Evidence for the Health Claim | Evidence Against the Health Claim | Conclusion

mythbuster graphic Are you concerned that your metal implants may set off metal detectors at the airport? The possibility exists, and it depends on factors, such as the size and metal content of your implants and the sensitivity of the metal detector.

Evidence for the Health Claim

Since the probing energy of metal detectors are capable of penetrating body tissue, the presence of metal inside your body may sound the alarm. However, studies examining patients with orthopedic implants (eg, knee or hip replacements) found variable results from airport screening detectors.

One study conducted by Basu and colleagues compared patients with various types of implants. They also looked at the metal detector response to individuals with implants and volunteers with metal prosthetics strapped to their bodies. This study found that Richards cannulated screws (a type of hardware used in implant surgery) were the only metallic objects to consistently set off the detectors. Some artificial joints did sound the alarm, most notably Austin Moore prostheses, but others—specifically single joint replacements—did not. The results were similar for the implants and metal prosthetics strapped outside the body.

Travelers’ mixed experiences with metal detectors at airports are due to a number of factors. The sensitivity of metal detectors is based on a scale of 1 to 15 (1 being the least sensitive, 15 being the most sensitive), and the average airport detector is set at five. Some detectors, particularly in high-risk security areas of the world, are set at seven. Detectors set at 10 will be activated by objects with very low metal content, such as coins and jewelry, and thus would create many false alarms and even longer lines at security checkpoints.

Implants with high iron content, such as Austin Moore prostheses, are the most likely to set off the alarms. Newer implants are often made with metals such as titanium and are less likely to set off detectors. These characteristics may also be influenced by outside factors, such as nearby sources of electromagnetic radiation.

Evidence Against the Health Claim

Not all studies have found that surgical hardware in the body sets off metal detectors. In fact, with recent medical advances, many implants contain metals less likely to set off metal detector alarms. However, if you are traveling in an area considered high-risk, heightened security measures may require higher detector sensitivity settings, increasing your risk of setting off the alarm with your implant.

Conclusion

If you have metal implants in your body, it is possible that an airport metal detector will find it. Some doctors will give you a note explaining your condition. However, since there is no official card you can carry to verify the existence of your implant, if you set off the detector you will be asked to step aside for further screening.

Setting off the detector is not harmful to your body, but it may be an inconvenience in your travel schedule. So be prepared, especially in the United States and other areas with elevated security, to undergo further inspection and questioning at the airport. It is important to know that the possibility of your metal implant activating a detector does exist, so you should be prepared for a longer wait at the security checkpoint.