Childhood vaccines contain doses of mercury that are in excess of the Federal Safety Guidelines, and evidence shows a link between these excessive doses of mercury, found in thimerosal-containing vaccines, and neurodevelopment disorders such as autism and speech disorders, as well as heart disease, according to a study.

Since the introduction of thimerosal to vaccines, rates of autism have drastically increased. In the mid-1980s, one in 2,500 children had autism compared with one in about 300 children in 1996--an increase of over 800 percent in 20 years.

Researchers say that thimerosal should be banned from all U.S. vaccines and hope such a ban would curb the epidemic of autism and speech disorders facing America.

The study found a two- to six-fold increased occurrence of neurodevelopment disorders after an additional 75- to 100-microgram dosage of mercury from thimerosal-containing vaccines as compared to thimerosal-free vaccines.

To investigate, researchers analyzed the doses of mercury from thimerosal-containing vaccines that children received from routine childhood immunizations. They also evaluated the incidence of rates of neurodevelopment disorders and heart disease following thimerosal-containing vaccines and thimerosal-free vaccines.

Additionally, researchers looked at data on children with various types of disabilities in comparison to the amount of mercury they received from thimerosal in their childhood vaccines.

Based on the results, which found thimerosal-containing vaccines to contain mercury in excess of Federal Safety Guidelines, researchers confirmed a link between thimerosal-containing childhood vaccines and neurodevelopment disorders and heart disease.

Journal American Physicians & Surgeons Spring 2003 (PDF)