According to the WHO, mercury is considered to be one of the ten most dangerous chemicals. According to the WHO, Mercury is especially dangerous for intrauterine fetal development and infants in early stages of life. Mercury is dangerous in elemental form (metal), as well as in inorganic (mercury chloride) and in organic (methylmercury) compounds.
However, there is one organic compound of mercury, which is so safe, that infants and pregnant women can be safely injected with it. This compound is called ethylmercury.
Thiomersal (sodium orthoethylmercurithiosalicylate) is a preservative that is added to multi-dose vaccine vials to prevent microbial contamination after opening the vial. Multi-dose vaccine vials are 2.5 times cheaper than single-dose vials. That is, a multi-dose vaccine costs 10 cents per dose, and a single-dose vaccine costs 25 cents. Moreover, single-dose vaccines take up more space in refrigerators. These are the main reasons for using thiomersal. The concentration of thiomersal in vaccines is 0.01% or 25-50 μg per dose. Mercury makes up 50% of the thiomersal weight, which means that one dose of the vaccine contains from 12.5 to 25 μg of mercury.
Mercury, vaccines, and autism: one controversy, three histories.
Am J Public Health
Thiomersal was patented in 1928 under the trade name of "Merthiolate". It turned out that thiomersal is 40 times more effective as an antibacterial agent than phenol. Toxicity studies revealed that mice, rats and rabbits, injected intravenously with thiomersal, had almost no reaction to it. They were only observed for a week though.
A 1929 meningococcal epidemic in Indianapolis became an opportunity to test the drug on humans. 22 meningitis patients received a large dose of thiomersal intravenously, and it did not cause an anaphylactic shock in any of them. Researchers have concluded that thiomersal is safe. Subsequently, it turned out that all these 22 patients died.
This was the only clinical study and since then, no more thiomersal safety studies have been conducted. FDA director acknowledged these facts on a congressional hearing.
Thimerosal: clinical, epidemiologic and biochemical studies.
Clin Chim Acta
It was already known that thiomersal is not perfect as a preservative in 1943, and that microorganisms survive at a concentration used in vaccines (1:10,000).
In 1982, outbreaks of streptococcal abscesses, resulting form DTP vaccines, were observed. It turned out that streptococci survive in vaccines with thiomersal for two weeks. In another study, it turned out that thiomersal does not meet the European requirements for antibacterial effectiveness.
In 1999, the American Academy of Pediatrics (AAP) recommended excluding thiomersal from vaccines as soon as possible, as it turned out that its amount in vaccines exceeds the guidelines. In the early 2000s, more and more vaccines without thiomersal became available, and it would be expected that children would receive it in smaller amounts. This is not exactly what happened, however.
Starting in 2002, the CDC started recommending influenza vaccines for infants, and the only licensed vaccine for them contained thiomersal. The CDC also started recommending influenza vaccines for pregnant women, which also contained thiomersal. Since 2010, infants started to receive two doses of influenza vaccine, and then one dose each year.
Therefore, even though thiomersal was removed or almost removed from other vaccines, the amount of mercury received from the vaccines remained approximately the same since 2000, and doubled over the course of lifetime. Thiomersal also remained in one of the meningococcal vaccines and in one tetanus and diphtheria vaccine.
In almost all the rest of the world, thiomersal also remained in childhood vaccines. The AAP and the WHO persuaded the UN to not ban the use of mercury in vaccines in 2012.
Iatrogenic exposure to mercury after hepatitis B vaccination in preterm infants.
The blood concentration of mercury in premature infants increased more than 13-fold after the hepatitis B vaccine (form 0.54 to 7.36 μg/l). The concentration of mercury in full-term infants increased 56-fold (from 0.04 to 2.24 μg/l). The initial level of mercury in premature infants was 10 times higher, than in full-term infants (no statistical significance), which hints at a higher maternal level of mercury in premature infants.
Although, according to the HHS (Health & Human Services) guidelines, 5-20 μg/l is considered to be the normal level of mercury in the blood, there are discrepancies in the published literature about which levels are considered toxic and which are normal. Moreover, this data was obtained from adults who were exposed to mercury in the workplace.
Hair mercury in breast-fed infants exposed to thimerosal-preserved vaccines.
Eur J Pediatr
Mercury levels in the hair of infants (receiving thiomersal vaccines) increased by 446% in the first six months. During this time, the mercury levels in the hair of mothers decreased by 57%.
Comparison of blood and brain mercury levels in infant monkeys exposed to methylmercury or vaccines containing thimerosal.
Environ Health Perspect
Infant monkeys received vaccines containing thiomersal in doses equivalent to those used for humans. The other group of monkeys received the same dose of methyl mercury through oral tube.
The half-life of mercury in the blood was much shorter for thiomersal (7 days), than for methyl mercury (19 days), and the concentration of mercury in the brain was 3 times lower in those who received thiomersal, as compared to those who got methyl mercury. However, 34% of mercury in the brain of thiomersal recipients was in an inorganic form, while methyl mercury recipients only had 7%. The absolute level of inorganic mercury in the brain was twice as high in thiomersal recipients, than in methyl mercury recipients. The level of inorganic mercury in the kidneys was also significantly higher in those who received thiomersal.
Moreover, the level of inorganic mercury in the brain did not change for 28 days after the last dose, unlike the level or organic mercury, the half-life of which was 37 days. Other studies also found that the level of inorganic mercury in the brain does not decrease.
Recent publications have suggested an association between thiomersal in vaccines and ASD. In 2001, the Institute of Medicine (IOM) concluded that there was no sufficient evidence of a link between mercury in vaccines and developmental disorders in children. It was noted, though, that such a relationship is possible and further studies were recommended. In the subsequent review in 2004, the IOM waived their recommendations, and also backtracked on the AAP’s goal (to remove thiomersal from vaccines). This approach is difficult to comprehend, given our limited knowledge of the toxicokinetics and neurotoxicity of thiomersal – a compound that had been and will be administered to millions of newborns and babies.
Inorganic mercury remains in the brain for years and decades.
Neurotoxic effects of thimerosal at vaccine dosages on the encephalon and development in 7 days-old hamsters.
Ann Fac Med Lima
Hamsters were given thiomersal injection in doses equivalent to those used for humans. They had lower brain and body mass, low density of neurons in the brain, neuronal death, demyelination and damage to Purkinje cells, which is characteristic of ASD.
Male voles that had mercury or cadmium added to the water, started showing autism symptoms.
Alkyl Mercury-Induced Toxicity: Multiple Mechanisms of Action.
Rev Environ Contam Toxicol
A CDC review article, which analyzes studies of ethylmercury and methylmercury, and concludes that both forms are equally toxic. Among other things, both lead to DNA disorders and impair its synthesis, lead to changes in intracellular calcium homeostasis, disrupt cell division mechanism, lead to oxidative stress, disrupt glutamate homeostasis and decrease glutathione activity, which, in turn, further weakens the protection against oxidative stress.
Mercury disposition in suckling rats: comparative assessment following parenteral exposure to thiomersal and mercuric chloride.
J Biomed Biotechnol
Infant rats were divided into two groups. First group received thiomersal injections, and second group received inorganic mercury (HgCl2) injections. They were observed for 6 days after that. Thiomersal receiving rats had brain and blood concentration of mercury much higher than the inorganic mercury recipients did. Thiomersal recipients had significantly less mercury secreted in the urine. Brain concentration of mercury remained virtually unchanged during this period.
Comparison of organic and inorganic mercury distribution in suckling rat.
J Appl Toxicol
Infant rats, which received thiomersal injections, had 1.5-fold higher brain concentration and 23-fold higher blood concentration of mercury, than the rats that received inorganic mercury injections.
Rats, which received inorganic mercury, had a significantly higher level of mercury in the liver and kidneys, which indicates its excretion through feces and urine.  
The comparative toxicology of ethyl- and methylmercury.
Rats that received ethylmercury orally had higher blood concentration of mercury, and lower brain and kidneys concentration of mercury, than the rats that received methylmercury. However, the concentration of inorganic mercury was higher in all tissues in rats, which received ethylmercury. They also had more weight loss and kidney damage.
It another study, it turned out that ethylmercury is 50 times more toxic for cells than methylmercury.
Ethyl mercury crosses the placenta easier than methyl mercury.
Lasting neuropathological changes in rat brain after intermittent neonatal administration of thimerosal.
Infant rats were injected with thiomersal in doses equivalent to those used for human infants. Ischemic degeneration of neurons in the prefrontal and temporal cortex, diminished synaptic reactions, atrophy in hippocampus and cerebellum, and pathological changes of the blood vessels in the temporal cortex were observed.
- Infant rats that were injected with 20-times the dose of thiomersal of the Chinese immunization schedule, showed developmental delays, lack of social interaction skills, tendency for depression, synaptic dysfunction, endocrine system disorders and autistic behavior.
- Infant rats injected with thiomersal showed degeneration of brain neurons.
- Infant rats injected with thiomersal started showing characteristic ASD symptoms, such as impaired locomotion, anxiety, and antisocial behavior.
- Pregnant and nursing rats were injected with thiomersal. Infant rats showed a delay in the fright reflex, impaired motor skills, and an increased level of oxidative stress in the cerebellum.  
Effect of thimerosal on the neurodevelopment of premature rats.
World J Pediatr
Premature rats were injected with different doses of thiomersal after birth. Impaired memory, decreased learning ability and increased apoptosis (cell death) in the prefrontal cortex of the brain were observed. The authors conclude that vaccination of premature babies with thiomersal might be associated with neurological disorders, such as ASD.
Administration of thimerosal to infant rats increases overflow of glutamate and aspartate in the prefrontal cortex: protective role of dehydroepiandrosterone sulfate.
Mice that were injected with thiomersal had high levels of glutamate and aspartate in the prefrontal cortex, which is associated with death of nerve cells. The authors conclude that thiomersal in vaccines may cause brain damage and neurological disorders, and that the insistence of the vaccine manufacturers and healthcare institutions on continuing the use of this proven neurotoxin in vaccines is evident of their disregard for the health of future generations and the environment.
Integrating experimental (in vitro and in vivo) neurotoxicity studies of low-dose thimerosal relevant to vaccines.
The authors analyzed the studies of the effects of low doses of thiomersal and concluded:
1) All studies determined that thiomersal is toxic for brain cells;
2) The combined neurotoxic effect of ethylmercury and aluminum has not been studies;
3) Animals studies have shown that thiomersal exposure can cause accumulation of inorganic mercury in the brain;
4) Relevant doses of thiomersal can potentially affect the development of the nervous system in humans.
Mercury and autism: accelerating evidence?
Neuro Endocrinol Lett
- Despite the fact that thiomersal has been used for 70 years, and amalgam fillings for 170 years, no controlled and randomized studies of their safety have been conducted so far.
- Vaccinated patients with ASD secreted 6 times more mercury during chelation, as compared to the control group.
- Safety of ethylmercury is usually justified only by the fact that the blood concentration of mercury decreases much faster than in the case with methylmercury. However, that does not imply that mercury is quickly removed from the body. It is simply absorbed by other organs much quicker. In studies on rabbits, which were injected with thiomersal and radioactive mercury, the level of mercury in the blood decreased by 75% within 6 hours of the injection, but it increased significantly in the brain, liver and kidneys.
- Thiomersal inhibits phagocytosis in nanomolar concentrations. Phagocytosis is the first step in the work of the innate immune system. It is logical that thiomersal injection will be suppressing the immune system of infants, since they do not have acquired immunity yet.
- Thiomersal caused autoimmune response in predisposed mice, unlike methylmercury.
- Epidemiologic studies do not take into account factors of genetic susceptibility to mercury, and are thus unable to detect a statistically significant effect, even if there is one.
Kawasaki's disease, acrodynia, and mercury.
Curr Med Chem
Kawasaki disease was first described in 1967 in Japan. Its cause is still unknown. In 1985-90, when the amount of thiomersal received through vaccination increased significantly, the Kawasaki disease incidence increased 10-fold, and by 1997 20-fold. Since 1990, 88 cases of Kawasaki disease were reported to the CDC within several days of vaccination, and in 19% of the cases, the disease started on the day of vaccination. In the countries that use less thiomersal, the incidence of the disease is significantly lower than in the USA.
Another disease with an unknown cause is acrodynia. The peak of its epidemic occurred in 1880-1950, when this disease affected one in every 500 children in developed countries. It was determined in 1953 that acrodynia is caused by mercury, which was added to tooth powder, baby powders, and the powder used in diapers. In 1954, mercury-containing products were banned, after which acrodynia disappeared. It was also reported, that in some cases acrodynia occurred after vaccination.
Diagnostic criteria and clinical presentation are similar for Kawasaki disease and acrodynia. Symptoms and laboratory test results, which are seen in Kawasaki disease, were also described for mercury poisoning. Kawasaki disease affects boys twice more often than girls. This is explained by the studies, which show that testosterone increases the toxicity of mercury, while estrogen protects from its toxicity.
According to EPA, 8%-10% of American women have mercury levels high enough to cause neurological disorders in most of their children.
Another similar disease was the Minamata disease, which appeared in 1956 in Japan, as a result of mercury release into the waters of Minamata Bay. For a long time it was believed that both acrodynia and Minamata disease were caused by an infection. The cause of Kawasaki disease is unknown, but it is also believed that it is probably caused by an infection, despite the fact that it is not contagious.
Calomel (Hg2Cl2), a type of mercury, which was responsible for acrodynia, is 100 times less toxic for neurons than ethylmercury.
Ancestry of Pink Disease (Infantile Acrodynia) Identified as a Risk Factor for Autism Spectrum Disorders.
J Toxicol Environ Health A
Despite the fact that the use of mercury was widespread in the first half of the 20th century, only some children had acrodynia. Similarly, only some children develop ASD nowadays. The authors decided to test the hypothesis that autism, like acrodynia, is a consequence of hypersensitivity to mercury. They checked the number of autistic children among the grandchildren of people who survived acrodynia, and it turned out, that the incidence of ASD among them was 7 times higher than the national average (1:25 vs. 1:160).
An 11-month-old boy with psychomotor regression and auto-aggressive behaviour.
Eur J Pediatr
An 11-months-old boy in Switzerland started showing symptoms, resembling ASD. He did not laugh, did not play, was restless, hardly slept, lost weight and could no longer crawl or stand up. He had multiple check-ups, but could not be diagnosed. Three months later he was hospitalized, and after numerous repeat tests, only when the parents were asked, it turned out that 4 weeks prior to the onset of the symptoms, a mercury thermometer got broken in the house. It turned out that the boy had mercury poisoning (acrodynia).
Synergism in aluminum and mercury neurotoxicity.
Integr Food Nutr Metab
Aluminum and mercury are toxic to the glial cells of the central nervous system, and cause an inflammatory reaction. It turned out in this study that they have a synergistic effect, and enhance each other’s response. It also turned out that aluminum sulfate is 2-4 times more toxic than mercury sulfate.
For example, at a concentration of 20 nM aluminum and mercury enhance the inflammatory response by 4 and 2 times respectively, and together, at the same concentration level, by 9 times. At a concentration of 200 nM, aluminum and mercury enhance the response by 21 and 5.6 times respectively, and by 54 times together.
Thimerosal exposure and increased risk for diagnosed tic disorder in the United States: a case-control study.
Thiomersal vaccination is associated with an increased risk of nervous tics. Although nervous tics were once considered very rare, today they are considered the most common motor impairment.
The first case of nervous tics due to mercury poisoning was described in 2000. Epidemiological studies, conducted subsequently, found the link between thiomersal in vaccines and an increased risk of nervous tics.
A dose-response relationship between organic mercury exposure from thimerosal-containing vaccines and neurodevelopmental disorders.
Int J Environ Res Public Health
Each microgram of mercury in vaccines is associated with an increase in the odds of pervasive developmental disorder by 5.4%, the risk of specific developmental delay by 3.5%, nervous tics by 3.4%, and hyperkinetic disorder by 5%.
Thimerosal-containing hepatitis B vaccination and the risk for diagnosed specific delays in development in the United States: a case-control study in the vaccine safety datalink.
N Am J Med Sci
Hepatitis B vaccine with thiomersal is associated with a 2-fold increase in the risk of developmental delays. For those who received 3 doses of such vaccine, the risk of developmental delays was 3 times higher, as compared to those, who received the vaccine without thiomersal. This same vaccine is also associated with a 10-fold increase in the need for special education in boys.
Thimerosal exposure & increasing trends of premature puberty in the vaccine safety datalink.
Indian J Med Res
The risk of premature puberty was 5.6 times higher in children that received 100 μg of mercury from vaccines in the first 7 months of life. Premature puberty was detected in one in 250 children in this study, which is 40 times higher than previous estimates.
It is reported in another study that hepatitis B vaccine with thiomersal is associated with a 3.8-fold increase in the risk of childhood obesity.
Autism: a novel form of mercury poisoning.
ASD symptoms are similar to mercury intoxication symptoms.
Gender-selective toxicity of thimerosal.
Exp Toxicol Pathol
Reduced levels of mercury in first baby haircuts of autistic children.
Int J Toxicol
The authors measured the amount of mercury in the hair from the first haircut of 94 children with ASD, and found that the concentration of mercury in the hair of children with ASD is significantly lower than in the hair of the control group (0.47 vs. 6.63 ppm).
The mothers of children with ASD had significantly higher levels of mercury exposure (through injections of anti-rhesus immunoglobulin and amalgam fillings) than the mothers in the control group.
Among the children with autism, the more severe symptoms were, the lower was the level of mercury concentration in the hair.
Mercury concentration in the hair of the control group correlated with the number of amalgam fillings in mothers, with fish consumption during pregnancy and with the number of vaccines received. In the ASD group, such correlation was absent.
46% of mother of children with ASD have received injections of anti-rhesus immunoglobulin Rho(D), as compared to 9% of mother in the control group.
Mothers of children with autism also had more amalgam fillings (8.35 vs. 5.5). 37% of mother of children with autism had 10 and more fillings, as compared to 18% of mother in the control group.
The authors conclude that the results support the hypothesis that children with ASD retain mercury in tissues, and are worse at secreting it. The absence of mercury in the hair is probably due to its low level in the blood, which nourishes the hair follicles, and its low level in the blood is due to mercury being retained in the cells, where it causes the greatest biological harm.
A prospective study of thimerosal-containing Rho(D)-immune globulin administration as a risk factor for autistic disorders.
J Matern Fetal Neonatal Med
There were 2.35 times more mothers with rhesus-conflict in the group of children with ASD. Each of them received anti-rhesus immunoglobulin during pregnancy, which contained thiomersal at the time. Injections of anti-rhesus immunoglobulin started to be given during pregnancy in the late 80s – early 90s. 
Associations of prenatal and early childhood mercury exposure with autistic behaviors at 5years of age: The Mothers and Children's Environmental Health (MOCEH) study.
Sci Total Environ
Higher levels of mercury in the blood of mothers at late stages of pregnancy and the levels of mercury in umbilical cord are associated with autism at the age of 5 years old.
Blood levels of mercury are related to diagnosis of autism: a reanalysis of an important data set.
J Child Neurol
The Ip, 2004 study did not find an association between ASD and the level of mercury in the blood and hair. The authors of this article (Desoto, 2007) drew attention to an error in the statistical calculations, after which (Ip, 2004) corrected the p-value from 0.15 to 0.056, but did not change their conclusion.
However, after the authors of this article conducted their own statistical analysis of the same data, they found a statistically significant correlation between the level of mercury in the blood and autism. They also found that the level of mercury in the hair, as compared to the blood, was lower in children with ASD than in the control group. 
The association between mercury levels and autism spectrum disorders: A systematic review and meta-analysis.
J Trace Elem Med Biol
A systematic review and meta-analysis of 44 studies. Children with ASD have a significantly higher level of mercury in the blood and brain than healthy children do, while the level of mercury in the hair of children with ASD is significantly lower.
Mercury, lead, and zinc in baby teeth of children with autism versus controls.
J Toxicol Environ Health A
The level of mercury in baby teeth of children with ASD was 2.1 times higher than that of the control group, while the levels of lead and zinc were the same for both groups. Children with autism also received a significantly higher amount of antibiotics during their first year of life (mainly due to otitis media). It is known that antibiotics almost completely suppress the secretion of mercury in rats, due to changes in intestinal microflora. Thus, an increased use of antibiotics in children with autism might have reduced their ability to secrete mercury, and therefore, might partially explain its higher levels in the teeth. The use of antibiotics in infancy might also partially explain the high incidence of chronic gastrointestinal diseases in children with ASD.
It is reported in another study that the levels of mercury in the cerebellum of children with ASD was 68% higher that that of the control group (but there's no statistical significance).
Porphyrinuria in childhood autistic disorder: implications for environmental toxicity.
Toxicol Appl Pharmacol
The level of porphyrins in the urine is an indirect biomarker of the presence of heavy metals in the body.
This study of Parisian children determined that children with ASD secrete significantly more porphyrins in the urine than children in the control group. However, this does not apply to children with Asperger syndrome.
Subsequently, similar results were obtained in the studies in the USA, Australia, Korea and Egypt.    
The value of ecologic studies: mercury concentration in ambient air and the risk of autism.
Rev Environ Health
The higher the state’s concentration of mercury in the air, the higher the risk of autism in it.
Environmental mercury release, special education rates, and autism disorder: an ecological study of Texas.
Every 1,000 pounds of mercury released into the atmosphere in the school district in Texas, increased the number of children in special education by 43%, and the number of children with ASD by 61%.
The number of children with autism was 437% higher in the cities and 255% higher in the suburbs than in the rural areas.
A different study reports that for every 1,000 pounds of industrial waste released, the number of children with autism increases by 2.6%, and if this waste comes from power plants, than the number of children with ASD increases by 3.7%.
Every 10 miles of distance from industrial sources of mercury or power plants are associated with a decrease in the number of children with ASD by 2% and 1.4% respectively.   
A two-phase study evaluating the relationship between Thimerosal-containing vaccine administration and the risk for an autism spectrum disorder diagnosis in the United States.
The authors analyzed VAERS database and found that the risk of ASD was 2 times higher in infants who received DTaP vaccine with thiomersal than in those who received a mercury-free vaccine. An analysis of Vaccine Safety Datalink (VSD), a different database, showed that hepatitis B vaccine with thiomersal is associated with an increase in the risk of ASD (OR=3.4).
Infant boys vaccinated against hepatitis B had a 3-times higher risk of developing autism, as compared to unvaccinated boys, or boys vaccinated at least one month after birth.
The risk of neurodevelopmental disorders following Thimerosal-containing Hib vaccine in comparison to Thimerosal-free Hib vaccine administered from 1995 to 1999 in the United States.
Int J Hyg Environ Health
The Hib vaccine with thiomersal is associated with a 2.75-fold increase in the risk of ADS, 5.4-fold increase for developmental delays, 2.4-fold increase for psychomotor disorders, and 2.7-fold increase for neurological disorders, as compared to those vaccinated with a thiomersal-free vaccine.
The risk of neurodevelopmental disorders following a Thimerosal-preserved DTaP formulation in comparison to its Thimerosal-reduced formulation in the vaccine adverse event reporting system (VAERS).
J Biochem Pharmacol Res
The DTaP vaccine with thiomersal is associated with a 7.7-fold increase in the risk of ASD, 8.7-fold increase for metal retardation, 3.5-fold for speech disorders, 4.8-fold for neurological disorders, as compared to the vaccine without thiomersal.
It is reported in another study that DTaP with thiomersal is associated with a 2.6-fold increase in ASD, 2.6-fold for mental retardation, 1.5-fold for personality disorders, as compared to the vaccine without thiomersal.
Every microgram of mercury increased the odds of autism by 2.9%, metal retardation by 4.8%, and personality disorder by 1.2%.
Methodological issues and evidence of malfeasance in research purporting to show thimerosal in vaccines is safe.
Biomed Res Int
As of today, more than 165 studies have shown the harm of thiomersal, and 16 of them have shown the harm of thiomersal specifically for infants and children who have had outcomes of death, acrodynia, poisoning, allergies, developmental defects, autoimmune responses, developmental delays, and nervous system disorders, including tics, speech and language delays, ADHD and ASD.
Nonetheless, the CDC still insists that there is no link between thiomersal in vaccines and ASD. This is confusing, since the epidemiological study, conducted by the CDC themselves, found a 7.6-times increase in the risk of autism in children, who received vaccines with thiomersal. The same study found that the risk of inorganic sleep disorders was 5 times higher, the risk of speech disorders was 2.1 times higher, and the risk of neurological disorders was 1.8 times higher.
The CDC’s position is based on 6 epidemiological studies, which they funded themselves. All these studies are analyzed in the article:
1) Madsen, 2003. The authors analyzed the data from psychiatric clinicс in Denmark from 1971 to 2000, and determined that after the removal of thiomersal from the vaccines (in 1992), the incidence of ASD increased. However:
- The data from 1971 to 1994, only included inpatient diagnoses, while starting in 1995, they also included outpatient diagnoses. Thus, the inclusion criteria expended significantly 2 years after the removal of thiomersal, which created an artificial increase in the autism incidence. There were 4-6 times more outpatients than inpatients. Another study by the same authors analyzing the same data, reported that there were 13.5 times more outpatients. A large Copenhagen clinic, which registered 20% of the ASD patients in Denmark, was only included in the study in 1993, which also artificially inflated the number of autism cases after the removal of thiomersal. The authors do not report it, nor do they correct this anomaly.
- Diagnostic criteria for ASD changed in 1994 (during the transition from ICD-8 to ICD-10). This could cause a 25-fold increase in the number of ASD cases.
- The 2001 data, which showed a decline in the autism rate since 1991, was included in the first version of the article, which was submitted to JAMA. JAMA rejected the article and the authors submitted it to the Pediatrics. One of the reviewers at Pediatrics noticed that the authors do no analyze the decrease in the autism incidence, which could point to the possibility that removal of thiomersal could have played a role in it. In response to this, the authors removed the 2001 data from the article and it got published. If the authors had not removed this data, the results of the study would have been consistent with the results of a more recent study, according to which, the autism incidence in Denmark after 1992 decreased from the peak 1.5% in 1994 to 1% in 2002-4.
2) Stehr-Green, 2003. Conducted in response to a California study, which discovered a correlation between thiomersal and autism. The authors compared the data from 3 countries (Denmark, Sweden and California). Danish data was the same as in the previous study. Swedish data was based only on inpatient cases (that is, on just a small fraction of all ASD cases). Part of the data from California was excluded from the final publication.
3) Hviid, 2003. The authors state that the mean age of autism diagnosis is 4.7 years, but nonetheless, they included 1-year-olds in the analysis. Moreover, rather than counting the number of children, they counted the number of person-years. Thanks to this technique, each group was considered equally, despite the fact that the probability of diagnosis in younger age groups was much lower.
4) Andwers, 2004. A retrospective study in the United Kingdom. It has the same issues, as did the previous study. The authors did not publish the initial data, so it could not be analyzed properly.
5) Verstraeten, 2003. The publication states that there was no association between thiomersal and ASD. However, the first phase of this study, released in an internal presentation, showed that infants who received more than 25 μg of mercury in vaccines and immunoglobulin at the age of one month, had 7.6-fold higher risk of autism, as compared to those who did not receive any mercury. The second phase of the study showed that infants, who received 62.5 μg of mercury before the age of three months, had 2.5-fold higher risk of autism, as compared to those who received less than 37.5 μg. In the third phase, after playing around with statistics, the risk of autism decreased to 1.69. Apparently, the author had been under pressure, since he wrote in an internal CDC correspondence: “I do not wish to be the advocate of the anti-vaccine lobby and sound like being convinced that thimerosal is or was harmful, but at least I feel we should use sound scientific argumentation and not let our standards be dictated by our desire to disprove an unpleasant theory.”
The fourth and fifth phases of the study were based on partial data only and included children at the age of 0-3 years old, even though the average age for autism diagnosis at the time was 4.4 years. Nevertheless, the study found an increased risk for tics and speech delays.
6) Price, 2010. A case-control study in the USA in which the control group received the same vaccines. It is called overmatching, and it is impossible to draw conclusions from this kind of study. Moreover, the initial report discovered that prenatal exposure to thiomersal correlated with an 8-fold increase in the risk of ASD, but for some reason, this data was excluded from the publication.
Five out of the six studies were directly controlled by the CDC, which may indicate a conflict of interest, since vaccine promotion is a central mission of the CDC.
The third phase of Verstraeten study was presented at the CDC secret conference in 2000, which was dedicated to thiomersal (Simpsonwood meeting). Among other things, Dr. Clements from the WHO stated that this study probably should not have been conducted, since its result could have been predicted, and now it puts everyone in an uncomfortable position.
Here, an FDA representative admits to Congress that given the existing studies, it is impossible to conclude that thiomersal in vaccines does not cause ASD.
The relationship between mercury and autism: A comprehensive review and discussion.
J Trace Elem Med Biol
The authors analyzed all studies about the possible relationship between mercury and autism published between 1999 and 2016. They found 91 studies, and 74% of them found a link between mercury and ASD.
Predictors of mercury, lead, cadmium and antimony status in Norwegian never-pregnant women of fertile age.
Norwegian women who ate fish one or more times a week had the blood levels of mercury 70-fold higher than women, who did not eat fish or ate it rarely.
The levels of lead in blood correlated with the amount of alcohol consumed, and the levels were higher in smokers. The levels of mercury and antimony were lower in vegetarians.
The level of mercury in umbilical cord is 70% higher than in mother’s blood. 15.7% of mother had blood mercury levels above 3.5 μg/l, which is the level associated with an increased risk for defects in the development of the fetal nervous system.
Alzheimer’s disease, Parkinson’s disease and multiple sclerosis develop faster when exposed to toxic metals. ASD is accompanied by impaired metal homeostasis.
Altered pairing behaviour and reproductive success in white ibises exposed to environmentally relevant concentrations of methylmercury.
Proc Biol Sci
Ibises were divided into three groups, and starting from the age of three months, low doses of methylmercury were added into their diets (0.05, 0.1 and 0.3 ppm), and they were observed for three years. Males of these ibises were much more likely to form homosexual couples (up to 55%) than the control group, which did not receive methylmercury.
Heterosexual couples laid 35% less eggs (no statistical significance).
The authors conclude that even low doses of methyl mercury, in concentrations found in the wild nature, could reduce the number of chicks by 50%, and these estimate might be conservative. Moreover, in the conditions of the experiment the birds had 4 attempts at breeding each season, while there are only 1-2 attempts in the wild, which could magnify the effect of homosexual attempts on the population of chicks.
The effect of the vaccination of mercury levels
Ethyl, methyl and inorganic mercury
Acrodynia and Kawasaki disease
Nervous tics and developmental delays