Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blast overpressure is generated from the firing of weapons and may cause brain injury

19.01.2009
The brain may be injured by the noise, which is produced when, for example, an anti-tank weapon (Bazooka, Karl Gustav) or a howitzer (Haubits) is fired. Scientists at the Sahlgrenska Academy demonstrated mild injury to brain tissue. In response to this, the Swedish Armed Forces restricted the number of rounds per day Swedish personnel can be exposed to.

A number of reports, which have appeared during the last few years, have shown that the brain is sensitive to blast. This study determines whether the occupational standards for the highest levels of blast exposure were valid enough to avoid brain injuries.

Traumatic brain injury is very common among war veterans from Iraq and Afghanistan and the majority has been exposed to explosions. The soldiers have symptoms of disorders of memory, mental processes, emotion, sleep, speech, vision and hearing. The symptoms may be similar to those of post traumatic stress syndrome, which may be caused by factors other than combat experience.

The brain may be affected by the blast, which is generated during firing of weapons

The Swedish Armed Forces sponsored a study, which has been carried out by scientists at the Sahlgrenska Academy, University of Gothenburg, Sweden. They have examined the effects of noise after the firing of a Haubits, an anti tank weapon (Karl Gustav) and an automatic rifle and by the detonation of plastic explosives underwater. The study was done on anaesthetized pigs and rats.

“We examined the maximal peak level of the blast in the brain transmitted from the blast in the air, as well as, brain tissue changes that were detected with the microscope, says Annette Säljö, one of the scientists who conducted the study.

The noise produced by the firing of both the haubits and the anti-tank weapon exceeds the occupational standards for highest levels of blast exposure. The scientists found that the maximal peak levels of the blast were unexpectedly high in the brain, i.e. that skin and bone appeared to protect the brain poorly. The results suggest that the degree of transmission of a pressure wave from air or water to the brain depends on the dominating frequencies in the frequency spectrum of the noise; low frequencies are transmitted considerably better than high frequencies.

Blast overpressure may result in haemorrhages in the brain

The microscopic examination of the brain showed that the blast from certain weapons produces small haemorrhages (bleeding) in the brain tissue and the meninges (lining of the brain). The examination also suggested that blast exposure leads to the development of brain edema, i.e. increased fluid content. The scientists were later able to support this finding with other measurements. The results are in agreement with findings in the brains of soldiers who had been injured or died after being exposed to explosions in wars, from WW1 to the war in Iraq.

The Swedish Armed Forces have restricted their safety regulations

In summary, the study shows that the maximal peak levels of blast generated by the firing of certain weapons led to a small but measurable effect on the brains of pigs and rats.

The study also showed that this effect on the brain becomes worse with increasing maximal peak blast levels. The results poses the question as to whether exposure to even lower levels of blast than previous thought injurious might be contributing to the large numbers of mild traumatic brain injuries in American military personnel.

“This is of course an occupational question for Swedish Armed Forces. In light of the results of the study, the Swedish military has instituted restrictions in the number of firing rounds a person is allowed to be exposed to in a single day”, says Annette Säljö.

Direct studies on humans are difficult to perform, since biomarkers of injury in cerebrospinal fluid or blood and imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) do not appear to be specific or sensitive enough to detect mild brain injury.

Helena Aaberg | alfa
Further information:
http://www.liebertonline.com/doi/abs/10.1089/neu.2008.0602

More articles from Health and Medicine:

nachricht Second cause of hidden hearing loss identified
20.02.2017 | Michigan Medicine - University of Michigan

nachricht Prospect for more effective treatment of nerve pain
20.02.2017 | Universität Zürich

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>