ISLIP - As millions of people prepare to head out on Labor Day getaways, a local politician is warning travelers about potential health risks posed by airport security.Rep. Steve Israel (D-N.Y.) says he wants to warn passengers that they may be exposed to ionizing radiation as they pass through full-body scanners at some airport security checkpoints. Experts say the machines, including ones at LaGuardia and JFK International Airport, emit extremely low doses of ionizing radiation. They warn that the machines could malfunction, and that little is known about the effects of repeated exposure. The Transportation Security Administration (TSA) says the scanners have been tested by the Food and Drug Administration and haven't been found to pose any health risks. Israel argues that he wants a thorough, independent study of the potential risks posed by the scanners.Typically, travelers can opt out of passing through the scanners by submitting to a pat-down by TSA agents.