Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Metal detectors pass safety test on pregnant women

21.07.2003


Hand held metal detectors (HHMDs), such as those used for security checks in airports, do not cause harmful heating or nerve stimulation in pregnant women, according to research published today (22 July 2003) in the Institute of Physics journal Physics in Medicine and Biology. The role of the Center for Devices and Radiological Health (CDRH), Maryland, is to ensure the safety of radiological products, so electromagnetic wave emitting HHMDs were an obvious choice for them to investigate, especially following the heightened security measures of recent years.



Dr Wolfgang Kainz and his colleagues at CDRH tested nine different HHMDs on a model of a pregnant woman to see if they caused nerve stimulation or a temperature rise in the mother or foetus, and found that none of them did. They also compared their measurements against two international safety standards*, neither of which give specific guidelines on safe exposure levels for pregnant women. All the metal detectors operated at well below the recommended levels, but this raises the question of whether there should be separate guidelines for pregnant women. Future research could tackle this possibility, as well as potential long term effects from the HHMDs, which were not explored in this study.

The team used measurements of the surface shape of a woman in her 34th week of pregnancy to create a computer model of a pregnant woman. They approximated the foetus to be spherical, 20cm wide, and positioned one centimetre below the surface of the mother’s skin.


Then, the team measured the magnetic field emitted by each of the nine HHMDs in horizontal planes one, two, five and 11cm away from each detector. With these measurements, they computed the "induced current density" and the "specific absorption rate" (SAR) in the pregnant woman. Induced current density is the amount of electrical current flowing in a unit of area generated by the metal detector, and can cause harmful nerve stimulation if it is too high. The SAR is a measurement of the heat absorbed by the tissue, which tells you if there is a temperature rise in the body as a result of using the HHMD. If a device’s electromagnetic emissions cause a temperature rise of more than one degree Centigrade, it is considered damaging to the body.

Their results were compared to two international standards that set recommended upper limits for the induced current density and the SAR to protect exposed people from immediate effects of radiation. They found that the levels of both quantities were at least three times lower than the limits, and in some instances levels were thousands of times lower. This is due to the variation between the range of metal detectors, and the fact that the standards use different thresholds for safety.

"This study shows that, based on existing exposure standards, these metal detectors do not cause harmful heating or nerve stimulation in pregnant women. We are delighted to publish this good news, as metal detectors are used in our everyday lives for security checks in buildings and airports," said Jane Roscoe, senior publisher for Physics in Medicine and Biology.

Michelle Cain | alfa
Further information:
http://www.iop.org

More articles from Health and Medicine:

nachricht On track to heal leukaemia
18.01.2017 | Universitätsspital Bern

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

How gut bacteria can make us ill

18.01.2017 | Life Sciences

On track to heal leukaemia

18.01.2017 | Health and Medicine

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>