For my analysis of a real world security issue, I chose to cover explosive trace detection in airports. Initially, I had no idea what ‘explosive trace detection’ even was. As a college student flying home frequently for every break, though, I always wondered why TSA was swiping random passengers’ hands and what they were testing for. With some quick research, I found that these tests were part of explosive trace detection techniques, which identify potential threats by catching small residue amounts of explosive materials.
Explosive Trace Detection In Airports
ETD has been used by the TSA in airports since 2010 and is a relatively simple procedure. TSA workers quickly and painlessly swab passengers hands with a testing paper, then insert the paper into an ETD machine, which reports whether or not explosive materials have been detected on the swab. These machines, using technologies like Ion Mobility Spectrometry (IMS), detect trace particles of materials frequently used in explosives. While varying in accuracy, ETD machines are capable of detecting explosive compounds like TNT or RDX in terms of parts per million or parts per billion. ETD machines can also be used to detect other controlled substances, like narcotics, by altering which trace chemicals they attempt to detect.
TSA worker using ETD machine
Security Risks
Because of the purpose of ETD machines, their security risks have much larger consequences. Not detecting an explosive material can lead to passenger deaths, but falsely identifying a passengers as being a threats in too large a number is also unacceptable. The ETD machines can be adjusted to operate at higher or lower sensitivity ranges – at a higher sensitivity, chemicals must be very similar to known explosive materials, while at lower sensitivities, they can differ more. Because of this variance in sensitivity, the ETD machines can falsely identify innocuous substances as threats. For example, many compounds in house-hold fertilizers can also be used in home-made explosives. If a passenger had recently worked in their garden, with a less sensitive ETD test, they could be investigated and searched for bombs. Conversely, with a too-sensitive ETD test, a passenger who actually does pose a threat could be undetected. ETD machines must also be programmed for which substances to detect and therefore miss any threating substances they are not aware of.
Conclusion
While Explosive Trace Detection technology currently in airports is at risk for false positives and false negatives, I believe that the machines take a step in the right direction for passenger scanning. The tests are non-invasive, and rely on concrete scientific evidence in identifying possible threats. By investing in ETD tests – by swabbing and testing every passenger rather than randomly selected individuals, improving the IMS detection science, and by increasing the number of substances a machine can detect – I believe that the TSA can quickly scan for threats while maintaining passenger rights.
References
http://blog.tsa.gov/2010/02/explosive-trace-detection-usage.html