In an effort to strengthen security at the nation's airports, and create local jobs, the Department of Homeland Security (DHS) has announced the deployment of its advanced imaging technology (AIT) at 28 additional airports, bringing the total to 142. Up to 450 will be in operation in 2010. AIT technology is designed to bolster airport security by screening passengers for metallic and non-metallic threats, such as weapons, explosives and other objects concealed under layers of clothing. The machinery is funded by the American Recovery and Reinvestment Act. AIT screening is optional, allowing passengers to opt for physical pat-downs if they have privacy or other concerns. The DHS press release, which contains the list of the 28 additional airports, can be found here.