Uncovered documents show that the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) knew that infant vaccines were exposing American children to mercury far in excess of all federal safety guidelines since 1999. The documents, created by a FDA consulting toxicologist, show how federal regulators concealed the dangerous impacts and lied to the public.

In 1997, Congress passed the FDA Modernization Act. A provision of that statute required the FDA to "compile a list of drugs that contain intentionally introduced mercury compounds, and provide a quantitative and qualitative analysis of the mercury compounds on the list." In response, manufacturers reported the use of the mercury-based preservative, thimerosal, in more than 30 licensed vaccines.

FDA's Center for Biologics Evaluation and Research (CBER) was responsible for adding up the cumulative exposure to mercury from infant vaccines, a simple calculation that, astonishingly, had never been performed by either the FDA or the CDC. When the agency finally performed that basic calculation, the regulators realized that a six month-old infant who received thimerosal-preserved vaccines following the recommended CDC vaccine schedule would have received a jaw dropping 187.5 micrograms of mercury.