. . . And it was from what the mothers told us of
these children that it became recognized that the children
who had died of cancer -- let's say an early death from
cancer, before the age of ten as it happened -- had been
twice as often x-rayed before they were born as the live
children. X-ray, just an x-ray photograph. We've seen
the cameras clicking 'round this hall all this
morning. It's difficult to imagine a dose of radiation
that is as small, as temporary as an x-ray
photograph. Click -- it's over.
By the end of the time we did the survey -- we met of course with terrible
opposition when we produced this fact, but we've been given now 30 years
to establish what everybody now agrees to, and that is, that if single,
non-repeated exposure to a small dose of ionizing radiation before you are
born is sufficient to increase the risk of an early cancer death, and that
the sooner this event happens after conception, the nearer you are to
conception, the more dangerous it is. Probably every childhood cancer,
except the man-made ones from x-rays, could be due to background
radiation. Are you going to play with that ball of fire and say it's
safe? Are you going to introduce into the human race the possibility of
causing not only -- shall we put it into technical terms -- adding to
population loads of cancer? Are you going to be happier by adding to
population loads of defective genes for future generations?
Dr. Alice Stewart, Great Britain. Medical doctor,
Professor for Social Medicine, expert on low-level
radiation, Alternative Nobel Prize.
Well, of course they've had to admit that radiation is a cause of
mutations -- by mutation we mean a disturbance of the behavior of a
cell brought about by damage to the DNA --, and they've had to admit
that there is no such thing as a dose of radiation which is too small
to cause this damage and that the damage, once incurred on a cell,
as long as the cell lives and continues to divide, will be passed on
to daughter cells, so they've had to admit that there is some element
of danger here. But now, we all change our tune and refer -- I'm
still talking on behalf of the advocates of nuclear power -- to the
experience of a well-defined population that was in fact exposed to
radiation and even exposed to major doses of radiation or at least
estimates of it, namely the Japanese atomic bomb survivors. And they
will refer to a long, drawn-out study where they failed to find any
effect of low doses. They admitted, of course, that high doses could
actually kill you immediately, or they could cause acute radiation
damage. But at the end of a very long follow-up, they finally
decided that the people who had been exposed to -- I'll give you a
rough figure -- about ten times background radiation -- which was
considered of course very low -- had not only not suffered at all,
but actually were slightly better off. This started another train
of thought that perhaps, as a result of human beings having been
exposed to radiation, ever since the race was there and back into
geological time history, perhaps we have developed some sort of
immunity to radiation and actually it could be arguable that perhaps
a little radiation could do you good. So there's even a thesis in
the literature on this subject.
Now, that is one side of the story, and it's far, far and away the
most important. But, of course, there is the other side of the
story, and that is the story in which a person like myself who has
to try and find out where the truth lies of people who have
exaggerated the effects of low-level radiation. They've tried to
ascribe to small events or happenings in their lives some
exaggerated notion of what has gone wrong as a result of being exposed
to radiation. I wouldn't quote this, but I'm sure you're well aware
that a natural anxiety would lead to this and might lead to some,
scientifically speaking, slightly unfortunately exaggerated
remarks. So I'm really trying to spend the few minutes I have with
you today to try and explain to you some of the difficulties that
face somebody trying to find out exactly where we do lie with regard
to low-level radiation.
I want, first of all, to tell you that my heart is with you. I would
be against nuclear energy for all the instinctive reasons that one has,
that we human beings are playing with a very, very, very dangerous
toy. The benefit of any doubt should be given to the people who --
should be against, strongly against anybody who says there is no
danger. In other words, there should be an instinctive feeling
amongst us that this might be a mistake, that there was a danger that
they had failed to detect on the grounds of one thing alone: Can you,
or is it at all easy to, detect a small effect?
Now, that is going to be the thesis of my lecture: I'm going to explain
to you why it is so difficult to establish this and why it's been so
easy for the other side to say that there has been no effect. And
there are three things that I would like you, especially anybody among
you who is a real activist on this subject and has to go out from this
room and tell other people about, that there are three reasons why it is
so hard to actually establish that there is a danger from very low-level
radiation in spite of natural background radiation being inescapable.
The first and most obvious reason is, of course, that any small-dose
effect is bound to be weak. You're looking for something very small --
small and rare. It's not going to be obvious. And any idea that you're
going to get an epidemic springing up as a result of leakage, say, small
leakage from a radioactive nuclear power station or anything of that
order, please dismiss from your minds at all. You are looking for
evidence of a small, very rare event. That's the first difficulty.
The second difficulty is that this event is going to be long
delayed. What does it matter whether a cell that I've told you about has
a damaged form of behavior? Does it matter? Can't it live with all the
other cells in your body and not necessarily do any harm? You've got
millions, billions of these cells. Does it matter? Well, of course, the
reason why it matters is two-fold. There are two situations: If it's what
we call a somatic cell, a body building cell, then as a result of this
damage the cell doesn't obey the full central instructions of the body as a
whole, and should circumstances change or should there be a gradual
deterioration in general health, which inevitably comes about with age, the
effects of age and changing circumstances may be such that the cell becomes
liberated from the usual restraining influences and causes what we all know
to be under the general heading of cancer. By cancer, of course, I include
leukemia, but leukemia is just one form of cancer -- it's a blood cancer,
and the others are cancers of other tissues. You can get a cancer in any
tissue. You don't need to be a human being to get a cancer, you can be an
animal and you can be a plant. Any living organism in this world is at risk
of a mutation at some longish delayed period of time getting free from the
restrictions that make you function as a whole being and end up with a
cancer. Now, I've said "a long time". Is it measurable? Well, it turns out
it's not only long but it's very, very variable. You could be very unlucky
and be hitting these particular circumstances and go off fairly soon. So,
this is for purposes or people who are looking for this trouble we're now up
against two difficulties: A rare event that is going to occur almost any
time thereafter in the form of cancer. And I mean that. It can -- in very
rare circumstances of an embryo being attacked -- it can occur within a
year. But usually, in adults it might be delayed 80 years.
And I must come back to the second stream of thought that if it's germ
cell-damage, it's going to skip a generation before you see anything, and it's
not only going to skip one generation, it's going to skip one, two and three
generations, because it's got to meet up with a pair before it shows that the
damage has been done. So, the time scale of the thing you're looking for is
astronomically large imposing all sorts of difficulty for the investigator.
And what will be the effect of the germ cell-damage? And this I want you to
bear in mind: If there's any proof that a cancer is there, there's going to
be an implication, a certain implication, a certainty, that there will be a
genetic damage that may not express itself for several generations, but when
it does it will lead to the deterioration of the unique human development,
namely the brain. You're going to feed into the genetic pool of human genes
damage which will deteriorate the one thing for which we are famous, namely
that we have the capacity to think for ourselves.
Those are two reasons. I promised you a third one, and the third one is
perhaps the most difficult of all to conceive. It is that this event that you
are looking for, which is rare and long delayed, is also going to be a very
common, natural event. This follows from the concept of there being any effect
to background radiation. You'll notice, that if there's going to be a
low-level radiation effect, there's bound to be a background radiation
effect. Therefore, the thing you're looking for is a natural phenomenon, isn't
it? It must be there, must be happening all the time. You know we're all
whirling around in space, but we all have the impression that we are sitting
quietly, absolutely still in this hall. This is exactly the same impression
that we're getting from any ill effect of background radiation, that it isn't
there. But it is there. But we're all suffering from it equally or
sufficiently equally for all practical purposes not to show.
Now you've got three things that are going to make it extremely difficult to
prove that low-level radiation has any bad effect. It's going to be rare, it's
going to be long-delayed and follow two tracks, either the track of cancer or
the track of the defective inherited gene, and it's going to be an everyday
event. How on earth do you ever establish any proof that this is so at all,
never mind, say, that you'll require this before you're going even to
contemplate the idea that nuclear could be dangerous?
Well, the reason I am here on this platform is really a fluke. But it is also
in the context of saying that it has something to do with women and I think a
rather nice fluke. First of all, of course, I'm a woman, but that wasn't the
point. What led to the discovery, the first and to this day the only most
certain effect of a very low dose of radiation in the human population was
the result of my saying: "Why don't we go and ask the mothers?"
The situation was as follows: Way back in the 1950's, there was a worldwide
increase in leukemia. I can tell you today that this was an unnecessary
alarm. It was an alarm due to the fact that because anti-biotics had come
into our lives, we were seeing for the first time very many cases of leukemia,
and normally don't. These children -- or adults, for that matter -- would
have died of infections before you realized that they were truly suffering
from a latent form of a blood cancer. But (..?) the anti-biotics in these
cases emerge? Now, we didn't know this, but what we did notice -- we as
medical people -- we noticed that children between two and four were suffering
more than any other age group. And we were sufficiently expertised to know
that this was very unusual. If children get troubles -- they either get them
as babies; new born babies are very vulnerable, or they get trouble after
they go to school, which is usually at the age of five and they are meeting
other children -- why children between two and four?
And this was where I said: "Why don't we go and ask the mothers?" And we
picked out -- we needed all the cases in Britain -- we got the death
certificates of every child who had died of leukemia in the last three
years; we had as control groups every child who died of any other form of
cancer, and a live child for each dead child. And I must now tell
you . . . we set out to do a survey -- it's known as the "Oxford Survey of
Childhood Cancers" because that was where I was actually working at the
time --, and it set out to interview the mothers of children who had recently
died, either from leukemia or from another malignant disease, and for each
dead child we had a live child. And it was from what the mothers told us of
these children that it became recognized that the children who had died of
cancer -- let's say an early death from cancer, before the age of ten as it
happened -- had been twice as often x-rayed before they were born as the live
children. X-ray, just an x-ray photograph. We've seen the cameras
clicking 'round this hall all this morning. It's difficult to imagine a
dose of radiation that is as small, as temporary as an x-ray
photograph. Click -- it's over.
By the end of the time we did the survey -- we met of course with terrible
opposition when we produced this fact, but we've been given now 30 years
to establish what everybody now agrees to, and that is, that if single,
non-repeated exposure to a small dose of ionizing radiation before you are
born is sufficient to increase the risk of an early cancer death, and that
the sooner this event happens after conception, the nearer you are to
conception, the more dangerous it is. Probably every childhood cancer,
except the man-made ones from x-rays, could be due to background
radiation. Are you going to play with that ball of fire and say it's
safe? Are you going to introduce into the human race the possibility of
causing not only -- shall we put it into technical terms -- adding to
population loads of cancer? Are you going to be happier by adding to
population loads of defective genes for future generations?
Naturally, I'm on your side.