April, 1948 an article is published in the journal Pediatrics:
"Inspection of the records of the Children's Hospital for the past ten years has disclosed 15 instances in which children developed acute cerebral symptoms within a period of hours after the administration of pertussis vaccine. The children varied between 5 and 18 months in age and, in so far as it is possible to judge children of this age range, were developing normally according to histories supplied by their parents. None had convulsions previously."

"Twelve of the children were boys and three were girls, a sex difference also encountered in relation to other substances, such as lead, causing gross injury to the developing nervous system. At inoculation time, the children varied in age between 5 and 18 months. Developmental data were obtained in detail on all but two of the children, whose mothers simply stated that they had developed normally. Reference to the case histories showed that such objective activities such as sitting, walking, and talking had appeared in many of the children prior to the inoculations; and the regressions or failure of further development occurred after the encephalopathies [Any disease or symptoms of disease referable to disorders of the brain] in several instances. In so far as it was possible to judge none of the children were defective prior to their acute illness."

"In common with many other biologic materials used parenterally [not by mouth], an important risk of encephalopathy attends the use of prophylactic pertussis vaccine. The mechanism whereby the encephalopathy is produced is not elucidated by the present study. The universal use of such vaccine is warranted only if it can be shown to be effective in preventing encephalopathy or death from pertussis itself in large groups of children. If avoidance of the inconvenience of the average attack of pertussis is all that is expected, the risk seems considerable. Efforts to diminish the hazard by modification of the vaccine or new methods of administration seem indicated."
Fast forward 60 years to the present; parents state their children were developing normally until the time of a vaccine; boys are 3 to 4 times more likely to have autism than girls; often times sitting, walking, talking are all normal in a child until 12-30 months followed by a major regression. The parallels to the present day epidemic in childhood neurologic disorders to this 1948 article are striking and concerning. What is equally disturbing is the observation of the authors that the neurologic problem occurred near the administration of the pertussis vaccine and that the "sex difference" in the "gross injury to the developing nervous system" was similar to the heavy metal lead.

Coal-burning power plants, use of mercury in gold mining, industrial manufacturing, incineration of municipal and medical waste, are some of the sources of heavy metals found in our modern environment. These pollutants contaminate our environment and enter our food supply and eventually our bodies. In some cases heavy metals were added to products, such as in mercury amalgam fillings, and one substance in particular, Thimerosal, has been believed by many to be a major cause of neurologic problems that we encounter today.

Thimerosal is a mercury-containing organic compound or organomercurial. In the 1930s, Eli Lily developed Thimerosal as a preservative and it has been used in a number of biological and drug products, including many vaccines. Until the removal of Thimerosal, which contains 49.9% ethyl mercury by weight, from most pediatric vaccines in 2001, the source of the largest human exposure to mercury in the US was in children under 18 months of age undergoing routine childhood immunization schedules. Before 2001, a child may have received a cumulative dose of over 200 μg/kg [micrograms per kilogram] in the first 18 months of life.

Although Thimerosal has been removed from most childhood vaccines, it is still present in the flu vaccine, which is given to pregnant women, the elderly, and children. Also, many vaccines given to children in developing countries still contain Thimerosal.

Many still believe that Thimerosal is safe and effective and that there is little to no evidence that there is any health problems associated with this substance. According to the FDA website:
"Thimerosal has been the subject of several studies and has a long record of safe and effective use preventing bacterial and fungal contamination of vaccines, with no ill effects established other than minor local reactions at the site of injection."
The article references eight studies supporting their position. But is there evidence that shows Thimerosal isn't safe?

A Material Safety Data Sheet or MSDS is a document that provides the proper procedures for handling or working with a particular substance. The information includes physical data (such as melting point, boiling point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill/leak procedures.

The hazard rating information that appears on the MSDS is summarized on a diamond-shaped diagram that can rapidly alert personnel to substances that require special caution. Hazards are rated from 0 indicating no unusual hazard to 4 a severe hazard. The blue area of the diamond relates to health and a rating of 2 in the case of Thimerosal indicates "Intense or continued exposure could cause temporary incapacitation or possible residual injury unless prompt medical attention is given."

Here are some disturbing excerpts from the MSDS for thimerosal (trade name Merthiolate):
"Section 3: Hazards Identification - Potential Chronic Health Effects: 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."

"Section 6: Accidental Release Measures - Poisonous solid. Stop leak if without risk. Do not get water inside container. Do not touch spilled material. Use water spray to reduce vapors. Prevent entry into sewers, basements or confined areas; dike if needed."

"Section 11: Toxicological Information - Chronic Effects on Humans: MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells. May cause damage to the following organs: kidneys, liver, spleen, bone marrow, central nervous system (CNS). Special Remarks on Chronic Effects on Humans: May cause cancer based on animal data. No human data found."

"Inhalation and Ingestion: Repeated or prolonged exposure may cause kidney damage, and may affect the liver, and bone marrow. Chronic exposure to mercury vapors behavior/central nervous system and peripheral nervous system (depression, irritability, nervousness, weakness, ataxia, fatigue, tremor, jerky gait, limb spasms, personality changes), metabolism (anorexia, weight loss) and cause gastrointestinal disturbances which is collectively referred to as "aesthenic-vegetative syndrome." Chronic ingestion may cause accumulation of mercury in body tissues and may result in salicylism which is characterized by nausea, vomiting, gastric ulcers, and hemorrhagic strokes."
In addition Elli Lilly's 1999 MSDS contains more disturbing information:
"Section 3: Hazards Identification - ... Exposure to mercury in utero and in children may cause mild to severe mental retardation and mild to severe motor coordination impairment."

"Section 6: Accidental Release Measures - Wear protective equipment, including eye protection, to avoid exposure. This material is a mercury compound which are CERCL Hazardous Substances and SARA 313 Toxic Chemicals."
The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, was enacted by Congress on December 11, 1980. This law created a tax on the chemical and petroleum industries and provided broad Federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment. SARA 313 requires the EPA and State Regulatory Agencies to annually collect data on releases and transfers of certain toxic chemicals from industrial facilities, and make the data available to the public through a public database called the Toxics Release Inventory, or TRI.

These data safety sheets alone are certainly a cause for concern. One has to question why would anyone use such a dangerous substance in any medical product let alone one that is injected directly into the blood stream? But in addition to the MSDS there are numerous studies from the medical and scientific literature that clearly show thimerosal is not a safe substance. The following are a few excerpts from a number of scientific journals:

1977 - Archives of Disease in Childhood
"Although thiomersal [thimerosal] is an ethyl mercury compound, it has similar toxicological properties to methyl mercury and in long-term neurological sequelae [a pathological condition resulting from a disease, injury, or other trauma] produced by the ingestion of either methyl or ethyl mercury-based fungicides and indistinguishable ... Since it is clear that treatment of exomphalos [an umbilical hernia at birth in which some abdominal organs push into the umbilical cord] by the application of alcoholic mercurial antiseptics can produce blood and tissue levels of mercury well above the threshold at which damage occurs in all other age groups, it is extremely unlikely that these infants escape neurological damage, which may be subtle. We therefore suggest that treated survivors should be examined neurologically and psychologically as a matter of urgency. Organic mercurial antiseptics should be heavily restricted or withdrawn from hospital use, as the fact that mercury readily permeates intact membranes and is highly toxic seems to have been forgotten. Equally effective and far less toxic broad-spectrum antifungal and antibacterial topical antiseptics are currently available."
2003 - Toxicological Sciences
"In clinical cases of accidental or intentional usage in high concentrations, thimerosal was administered in doses from 3 mg/kg to several hundred mg/kg. Such doses resulted in local necrosis [The death of living cells or tissues] at the application site and severe central nervous system and kidney injury ... In this paper we demonstrated that extending the time of incubation with thimerosal from 2 to 6 hours is associated with toxicity that was not seen after a shorter time of exposure. For this reason, further studies of lower concentrations and longer exposure times appear to be warranted. These results indicate that additional research is needed to fully delineate the dose- and time-dependent toxicity of thimerosal in sub-micro-molar concentrations and suggests that toxicity may occur at even lower doses than those utilized in these experiments, with longer times of exposure. Because mercury can be retained in body organs for months to years, the study of longer incubation times is warranted."
2003 - Archives of toxicology
"In conclusion, thimerosal induced strong effects in the cytochalasin B in vitro [outside the living organism] micronucleus test in human lymphocytes ... Since thimerosal was repeatedly shown to be genotoxic [damaging to DNA] in vitro and in vivo [inside the living organism], there is reason for concern about its widespread use."
2004 - Toxicology
"Both thimerosal and methylmercury increased the [Ca2+]i and oxidative stress in cerebellar granule cells. In rat cerebellar granule neurons, the increase in [Ca2+]i induces an increase in oxidative stress while the oxidative stress increases the [Ca2+]i. It is a possibility that uncontrolled and sustained elevation of [Ca2+]I increases the formation of reactive oxygen species that induce a further increase in [Ca2+]i. If so, such insults induced by thimerosal and methylmercury would lead to cell injury or death in brain neurons ... In can be concluded that the potency of thimerosal to induce cytotoxic [substances that are toxic to cells] action on brain neurons dissociated from 2-week-old rats under the in vitro conditions is similar to that of methylmercury."
2005 - NeuroToxicology
"In both cell lines, a progressive increase in cytotoxicity [decrease in viability] was observed when Thimerosal dose was progressively doubled from 2.5 μmol/L [micromoles per liter] to 5, 10, and 20 μmol/L. Viability was reduced more than 50% in both cell lines with exposure to 10 μmol/L Thimerosal and less than 10% of cells survived a dose of 20 μmol/L. Thimerosal induces oxidative stress and apoptosis [programmed cell death] by activating mitochondrial cell death pathways. A subsequent study using cultured human neuron and fibroblast cell lines similarly showed that low micromolar concentrations of Thimerosal induced DNA strand breaks, caspase-3 activation, membrane damage and cell death."
2007 - Journal of Toxicology and Environmental Health
"The high order of toxicity from Thimerosal and its ethylmercury breakdown product has been known and published for decades. Nonetheless, Thimerosal remains in the drug supply, especially in various vaccines manufactured both for the United States and globally. The ubiquitous and largely unchecked place of Thimerosal in pharmaceutical products, therefore, represents a medical crisis in the modern day. Reforms in the manufacture and the licensing of vaccines and other drugs, which should have been accomplished proactively, had anyone properly assessed their mercury content, must now be conducted, reactively, under significant systemic stress. With no warning, recall, or ban of mercury in vaccines and other drugs as of yet, the victim of this mandated, unwarranted, and massive mercury exposure is still an unsuspecting public, and most especially its unborn and newborn children."
2007 - Anales de la Facultad de Medicina
"Due to the vast gaps in knowledge of thimerosal's pharmacokinetics and pharmacodynamics, as its toxic properties over the immune system, it is required to make more studies of quantitative character in animal models as soon as possible. Nevertheless, while it is true, it is difficult to extrapolate these findings to other animal experimentation groups and over human beings, our results, as the multiple scientific evidence recently published about thimerosal, clearly indicates the toxic nature of this substance, at the same dose and the same chronology as human immunizations; therefore we suggest the employment of alternative preservatives in vaccines, especially those intended to pregnant women, neonates, and small children based in the prevention and precaution principles of all medical interventions."
2008 - Neuroendocrinology Letters
"Thimerosal has been recognized by the California Environmental Protection Agency, Office of Environmental Health Hazard Assessment as a developmental toxin. This implies that Thimerosal may produce birth defects, low birth weight, biological dysfunctions, or psychological or behavior deficits that become manifest as the child grows. Maternal exposure during pregnancy may disrupt the development or even cause the death of the fetus. ... It is clear from these data that additional ND research should be undertaken in the context of evaluating mercury-associated exposures, especially from Thimerosal containing Rho(D)-immune globulins administered during pregnancy. Further studies should also be undertaken in additional databases/registries to assess the compatibility of the present results with trends in NDs in other US populations, and to observe whether Thimerosal-containing Rho(D)-immune globulins were associated with other birth defects in children. ... CONCLUSION: This study associates TCR [Thimerosal (49.55% mercury by weight) - containing Rho(D) immune globulins] exposure with some NDs [neurodevelopmental disorders] in children."
2008 - International Journal of Risk & Safety in Medicine
"Biological findings in autism that are consistent with mercury poisoning include elevated oxidative stress, depleted levels of glutathione, neurochemical irregularities, gastro-intestinal distress, immune dysregulation and generalized and neural inflammation. All of these are also well documented effects of mercury poisoning and, specifically, mercury poisoning in infants ... Autism is a modern disease. It was first identified in the late 1930s and reported in 1943 by Kanner. It is important to place the arrival and subsequent epidemic growth of autism into the historical context of environmental exposure to mercury. Therefore, it is important to acknowledge that the commencement of widely available vaccinations (containing mercury) commenced in the 1930s. Additionally, the early 1900s saw the increasing availability and popularity of dental care where mercury amalgam fillings were the dominant restorative material ... The existing scientific literature provides grounds for strong suspicion that mercury plays a causal role in the development of autism. Given this suspicion, and the severe nature, devastating lifelong impact and extremely high prevalence of autism, it would be negligent to continue to expose pregnant and nursing mothers and infant children to any amount of avoidable mercury. Health authorities worldwide should move without hesitation to ban and remove all mercury in all medical products at the earliest possible date."
2009 - Behavioral and Brain Functions
"A disruption of the GSH (glutathione) system by mercury leads to GSH depletion and cell destruction. An in vitro study of Jurkat T cells exposed to thimerosal demonstrated concentration-dependent apoptosis. It was found that the mercury moiety [part of the molecule], not the thiosalicylic acid moiety, of thimerosal was responsible for glutathione depletion. GSH depletion is linked to several neurodegenerative disorders."
2009 - NeuroToxicology
Our study design does not enable us to determine whether it is the vaccine per se, the exposure to Th [thimerosal], or a combination of both that is causing the observed effects. None-the-less, the developing brain is considered the most vulnerable organ to mercury exposure, and experimental studies suggest that the brainstem - whose function is central to the reflexes described herein - may be one of the more sensitive targets ... Since the acquisition of motor reflexes is controlled by the brainstem, it is possible that very early exposure to ethyl mercury may adversely affect the emerging brainstem function ... this study provides preliminary evidence of abnormal early neurodevelopmental responses in male infant rhesus macaques [type of monkey] receiving a single dose of Th-containing [Thimerosal containing] HB [Hepatitis B] vaccine at birth and indicates that further investigation is merited."
There are still more studies not included in this article simply because the volume of information would be overwhelming, but the Material Data Safety Sheets and these scientific excerpts speak for themselves - Thimerosal is clearly a dangerous substance.

What the authors of that 1948 study probably didn't know when they said "If avoidance of the inconvenience of the average attack of pertussis is all that is expected" was that the historical data shows the death rate from pertussis had already fallen by 99% by the time they were writing their article and that their call to "diminish the hazard" of the vaccine would be apparently largely unheeded.


Randolph K. Byers, M.D. and Frederic C. Moll, M.D., Encephalopathies Following Prophylactic Pertussis Vaccine, Pediatrics, April 1948, Vol. 1, No. 4, pp. 437-456

FDA website Thimerosal in Vaccines

Thimerosal Material Safety Data Sheet

Thimerosal Material Safety Data Sheet - Elli Lilly and Company, 22-Dec-1999

Fagan DG, Pritchard JS, Clarkson TW, Greenwood MR., Organ mercury levels in infants with omphaloceles treated with organic mercurial antiseptic. Archives of Disease in Childhood. 1977 Dec;52(12):962-4.

David S. Bakin, Hop Ngo, and Vladimir V. Didenko, Thimerosal Induced DNA Breaks, Caspase-3 Activation, Membrane Damage, and Cell Death in Cultured Human Neurons and Fibroblasts, Toxicological Sciences, Aug 2003, pp. 361-8.

WESTPHAL Götz A.; ASGARI Soha; SCHULZ Thomas G.; BÜNGER Jürgen; MÜLLER Michael; HALLIER Ernst; Thimerosal induces micronuclei in the cytochalasin B block micronucleus test with human lymphocytes, Archives of toxicology, 2003, vol. 77, no1, pp. 50-55

Toshiko Ueha-Ishibashi, Yasuo Oyama, Hiromi Nakao, Chisato Umebayashi, Yasutaka Nishizaki, Tomoko Tatsuishi, Kyoko Iwase, Koji Murao and Hakaru Seo, Effect of thimerosal, a preservative in vaccines, on intracellular Ca2+ concentration of rat cerebellar neurons, Toxicology, Volume 195, Issue 1, 15 January 2004, Pages 77-84

S.J. James, William Slikker III, Stepan Melnyk, Elizabeth New, Marta Pogribna, Stefanie Jernigan, Thimerosal Neurotoxicity is Associated with Glutathione Depletion: Protection with Glutathione Precursors, NeuroToxicology, Vol. 26, 2005, pp. 1-8


Jonny Laurente, Fany Remuzgo, Betthina Ávalos, Johnnie Chiquinta, Bladimir Ponce, Ronald Avendaño, Luis Maya, Neurotoxic effects of thimerosal at vaccine doses on the encephalon and development in 7 day-old hamsters, Anales de la Facultad de Medicina, 2007; 68(3), pp. 222-237

David A. Geier, Elizabeth Mumper, Bambi Gladfelter, Lisa Coleman, and Mark R. Geier, Neurodevelopmental Disorders, Maternal Rh-Negativity, and Rho(D) Immune Globulins: A Multi-Center Assessment, Neuroendocrinology Letters, Volume 29, No. 2 2008

David Austin, An epidemiological analysis of the 'autism as mercury poisoning' hypothesis, International Journal of Risk & Safety in Medicine, 20 (2008) pp. 135-142

Renee Dufault, Roseanne Schnoll, Walter J Lukiw, Blaise LeBlanc, Charles Cornett, Lyn Patrick, David Wallinga, Steven G Gilbert and Raquel Crider, Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children, Behavioral and Brain Functions, 2009, 5:44

Laura Hewitson, Lisa A. Housera, Carol Stottc, Gene Sackett, Jaime L. Tomko, David Atwood, Lisa Blue, E. Railey Whited and Andrew J. Wakefield, Delayed acquisition of neonatal reflexes in newborn primates receiving a thimerosal-containing Hepatitis B vaccine: Influence of gestational age and birth weight, NeuroToxicology, October 2009