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 One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>