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 World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>