RF Exposure from Small Transmitting Loops
John Smith I wrote:
Anonymous wrote:
...
Does it really matter? What are the odds of serious health consequences
from RF exposure? If I quit smoking and avoid RF over-exposure will I
live forever, or will I be dead as a doornail 100 years from now just
like everyone else currently participating in this newsgroup?
I worry little about exposure to rf 30 Mhz and 1kw or less ...
I am NOT aware of any malady/disease which strikes hams any more often
than any other group ... which suggests the safeguards in place (simple
plain common sense) is/are more than adequate.
Not to be too hostile here, but that suggests ignorance rather than
knowledge.
a) one of the early studies that triggered the whole "currents of death"
fiasco happened to be one that showed that radio amateurs (among some
other groups) happened to have higher incidence of some forms of cancer.
Later shown to be statistically insigificant and confounded by other
factors, but there it is.
b) There is ample evidence of adverse effects of RF exposure in this
frequency and power range. One of the more interesting is the ankle and
wrist pain experienced by workers on the flight line in a high RF field
environment. The eventual analysis was that the pain was likely due to
RF currents flowing through the body from hand (on or near airplane) to
feet(then to ground). There's also some interesting cases of things
like people on transmitting towers when the transmitter was turned back
on (or the power turned on), but that's not necessarily a credible
situation for a ham.
Common sense is a good start (don't look into the waveguide with your
remaining good eye)(don't turn on the transmitter when someone is
working on the antenna), but it actually takes a bit more thought to
figure out the RF exposure hazards in a off-nominal situation. A dipole
30 feet up in the trees is easy, so is a 3 element yagi on a 100ft tower.
But something like a flagpole vertical in your yard, or an attic dipole,
or a compact loop on a picnic table is a much trickier situation.
However, as frequency of the rf increases so does my concern ...
everyone is aware microwaves can cook, maim and kill biological entities.
And so can MF, HF, VHF, and UHF...
Jim
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