Newsgroups: rec.radio.amateur.misc

In rec.radio.amateur.misc, oopdavid@ubvmsd.cc.buffalo.edu (D.RODMAN) writes:

>Gentlemen, lets get a few things straight.  First, Dr. Milham did not report
>that amateur radio causes cancer.  

What he said was:

     "... This large population-based study indicates that amateur radio
     operator licensees in Washington State and California have significant
     excess mortality due to acute myeloid leukemia, multiple myeloma,
     and perhaps certain types of malignant lymphoma.  Avocational and/or
     occupational exposures to electric and magnetic fields should be among
     the possible etiologies considered in explaining this excess mortality."

That's about as close as a scientist writing in a technical jourmal will
ever get to saying "ham radio causes cancer."  Actually what I said was
that the study "purportedly" showed that ham radio causes cancer.  "Purport"
means to have the appearance of claiming something.

>He did perform a statistical analysis
>of death certificates in his west coast area and compared causes of death
>with avocation.  He did find that several diseases had a higher than expected
>rate of occurence than the normal population.  

That is what I disagree with.  I did a Monte Carlo analysis, assuming that
the ham radio population had the same incidence of disease as the general
population.  Most of my simulation runs showed results similar to his.

>But recent European data is highly suggestive
>that 50 Hz fields are again associated with increased risk of childhood
>leukemia.  Readers should try to understand this concept:  Use of ham
>equipment has such low frequency fields, like any appliance with a 
>large transformer.  

... etc.

The fields from such transformers and similar sources are in the few
milligauss range (typically 1 to a few ten's of milligauss.)  As a point
of reference, note that the earth's magnetic field is about 500 milligauss.
Now I understand that the theory is that the human body is more sensitive
to 50-60 Hz fields than to a "DC" field, but it would have to be
a LOT more sensitive for there to really be a problem.

Also note that the field in a typical home just due to the house wiring
is typically around 1-2 milligauss.  And the field around something like
a stove burner or microwave oven is in the high ten's of milligauss.
If there really is a health problem assiciated with low levels of AC
magnetic fields, we better rewire the whole country for DC.

Also, how come all the concern is about magnetic, rather than electric,
fields?  House wiring is roughly balanced (low emission) for magnetic
fields, but not for electric.  Anyone who has ever hooked a clip lead
to a scope input has seen how much 60 Hz electric field we have
floating around.  

I'm all in favor of continued research into the health effects, if any,
of E/M fields, but I feel that the sensationalistic media stories on the
subject are way out of proportion to the probable dangers.  It's likely
that there is no significant effect.  And even if there does turn out to
be some effect, it's clear that it must be pretty small.  (Even those
studies that do show an effect place it far below the dangers of, say, 
cigarette smoking.)

AL N1AL