WASHINGTON - AIRPORT security lines can annoy passengers, but there is no evidence that they make flying any safer, United States researchers reported on Thursday.
A team at the Harvard School of Public Health could not find any studies showing whether the time-consuming process of X-raying carry-on luggage prevents hijackings or attacks.

They also found no evidence to suggest that making passengers take off their shoes and confiscating small items prevented any incidents.

The US Transportation Security Administration told research teams requesting information their need for quick new security measures trumped the usefulness of evaluating them, researchers Eleni Linos, Elizabeth Linos, and Graham Colditz reported in the British Medical Journal.

'Even without clear evidence of the accuracy of testing, the Transportation Security Administration defended its measures by reporting that more than 13 million prohibited items were intercepted in one year,' the researchers added. 'Most of these illegal items were lighters.'

The researchers said it would be interesting to apply medical standards to airport security. Screening programmes for illnesses like cancer are usually not broadly instituted unless they have been shown to work.

'We'd like airport security screening to be of value. As passengers and members of the public we'd like to know the evidence and the reasoning behind these measures,' Ms Linos said in a telephone interview.

With US$5.6 billion (S$8.2 billion) spent globally on airport protection each year, the public should be encouraged to query some screening requirements - such as forcing passengers to remove their shoes, the researchers said.

'Can you hide anything in your shoes that you cannot hide in your underwear?' they asked. -- REUTERS