Do thimerosal containing vaccines cause Autism, or a form of Mercury poisoning?

One of the most disputed questions between parents and healthcare professionals today is, ‘do thimerosal containing vaccines cause Autism?’ With the recent rise in Autism Spectrum Disorder (ASD) diagnoses over the last two decades, parents are fearful that vaccinating their children will lead to devastating and irreversible consequences. It’s no wonder parents are so frightened. According to the CDC, the ratio of children being diagnosed with ASD is 1:68. When those statistics are combined with the horror stories plastered on every parenting blog, and online baby forum, it’s amazing parents even take their children out of the house.   

As a medical professional who has studied the human body, and genetics, I have always been inclined to believe that Autism was a genetically linked disease.  I have never been convinced that Autism could develop overnight, or over the course a few weeks.  It is important to approach this topic with facts, and proof.  The internet is filled with unlimited testimonials from parents and family members, recounting the almost ‘overnight change’ in their child.  However, what the internet lacks is the quantitative information needed to properly answer this question.  Therefore, we should closely examine the facts about the vaccines, and make a better informed decision.

The most controversial ingredient in childhood vaccines is an ingredient called thimerosal. Advocacy groups claim that thimerosal is the ingredient responsible for the rising number of autism diagnoses in the United States and around the world. Thimerosal is a mercury containing compound (49.6% mercury), which acts as a preservative inside the vaccine.  This preservative prevents life threatening bacteria and fungus from growing inside the vaccine.  Ironically, the  mercury contained in this preservative may be more harmful  than the bacteria and fungus it sought to prevent.  Thimerosal is what’s known as an ethylmercury. Ethylmercury is a generic term meaning that it is of organic origin, and the single type of mercury which, when studied, rendered the greatest variability in outcomes. Proponents argue that the lack of consistent evidence to disprove  the theory that thimerosal causes autism, coupled with the dramatic increase in Autism diagnoses during the same time that the number of routine vaccines were given to children in the 1990’s, lead to the removal of thimerosal between 1999-2001. I found this to be unusual that so little research has been conducted on this chemical, yet, it has been introduced to almost every vaccine since 1928.  It seems perplexing that over the course of 88 years such limited research has been conducted on the long-term exposure to ethylmercury after we have readily dispersed it to millions of people.   Perhaps these advocacy groups have struck a chord after all.  

The obvious follow-up question is this: what happens to the human body once it has been exposed to Mercury?  According to U.S National Library of Medicine and National Institutes of Health, “Acute or chronic mercury exposure can cause adverse effects during any period of development. Mercury is a highly toxic element; there is no known safe level of exposure. Ideally, neither children nor adults should have any mercury in their bodies because it provides no physiological benefit.”  In children exposed to mercury, the side effects presented as moderate to severe neurocognitive deficits and neuromotor disabilities.  This essentially describes a range of delays in areas such as language, reading, and writing (dyslexia). When observed, these children were characterized by their nonverbal behavior, and  limited expressive language  These children also had difficulties with mathematics, particularly understanding and computing units of measure and often reversed numbers, a condition known as dyscalculia. Finally, children exposed to mercury presented with clinical syndromes such as Attention deficit/hyperactivity disorder, and executive functioning disorders.  According to the research, these children had significant emotional outbursts, difficulty modulating their behaviors when routines were altered, and difficulty with social interactions and reading social cues.    

At this point, it is important to review the most typically presenting symptoms in a child with Autism.  The following signs of Autism were retrieved directly from The National Autism Association database:

  • Social impairments
  • Cognitive impairments
  • Communication difficulties
  • Repetitive behaviors
  • Difficulty understanding, or showing understanding, or other people’s feelings or their own
  • No speech or delayed speech
  • Repeat words or phrases over and over (echolalia)
  • Give unrelated answers to question
  • Reverse pronouns (e.g., says “you” instead of “I”)
  • Become upset by minor changes
  • Hyperactivity (very active)
  • Impulsivity (acting without thinking)
  • Short attention span
  • Aggression
  • Causing self injury
  • Meltdowns
  • Unusual eating and sleeping habits
  • Unusual mood or emotional reactions
  • Lack of fear or more fear than expected
  • Unusual sleeping habits


Could it be possible that Autism is not running rampant in our society, but instead a vast outbreak in mercury poisoning?


updated 5/12/16