Egged on by U.S. Rep. Robert Wexler, Gov. Charlie Crist has asked the federal government to study the effects of Chinese drywall that has corroded wiring in walls and air conditioners in scores of homes built in Florida from 2005 to 2007. In a letter last week, Crist urged the Environmental Protection Agency and the Centers for Disease Control and Prevention to get involved. Wexler claimed that Chinese drywall, confirmed in fewer than 300 Florida homes, is a "significant statewide problem whose devastating impact on families and our state is similar to natural disaster such as a hurricane, fire, or flood." State toxicologists have said that while the drywall can be corrosive it poses no immediate health threat to people sniffing the sulfurlike fumes emitted when the plaster gets damp. Several customers of Lennar Homes are having their drywall replaced free of charge by the builder.