"Ethyl mercury compounds display a very high toxicity not only for the brain, but also for the spinal motoneurones, peripheral nerves, skeletal muscles, and myocardium." - Cinca et al, 1979 23

"The scientific evidence that thimerosal causes reproductive toxicity is clear and voluminous. Thimerosal dissociates in the body to ethyl mercury.  The evidence for its reproductive toxicity includes severe mental retardation or malformations in human offspring who were poisoned when their mothers were exposed to ethyl mercury or thimerosal while pregnant, studies in animals demonstrating developmental toxicity after exposure to either ethyl mercury or thimerosal, and data showing interconversion to other forms of mercury that also clearly cause reproductive toxicity." - OFFICE OF ENVIRONMENTAL HEALTH HAZARD ASSESSMENT, 2004 2

"Potential Chronic Health Effects:Hazardous in case of skin contact (irritant), of ingestion, of inhalation. Mutagenic for mammalian somatic cells. The substance may be toxic to kidneys, liver, spleen, bone marrow, central nervous system (CNS). Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure to a highly toxic material may produce general deterioration of health by an accumulation in one or many human organs." - MSDS Data Sheet 26

"There is a worldwide increasing concern over the neurological risks of thimerosal (ethylmercury thiosalicylate) which is an organic mercury compound that is commonly used as an antimicrobial preservative. In this study, we show that thimerosal, at nanomolar concentrations, induces neuronal cell death through the mitochondrial pathway. Thimerosal, in a concentration- and time-dependent manner, decreased cell viability… and caused apoptosis (programmed cell death)." 32

"Taken together these findings suggest deleterious (harmful) effects on the cytoarchitecture (cellular arrangement in the cerebral cortex of the brain) by thimerosal and initiation of mitochondrial-mediated apoptosis (programmed cell death)." 33

Information extracted from studies indicates that:
a) activity of low doses of Thimerosal against isolated human and animal brain cells was found in all studies and is consistent with Hg neurotoxicity;
(b) the neurotoxic effect of ethylmercury has not been studied with co-occurring adjuvant-Al in Thimerosal-containing vaccines;
(c) animal studies have shown that exposure to Thimerosal-Hg can lead to accumulation of inorganic Hg in brain, and that
(d) doses relevant to Thimerosal-containing vaccines exposure possess the potential to affect human neuro-development. Thimerosal at concentrations relevant for infants' exposure (in vaccines) is toxic to cultured human-brain cells and to laboratory animals. 44

"This analysis suggests that in our study population, the risk of tics, ADD, language and speech delays, and developmental delays in general may be increased by exposure to mercury from thimerosal containing vaccines during the first six months of life."21

"The Public Health Service (including the FDA, National Institutes of Health (NIH), Center for Disease Control and Prevention (CDC) and Health Resources and Services Administration (HRSA) and the American Academy of Pediatrics issued two Joint Statements, urging vaccine manufacturers to reduce or eliminate thimerosal in vaccines as soon as possible (CDC 1999) and (CDC 2000)." 4 

"Since the first Vaccine Injury Compensation claims were made in 1989, 3,149 compensation payments have been made, $2,396,574,630.52 disbursed to petitioners and $96,060,500.79 paid to cover attorney's fees and other legal costs."19

A thorough review of medical literature and U.S. government data indicates:
(i) that many and perhaps most cases of idiopathic autism, in which an extended period of developmental normalcy is followed by an emergence of symptoms, are induced by early exposure to Hg;
(ii) that this type of autism represents a unique form of Hg poisoning (HgP);
(iii) that excessive Hg exposure from thimerosal in vaccine injections is an etiological mechanism for causing the traits of autism;
(iv) that certain genetic and non-genetic factors establish a predisposition whereby thimerosal's adverse effects occur only in some children; and
(v) that vaccinal Hg in thimerosal is causing a heretofore unrecognized mercurial syndrome.8

The overwhelming evidence from the peer-reviewed scientific and medical literature favours acceptance that mercury exposure is capable of causing some Autism Spectrum Disorders, particularly in children who are biochemically and/or genomically susceptible to mercury intoxication.9

The children with Autism Spectrum Disorder had a significant dose-response relationship between the severity of the regressive Autism Spectrum Disorder and the total mercury dose children received from Thimerosal-containing vaccines/Rho (D)-immune globulin preparations, and suffered mercury toxic encephalopathies (brain injury) that manifested with clinical symptoms consistent with regressive Autism Spectrum Disorders.10

Children with severe Autism Spectrum Disorder had biomarkers consistent with mercury toxicity. This study concludes mercury intoxication is significantly associated with autistic symptoms.11

The data from this study, along with emerging epidemiological data showing a link between increasing mercury doses from childhood vaccines and childhood neurodevelopmental disorders, increases the likelihood that mercury is one of the main factors leading to the large increase in the rate of autism and other neurodevelopmental disorders.12

There was significant difference in blood mercury levels between cases and controls, which persists after adjustment for age, gender and parental occupational status. The geometric mean blood mercury level was also significantly higher in children with inattentive and combined subtypes of ADHD. High blood mercury level was associated with ADHD.28

This study demonstrates that the levels of mercury in the birth hair of autistic children were significantly lower than their control peers. While this may at first appear contradictory, it highlights one of the critical insights to understanding mercury poisoning and autistic children: many autistic children are non-excretors of mercury. This means their capacity to excrete mercury is significantly lower than their neurotypical peers and contributes to their condition.29

Boys who received the hepatitis B vaccine during the first month of life had 3 fold greater odds for ASD compared to boys vaccinated later or unvaccinated boys. 14, 36

Boys who were vaccinated with the Hep B triple series vaccine were 9 times more likely to need early intervention or special education services, than boys who were not vaccinated with the Hep B vaccine.13

This study presents the first epidemiologic evidence, based upon tens of millions of doses of vaccine administered in the United States, that associates increasing thimerosal from vaccines with neurodevelopmental disorders. Specifically, an analysis of the Vaccine Adverse Events Reporting System (VAERS) database showed statistical increases in the incidence rate of:

• autism - 6 fold more at risk
• mental retardation - 6 fold more at risk
• speech disorders - 2.2 fold more at risk

…after thimerosal-containing diphtheria, tetanus, and acellular pertussis (DTaP) vaccines in comparison with thimerosal-free DTaP vaccines.30

Infants receiving vaccines with 100ug mercury more than other infants were:37

• 2.6 fold more likely to have Autism
• 2.2 fold more likely to have Autism spectrum disorders
• 4.5 fold more likely to have Hyperkinetric syndrome of childhood
• 1.8 fold more likely to have a developmental disorder or learning disorder not already specified
• 3 fold more likely to have a disturbance of emotions specific to childhood and adolescence
• 4 fold more likely to have Tics

The results showed the prevalence rate of Autism spectrum disorders among the grandchildren of pink disease (infantile mercury poisoning) survivors (1 in 22) to be significantly higher than the comparable general population prevalence rate (1 in 160). The results support the hypothesis that mercury sensitivity may be a heritable/genetic risk factor for Autism spectrum disorders.15

Thimerosal at low nanomolar (nM) concentrations induced significant cellular toxicity in human neuronal and fetal cells. Thimerosal-induced cytoxicity is similar to that observed in Autistic Disorder pathophysiologic studies.43

Biomarkers associated with the presence of heavy metals were found in the brains of mice injected with 12mcg of thimerosal per kg of bodyweight. The authors of the study note: As a result of the present findings, in combination with the brain pathology observed in patients diagnosed with autism, the present study helps to support the possible biological plausibility for how low-dose exposure to mercury from thimerosal-containing vaccines may be associated with autism.34

Mercuric chloride stimulates vascular endothelial growth factor (a chemical signal produced by cells that stimulates the growth of new blood vessels) and Interleukin-6 (a protein that promotes inflammation) release from human mast cells. This phenomenon could disrupt the blood-brain-barrier and permit brain inflammation. As a result, the findings of the present study provide a biological mechanism for how low levels of mercury may contribute to ASD pathogenesis.35

Numerous neuropathological changes were observed in young adult rats which were treated postnatally with thimerosal. They included:38

• Ischaemic (lack of blood flow) degeneration of neurons and "dark" neurons in the prefrontal cortex (part of the brain involved in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behaviour), the temporal cortex (part of the brain involved with memory, speech, hearing, and some aspects of vision), the hippocampus (part of the brain involved in memory forming, spatial navigation, and emotion) and the cerebellum (part of the brain involving co-ordination, speech, attention, and emotion)
• Pathological (harmful) changes of the blood vessels in the temporal cortex diminished synaptophysin reaction in the hippocampus (this reaction is associated with mental retardation)
• Atrophy of astroglia (tissue that supports neurons) in the hippocampus and cerebellum
• Positive caspase-3 reaction (promotes programmed cell death) in Bergmann astroglia (tissue that supports neurons located in the cerebellum)

These findings document neurotoxic effects of thimerosal, at doses equivalent to those used in infant vaccines or higher, in developing rat brain, suggesting likely involvement of this mercurial in neurodevelopmental disorders.38

Application of thimerosal to the prefrontal cortex (of rats)… evoked a rapid increase of glutamate overflow (glutamate is an excitatory neurotransmitter that in excess leads to excitotoxicity, causing neuron damage or death). Since excessive accumulation of extracellular glutamate is linked with excitotoxicity, our data imply that neonatal exposure to thimerosal-containing vaccines might induce excitotoxic brain injuries, leading to neurodevelopmental disorders.39

The risk of autism was elevated by 50% in areas with the highest levels of chlorinated solvent and heavy metal air pollution. The highest risk compounds were mercury, cadmium, nickel, trichloroethylene, and vinyl chloride. Our results suggest a potential association between autism and estimated metal concentrations, and possibly solvents, in ambient air around the birth residence.40

On average, for each 1,000 lb of environmentally released mercury, there was a 43% increase in the rate of special education services and a 61% increase in the rate of autism. The association between environmentally released mercury and special education rates were fully mediated by increased autism rates.42

We suspect that persistent low-dose exposures to various environmental toxicants, including mercury, that occur during critical windows of neural development among genetically susceptible children (with a diminished capacity for metabolizing accumulated toxicants) may increase the risk for developmental disorders such as autism.41