WiFi radiation measurement methods and preventive fabric details

Collection of some useful weblinks for radiation safety of human health, due to exposure of high frequency wireless environment, were given below
www.4ehsbyehs.com/rf-blocking-fabrics
Electromagnetic Hyper Sensitivity(EHS) affected persons usually feel paid in ears or headache with little time of exposure with cell phone usage

Map WiFi coverage and make it faster software is freely downloadable with limited time version

EMF "Safety standards" not so safe

A Safety Standard is a problematic term. Safety standard are set by a committee of experts who tried to validate how much radiation is safe and how much is not safe. In the process of setting the standard many aspects, other then safety or health, are taking into consideration. For example: financial, technical and political. Sometimes when you can not technically meet the standard, or meeting it will result in financial cost, the standard is gently shifted to please everyone and to save money. The international standards for low (used to be 1000 milliGauss, since 2005 it is 2000mG) and high frequency(1000-400 micro watts square centimeter) electromagnetic radiation are very high. Both takes into account only the immediate, obvious and permanent damage to the body and does not take into account any long-term or biological effects. Some companies and organizations will use these outrageous high so called "safety standards", without explanation of the true essence of it and its limitations. 

ICNIRP(The committee that set the standards) takes IEEE standards, approve them for humans, and recommend them to the WHO's EMF study group(EMF Project). The EMF Study group, approve these standards and give them an "international" validity. Then the WHO's EMF study group(EMF Project) introduce the standards as recommendation to countries around the world. Most Countries that embrace the WHO standards for EMF exposure of humans

Assessment of the exposure load

As far as exposure to EMF radiation is concerned, EHS people that are exposed to EMF will feel pain and suffer from symptoms. Therefor EHS people should try to reduce their exposure to the absolute minimum possible. For people who are not EHS (yet) it is recommended to reduce the exposure load as much as possible.  

Exposure load should be assessed based on several elements, some are measurable and some should be based on knowledge and understanding of the EMF subject and "big picture". The elements are:

1. Number of signal on the frequency span
2. The level-strength of the signals
3. Exposure time

The number of signal could be measured only by using a spectrum analyzer. This equipment is expensive and is rarely used in EMF safety surveys. So usually we will use our knowledge of EMF and RF. The level of the radiation can be roughly measured (only " roughly " because of the multi sources, low duty cycle, and multi frequency issues, please see above) using EMF meters. The time of exposure can be easily assessed in most cases.

Lets take for example the exposure of a person to EMF radiation from a mobile phone. The phone can emits several frequencies (RF) while transmitting. In addition it will emits some levels of ELF.  We don't have control over the number of frequencies emitted, but we should take that into consideration while assessing the exposure load (and while doing the measurement). The radiation level can be partially and roughly measured using and EMF meter, just keep in mind that you are not measuring all of it. The radiation level can be controlled by using the phone in open environment (not in elevators, trains, cars or indoors) where the reception is better and where the phone will emit less RF radiation. In addition using the speaker phone function or a wired earpiece will reduce the exposure even more. The time of exposure can be easily assessed and reduced buy keeping the conversation short and to the point. 

Duty Cycle

Duty Cycle is measured in %. It marks the parentage of the second the signal (RF signal) was present. In case of AM and FM broadcast the duty cycle is 100%. In case of cellphone towers the duty cycle is usually between 50%-80% depending on the traffic. In case of WIFI, DECT, UMTS and CDMA cell phones, Bluetooth devices and many more modern RF signals, most of the time the duty cycle is lower than 10%. A single with low duty cycle will be noticeable only by a meter with a very high sampling rate. 

The ratio between the peak value and the average measured value, can give some clue about the duty cycle. A high ratio, for example Peak=1mW/m² and Average=0.001mW/m² will mean low duty cycle (like WIFI). A low ratio, for example Peak=1mW/m² and Average=0.8mW/m² will mean a high duty cycle(like from a cellular tower). 

Regarding the possible biological effect of RF radiation I think that also low duty cycle signals, like for example WIFI, have the ability to effect and disturber biological systems. These effects can result into health issues. Therefor I don't take lightly the possible health effect that can be caused by low duty cycle signals. I actually look at law duty cycle signals at the same severity as high duty cycle signals.

Multi frequency and multiple sources measurements

Please note that most of the High-frequency electromagnetic radiation meters that I encountered to date (both professional and simple) are not able to measure multiple frequencies and multiple radiation sources correctly (mobile, WIFI, cellular antennas, cordless phones, etc.). This limitation is due to the difficulty of measuring and summing up all the radiation levels in all the frequencies. Therefore the measurement of radiation sources that emit RF radiation in several frequencies (eg: WIFI, mobile phone antennas mailman third or cellular) or measuring several radiation sources at once may not be accurate and the results will generally be lower than the radiation levels in reality. It is still possible to use these meters to expose radiation sources and to understand how to shield and how to reduce your exposure from them. The only why to measure multi-frequency and mutli-sources environment is by using a vary fast spectrum analyzer.