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Hi, I am interested in your knowledge about emergency alert pendants worn by older persons. Are there any that do NOT have a wireless component? Do you know anything about the frequencies used and their intensities?
I hope you don't mind, but I have taken the liberty to start a new topic so your question (above) will not be overlooked.
There are, of course, inexpensive personal safety alarms that emit only an attention-getting sound and no radiation.
"Wireless" implies some form of transmission. Systems currently in use include Bluetooth, 433MHz, 900MHz spread spectrum (most require a dedicated base unit) and SIMM card.
The latter sends SMS alerts to a nominated mobile phone, so signal characteristics depend upon the subscriber's existing network. These normally incorporate GPS, and may thus intermittently transmit geo-location data.
To minimse exposure, one would logically choose a product that only emits when manually activated, and utilises a Bluetooth class with the shortest possible range. See chart below.
If this is not practical, devices of the other types can be kept at an appropriate distance from the body to reduce absorption.
In Victoria there is free alert pendant service to applicable pensioners arranged through the local council which use the MePACS home base system. My wife and mother in law use this system. The hardware they use, appears to be updated to new hardware used for new customers.
The pendant button I assume uses a RF signal to the home base station. The home base station use the telcos 3G network to communicate to the MePACS operator. As none of us appear to have a problem with this system, I have not looked into this system RF wise.
At the moment we have used the 3G network for along time with no apparent health issues to ourselves. Wifi, WifiMax and 4G is an immediate health issue to ourselves. I know of some individuals that are sensitive to 3G.
From my own observations on power levels of RF transmitting devices, such as our microwave oven that leaks a 2.4 Ghz frequency, does no immediate harm, unlike this personal computer I'm using at the moment, turning the Wifi on, which uses the same 2.4 Ghz frequency causes immediate harm. Its the way the frequency is pulsed/modulated that make the difference.
Getting back to your question, "Do you know anything about the frequencies used and their intensities?".
My honest answer is, I don't know. I do know that most people may not be effected at all, while a few people maybe effected in varying ways.
Thanks to both of you for your postings and the good information - will talk further with suppliers now that you have given me a background on this. At least I can ask them some sensible questions now. It seems there are many possibilities but I guess it may not be easy to find out in advance how one may react, as it's the suppliers may not know much about the way their devices use pulses/modulations.
You are not alone. According to experts, over 35% of the world’s population feels some form of unwanted reaction to EMR exposure. Additionally, everyone is susceptible to induced biological abnormalities that may not manifest perceptibly for years or even decade.