Jim Yardley has seen firsthand how the nanotechnology field has exploded over the past decade. “It’s extremely exciting,” says the managing director of Columbia’s Nanoscale Science and Engineering Center. “The work here has helped create a whole new world of research, a completely new field.” The nanotechnology projects Yardley oversees bring together faculty and students from a host of different departments, including chemistry, engineering, biology and physics, to broaden and deepen our understanding of materials at the molecular level.

Backscatter machines also can be found in the Los Angeles, Chicago and Boston airports and at New York’s JFK.The agency also uses more than 540 millimeter wave scanners, considered a safer option because they don’t rely on radiation. Those machines are in use at Miami and Palm Beach international airports.That prompted a renewed wave of concern in the United States.”Why would you buy a machine that emits radiation if you could buy one that didn’t?” said Broward County Mayor John Rodstrom, a frequent flier who makes it a point to avoid the scanners.At Rodstrom’s urging, the Broward County Commission asked the TSA to consider removing backscatter scanners from the Fort Lauderdale airport unless the agency can prove the machines are safe.TSA: Scanners safeFrom the moment the machines were introduced in Fort Lauderdale, in May 2010, the TSA asserted they are safe for all passengers, emitting less radiation than the amount travelers receive during two minutes of flying in an airliner.”The safety and security of the traveling public is TSA’s number one priority, and TSA would not use technology that could jeopardize the health of passengers or our employees,” agency spokeswoman Sari Koshetz said.However, comparing the scanners’ radiation to that received during an airline flight is “misleading,” according to a group of scientists from the University of California, San Francisco.They said the cosmic radiation that infiltrates airliners is absorbed by the whole body and is thus less dangerous than the low level radiation of the scanners, which permeates only the skin and underlying tissues. In addition to Dauer’s concerns, they said blood and male testicles could be endangered.In a letter to the Obama administration, John Sedat, a professor emeritus in biochemistry and head of the University of California group, said scanner radiation poses a particular risk to those over age 65 and intensifies the danger to people who already have cancer or HIV.