Human-Nets-Request%rutgers@brl-bmd.UUCP (08/05/83)
HUMAN-NETS Digest Thursday, 4 Aug 1983 Volume 6 : Issue 42
Today's Topics:
Computers and People - The Worth of Technology &
Icons and Direct Manipulation,
News Article - Non-ionizing radiation effects?
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Date: 3 Aug 83 21:06-EST (Wed)
From: Steven Gutfreund <gutfreund%umass-cs@UDel-Relay>
Subject: Technology and the MIND
I think there have been strong connections made between how technology
can change the way we think.
At the lowest level, the technology of language causes changes in the
way we think. (see Sapir-Whorf theory)
At an intermediate level I think a strong case can be made that
literate people think different than illiterates. (or merely the
existance of paper to supplement Short Term Memory) Morton Hunt has
several stories in his book that illustrates this. The most striking
is the inability for illiterates to solve syllogisms. I can't think of
anything more indicative of ones thinking patterns than ones ability
or inability to use Logic.
For an indication of how computer technology can restructure the mind,
read "Mindstorms" by Seymour Papert. One really does approach problem
solving differently given different tools.
- Steven Gutfreund
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Date: Thu 4 Aug 83 10:15:30-PDT
From: Ken Laws <Laws@SRI-AI.ARPA>
Subject: Icons and Direct Manipulation
The August issue of IEEE Computer contains (as a special feature)
"Direct Manipulation: A Step Beyond Programming Languages" by Ben
Shneiderman of the University of Maryland. The author is fairly
persuasive that manipulation of icons can and should turn the office
of the future into one vast video game. He presents examples of
screen editors, Visicalc, spatial data management, CAD/CAM,
industrial plant monitoring, interactive Plato experiments, etc.
I am not persuaded, however, that scrolling through a simulated
Rolodex file is more productive than scrolling through a text file.
The advantage of the icon system is not really
in the graphics, but in the existence of a customized subsystem
for this one application. The user loses the power of a full
text editor, but is protected from screwing up the data fields.
This is the same goal sought in database systems and in structured-
code editors. The disadvantage is that, even with "directly
manipulable" icons, the user must learn a different interface for
each subsystem. It remains to be seen whether "dragging a directory
tree node to the printer icon" is easier or easier-to-learn than
typing a print command.
I hope we will finally get past this "user-friendly man-machine
interface" fad so that we can concentrate on what happens to the
information once it is in the computer. The friendliest interface
is one requiring (almost) no interaction--just state the high-level
task and let the computer figure out how to perform it. The
interface should model an administrative assistant, not a filing
cabinet.
-- Ken Laws
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Date: Tuesday, 2 Aug 1983 02:17-PDT
Subject: Non-ionizing radiation effects? -- Newswire story
This information, as inconclusive as it is, might be of at least
passing interest to HUMAN-NETS readers...
--Lauren--
--------
n073 1541 01 Aug 83
BC-RADIATION-II 2takes:
Science Times
(The second of two articles.)
By PHILIP M. BOFFEY
c. 1983 N.Y. Times News Service
NEW YORK - Unlike the dangerous ionizing radiation emitted by
nuclear fission and X-rays, the non-ionizing radiation that issues
from radio transmitters, radar, electric power lines, microwave ovens
and a vast array of modern devices has long been considered relatively
safe. But a spate of recent scientific reports has raised concern that
low doses of non-ionizing radiation can cause subtle biological
effects in humans and animals that might, conceivably, cause health
damage as well.
The evidence is murky, contradictory and inconclusive. No one is
suggesting that the nation is about to discover a new public health
catastrophe of major proportions. Indeed, there is no conclusive
evidence that exposures at current levels pose much danger at all to
the general public. But some scientists believe that enough warning
flags have been raised to justify a more vigorous research effort and
judicious caution until the results are in.
The issue has enormous political, social and economic
implications, because life in a modern industrial society would grind
to a halt if all sources of non-ionizing radiation were shut down.
Public-affairs groups fearful of potential health hazards are
currently opposing a Con Edison substation in Manhattan, a proposed
Navy transmitter in Wisconsin and upper Michigan, and various power
lines, television transmitters, microwave towers, laser installations
and satellite communication stations in scattered locations around the
country.
Microwave News, a New York-based newsletter devoted to all forms
of non-ionizing radiation, reports a sharp rise in litigation related
to non-ionizing radiation and increased efforts at state and local
levels to control exposures.
The chief concerns involve three different kinds of non-ionizing
radiation.
-Electromagnetic radiation from power lines and other electrical
sources.
-Electromagnetic radiation from communications networks and other
modern devices that operate at radio-frequency and microwave energies.
-Mechanical radiation from medical ultrasound, a diagnostic
procedure used to detect abnormalities in the fetus in the womb.
The common thread among these kinds of radiation is that they are
non-ionizing, that is, they lack the energy to knock electrons away
from atoms and molecules in the human body. For most of the 20th
century, radiation concerns have focused on the more potent ionizing
radiation from nuclear weapons, nuclear reactors and medical X-rays,
which clearly can produce cancer and other diseases. Virtually all
scientists agree that non-ionizing radiation is not nearly so
dangerous as the ionizing form. But some experts worry that the
apparent harmlessness of non-ionizing radiation has led to a relative
neglect of studies of its biological effects.
''We're at the point today where the ionizing field was 40 years
ago,'' says Zory R. Glaser, a senior scientist in radiological health
at the Food and Drug Administration. ''And keep in mind that the
effects of low levels of ionizing radiation are still being debated.
Until recently, nobody was even looking at low doses of non-ionizing
radiation as a potential problem.''
That oversight is being remedied by a rush of new studies. New
York state, the Federal Energy Department and the electric utilities
have started programs that will cumulatively support millions of
dollars' worth of research related to the biological effects of power
lines, and other federal agencies and industry sources are supporting
extensive research on electromagnetic effects relevant to
communications frequencies.
The sharpest scientific debate at the moment concerns the effect
of electrical and magnetic fields generated by electric power lines
and related facilities.
For example, Nancy Wertheimer and Ed Leeper of the University of
Colorado Medical Center reported in 1979 that a group of Denver
children who developed leukemia generally lived closer to electrical
transformers and secondary lines than did a control group of children
without leukemia. In 1982 they concluded that adult cancers were also
related to electrical wiring. Their findings stimulated a spate of
follow-up reports over the past year suggesting that Swedish children
living near power lines might have high cancer rates, and that workers
in jobs that placed them near electric or magnetic fields in the state
of Washington, Los Angeles and Britain appeared to have an increased
risk of leukemia. However, other epidemiologic surveys of children and
workers have found no adverse health effects at all.
The chief weakness in most such reports is that there are no good
data on the amount of radiation the subjects actually received. Just
because there is a power line outside, some scientists say, does not
necessarily mean the electric and magnetic fields inside a home are
particularly high or are the cause of any health problems among the
residents.
The Lancet, a respected British medical journal, concluded in an
editorial in January that ''at this stage it is impossible to know
what the observations mean, although the cluster of reports relating
to acute myeloid leukemia is worrisome.'' But the journal added that,
since all of us are exposed to some electrical and magnetic fields,
''it is important to know what risks, if any, are entailed.''
Leading scientists from the electric utility industry find the
data suggestive but not frightening. ''When you add it all up, it does
appear that something is going on,'' said Leonard Sagan of the
Electric Power Research Institute, a utility-supported group. ''But I
don't think there is any reason to alarm the public. At the moment, I
think you have to conclude that the question is unsettled and deserves
further investigation. To the best of my knowledge, there are no
animal data anywhere that would support a relationship between
electric field exposure and cancer.''
The most thorough recent review of the growing literature on
biological effects appears to have been done by Dr. Ascher Shepard,
assistant research professor of physiology at the medical school of
Loma Linda University in southern California, under contract with the
Montana Department of Natural Resources and Conservation, which had to
evaluate the health hazards of a 500,000-volt transmission line.
Shepard's report, published in February, said that recent research was
finally concluding that electric fields of the magnitude found around
high-voltage power lines, and perhaps even the lower field strengths
found in many homes, can indeed cause biological effects, a matter
that had long been in dispute.
However, Shepard's report stressed that ''while effects occur,
they are not generally of a pathological nature.''
The far less definitive data on humans includes reports that
certain Soviet and Spanish electrical workers suffered headaches and
fatigue, and that certain Swedish electrical workers suffered a high
rate of chromosome breaks and deformed children. Suicides have also
tentatively been correlated with transmission lines in England.
However, virtually all of these studies are difficult to interpret
because of complicating factors, and are flatly contradicted by other
studies that find no effects at all.
Summing up all the evidence, Shepard's report concludes that,
while biological effects occur, it is ''not very likely'' that any of
them will be ''strongly expressed'' in humans and ''even less likely''
that they will be pathological and produce disease.
''It's very murky,'' Shepard said in a telephone interview.
''There are a number of interesting effects that occur and must be
understood.''
A second major area of scientific attention is the radio-frequency
range, which includes radio, television, radar and microwave
radiation, among others.
For many years, Western scientists assumed that the only important
effects from radio-frequency radiation were caused by heating, much as
as microwave oven cooks the insides of a hamburger. High doses were
known to cause cataracts, burns and temporary sterility, but low doses
were considered relatively benign unless they caused subtle changes by
heating biological tissues.
In recent years, however, the consensus has swung toward
recognizing more low-level effects, even at doses too slight to cause
measurable heating. Low-dose animal studies by Western scientists have
reported changes in the immune system, behavioral effects,
neurological effects and possible synergism between microwaves and
certain drugs, as well as the release of calcium ions from brain
tissue at radio-frequency levels too low to produce heating. However,
much of the information is still in dispute.
The gradually shifting consensus led the American National
Standards Institute to issue a new safety standard for radio-frequency
exposures last September. The standard sharply reduced permissible
exposures in the range of frequencies from which human beings absorb
the most energy. Some scientists consider the new standard highly
conservative. But Nicholas H. Steneck, a professor of history at the
University of Michigan who has been studying microwave developments,
told a microwave power symposium in Philadelphia last month that the
values underlying the standards reflect military-industrial interests
rather than the interests of people exposed to the radiation.
Scientific opinion on potential hazards remains divided.
''While some biological effects have been observed in animals and
others claimed to occur in animals and humans as a result of exposure
to microwave-radio-frequency fields within the prevailing exposure
criteria,'' Sol M. Michaelson, of the University of Rochester, told
the same conference, ''none of these effects, even if substantiated,
could be considered hazardous or relevant to man.''
But Przemyslaw Czerski, a Polish expert now working at the Food
and Drug Administration, told a conference in June at Boulder, Colo.,
that microwave radiation at relatively low levels can cause chromosome
damage and abortions in mice. And he told the Philadelphia symposium
that some recent data are disturbing enough to justify still further
reassessment of permissible exposure levels.
Concern over ultrasound has been voiced by Alice Stewart, a
British epidemiologist who heads the Oxford Survey of Childhood
Cancers. She said in an interview last month that there are some
''very suspicious'' hints that children exposed in the womb to
sonograms appear to be developing leukemia and other cancers in higher
numbers than unexposed children.
Stewart acknowledges that the numbers so far are small and could
be a statistical fluke; it will take another three years at least to
determine the truth. But two dozen American health experts have signed
a statement urging the United States government, which has helped
support the Oxford survey, to continue because it is ''on the
threshold of determining the relation of obstetric ultrasound to
childhood cancers.''
nyt-08-01-83 1944edt
End of HUMAN-NETS Digest
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