Aug 24 2015

Antivaxxers Still Flogging Thimerosal

I gave a talk on the vaccine controversy over the weekend. I was not surprised that a couple of audience members had a lot of questions taken directly from anti-vaccine propaganda sites. What was interesting was that they were still pushing the idea that thimerosal, a mercury-based vaccine preservative, is linked to autism.

The reason this is interesting and illuminating is that the thimerosal hypothesis is not just mostly dead, it is most sincerely dead. It is pushing up the proverbial daisies.

A Brief History of Thimerosal

Thimerosal was developed as an organomercurial anti-microbial agent shortly after World War I. It was soon discovered that it has great anti-microbial properties and was well tolerated when injected into rabbits or rats even at high doses. This made it superior to anything else available at the time.

Bacterial contamination was a serious problem for vaccines in the first half of the 20th century. Thimerosal in tiny doses, well below safety limits, proved to be an effective agent for preventing contamination. By the 1940s thimerosal was being added to several vaccines for this purpose.

It should be noted that thimerosal can only be used in inactivated vaccines or those that contain just proteins, not in live attenuated virus or bacterial vaccines. Thimerosal would inactivate any live vaccines.

Safety concerns about thimerosal were first raised in the 1970s with increased awareness of the neurotoxicity of mercury. However the dose of mercury in vaccines was orders of magnitude below the levels showing any clinical effect. No safety concerns were raised with thimerosal and vaccines until the late 1990s. At this time Wakefield was raising alarms over the MMR vaccine (which never contained thimerosal) and autism. His research was later revealed to be flawed and even fraudulent, and independent studies showed convincingly that there was no connection between MMR and autism. So anti-vaxxers moved on to their next target, thimerosal.

Anti-vaxxer focus on thimerosal was given a huge boost by David Kirby and his book, Evidence of Harm. Robert Kennedy also jumped on the anti-thimerosal bandwagon, mainly coming from an environmental perspective.

A History of Dose and Thimerosal

The core of the anti-vaccine claim against thimerosal was that as the cumulative dose of thimerosal increased so did the incidence of autism. This claim was never scientifically validated. Correlation by itself is weak evidence for caustion, and the correlation itself really didn’t hold up. But the vague correlation of – both thimerosal and autism were increasing in the 1990s – was enough for the anti-vaxxers. Of course I have to show this graphic indicating that the correlation between autism and organic food is even better.

Despite the lack of any convincing scientific evidence, the CDC decided “out of an abundance of caution” to remove thimerosal from the routine vaccine schedule by 2002. This provided an opportunity for a mega-experiment. If the increasing dose of thimerosal caused increasing autism diagnoses, then a decreasing overall dose of thimerosal should cause the incidence of autism diagnoses to fall to pre-1990s levels.

David Kirby directly predicted a drop in autism incidence and correctly noted that if the rates do not drop that would call into question the role of thimerosal. In 2007 he was writing that the rates were starting to drop – extrapolating wrongly from short term fluctuations in the data.

The other game that anti-vaxxers were playing was that thimerosal was not really removed by 2002. There were still some vaccines with thimerosal. As autism rates continued to rise, they kept pushing back the date of when thimerosal was removed. Apparently doctors were holding onto their vaccines with thimerosal to the bitter end.

Vaccine manufacturers stopped making vaccines with thimerosal (except for some flu vaccines, more on that later) between 1999 and 2001. Vaccines have a two-year shelf life. Even if you take the latest estimates, the thimerosal-containing vaccines were gone by 2004. However, anti-vaxxers take the 2004 date then tack on two more years and claim that vaccines contained thimerosal as late as 2006. This is nonsense, however; 2004 is really the latest date that some doctor in the US might have given the last vaccine with thimerosal right before its expiration date. Even then the total dose of thimerosal given to the pediatric population was steadily declining between 1999 and 2004.

I can see why in 2007 anti-vaxxers were dickering about the exact date of thimerosal removal. But now we are in 2015 – 8 years later. We are a full 11 years after the latest realistic date of any lingering thimerosal in the vaccine schedule. Certainly anti-vaxxers cannot still be holding onto their thimerosal delusions. Well, of course they are.

Let’s review the historical dose of thimerosal in vaccines. In the 1970s, one vaccine contained thimerosal, diphtheria-tetanus-pertussis combination. One vaccine dose typically contains 25 micrograms of thimerosal. By the early 1980s, before the autism diagnosis increase, the total dose of thimerosal in the routine vaccine schedule was up to 100 micrograms. Total thimerosal dose to infants and young children peaked at 187.5 micrograms of thimerosal. This dose was by 6 months of age, and did not include any additional thimerosal from the flu vaccine, which is recommended but optional and not considered part of the routine schedule.

After around 2002 the 187.5 micrograms of thimerosal was completely removed. However, anti-vaxxers are now claiming that increased use of the flu vaccine has replaced this missing thimerosal. Simple math shows that they are wrong.

Multi-dose flu vaccines contain 25 micrograms of thimerosal. Even if a child gets the flu vaccine at six months, one year, and then every year after that they are still not getting anywhere near the total dose of thimerosal in the schedule prior to removal. Even if you include the shot their pregnant mother received (which the anti-vaxxers do) you are still not near the total dose.

Further still – in 2012 the CDC reported that only 1/3 of the flu vaccines produced in the US were mutli-dose vials. The single dose vials and the live virus vaccines do not contain thimerosal. So only one third of those flu vaccine doses in 2012 contained thimerosal, with similar numbers projected for this year.

So if we are considering the population dose of thimerosal, we have to drop the average dose from the flu vaccine to one third. That means that children who get all their flu vaccines by age six are getting about 50 micrograms of thimerosal total on average over six years, compared to at least 187.5 micrograms plus flu vaccines in 1999.

In addition to all this, some states, like California, have banned flu vaccines with thimerosal. So children in California get a total thimerosal dose of zero.

Autism Incidence

The CDC has statistics on autism incidence through 2010, which includes the birth cohort for 2002 – which is clearly after the total thimerosal dose had plummeted.

The CDC has also published data for 2011-2012, showing the autism rate has continued to increase, from 1 in 68 to 1 in 50 – that’s the 2003-2004 birth cohort. The rates in California are no different.

I should note that the evidence shows that the increasing rate of autism diagnoses is largely an artifact of expanding diagnosis, diagnostic substitution, and increased surveillance. There may not be any real increase in autism itself. A small real increase is possible, but unproven.


There is only one reasonable interpretation of this data – the removal of thimerosal from the vaccine schedule resulted in a dramatic decrease in the total thimerosal dose given to the pediatric population in the US, starting in 1999, completed by any reasonable estimate by 2004. Only one third of flu vaccines still contain a small dose of thimerosal, and some states, like California, have banned even those.

Despite this dramatic overall reduction in thimerosal, there has been no change in the rate of increase of autism diagnoses. The plummeting of autism diagnoses predicted by David Kirby and others never materialized.

Attempts to keep their thimerosal delusions alive are getting increasingly desperate and ridiculous. Antivaxxers are now at the point where they have to deny simple math.

38 responses so far

38 thoughts on “Antivaxxers Still Flogging Thimerosal”

  1. Lane Simonian says:

    Two more pertinent questions:

    Has the level of exposure to mercury in general dropped or increased in the past decade?

    What is the level of exposure to mercury (if any) that would trigger autism in an individual genetically prone to the disease?

  2. daedalus2u says:

    Lane, there is no evidence that mercury at any dose triggers autism in any individuals, “genetically susceptible” (which susceptibility has never been identified or characterized) or not.

    In the first half of the 20th century, mercury was used in teething powders ~1 grain per dose (~64,000 micrograms, usually as HgCl (calomel), or Hg(m) (elemental mercury)). Often multiple doses were given. Sufficient mercury was given that mercury poisoning (also known as Pink Disease) was a leading cause of death in children (more than 20% of child deaths were from Pink Disease). Over a thousand children died from Pink Disease. Many tens of millions of doses were sold per year.

    When mercury was removed from teething powders, Pink Disease disappeared and only recurred when old stocks of teething powder were used, or when there was mercury exposure from other sources.

    Thus many tens of millions of individual children received many thousands of times more mercury from teething powder than children ever received from thimerosal in vaccines (max dose ~200 micrograms). Injected thimerosal has less adverse effects (at equivalent dose) than methyl mercury (the mercury in sea food) taken orally. Injected thimerosal likely has much less adverse effects than inorganic mercury at equivalent dose.

    Mercury exposures in the 1990 time frame were much lower than in the 1940’s (based on teething powder production); thousands of times lower.

  3. The level of mercury measured in blood has been relatively flat over the last decade (2003-2010):

    However, if you focus on the 1-5 year olds the levels have dropped a little. Take a look at page 242.

    Most mercury exposure is from fish, which also contains methyl mercury which is more toxic than the ethyl mercury in thimerosal. Vaccines were never a big source of mercury exposure anyway.

    There is no known level of mercury that triggers autism because it has never been established as a trigger.

  4. Lane Simonian says:

    Good information. Part of my interest is in exposure to air pollution (and other environmental toxins) and increased risk of neurological diseases. This one is just correlation but still interesting.

    Exposure to high pollution levels during pregnancy may increase risk of having child with autism

    Boston, MA — Women in the U.S. exposed to high levels of air pollution while pregnant were up to twice as likely to have a child with autism as women who lived in areas with low pollution, according to a new study from Harvard School of Public Health (HSPH). It is the first large national study to examine links between autism and air pollution across the U.S…

    The results showed that women who lived in the 20% of locations with the highest levels of diesel particulates or mercury in the air were twice as likely to have a child with autism as those who lived in the 20% of areas with the lowest levels.

  5. Lane Simonian says:

    The mechanisms are likely correct for this studies, but perhaps not some of the conclusions (such as extrapolating from mice to humans).

    Neuro Endocrinol Lett. 2005 Oct;26(5):439-46.
    Mercury and autism: accelerating evidence?
    Mutter J1, Naumann J, Schneider R, Walach H, Haley B.
    Author information
    The causes of autism and neurodevelopmental disorders are unknown. Genetic and environmental risk factors seem to be involved. Because of an observed increase in autism in the last decades, which parallels cumulative mercury exposure, it was proposed that autism may be in part caused by mercury. We review the evidence for this proposal. Several epidemiological studies failed to find a correlation between mercury exposure through thimerosal, a preservative used in vaccines, and the risk of autism. Recently, it was found that autistic children had a higher mercury exposure during pregnancy due to maternal dental amalgam and thimerosal-containing immunoglobulin shots. It was hypothesized that children with autism have a decreased detoxification capacity due to genetic polymorphism. In vitro, mercury and thimerosal in levels found several days after vaccination inhibit methionine synthetase (MS) by 50%. Normal function of MS is crucial in biochemical steps necessary for brain development, attention and production of glutathione, an important antioxidative and detoxifying agent. Repetitive doses of thimerosal leads to neurobehavioral deteriorations in autoimmune susceptible mice, increased oxidative stress and decreased intracellular levels of glutathione in vitro. Subsequently, autistic children have significantly decreased level of reduced glutathione. Promising treatments of autism involve detoxification of mercury, and supplementation of deficient metabolites.

  6. hammyrex says:

    It’s important to emphasize that mercury poisoning does not clinically look like autism – period; they are different clinical presentations. The original strain of thought that mercury poisoning and autism were related were by two incompetents without a basis in diagnostic criteria and rationale; they basically said “oh my, they both are neurological!”

    I’m surprised how many people, even those that don’t subscribe to the autism/vaccine conspiracy, take it as a fact that enough mercury poisoning *will* causes autism if the dose is high enough. It’s one of those “big lies” of the anti-vaccine movement – they’re willing to lose the conclusion if it allows the premise to be uncritically accepted.

  7. locutusbrg says:

    Redressing a dead topic is the anti-vax way. Why if your ignoring all other evidence to favor ideology no great surprise that they continue to ignore the most obvious data in favor of rhetoric. Still they manage to continually keep the public consciousness that this is still a cause and effect. Harming parents perception and promoting general fear. The harm continues to expand even multiply. Given poor scientific literacy and headline favoring news media, it is no wonder that this continues to be whack-a-mole.

  8. LC says:

    Lane, on the air pollution issue, did the authors control for possible confounding factors. For example, as Steve noted, the increasing diagnoses of autism are an artifact of issues including increased surveillance. I believe there was another study that showed in increase in diagnosis among families living in close proximity to another family with an autism diagnosis (i.e, the “my kid has the same symptoms — maybe I should get this checked out” factor).

    The point being, urban areas are where factors like the above are more likely to occur. And coincidentally, urban areas are also more likely to have air pollution issues.

  9. daedalus2u says:

    All of the in vitro work with mercury is of zero value in extrapolating doses to in vivo.

    All forms of mercury are well known to partition into cells and attach to thiols because cell membranes allow mercury to pass through them and cells contain lots of thiols which bind mercury very strongly. At “equilibrium”, mercury partitions at least several thousand fold to the inside of cells. What is important is the dose of mercury inside a particular cell, not the concentration of mercury outside the cells.

    One mg of cells in 10 mL of culture media containing 100 micrograms of mercury (10 ppm) would be expected to have an internal concentration ~2000 times higher, ~ 20,000 ppm mercury (a possibly fatal dose). The initial mercury in the media is 100 micrograms, the final mercury in the cells is 0.02*1 mg = 20 micrograms.

    20 kg of cells (in a child) exposed to 20 micrograms (by injection) would (if uniformly distributed) have an “extra” 20 micrograms/20 kg = ~ 1 ppb. This is well below levels known to be harmful, and is less than is commonly obtained from food. A single serving of tuna fish can have more methyl mercury than that and methyl mercury is better absorbed though the gut than is thimerosal by injection.

    The “air pollution study” wasn’t a “real” study, it didn’t measure any types of air pollution, it simply took EPA air pollution figures and correlated them (by county as I remember) with autism births.

    There is no good data implicating mercury and autism. Children with the highest levels of mercury in cord blood (from the Faroe Islands study of 1,000 consecutive births) didn’t have an excess of autism even though the levels were high enough that some doctors would consider treating for mercury poisoning.

  10. DanDanNoodles says:

    Ye have little faith in the ingenuity of anti-vax stupidity. In a classic maneuver, they now claim that aluminum adjuvants were added to vaccines around the time that thimerosal was removed, and that aluminum ALSO causes autism, and that is why the autism rate continues to rise.

    I wish I was kidding about this.

  11. Lane Simonian says:

    I like the careful “conclusion” reached in this abstract:

    The reasons for the rise in autism prevalence are a subject of heated professional debate. Featuring a critical appraisal of some research used to question whether there is a rise in cases and if rising levels of autism are related to environmental exposure to toxins (Soden et al. 2007, Thompson et al. 2007, Barbaresi et al. 2009) we aim to evaluate the actual state of scientific knowledge. In addition, we surveyed the empirical research on the topic of autism and heavy metal toxins. Overall, the various causes that have led to the increase in autism diagnosis are likely multi-faceted, and understanding the causes is one of the most important health topics today. We argue that scientific research does not support rejecting the link between the neurodevelopmental disorder of autism and toxic exposures.

    And this is a very insightful observation:

    If a person has publicly staked his/her career on a certain position being right, it may become harder to keep a truly open mind, even when new data become available and even when the original intent was to be objective. A way this bias might manifest itself is an overstatement or slight misstatement of results. We feel that both sides have been guilty of this, and this happens when a person becomes so confident in the correctness of his/her own view that he/she no longer reviews evidence to the contrary. Unconscious bias may exist even in the best scientists.

    The tendency is this: not to critically analyze studies that support your position and to be highly critical of studies that do not support your position. This does not mean that all studies are equally well-conducted, but it means that one should be able to see the flaws in studies–whether they support one’s position or not. In some areas of science, the evidence is overwhelming but in other areas it is considerably more muddled. It is not good to declare absolute truth before you actually have it.

  12. Lane Simonian says:

    For daedalus:

    J Toxicol Environ Health A. 2011;74(18):1185-94. doi: 10.1080/15287394.2011.590097.
    Ancestry of pink disease (infantile acrodynia) identified as a risk factor for autism spectrum disorders.
    Shandley K1, Austin DW.
    Author information
    Pink disease (infantile acrodynia) was especially prevalent in the first half of the 20th century. Primarily attributed to exposure to mercury (Hg) commonly found in teething powders, the condition was developed by approximately 1 in 500 exposed children. The differential risk factor was identified as an idiosyncratic sensitivity to Hg. Autism spectrum disorders (ASD) have also been postulated to be produced by Hg. Analogous to the pink disease experience, Hg exposure is widespread yet only a fraction of exposed children develop an ASD, suggesting sensitivity to Hg may also be present in children with an ASD. The objective of this study was to test the hypothesis that individuals with a known hypersensitivity to Hg (pink disease survivors) may be more likely to have descendants with an ASD. Five hundred and twenty-two participants who had previously been diagnosed with pink disease completed a survey on the health outcomes of their descendants. The prevalence rates of ASD and a variety of other clinical conditions diagnosed in childhood (attention deficit hyperactivity disorder, epilepsy, Fragile X syndrome, and Down syndrome) were compared to well-established general population prevalence rates. The results showed the prevalence rate of ASD among the grandchildren of pink disease survivors (1 in 22) to be significantly higher than the comparable general population prevalence rate (1 in 160). The results support the hypothesis that Hg sensitivity may be a heritable/genetic risk factor for ASD.

  13. hammyrex says:

    Look guys, the emperor is wearing clothes! I found a single thread on his skin! I was right all along!

  14. Average Joe says:

    And the take down of that biased journal and article.

  15. Lane Simonian says:

    Here is what it comes down to either mercury increases the risk for autism or it does not and there is no definitive study that will answer this question. For example, a follow up on the Faroe Island study found that the rates of autism were much higher than originally registered (especially overlooked were females with autism).

    Nor does logic help much either. Many children with autism are deficient in the most important thiol of all-glutathione. The mercury is not being bound out of their system.

    However, most children with autism also cannot easily breakdown polyphenols which are antioxidants and which limit the cognitive damage set forward by mercury (this is why they are not “mad as a hatter”).

    There are almost always flaws in studies (although again people tend to exaggerate the flaws in studies they don’t like and ignore flaws in studies they do like) and there are often flaws in logic.

    I am not a scientist (although I do have a background in biology) and I am not a skeptic, but the key to all of this is mechanism. Mechanism does not prove studies or confirm logic, but it strengthens both.

    Examples: temperatures are rising, the burning of fossil fuels increases the greenhouse effect, humans are responsible for much global warming.

    Risk factors for Alzheimer’s disease increase peroxynitrites, peroxynitrites are responsible for most of the features of Alzheimer’s disease, some peroxynitrite scavengers have partially reversed Alzheimer’s disease.

    Many children with autism are deficient in glutathione, the mercury stays in their system, the mercury causes oxidative stress that is only partially offset by high levels of polyphenols.

    Mercury is likely one of many causes of autism. In a general population, a person not exposed to acute levels of mercury will not develop autism. A susceptible individual exposed to lower levels of mercury might develop autism. Would they have developed autism anyway without the thimerosal in the vaccine? Impossible to prove one way or the other.

  16. arnie says:

    Lane: You are very convincing when you say you are neither scientist nor skeptic. However, I doubt that anyone on this blog, or previous Neurologica blogs, would have guessed otherwise. I suppose it doesn’t hurt to state the obvious, though.

  17. Lane Simonian says:

    Neither, however, automatically negates what I have to say. Scientists often think they are unbaised, and skeptics think they are free from ideology. My bias and ideology is that environmental toxins contribute to many disease.

    I at least understand that there is uncertainly still in much of science and that better identifying the pathways that lead to disease is critical for understanding both what causes them and how to treat them.

  18. Lane Simonian says:

    You will see nearly all of these in Alzheimer’s disease as well:

    Acta Neurobiol Exp (Wars). 2012;72(2):113-53.
    Evidence of parallels between mercury intoxication and the brain pathology in autism.
    Kern JK1, Geier DA, Audhya T, King PG, Sykes LK, Geier MR.
    Author information
    The purpose of this review is to examine the parallels between the effects mercury intoxication on the brain and the brain pathology found in autism spectrum disorder (ASD). This review finds evidence of many parallels between the two, including: (1) microtubule degeneration, specifically large, long-range axon degeneration with subsequent abortive axonal sprouting (short, thin axons); (2) dentritic overgrowth; (3) neuroinflammation; (4) microglial/astrocytic activation; (5) brain immune response activation; (6) elevated glial fibrillary acidic protein; (7) oxidative stress and lipid peroxidation; (8) decreased reduced glutathione levels and elevated oxidized glutathione; (9) mitochondrial dysfunction; (10) disruption in calcium homeostasis and signaling; (11) inhibition of glutamic acid decarboxylase (GAD) activity; (12) disruption of GABAergic and glutamatergic homeostasis; (13) inhibition of IGF-1 and methionine synthase activity; (14) impairment in methylation; (15) vascular endothelial cell dysfunction and pathological changes of the blood vessels; (16) decreased cerebral/cerebellar blood flow; (17) increased amyloid precursor protein; (18) loss of granule and Purkinje neurons in the cerebellum; (19) increased pro-inflammatory cytokine levels in the brain (TNF-α, IFN-γ, IL-1β, IL-8); and (20) aberrant nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB). This review also discusses the ability of mercury to potentiate and work synergistically with other toxins and pathogens in a way that may contribute to the brain pathology in ASD. The evidence suggests that mercury may be either causal or contributory in the brain pathology in ASD, possibly working synergistically with other toxic compounds or pathogens to produce the brain pathology observed in those diagnosed with an ASD.

  19. daedalus2u says:

    The “symptoms” of autism and the “symptoms” of mercury exposure are not at all alike. The most important symptom of mercury poisoning (elevated levels of mercury) are not present at all in people with autism. An extremely common symptom of autism is a larger brain with more neurons. How does mercury cause that? It doesn’t.

    The “mercury causes autism” idea has been pursued by people trying to win the legal lottery by going after the deep pockets of vaccine manufacturers.

    The “hypersensitivity” to mercury that led to Pink Disease was due to exposure to a few hundred mg. Exposure to mercury in vaccines is much less (tens of micrograms), and is the less toxic ethyl mercury. If hypersensitivity to mercury caused Pink Disease due to exposure to hundreds of mg mercury, where is the autism from that mercury exposure? Tens of millions of children were exposed to hundreds of mg of mercury. If mercury causes autism, where are the autism cases associated with Pink Disease?

    Glutathione levels in blood are unimportant, at micromolar levels. Where glutathione is important is inside of cells where it is present at millimolar levels.

    There is no data that associates mercury with autism. There is a lot of cherry-picked and motivated reasoning trying to link mercury with autism so that lawyers can scam money from vaccine manufacturers.

    The “carefully worded conclusion” that you like is based on carefully chosen statistical methods; where the “selected” choice of a particular statistical test gave the “significant” result. That result is only “significant” in a statistical sense, not in a clinical sense. The entire sample that the DeSoto Hitlan “significance” was based on was only 137.

    “The mean blood mercury levels of the autistic and control groups were 19.53 and 17.68 nmol/L.”

    It you look at the Faroe Island mercury study, they measured cord blood mercury in ~1000 consecutive births.

    If you look at table 2, the inter-quartile range for 860 individual cord blood mercury measurements was 13.1-40.8 micrograms/L. Converting to nmol/L, the range is 65.5-204 nmol/L. What that means is that only 25% of the samples (~215 individuals) had less than 65.5 nmol/L mercury and 25% had more than 204 nmol/L mercury.

    If 25% of the children in this study had blood mercury levels that were more than an order of magnitude higher than the mean level of the autistic group (at 19.53 nmol/L), with no apparent autism, that very strongly suggests that differences of a few nmol/L at the very low end of the exposure range are not clinically significant. Clinical significance and measurement significance are two completely different things. They are being deliberately conflated by DeSoto and Hitlan to generate “hype” for their “results”.

    The idea that mercury is an important cause of autism is simply wrong. It isn’t. It is way past time to stop wasting resources beating that dead horse.

  20. Lane Simonian says:

    The larger levels of polyphenols in individuals with autism are likely the cause of more neurons not mercury. This may also explain why the symptoms of mercury intoxication are different from autism. Many of the biomarkers however are quite similar.

    One has to separate out two different things: one the mercury in vaccines caused autism by itself; two mercury exposure from various different sources perhaps in conjunction with other toxins can cause autism. The first assertion can be false and the second can still be true. And again, some individuals are more susceptible to mercury exposure than others.

    Was autism being diagnosed at the time of Pink Disease? Are there overlaps between the two diseases?

    To say that there is no data associating mercury exposure to autism is false. We can argue over the quality of the data, but that is another matter.

  21. daedalus2u says:

    The only way that you can say there is “data” associated with “mercury causing autism” is if you disingenuously cherry pick the data and keep moving the goalposts. If you are intellectually honest and look at the totality (and quality) of the data on autism and mercury there is no hint of a signal. The most parsimonious explanation is that mercury does not cause autism. Of course “proving a negative” is difficult when the underlying physiology is not well understood.

    Asperger used the term in 1938, and Kanner used the term in 1943, so yes, autism was being diagnosed at the same time there were many deaths due to Pink Disease.

    There have been numbers of mercury poisoning events when grain treated with methyl mercury as a fungicide was consumed. Events where many people had frank acute mercury poisoning and including many deaths. Never has increased autism been associated with those poisoning events.

    The number of minicolumns in the brain is fixed at ~8 weeks gestation. The number of minicolumns is increased in autism. How do polyphenols get to the fetal brain to trigger increased minicolumns? The placenta is quite good at blocking them.

  22. hammyrex says:

    I’m sorry daedalus, your attempt to bring the epidemiological data in on an epidemiological question just doesn’t work for me. Could you instead post the conclusions of several obscure articles from pubmed about hypothetical biochemical mechanisms? That would be far more convincing.

  23. ChrisH says:

    Lane: “Kern JK1, Geier DA, Audhya T, King PG, Sykes LK, Geier MR.”

    What is the status of Mark Geier’s medical license?

    Here is some interesting reading on some of the activities of a few of those authors. It is not like they have a conflict of interest or anything.

    Also, about that 2010 DeSoto and Hitlan article you linked on from an obscure Polish journal:

  24. Lane Simonian says:

    I could do this until the cows come home. But it does not matter–if you believe that there is no evidence connecting mercury to autism than all the studies showing that there may be linked to autism are cherry-picked and come from a bunch of biased hacks. And yes, there is a difference between mercury poisoning and autism based on levels of exposure and the genetic and physiological makeup of the individual. People with bias on both sides overstate their claims, and try to discredit evidence that they do not like.

    Multiple observations indicate that environmental and epigenetic factors play an important role in the emergence of autism spectrum disorders (ASD). Growing ASD incidence rates, the incomplete penetrance of many rare variants linked to autism, and increased exposure to environmental contaminants all strongly support the role of gene × environment interactions in a substantial fraction of autistic patients. Within this framework, genetically susceptible individuals exposed to detrimental environmental factors at critical times during neurodevelopment might undergo disrupted brain morphogenesis, neuronal connectivity, and synaptic functioning consequently yielding ASD. Several teratogenic drugs and prenatal viral infections are able to cause autism in humans, as supported by case reports, cohort studies, and animal models. Moreover, recent studies have shown that some newly identified potential neurotoxicants may negatively affect developmental trajectories, leading to altered cognitive, attentive, behavioral, and motor performances, as well as to systemic abnormalities frequently seen in autistic individuals. A variety of mechanisms are potentially involved, ranging from oxidative and inflammatory brain damage to altered gene expression and impaired signal transduction. More research is needed to thoroughly investigate the effects of these compounds on neurodevelopment, to validate their involvement specifically in ASD, to study gene × environment interactions in potentially susceptible individuals, and to plan targeted prevention strategies.

  25. BillyJoe7 says:

    I like ants. I study them intensely. Every little detail. Before long I will know everything there is to know about the animal kingdom.

  26. Lane Simonian says:

    Working off the ant metaphor:

    Low mercury exposure also causes oxidative stress, and a fast interaction between NO
    and superoxide anions results in the formation of peroxynitrite, which causes

    Targeting Peroxynitrite as a novel hypothesized treatment for autism spectrum disorders

    Some people have the capacity of putting A and B together; others insist that A and B should never be put together and throw out a barrage of reasons and insults as to why not.

  27. ChrisH says:

    Lane, please answer my question: can Mark Geier still legally practice medicine? And why not?

  28. ChrisH says:

    By the way, it is a ten year anniversary of something very pertinent to this subject:

  29. Lane Simonian says:

    I have now read some bitter accusations made on both sides of this dispute, including some launched against this blog (talk about harsh, but perhaps some of you do have your own agendas). I would have to go through every proceeding and try to determine what was alleged and what underlay each decision (which may or may not be the stated reason). I have seen charges leveled against other controversial doctors and scientists–some deserved what they got and some did not.

    Rachel Carson was excoriated for her views that pesticides harmed human health and she turned out to be right. I am not comparing Mark Geier to Rachel Carson, but sometimes the outliers are really dangerous quacks and sometimes they are vindicated.

  30. ChrisH says:

    What is the status of Mark Geier’s medical license?

  31. hammyrex says:

    Yes, I’m sure the guy who castrated children “because glutathione” will be vindicated one day as the hero who saved us from autism. Any day now.

    This is the lesson we are trying to teach you. It’s perfectly reasonable to play armchair internet scientist and mentally masturbate to your lovely hypothetical biochemical mechanisms. It’s another thing to begin experimenting on human beings with those ideas when prior plausibility has not been properly established through other research means. There are consequences if you are wrong, and they should be taken seriously.

  32. Lane Simonian says:

    His medical license was revoked. Simple, factual answer. Why it was revoked depends on whether you consider him to be the devil or some kind of hero.

    When it comes to autism, environmental toxins, GMOs, alternative medicines, etc. some people are attacking a structure that other people are defending. It is not a matter of skeptics versus non-skeptics, or scientists versus pseudoscientists, it is about issues that have as much to do with political beliefs, environmental beliefs, and beliefs regarding authority as it does with the actual science itself. And when some of the science produces results that challenge ingrained beliefs, it produces a backlash–the study cannot be true because it is not what I believe. You just think one side does that, but both sides do it because each side believes its world view is correct.

  33. Lane Simonian says:

    Just to be clear, I don’t support the use of lupron for autism. Its approved use for other diseases is questionable. I thought they lost their license because they advocated the removal of thimerosal from vaccines.

    In terms of the language used in the post above, I don’t mind insults but try to be somewhat more creative. If you just stick to what you believe, and don’t look at the biochemical mechanisms and pathways, no progress is made. A good scientist has to be inductive as well as deductive. Just trying to flog people with insults advances nothing.

  34. Lane Simonian says:

    I posted the above link just to show how the other side perceived this controversy. I don’t endorse most of it.

    Having said that, this is not a good place for me to be. Sorry if I disturbed you.

  35. hammyrex says:

    “I thought they lost their license because they advocated the removal of thimerosal from vaccines.”

    Uh? Why on earth would you think that. There are plenty of quack doctors that bought into the mercury/autism conspiracy – none lost their licenses *on those grounds alone* – boards regulate practices, not opinions.

    “If you just stick to what you believe, and don’t look at the biochemical mechanisms and pathways, no progress is made”

    This is a gross misrepresentation. The belief that autism could be caused by thimerosal and/or MMR was taken *very* seriously and extensively studied. In the end, there was no compelling evidence from the studies. You keep treating these questions like they are completely open and unanswered – that is false and bordering on dishonest – you’ve been made aware of the the epidemiological data over and over again, you are actively ignoring it.

    As for the Bolen report. It’s so chocked full of blatant lies (accusing Dr. Novella of fraudulently working for Yale?) and childish insults (attacking his hair style and weight) that I think it speaks for itself. That you even take it remotely seriously says a lot. You are trying to paint a picture of “us vs. them”, but this demonstrates why that isn’t the case – the behavior on both sides is not identical. I have no problem going up to bat when I see non-experts abuse epidemiology and have no problem calling them out on sloppy logic and methods, but I am certainly not calling you or anyone else a fatty.

  36. RickK says:

    Lane, I can’t believe you linked the bolenreport. Does that really reflect the level of your intellectual rigor, your ability to weigh evidence and the maturity of your debate? There have been many commenters who opposed the views of this blog, but you are the first I’ve seen that sunk to referring to Bolen.

    If you are using Bolen in your debate and comparing the Geiers to Rachel Carson, then you cannot claim to be searching for truthful answers. You are just another committed ideologue fully invested in your position regardless of evidence. In which case, you’re right – this is not a good place for you.

  37. Sylak says:

    So, the book title should be “No evidence of harm”, it must be a typo… or the anti-vaxxer are liars? Can it be? Impossible!

    LOL, of course they are, a bunch of crap to sell books.

  38. ChrisH says:

    Lane: “I thought they lost their license because they advocated the removal of thimerosal from vaccines.”

    No, it was for torturing children for fun and profit. A review of the charges includes this quote from the Medical Board report:

    The Respondent [Mark Geier] endangers autistic children and exploits their parents by administering to the children a treatment protocol that has a known substantial risk of serious harm and which is neither consistent with evidence-based medicine nor generally accepted in the relevant scientific community.

    The blaming of thimerosal was just to exploit parents.

    Also, his son, David Geier, was charged with practicing medicine without a license.

    Next time you decide to post a PubMed indexed article make sure the authors are qualified and reputable. The Geiers, and Lisa Sykes are neither qualified nor reputable.

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