Two dozen Iowa parents rallied on the steps of the statehouse today (Wednesday), complaining that some childhood vaccines can be dangerous. Dana Halvorson of Northwood is president and co-founder of a group that encourages parents to avoid vaccines that contain a mercury preservative which they believe can cause autism. “We’re not anti-vaccine,” she says. “Some people may choose not to vaccinate and that s their personal choice.” Few vaccines on the market today contain mercury as a preservative, yet Halvorson says parents need to be on-guard. Halvorson says it doesn’t take much mercury to harm an infant. Halvorson’s daughter is now seven. She was diagnosed as autistic at age three, and Halvorson believes she was the victim of mercury-poisoning. “What most people don’t realize is the signs and symptoms of mercury poisoning versus autism are almost identical,” Halvorson says. A new Iowa law bars the mercury additive from vaccines administered after January 1st of next year, but Halvorson warns the preservative could be used in flu shots. Still, former state Senator Ken Veenstra of Orange City — one of the authors of the law that bans the mercury additive from vaccinations given in Iowa — believes it’ll be effective. Veenstra says it was a significant step and at least a dozen other states have followed Iowa’s lead. However, there’s legislation pending in Congress which would strike down those state laws. Veenstra says Congress should instead be moving to ban mercury as a preservative in flu vaccines. “That would be a huge step to take…that would essentially remove it from use in the vaccine field,” he says. Parents who believe mercury poisoning from childhood vaccines caused their childrens’ autism also rallied in Washington, D-C and 12 other states today (Wednesday). On Tuesday, officials from the Centers for Disease Control and Prevention held a news conference to cite scientific evidence they say shows mercury additives in childhood vaccines do NOT cause autism.