Body Scanners

After the attempted attack on 25 December 2009 on a flight between Amsterdam and Detroit, the French Directorate General for Civil Aviation (DGCA) decided to install body scanners to improve the safety of air transport. These devices provide ‘whole body’ images of people for security purposes without exposing them to ionising radiation. The stated benefits of these devices are reliability and the fact that scans are less intrusive than pat-down searches.

In January 2010, the DGCA first requested that ANSES immediately assess the potential health risks of the ProVision 100millimetre wave portal.

This formal request resulted in a report and a note dated 15 February 2010, as well as a report by the French Institute for Radiological Protection and Nuclear Safety (IRSN) on X-ray scanners.

Since these publications, a European regulation on the use of this device in airports was adopted on 10 and 11 November 2011, and their performance has been improved, especially in automatic mode (that is, without producing an image requiring analysis by an operator). These developments, in particular, have convinced the DGCA to install security scanners in the near future at the ‘inspection – filtering’ sections of airports.

In this new context, on 6 March 2012, the DGAC made another formal request to ANSES to assess the health risks associated with the using the Eqo millimetre wave body scanner.

The Agency’s Conclusions

From the perspective of regulating human exposure to electromagnetic fields, the values ​​measured for the Eqo millimetre wave body scanner (0.76 mW/m² maximum for the passenger and 0.05 mW/m² for the operator according to the UK Health Protection Agency) are well below regulatory requirements[1].

Based on current knowledge on the health effects of millimetre waves, and on the technical information gathered for the Eqo portal, this type of scanner does not present a risk to human health. Nevertheless, since there is a lack of data on several technical aspects of the Eqo scanner, on exposure scenarios, and on the biological effects of this frequency range, the Agency has issued a series of recommendations concerning all millimetre wave body scanners.

Recommendations

Concerning the proper functioning of millimetre wave security portals, ANSES recommends establishing regular monitoring of the power density emitted by the detection equipment.

To improve the characterisation of human exposure to millimetre waves given off by security scanners, ANSES recommends that manufacturers be required to keep a technical file available for inspection that lists the instrument’s specifications (maximum power delivered to the transmitting antenna, the antenna gain and factor, the duration and frequency of scanning, etc.) showing that the actual exposure of people scanned does not exceed the maximum theoretical exposure (a regulatory value expressed in terms of surface power density or the electric field).

In order to improve the metrology of millimetre waves emitted by body scanners, ANSES recommends that a suitable measurement protocol be drafted (a clearly-defined measurement system, results also expressed in terms of electric field, reduced background noise, non-directional antenna, range of radiation, actual conditions of use, etc.).

In order to reduce human exposure to radiation from the Eqo scanner, ANSES recommends, in terms of the specific features of the Eqo scanner:

• making the emission zone of the scanner clearly visible (markings on the ground, for example);
• that the operator remains outside the exposure zone during the scan (manual activation of the scanner from the operator's station, for example);
• that the operator’s station be located away from the exposure zone;
• that exposure to millimetre waves take place only at the time of the scan, when the person is in place (and not continuously);
• preventing anyone other than the person being scanned from entering the exposure area during the scan (operator at his/her post, the passenger queue located at 1 m from the scanner arch, for example).

Concerning the testing of the equipment organised by the French Civil Aviation Technical Department (STAC), ANSES recommends:

• submitting the test protocols for an opinion from an Ethics Committee;
• seeking the occupational physician’s opinion on each employee’s aptitude prior to testing;
• submitting the conditions for conducting tests to the Health & Safety Committee and to the representative body for their approval.

To improve knowledge on the potential biological and health effects of millimetre waves, ANSES recommends promoting research:

• on the biological effects of electromagnetic fields (particularly the long-term effects of chronic exposure, the combined effects of repeated and/or chronic exposure, and on different types of cellular stress);
• on the biological effects of millimetre waves, notably on the cornea and epithelial tissues and cutaneous nerve endings, which are the tissues directly exposed to this type of wave;
• on the potential health effects of electromagnetic fields, especially long-term effects;
• on the potential health effects of millimetre waves, particularly in occupationally exposed groups.

With regard to informing the public and users of scanning devices, ANSES suggests: extending the posting of signs destined for people with implanted medical devices to all security check-points that emit electromagnetic fields.

Moreover, ANSES also recommends: continuing to gather information on the use of alternative detection methods, especially ‘passive’ ones, and studying their performance and potential implementation compared with millimetre techniques.

[1] From the Decree n° 2002-775 concerning public exposure limits to electromagnetic fields emitted by telecommunications equipment or radioeletrical installations.