Efforts to increase security have some airports using full-body scanners. Some are concerned if these scanners increase a person's risk of cancer. According to U.S. researchers, the risk is low. Officials tested 40-whole body scanners as part of a pilot program which began after the september eleventh terrorist attacks. In fact, reports say 150 more were ordered last fall.

Two types of machines can be used for full-body scans. One is a millimeter wavelength imaging scanner; the other is a backscatter x-ray scanner. Both are used to view under clothing as well as identify unusual objects.

Officials say only one, the backscatter x-ray machine, will expose a person to ionizing radiation used in typical medical x-rays. The bottom-line, u-s researchers say cancer risk from security scans is low and unlikely. Airports in Britain, Canada, and the Netherlands plan to use full body scanners to avoid terrorist attacks like the failed attempt to blow up a Detroit-bound flight last month.