In developing an opinion on mercury toxicity from exposures to dental amalgam and thimerosal I have reviewed toxicologic data relevant to animal and human studies to environmental mercury, methylmercury, thimerosal and exposure to mercury from amalgam fillings. I have reviewed literature searches conducted on various computerized databases; evaluated published literature on primary studies as referenced in part herein. I have reviewed relevant unpublished reports, consulted review articles, where appropriate, and held working meetings with experts in the field. I have also conducted experiments in my laboratory at the University of Kentucky with regards to the enzyme and cellular toxicity of both dental amalgams and thimerosal, including vaccine with and without thimerosal added as a preservative. In addition, I have reviewed evaluations and conclusions of various governmental agencies, including the International Agency for Research on Cancer (IARC), the World Health Organization (WHO), the National Institute of Health (NIH), the United States Environmental Protection Agency (EPA), and other groups regarding this issue. I have come to the following conclusions.