Door frame metal detectors (DFMDs) and hand-held metal detectors are used to screen passengers at Indian airports. However, DFMDs can’t detect non-metallic weapons, explosives and metal hidden inside shoes. To identify explosives and drugs on a person and in baggage, explosive trace devices and explosive vapour devices are used randomly at airports.
Though some of these technologies and procedures are available at Indian airports to detect suspicious people or objects, they have limitations and are not foolproof devices, particularly when it comes to detecting explosives hidden on the body of a person.
Body scanners are more reliable than currently available techniques and gadgets to recognize threats involving explosives and contraband items hidden anywhere on the body. Installing them will certainly help security personnel to perform their jobs efficiently with zero error, and help boost airport security.
Besides, passenger traffic is increasing manifold and manual checks of passengers is an extremely time-consuming process leading to delays. Considering all these aspects, the Bureau of Civil Aviation Security has issued an order to install body scanners at Indian airports in a phased manner.
Generally, there are two types of body scanners: The millimeter wave scanner and the backscatter X-ray. The millimeter wave scanner uses high frequency radio waves to make an image of the body, which shows objects hidden under clothes. The backscatter X-ray scanners detect the radiation that reflects from the human body.
Full body scanners have become an important part of the security and threat detection toolkit around the world. The system eliminates the ambiguity of hand searches and detects a range of threats metal detectors simply cannot. It is one of the most effective means of determining and detecting whether somebody is moving a non-metallic device through the system. Metal detector walk-through scanners have an obvious weakness regarding liquid, gel or plastic contraband that could be concealed on the body. Many plastic or liquid items can be highly dangerous.
At the same time, body scanners are able to screen adequately for security threats that may be concealed inside turbans, hijab, burqas and prosthetics.
During a trial run of body scanners at Delhi’s Indira Gandhi International Airport, it was observed that these scanners do not set off any alarm below the ankles. Gives many false alarms because of thickness of clothing and other such factors, each alarm has to be reconciled by physical checking.
There are, however, some lacunae and perception challenges that need to be addressed. There seems to be a perception that contours of body are seen and recorded—this is incorrect. Also, passengers don’t even have to remove all metallic items. The average passenger is not easily ready to remove all metallic items from the body because of religious sentiments and other reasons. In India, especially, women passengers who wear jewellery are required to remove them at the time of scanning—this can be problematic as passengers do not generally agree with this because of the fear of theft of jewellery from their bags.
The scanners add another layer of security at checkpoints besides metal detectors, explosives-detection systems and bomb-sniffing dogs. And, as they continue to ease congestion, travellers can move faster compared to a pat-down search.
R.R. Sahay is former inspector general, CISF airport sector.