Are Airport X Ray Scanners Harmful? | Safe Travel Facts

Airport X-ray scanners use extremely low levels of ionizing radiation, generally considered safe for the vast majority of travelers.

Navigating airport security is a routine part of travel, and it’s natural to wonder about the technology used to keep everyone safe. Many travelers express concerns about the X-ray scanners, seeking clarity on their safety and impact.

Understanding Airport Security Scanners

When you step into the security line, you’ll encounter a few different types of technology designed to screen for prohibited items. The primary goal is to ensure safety and efficiency, making your journey smoother.

Types of Scanners You’ll Encounter

• Millimeter Wave Scanners: These are the most common advanced imaging technology (AIT) scanners found in airports today. They use non-ionizing electromagnetic waves, similar to radio waves, to create a generic image of the body.
• Backscatter X-ray Scanners: While less prevalent now, some airports still use these. They emit very low-dose ionizing X-rays to create an image of items concealed under clothing.
• Walk-Through Metal Detectors: These are older, non-ionizing devices primarily used to detect metallic objects. Many travelers pass through these before or after AIT scanning.

Each scanner type operates on different principles, but all are designed with traveler safety as a core consideration. The choice of scanner often depends on the airport’s specific needs and equipment availability.

The Science of Radiation Exposure

The term “radiation” often triggers concern, but it’s important to differentiate between types and doses. Understanding the science behind airport scanners helps demystify their operation.

Ionizing vs. Non-Ionizing Radiation

• Non-Ionizing Radiation: This type, used by millimeter wave scanners and metal detectors, has insufficient energy to remove electrons from atoms. Examples include radio waves, microwaves, and visible light. It does not damage DNA.
• Ionizing Radiation: This type, used by backscatter X-ray scanners, carries enough energy to remove electrons from atoms, which can potentially damage DNA in high doses. Examples include X-rays and gamma rays. The key factor is the dose received.

The human body is constantly exposed to natural background radiation from cosmic rays, the earth, and even food. Airport security scanners contribute a minuscule fraction to this daily exposure.

Dose Equivalence and Measurement

Radiation dose is measured in sieverts (Sv) or, more commonly for small exposures, microsieverts (µSv). To put scanner exposure into perspective:

• A single backscatter X-ray scan delivers approximately 0.05-0.1 µSv.
• A millimeter wave scan delivers 0 µSv of ionizing radiation.
• A typical chest X-ray delivers about 100 µSv.
• A transatlantic flight exposes a traveler to approximately 30-40 µSv of cosmic radiation.
• The average person receives about 3,100 µSv annually from natural background sources.

The FDA, which regulates radiation-emitting electronic products, confirms that the radiation dose from airport X-ray scanners is extremely low and falls well within safety standards.

Millimeter Wave Scanners: The Current Standard

Millimeter wave scanners have become the predominant technology in airport security checkpoints. Their widespread adoption is due to their effectiveness and the nature of the radiation they employ.

These scanners use a form of electromagnetic radiation that is non-ionizing, meaning it does not carry enough energy to cause changes at the cellular level. The waves reflect off the body, and a computer algorithm interprets these reflections to identify objects concealed under clothing. The image displayed to the security officer is a generic, privacy-protective outline, not a photographic representation of the traveler.

Health organizations globally, including the World Health Organization (WHO) and the U.S. Food and Drug Administration (FDA), have evaluated millimeter wave technology and concluded that it poses no known health risks. For travelers concerned about radiation exposure, these scanners offer a reassuring option.

Backscatter X-Ray Scanners: Less Common, Still Safe

While less common than millimeter wave technology, backscatter X-ray scanners still exist in some locations. These devices use a very low-dose X-ray beam to create an image of the body, revealing objects hidden beneath clothing.

The X-ray dose from these machines is exceptionally small, comparable to the amount of cosmic radiation received during a few minutes at cruising altitude on an airplane. The FDA has rigorously tested these devices and found that the radiation emitted is well below the levels that would cause any adverse health effects. The dose is so minimal that even frequent flyers would accumulate a negligible amount of radiation over many years of travel.

Despite their safety, public perception and privacy concerns led to a reduction in their deployment. However, where they are used, they meet strict safety guidelines enforced by regulatory bodies.

Table 1: Airport Scanner Type Comparison

Feature	Millimeter Wave Scanner	Backscatter X-Ray Scanner
Radiation Type	Non-ionizing (Radio Waves)	Ionizing (X-rays)
Health Risk	No known health risk	Negligible health risk (extremely low dose)
Image Display	Generic avatar/outline	Generic avatar/outline (historically more detailed)
Prevalence	Most common AIT	Less common, being phased out

Special Considerations for Travelers

Certain groups of travelers often have specific questions regarding airport security scanners. Understanding the guidelines and available options can ease anxieties.

Pregnancy

Pregnant travelers frequently ask about scanner safety. Both millimeter wave and backscatter X-ray scanners are considered safe for pregnant individuals. The non-ionizing radiation from millimeter wave scanners poses no risk. For backscatter X-ray scanners, the dose is so small and localized to the skin surface that it does not reach the fetus. Still, any traveler, including those who are pregnant, can request a pat-down as an alternative to scanner screening.

Medical Devices

Travelers with pacemakers, cochlear implants, or other implanted medical devices can generally use both types of scanners without issue. The electromagnetic fields of millimeter wave scanners are not strong enough to interfere with these devices. Similarly, the very low-dose X-rays from backscatter scanners do not pose a risk. If you have concerns, you can always inform a security officer and request a pat-down. Carrying a medical device identification card can be helpful, though not typically required.

Children

Children are not at an increased risk from airport scanners. The radiation doses are too low to have any significant effect on developing bodies. The same safety standards apply to all ages.

Frequent Flyers

Even for individuals who fly often, the cumulative radiation dose from airport security scanners remains extremely low. The total exposure from scanners over a year for a frequent flyer would still be a tiny fraction of the natural background radiation received annually. The FAA provides guidance on cosmic radiation exposure during flight, which contributes a far greater dose than security screening.

Table 2: Estimated Radiation Exposure Comparison

Source of Exposure	Approximate Dose (µSv)	Notes
Airport Backscatter X-ray Scan (single)	0.05 – 0.1	Extremely low, localized to skin
Airport Millimeter Wave Scan (single)	0	Non-ionizing radiation
Transatlantic Flight (one way)	30 – 40	Cosmic radiation at altitude
Natural Background Radiation (daily average)	8.5	From earth, cosmic rays, food
Dental X-ray (single)	5	Localized diagnostic imaging

Your Options at the Security Checkpoint

Understanding your choices at the security checkpoint can make the process less stressful. Travelers always have the right to decline advanced imaging technology (AIT) screening.

If you prefer not to go through a scanner, you can request a pat-down. This is a standard procedure and a recognized alternative to AIT screening. Simply inform the security officer at the entrance to the screening area of your preference. A pat-down is conducted by an officer of the same gender and involves a thorough physical inspection. It may take slightly longer than scanner screening, but it is a valid option for any traveler.

Official Guidance and Regulations

Airport security protocols are governed by strict regulations and oversight from multiple agencies, ensuring traveler safety and security effectiveness.

The TSA is responsible for implementing security procedures at airports, including the use of screening technologies. They work closely with other federal agencies, such as the FDA, to ensure that all equipment meets safety standards. The FDA evaluates radiation-emitting devices like backscatter X-ray scanners to confirm they operate within safe limits for public exposure. These agencies adhere to guidelines established by international bodies, ensuring consistency and safety across global travel.