BEIJING, December 30 (Xinhuanet) -- New technology exists that might have detected explosives hidden in the underwear of a Nigerian man who is accused of trying to blow up a plane over Detroit. However, cost and privacy concerns have prevented its widespread use.
Umar Farouk Abdulmutallab, 23, is suspected of trying to ignite an explosive called PETN using a chemical-filled syringe as Northwest Flight 253 approached Detroit on Christmas morning. Despite passing through security checks at Lagos and Amsterdam, where standard metal detector archways are employed, his explosives were not spotted.
Amsterdam's Schiphol Airport has at least 15 full-body "millimetre wave" scanners that can see underneath passengers' clothing to detect suspicious packages or weapons. Dutch airport authorities want the EU to make passenger scanners mandatory, arguing that they might have stopped the man who tried to blow up a U.S. airliner. But their use remains voluntary because of concerns that the scans reveal passengers as "naked" to the operators and anyone else passing by the machine's screen.
The costs are also substantial. A traditional archway metal detector can cost up to 15,000 U.S. dollars. The more intensive whole-body scanners cost around 10 times as much. With airport operators strapped for cash the implementation of such equipment may not come soon. There are two types of body scanners the "millimetre wave" and "backscatter X-ray" scanners both carry out a similar scan of an individual displaying the person as virtually naked.
While the usefulness cannot perhaps be argued, there is a strong debate about their safety and of concerns over privacy. Industry experts say public fears about radiation from the X-ray machines are unwarranted. In contrast to the traditional X-ray machine, which detects hard and soft materials by the variation in transmission through the target, backscatter X-ray is a newer imaging system which detects the radiation which comes back from the target. It has potential applications in almost every situation in which non-destructive examination is required, but only one side is available for examination.
But some are concerned with exposure to radiation emitted by backscatter X-rays. At airports, lead vests are not used and people fear being exposed to "dangerous level of radiation if they get backscattered too often." The Health Physics Society (HPS) reports that a person undergoing a backscatter scan receives approximately 0.005 millirems of radiation while the American Science and Engineering Inc. reports 0.009 millirems. According to U.S. regulatory agencies, "1 millirem per year is a negligible dose of radiation, and 25 millirem per year from a single source is the upper limit of safe radiation exposure."
The other type of scanning device is the millimeter wave scanner which employs extremely high frequency waves in the terahertz range. Although terahertz photons are not energetic enough to break chemical bonds or ionise atoms or molecules, the chief reasons why higher energy photons such as x-rays and UV rays are destructive, there may be other mechanisms at work. The evidence that terahertz (THz) radiation damages biological systems is mixed.
"Some studies reported significant genetic damage while others, although similar, showed none," says Boian Alexandrov at the Center for Nonlinear Studies at Los Alamos National Laboratory in New Mexico. Alexandrov and his scientific colleagues have created a model to investigate how THz fields interact with double-stranded DNA. They say that although the forces generated are tiny, resonant effects allow THz waves to unzip double-stranded DNA, creating bubbles in the double strand that could significantly interfere with processes such as gene expression and DNA replication.
As for privacy issues there is a lively debate ongoing both in the United States and especially in Europe. Germany's interior ministry, which sets the standards for domestic airport security, declined to use body scanners last year after it decided they were an invasion of privacy, although their usefulness and safety are still being tested. "They were rejected as going too far into the private sphere of travellers," said Verena Meyer, spokeswoman for the Federal Commissioner for Data Protection and Freedom of Information, an independent parliamentary watchdog.
In Britain, Home Secretary Alan Johnson said, "We intend to be at the cutting edge of all this new technology and to ensure that we put it in place as quickly as possible." However, progress has been slow. A spokesman for Manchester airport said it was running trials but had made no decision on implementation, while Heathrow operator BAA said it was not using body scanners at all.
The European Parliament has consistently opposed body scanners on privacy and health grounds and has asked for more studies in both these areas. Nonetheless, "there are no EU rules preventing member states from using them if they want to," a spokesman for the Commission said on Tuesday. Schiphol's chief operating officer and director of security said on Monday they intend to make millimetre wave scanners mandatory once they get EU approval. Schiphol officials rejected X-ray machines as too unsafe for the public for regular use.
The possibility of increased use as the terror threat continues has affected the stocks of the companies who make the devices. Some smaller companies such as ICX Technologies and OSI Systems, worth only a few hundred million dollars to begin with, rose 10 percent or more on Monday. Larger players like Smiths Group and L-3 Communications have also benefited, with their machinery already in trials in airports around the world.
Even if the new technology becomes widespread officials say there is no guarantee it will catch every potential attacker. Abdulmutallab may not have even been spotted according to one official. "There is no 100 percent guarantee we would have caught him," Schiphol Group COO Ad Rutten said. Jane's Aviation analyst Chris Yates said that several procedures need to be put in place rather than just one technology. "Absolutely without a shadow of doubt this is a good thing. But one solution will not address every vulnerability. It needs to be a set of solutions," Yates said.
(Agencies)
