At 08:40 PM 3/10/98 -0800, Ed Schulz wrote:

> I think the leukemia study Jerry refers to is an epidemiological
>study done in the Denver area that found that there was a higher
>incidence of certain leukemia's among children living along power
>lines. Another study found higher cancers among amateur radio
>operators.

These studies have been attacked on grounds of statistical weakness.
There really are no conclusive studies. This doesn't exonerate
high-tension lines. As Ed says, more studies are needed. The
studies I've read about seek medical data, i.e. increased cancers
and the like. I don't know of any that suggest, say, sub-par job
performance due to subtle effects on the brain's electrical field.
Since relatively few people live under high-tension lines, such
studies may be difficult to design.

I'm interested in the turtle stories. Fish have a lateral line
which is sensitive to electrical disturbance (highly evolved in
some fishes, the mormyids or something close to that - I'm too lazy
to dig). Possibly turtles have an enhanced sensitivity to electrical
fields? The platypus does. Clearly vertebrates have the capacity
to evolve sensors which can detect low levels.

With turtles, I'd bet on some sort of sensory overload over a general
nervous effect leading them to be in a "dreamy state" or whatever.

>the
>fact that they are shorter lived animals than human may be a factor
>in their favor.

In general, environmental effects that take a long time to develop as
cancers or whatever have no real effect on wildlife. That's one reason
why negative effects on wildlife are so scary - they're evidence of
short-term gross effects. Gross effects that may not show up in younger
humans, but which might balloon into health hazards for a lot of 40 or
50 or 60 year olds.

I have no doubt that crows (like in the old cartoons) can smoke cigs
with no ill effects (given they'll mostly all die young anyway). We
can't.

> I think it would be surprising if there were not
>some adverse effect of high fields on living organisms.

All sorts of stuff have adverse effects. Living in cities. Staring at
computer terminals, etc. So the real question is whether or not the
adverse effects of high-tension lines are high enough to worry about.
In many areas, they border highways, and one could ask, for instance,
if any adverse effect makes any statistical difference in wildlife
mortality, due to the fact that incredible numbers of birds and other
wildlife end up as road kill. If you have a stretch of highway where,
for instance, 1,000 dead road kill carcasses are found, you might not
worry overmuch about a bordering high-tension line that kills 10.

People who measure road kills count awesome numbers. So far, high-tension
lines would appear to have much more subtle effects, which might be
important for some species like aquatic turtles (and as the public
distaste for being near these lines grows, we'll see more and more of
them crossing uninhabited preserves like wetlands). In general, though,
they're not particularly dangerous compared to other habitat modifications
like wetlands draining, forest conversion into plantations, chaining of
sage-steppe in to crested wheatgrass, and the like.

So, wonder and pay attention to this issue, but don't lose sight of the
triage principle...


- Don Baccus, Portland OR <dhogaza at pacifier.com>
Nature photos, on-line guides, and other goodies at
http://donb.photo.net