Autism is costing the Centers for Disease Control (CDC) and Prevention some of its credibility, according to an article yesterday in the Atlanta Journal-Constitution. At issue is the role that mercury (in the form of thimerosal) plays as a preservative in many vaccines and the failure of the CDC to look more closely at the issue. Mercury is toxic and many autism advocacy groups think that the rise in diagnosed cases of autism over the last decade is due to the use of thimerosal in the vaccines that children receive early in life.