Airport Machines: A Danger To Travelers?

Airport security systems use metal detectors, backscatter X-ray machines, millimeter-wave scanners, and cabinet X-ray machines to ensure the safety of passengers and staff. While these machines emit radiation, the amount is extremely low and comparable to the radiation emitted by cell phones. The consensus among experts is that the benefits of enhanced security far outweigh the minimal radiation risk posed by these scanners. However, for those who are concerned or particularly vulnerable, there are additional precautions that can be taken to minimize exposure.

X-ray machines emit ionizing radiation, which can cause DNA damage

X-ray machines emit ionizing radiation, which has enough energy to knock electrons away from atoms, creating free radicals. These chemically reactive particles can damage DNA and increase the risk of cancer. However, the dose of radiation in airport X-ray machines is very low and not considered harmful.

Ionizing radiation is a type of radiation that has a high level of energy. It gets its name from its ability to ionize atoms or molecules, which means it can knock electrons away from their atoms, creating free radicals. These free radicals are highly reactive and can cause damage to the DNA in our cells, leading to an increased risk of cancer. While ionizing radiation is beneficial in medical settings, such as X-ray imaging in hospitals, it is important to limit exposure to it as much as possible due to its potential health risks.

Airport X-ray machines, including backscatter X-ray scanners and cabinet X-ray systems, emit low levels of ionizing radiation. These machines are used to scan luggage and carry-on items for prohibited items, ensuring the safety of passengers and staff. While these machines do emit ionizing radiation, the dose is not high enough to cause any bodily harm. According to Dr. Lewis Nelson, a professor and chair of emergency medicine, the amount of radiation delivered by an airport X-ray is minuscule compared to other sources, such as medical X-rays or even the radiation exposure during air travel.

To ensure the safety of travelers and staff, airports have implemented several safety measures. These include using shielded machines with thick walls and lead curtains to prevent radiation leakage, as well as adhering to strict standards and regulations for radiation exposure. Additionally, alternative screening methods, such as metal detectors and millimeter-wave scanners, are also available for those who wish to avoid X-ray scanners.

In summary, while X-ray machines in airports do emit ionizing radiation, which has the potential to cause DNA damage, the dose is extremely low and does not pose a significant health risk. The benefits of enhanced security and the implementation of safety measures outweigh the minimal risk associated with these machines.

Millimeter-wave scanners use non-ionizing radiation, which is safer

The machines used in airports are often a cause for concern for travellers. Many people have voiced concerns about the health risks of the scanning process, particularly the amount of radiation these machines produce and whether it is enough to increase cancer rates in the general population.

Millimetre-wave scanners use non-ionizing radiation, which is safer than the alternative, ionizing radiation. Non-ionizing radiation does not have enough energy to remove electrons from atoms, so it does not alter the structure of biological molecules, such as proteins and nucleic acids. In other words, it cannot cause cancers by radiolytic DNA bond cleavage.

Millimetre-wave scanners emit a special type of microwave, not X-ray. They produce electromagnetic radiation with wavelengths between 1 millimetre and 10 millimetres. These waves are much larger than X-rays and, due to their wavelength, tend to pass through most materials, such as clothing, making them ideal for scanning technologies.

The energy density required to produce thermal injury in the skin is much higher than that typically delivered in an active millimetre-wave scanner. The waves are also far lower in energy than ultraviolet radiation, which is the nearest radiotoxic neighbour in the electromagnetic spectrum.

Millimetre-wave scanners are also safer than X-ray backscatter machines, which were previously used in some airports. Any dose of X-rays is worth avoiding when you have millimetre-wave scanners available, as X-rays are ionizing and have the potential to be mutagenic.

Backscatter X-ray scanners were phased out in many countries due to health risks

Backscatter X-ray scanners were once used in airports to detect hidden weapons, tools, liquids, narcotics, currency, and other contraband. They were introduced in the US after the terror attacks of 9/11 to minimise the chances of future attacks. However, they were phased out in many countries, including the US and the European Union, due to health risks and privacy concerns.

Backscatter X-ray scanners use ionizing radiation, which is considered carcinogenic even in small doses. While the doses used in airport scanners are believed to be negligible for an individual, some studies have estimated that exposing a large number of people to multiple scans could lead to additional cancer cases. For example, one study suggested that if one million people were exposed to 520 scans in a year, there would be roughly four additional cancers due to the scanner. This risk is further highlighted by the fact that traditional X-ray machines used by doctors are shielded or require patients to wear protective gear, such as lead jackets, to minimise radiation exposure.

In addition to health concerns, backscatter X-ray scanners also raised privacy issues. These scanners created detailed images of a person's naked body, which many travellers felt was a violation of their privacy. There were also concerns that viewing these images could violate confidential medical information, such as the use of a colostomy bag or the presence of a missing limb. The American Civil Liberties Union (ACLU) referred to backscatter X-rays as a "virtual strip search" and advocated for their limited use only when absolutely necessary.

As a result of the health and privacy concerns, backscatter X-ray scanners were replaced with Advanced Image Technology (AIT) or millimetre wave scanning devices, which use non-ionizing radiation and are considered safer and less intrusive. These new scanners create generic or cartoon-like representations that highlight areas of concern, rather than detailed anatomical images. While there are ongoing debates about the safety and efficacy of different scanning technologies, the removal of backscatter X-ray scanners from airports reflects a prioritisation of traveller health and privacy.

Metal detectors use magnetic fields to identify metal objects

Metal detectors are an essential part of airport security, helping to ensure that no one brings a weapon onto an aircraft. Metal detectors use magnetic fields to identify metal objects.

Metal detectors work by creating a magnetic field using a brief pulse of electrical current. When a metal object, such as a watch or a belt buckle, passes through this field, the machine detects the changes in the field and alerts the operator with a beeping noise. The magnetic field interacts with any conductive objects it encounters, causing them to generate weak magnetic fields of their own. The polarity of the object's magnetic field is directly opposite to that of the transmitter coil's magnetic field.

Metal detectors use one of three technologies: very low frequency (VLF), pulse induction (PI), or beat-frequency oscillation (BFO). VLF metal detectors have two distinct coils: a transmitter coil and a receiver coil. The current moving through the transmitter coil creates an electromagnetic field, and the receiver coil picks up and amplifies frequencies coming from target objects. The closer the metal object is to the transmitter coil, the stronger the magnetic field it creates, and the easier it is for the metal detector to identify.

PI metal detectors send powerful, short bursts of current through a coil of wire, generating a brief magnetic field. When the pulse ends, the magnetic field collapses, resulting in a sharp electrical spike and another current called the reflected pulse. If there is a metal object present, it creates an opposite magnetic field, causing the reflected pulse to take longer to decay.

BFO metal detectors have two coils of wire, one in the search head and one in the control box. As pulses of current travel through each coil, they generate radio waves. When the coil in the search head passes over a metal object, the current flowing through the coil creates a magnetic field around the object, causing the frequency of the radio waves to deviate. This change in frequency results in an audible change in the tone, alerting the operator to the presence of metal.

Metal detectors have a wide range of applications beyond airport security, including building security, event security, archaeology, and treasure hunting. They are also used in the food industry to detect metal contaminants and in the construction industry to locate wires, pipes, and steel reinforcing bars.

The risk of health effects from airport scanners is very low

Types of Airport Scanners

There are two main types of body scanners used in airports: millimeter-wave scanners and backscatter X-ray scanners. Millimeter-wave scanners use non-ionizing radiation in the form of low-level radio waves to create a 3D image and detect concealed items. These scanners are considered safer than backscatter X-ray scanners, as they do not contribute to ionizing radiation exposure. The energy emitted by millimeter-wave scanners is extremely low, comparable to the energy emitted by cell phones.

Backscatter X-ray scanners, on the other hand, emit low levels of ionizing radiation (X-rays) that can penetrate the outer layer of clothing and skin. These scanners have been phased out in many countries due to privacy concerns and potential health risks. Metal detectors, which do not use radiation, are also commonly used in airports to screen passengers.

Tips for Minimizing Radiation Exposure

Although the risk from airport body scanners is very low, there are some steps you can take to minimize your exposure:

• Opt for a pat-down: You can ask for a physical pat-down instead of going through the body scanner, although this may depend on airport security rules.
• Minimize time near scanners: Spend as little time as possible in the immediate vicinity of the scanners to reduce your exposure.
• Opt for metal detectors: Metal detectors do not use ionizing radiation and can be used as an alternative to body scanners, depending on the airport's rules and regulations.
• Stay informed: Keep up-to-date with airport security technologies and their associated risks to make informed decisions about your safety.

Safety Measures and Regulations

It is important to note that safety measures and regulations are in place to ensure the safe use of airport scanners. Manufacturers are required to certify that their products meet Federal radiation safety performance standards. Additionally, the Transportation Security Administration (TSA) in the United States adheres to specifications and performs regular testing to ensure that the equipment is maintained and meets federal and state safety standards.

Frequently asked questions