Iowa’s top doctor says most childhood vaccines do not contain mercury as a preservative. Senator Ken Veenstra, a republican from Orange City, is sponsoring a bill to ban any vaccine which contains mercury as a preservative. State epidemiologist Patricia Quinlisk says starting in 1999, mercury has been phased out of childhood vaccines.Quinlisk says today, a child in Iowa could get all their vaccines without being exposed to thimerosal. That’s the name for the mercury-based preservative Senator Veenstra’s targeting. Veenstra believes mercury contained in childhood vaccines has led to the dramatic increase in the number of children who have autism. Quinlisk has a different view. Quinlisk says “almost all the studies have found no link whatsoever.” She says mercury’s been taken out of childhood vaccines because of concerns and because other preservatives were available.