ASA's 36th National Conference on Autism Spectrum Disorders (July 13-16, 2005)

• Recorded Presentation

Learning Objectives: 1) Learn the symptoms of infantile mercury toxicity, and the similarity to the symptoms of autism 2) Learn the major sources of exposure to mercury 3) Understand the factors that make some people more sensitive to mercury poisoning 4) Understand the scientific data that demonstrates high levels of mercury and other toxic metals in children with autism 5) Learn how to prevent mercury poisoning, and how to treat cases of it

Content: 1) Overview of the symptoms of infantile mercury toxicity, and their similarity to the symptoms of autism, based on the report of the Agency for Toxic Substances and Disease Registry (a branch of the CDC) and the article by Bernard et al in Medical Hypothesis.

2) Overview of the sources of exposure to mercury, including seafood, dental fillings, vaccines, power plants, and other sources. This will include a quantitative comparison of the amount and type of mercury exposure due to each source.

3) Explanation of the critical factors that make some people more sensitive to mercury poisoning, including: A) Antibiotics: A study of rats found that the half-life for excretion of mercury was increased from 10 days to 100 days during antibiotic usage. Our study and others have found that children with autism had a 5x higher exposure to oral antibiotics in early childhood, primarily due to ear infections. B) Low levels of sulfate/glutathione/metallothionein: glutathione and metallathionein are the primary mechanism for the excretion of mercury, and their level is highly dependent on sulfate status, which is very low in children with autism. C) Early exposure: Our study found that mothers of children with autism consumed twice the amount of seafood during pregnancy as the mothers of typical children, and this was confirmed by hair analysis which found twice as much mercury in the hair of mothers of children with autism.

4) Mercury in Baby Hair: A recent study found that children with autism have 1/8 the normal amount of mercury in their baby hair, suggesting an inhibited ability to excrete mercury which is consistent with their high oral antibiotic usage. Also, they found that the severity of autism had a strong inverse correlation with the hair level, such that the children with the lowest levels of mercury in their hair (least excretion) were the most severe. We will also report on our replication study, which we carried out with the help of NIH and researchers at MIT, and which generally supports the Holmes' et al study.

5) Baby Teeth: We will present our study with the Un. of Texas, which evaluated the level of mercury, lead, and zinc in the baby teeth of children with autism vs. controls, and found that children with autism have 3x as much mercury in their baby teeth.

6) Thimerosal Studies: We will review the 9 epidemiology studies which investigated the autism-thimerosal connection, including 4 that found a strong connection, one that was inconclusive, and four that failed to find a connection. We will also review the study by Hornig et al. which found that some genetically-susceptible strains of mice were injured by injections of thimerosal at the level used in childhood vaccines.

7) DMSA challenge results: DMSA is an FDA-approved medication for removing toxic metals from the body. We will present the results of our published study (led by Dr. Jeff Bradstreet) which found that DMSA results in significantly more excretion of heavy metals in children with autism vs controls. This is strong evidence that children with autism have excess amounts of heavy metals trapped in their body.

8) Treatment Reports: We will briefly mention the reports by clinicians on the effect of long-term DMSA treatments in hundreds of children with autism. We will also discuss two newer treatments, DMPS and TTFD, which are becoming more commonly used.

9) Treatment Study: We hope to be able to report on the results of our randomized, double-blind, placebo-controlled DMSA treatment study – it was just funded and we hope to start soon.

10) Question/Answer period

Note: Prof. Adams teaches a 1-semester course on Heavy Metal and Chemical Toxicity and a 1-semester course on the Biology of Autism at Arizona State University. He is also the representative of national ASA to the National Institute of Environmental Health Sciences, the branch of NIH that focuses on lead and mercury poisoning.