of a canard that attempts to align with EPA guidance where a. it does not exist, and b. what the actual available guidance is (for methylmercury) seems poorly understood at a very basic level.

You can’t have it both ways, Do’C.

“I think it’s fairly self-evident from several clue words like”

Yes, but it does change how the mechanisms that the body has available to rid itself of the substances, which is not obvious.

“What “short term max dose” are you referring to? Did you read the post and reference materials?”

Yes, I read the post and I have skimmed the EPA docs. I am referring to the fact that while the EPA guidelines talk about a daily dose, the shot delivers a greater dose directly which take a certain about of time to clear.

You state that the flu shot is a one time a year event and I am pointing out that they is not always the case. Children receiving the flu shot for the first time receive 2 doses, one month apart. In the worst case, if you added in the H1N1 shot this year you had 2 shots and then another 2 shots a month later.

So the idea is that at any point in time you have a certain burden from the shots - if you have 1 shot, wait 30 days, then potentially some of the mercury from the original shot has not been cleared so the second shot adds to that amount and pushes the entire burden higher - hence what I was calling the “short term max dose”. As in the highest burden generated in a short time period from multiple shots.

“The EPA hasn’t published “limits””

Sorry, the, the EPA “estimate of a daily exposure to the human population that is likely to be without an appreciable risk of deleterious effects during a lifetime”. I would call abbreviate that phrase to “limit”, but you are correct in that it isn’t a limit per se.

“Yeah, cause having the EPA evaluate ethylmercury exposure safety makes a whole lot of sense when the childhood immunization schedule (minus some flu shots) is essentially Thimerosal-free.”

Plus the tetanus shot and the Rhogam given to pregnant women. Then there is the fact that shots provided to other countries still have the full dose of thimerosal. Add to that some doctors are calling for thimerosal to be added back into the shots since it has been “proven” not to have a relation to autism.

But really, the best way to put the debate behind us all is to acknowledge the facts of the matter - admit that while it is likely there are no harmful since effects from the thimerosal in the flu shot that there are still potential questions about its safety so it is better to get the shot without it, and move on.

Regarding the thimerosal vs methylmercury you did not mention that the delivery path is different between the two.

I think it’s fairly self-evident from several clue words like:

“Flu Shots”
“Oral RfD”
“Seafood Consumption”

Third, for children receiving the flu shot for the first time they would normally receive two shots, one month apart. If they elected for the H1N1 shot, they would have as few as 3 shots or as many as 4 shots in a one month time. That changes the short term max dose by a factor of 3-4, at least for this year.

What “short term max dose” are you referring to? Did you read the post and reference materials?

“even by sensitive subgroups”

Where in the EPA limits is this stated? I have never seen anything that claimed the guidelines were for senstive subgroups.

The EPA hasn’t published “limits”. Read all the EPA documents, including the linked National Academies Press book, and you will have your answer - more than once.

If you want the shortcut, you could start by reading just the IRIS doc for methylmercury from the EPA (linked in the post). You could even use the CTL-F and search “sensitive” to have your browser highlight it on that first page you’ll already be looking at.

The last thing that you seem to be glossing over in your description is that while the guideline is intended to be a daily intake limit it is also designed to keep the body burden of mercury beneath a certain level on an ongoing basis.

I think most people who read the post, and skimmed some of the provided EPA docs understand this part:

“The oral Reference Dose (RfD) is based on the assumption that thresholds exist for certain toxic effects such as cellular necrosis. It is expressed in units of mg/kg-day. In general, the RfD is an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.”

If they don’t, well there is more than ample information - tons of it - in the reference sources I provided.

It would be a good thing if the EPA did evaluate what the “safe” exposure to ethyl-mercury was - that way this whole debate would be over quicker. Not that I have an hope that they will.

Yeah, cause having the EPA evaluate ethylmercury exposure safety makes a whole lot of sense when the childhood immunization schedule (minus some flu shots) is essentially Thimerosal-free.

Just a few minor things -

“Nevermind that they don’t acknowledge the general availability of Thimerosal-free flu shots for pediatric patients. ”

It has been my experience that the thimerosal-free flu shot is not readily available, at least in my area. Of the parents that I talk to, the majority are told that this verion is simply not available and only given the option of the thimerosal version.

Regarding the thimerosal vs methylmercury you did not mention that the delivery path is different between the two. Methylmercury is normally injested and processed via the stomach whereas thimerosal in shots is (presumably) absorded directly into the bloodstream.

Third, for children receiving the flu shot for the first time they would normally receive two shots, one month apart. If they elected for the H1N1 shot, they would have as few as 3 shots or as many as 4 shots in a one month time. That changes the short term max dose by a factor of 3-4, at least for this year.

” even by sensitive subgroups”

Where in the EPA limits is this stated? I have never seen anything that claimed the guidelines were for senstive subgroups.

The last thing that you seem to be glossing over in your description is that while the guideline is intended to be a daily intake limit it is also designed to keep the body burden of mercury beneath a certain level on an ongoing basis.

These single events (flu shot) can push that burden up, and all else being equal, the value would come back down fairly quickly. That is assuming that there isn’t any other substantial source of -mercury intake and a normal functioning of detoxification pathway.

“The EPA RfD for oral MeHg has absolutely nothing to do with vaccines”

It would be a good thing if the EPA did evaluate what the “safe” exposure to ethyl-mercury was - that way this whole debate would be over quicker. Not that I have an hope that they will.

It is long past time for the autism world to move past these debates.

I’m sorry, but I’m not terribly interested in discussing maternal seafood consumption guidance further than noting its existence and documentation (by the EPA).

My explanation is not intended to “fit with EPA guidance”. What I’ve offered is the explanation of a canard that attempts to align with EPA guidance where a. it does not exist, and b. what the actual available guidance is (for methylmercury) seems poorly understood at a very basic level.

The EPA states: “Outbreaks of methylmercury poisoning have made it clear that adults, children, and developing fetuses are at risk from dietary exposure to methylmercury. During these poisoning outbreaks some mothers with no symptoms of nervous system damage gave birth to infants with severe disabilities and it became clear that the developing nervous system of the fetus may be more vulnerable to methylmercury than is the adult nervous system. Mothers who are exposed to methylmercury and breast-feed their babies may also expose their infant children through their milk.”

http://www.epa.gov/mercury/exposure.htm

I don’t understand how your explanation fits with EPA guidance. How would you explain this?