Environmental Health News

What's Working

  • Garden Mosaics projects promote science education while connecting young and old people as they work together in local gardens.
  • Hope Meadows is a planned inter-generational community containing foster and adoptive parents, children, and senior citizens
  • In August 2002, the Los Angeles Unified School District (LAUSD) Board voted to ban soft drinks from all of the district’s schools

#184 - Radiation -- Part 2: Bad News About Low-Level Radiation, 05-Jun-1990

Radioactivity was first discovered in 1896, and its development for
medical purposes has been one of humanity's proudest achievements. By
various means, the nucleus of an atom can be made unstable and it
becomes "radioactive." Once something becomes radioactive, it
continuously gives off energy in small packets or "rays." These bundles
of energy (called nuclear or atomic radiation, or, more generally,
ionizing radiation) have many useful characteristics; for example, they
can pass through the human body and thus allow shadowy pictures of our
bones to be created on sensitized film; these are called "x-rays" and
nearly everyone in the U.S. has benefited from an x-ray at one time or
another. [The ionizing radiation from X-rays is produced by a high-
energy electric source, not by a radioactive source such as uranium,
which gives off ionizing radiation spontaneously and continuously
without any external source of power necessary.]

The penetrating power of ionizing radiation makes it useful but also
makes it dangerous. When radiation penetrates human tissue (which is
composed of billions of cells), the radiation pierces the cells like a
tiny but powerful bullet, disrupting the structure of any cells that
take a direct hit. Under certain circumstances, which are still not
understood, some disrupted cells start multiplying without limit, and
this is a condition known as cancer. By direct observation of humans
exposed to radiation, it has been definitely proven that radiation
causes cancer in humans; only the exact mechanism of causation remains
in doubt.

Americans began creating radioactive wastes shortly after 1896, but no
special precautions were taken for handling such wastes until 1954 when
the federal Atomic Energy Commission began licensing all radioactive
materials. During this period of neglect, many places, including large
sections of whole states (for example, New Mexico and Colorado, where
uranium mining occurred), were contaminated with low-level radioactive
trash.

As radiation became more widely used in industry and even in consumer
products, the public has become concerned about possible hazards and
about the carelessness of the people who handled and regulated
radioactivity in the past. Since tighter restrictions on radioactivity
could result from such concerns, and since tighter restrictions would
inevitably cost money, people who profit from radioactivity have
mounted a campaign in recent years to convince the world that there is
some "safe" dose of ionizing radiation. These people argue that there
is a "threshold" dose of radiation below which no damage occurs, and
above which someone might be hurt. Existence or non-existence of this
threshold is the key point in the radiation debate today. Pictures
explain this story best.

Figure 1 represents the "threshold theory." Look across the bottom of
Figure 1. As you move your eye from left to right, the numbers
represent an increasing dose of radiation. However, until you get to a
dose of 4, the line doesn't begin to move upward. When you get to 4 or
more, the line moves upward, representing an increase in the number of
cancers being caused by the dose. Four represents the "threshold dose"
in Figure 1. If Figure 1 accurately represents reality, it means you
could give everyone a small dose of radioactivity without any ill
effects whatsoever. Many people in the nuclear power industry favor
this theory.

Figure 2 shows a competing theory of how radiation affects people. It
is called the "linear theory" and it indicates that any dose of
radiation causes some consequences. Notice that, as soon as you move
your eye to the right across the bottom of the figure, the line rises,
indicating some cancer effect. The only way to get zero cancer effect
is to administer zero dose. (This does not mean that a low dose will
cause cancer in everyone who receives the dose; it means that a low
dose administered to a large group of people will cause cancer in some
number of those people--but everyone in the group is at risk.) This is
the theory that health authorities have used to set today's allowable
limits for radiation exposure.

Figure 3 represents a different theory (called the "supra-linear
theory" of how radiation affects humans. It shows that low doses cause
greater damage, per unit of dose, than do high doses. For example, look
across the bottom of Figure 3 until you get to a dose of 4; you can see
that this causes a cancer effect of between 6 and 7. But if you move
your eye to the left, to a dose of 2, the cancer effect has not been
cut in half; it is still up around 5. The "supra-linear theory"
indicates that low levels of radiation will cause more cancers, per
unit of radiation, that will large doses. This view of radiation chills
the hearts of those who profit from using radioactivity because it
means "low level" radioactive waste is more dangerous than previously
thought, and must be handled with greater care (and therefore greater
expense).

Two new books have just been published showing, from studies of humans,
that the supra-linear theory is the one that best represents the actual
facts. We will explore the human consequences of this information as
our series continues.

Get: John Gofman, RADIATION-INDUCED CANCER FROM LOW-DOSE EXPOSURE: AN
INDEPENDENT ANALYSIS (San Francisco, CA: Committee for Nuclear
Responsibility [P.O. Box 11207, San Francisco, CA 94101. First copy,
$29.95; $15.00 each copy thereafter.], 1990). This is one of the most
careful and thorough pieces of technical writing we have ever read.

And: Jay M. Gould and Benjamin A. Goldman, DEADLY DECEIT: LOW-LEVEL
RADIATION, HIGH LEVEL COVERUP (New York: Four Walls Eight Windows Press
[P.O. Box 548, Village Station, New York, NY 10015; $19.95]), 1990. A
shocking revelation of U.S. government efforts to hide evidence of
human birth defects caused by low-level radiation.

[See the PDF format version of this newsletter for Figures 1, 2 and 3].

--Peter Montague

=====

Descriptor terms: cancer; radiation; supra-linear theory; linear
theory; threshold theory; jay gould; john gofman; ben goldman; ionizing
radiation; risk assessment; health effects; atomic energy commission;
uranium; nm; co;