6 Mar 2017

Cellphones and brain cancer?

There has been debate for years and years about whether or not excessive use of cellphones increase the chances of getting brain cancers. I guess that prolonged use of a high power VHF or UHF handheld may pose similar risks?

According to Southgate News a judge in California has asked for a 2014 report to be made public. A quick read seems to suggest some sort of increased risk. Basically, this is all relative, but prolonged RF exposure is probably not good and is best avoided. Another argument in favour of QRP?

See https://drive.google.com/file/d/0B14R6QNkmaXuRmJlZDRWME5lN2M/view


David (G0LRD) said...

"Another argument in favour of QRP?"

No, I don't think so. To get the same field strength as you get from, say, 2W at 10mm distance requires you to be less than 140mm from a 0dB antenna fed with UK legal limit (400W).

I'm not for or against QRO or QRP, each to their own.

73 David G0LRD

Roger G3XBM said...

Thanks David.

I remember getting dry eyes when working professionally with 5W pep VHF PAs at about 0.5m. I think we all have to treat RF with respect.

As you imply, there are not many 400W handhelds, HI. Also most VHF and UHF handhelds have far less than 0dB ERP.

Mick said...

Flux density incident upon the target area.
Wavelength with respect to parts of the body.
Surface effect at higher frequencies.
Eyeballs are inefficient at dissipating induced energy.

Earlier mobile phones had a poor SAR rating as some 30% of the energy radiated by the antenna was absorbed by body tissue. Patch antennas greatly improved on this but they are also reliant upon well distributed network cells. At VHF I used to carry a two element beam which was compact and had a relatively useful front to back rejection ratio.

In any case, we should always prefer to get the RF out and away as efficiently as possible.