Nuclear dads
We were very concerned to read the article on nuclear plants and leukaemia
(This Week, 29 May, p 22).
The article was based on our paper in the British Medical Journal(vol 318, p 1443),
and we believe the results were not summarised appropriately.
Overall, we found no excess of cancer, and in particular of leukaemia, in the
children of nuclear workers compared with the general population. This important
finding was downplayed by your correspondent and the title of the article
(“Lethal legacy: The nuclear-dad-is-bad theory may have been right after all”)
bore no resemblance to the conclusions reached by the authors.
Our study was set up to investigate possible links between child health and
parents’ occupational exposure to ionising radiation. It was restricted to
employees at nuclear plants who had been the subjects of a report alleging an
increased incidence of leukaemia in young people living nearby. It was not, as
your article stated, set up as “an attempt to confirm or reject the work of the
late Martin Gardner”.
The quote “the children of men exposed to radiation while working at nuclear
plants are twice as likely to develop leukaemia” is taken out of context. The
risk estimate was not statistically significant and thus might have arisen by
chance.
Further, it is misleading to present the higher risk of leukaemia among the
children of men who had accumulated a radiation dose of more than 100
millisieverts prior to conception as support for the Gardner hypothesis when two
of the three cases on which it was based were included in Gardner’s original
study. We were careful to point out the overlap of the two studies and to
emphasise caution in the interpretation of this finding.
Bursting message
You report that a NASA astrophysicist has suggested that aliens might send
signals in the wake of gamma-ray bursts, as the powerful bursts would attract
the attention of other civilisations
(This Week, 8 May, p 16). However, contrary
to the article, detecting such a signal would reveal nothing about how far away
the aliens were.
A message beamed to us by aliens as soon as a gamma-ray burst passes them
heading in the Earth’s direction would take the same time to reach us as the
burst itself would need for the remainder of its journey to us. We would
therefore see their message immediately after the burst, whatever the distance
between the aliens and ourselves, so the timing would reveal nothing about the
distance between our planets.
The mistake lies in deducing that “because the sources of gamma-ray bursts
are extremely remote”, we and any aliens in our Galaxy would see them
simultaneously. The bursts do take a long time to reach us, and a long time to
reach the aliens, but the difference between two large quantities doesn’t have
to be zero.
Useless abilities
Matt Walker reports the work of zoologist Xavier Bonnet and his colleagues,
who discovered that blinded tiger snakes survived just as well as healthy ones
(This Week, 22 May, p 10).
The article says these results “may be the first direct evidence suggesting
some animals have abilities they could just as well do without”. However,
reports of such phenomena are not new. My studies of cave fish in the mid-1980s
showed not only that blind, subterranean individuals of the characid
Astyanax fasciatus were able to respond to light, but also that these
responses change in intensity during development鈥攁 behaviour totally
superfluous in a dark environment.
One of my colleagues, W. Pfeiffer from Germany, reported in 1966 that
A. fasciatus produces the “alarm substance” (a chemical that warns
conspecifics of an immediate danger), but does not respond to it.
My interest in this type of phenomenon was prompted by similar observations
by Walter Bock, who in 1959 showed that primitive woodpeckers, which had
switched to the behaviour of climbing on tree trunks and branches, still had
essentially the same diet as terrestrial birds.
Letter
Walker’s article reminds me of the stingrays that I used to study off the
Sussex coast in the 1950s.
They used to swarm each summer over the sandy bottom on the incoming tide to
mate, during which time they ceased to feed. Anglers generally remained unaware
of them for this reason but for trawling fishermen it was a different matter.
One year two fishing boats trawled a sand bank covered with mating stingrays.
About 400 of them were caught in the nets.
As well as having the venomous barb on the tail, these are difficult animals
to handle as they are covered with a slippery mucus. So the fishermen cut off
their tails before picking them up and returning them to the sea. For a few
years after this I caught and examined several specimens without tails. They
were quite healthy and taking part in mating.
This appeared to prove two things: first, that they came back to the same
area each year and second, that they did not need their tails.
Check on checkers
Your editorial on the poor record of recent US rocket launches suggests that
the answer is more people on the assembly line checking for faults
(Editorial, 15 May, p 3).
The idea of “inspecting in” quality after assembly has been abandoned by most
of the best manufacturers. Having inspectors to check work can make
manufacturing staff take the attitude that it is the inspectors’ responsibility
to find faults, not theirs. In the worst cases it can result in an “us and them”
mentality where people try to “get one past the inspectors”.
The modern approach is to invest the money that would have been spent on the
inspectors in training production staff to check their own work as they go
along, and to instil in them a pride and a sense of responsibility for the final
results. Combined with techniques such as redesigning plant and procedures to
reduce the chances of error in the first place, this approach can give much
better results than more and more inspection.
The Master's voice
John King is bothered by anthropomorphic language sometimes used in
summarising the results of evolution by natural selection, and seeks reassurance
from “someone who knows about these things”
(Letters, 15 May, p 51). Who better
than “the Master” himself?
“It has been said that I speak of natural selection as an active power or
Deity; but who objects to an author speaking of the attraction of gravity as
ruling the movements of the planets? Everyone knows what is meant and is implied
by such metaphorical expressions; and they are almost necessary for brevity. So
again it is difficult to avoid personifying the word Nature; but I mean by
Nature, only the aggregate action and product of many natural laws, and by laws
the sequence of events as ascertained by us. With a little familiarity such
superficial objections will be forgotten.” Charles Darwin, On the Origin of
Species (6th edition, 1872).
As for the evolutionary value of pedantry, it depends mainly on whether
you’re buying or selling. Considerable care and attention to detail have long
been recognised as necessary when exchanging known for unknown quantities.
Conversely, in the selling game of sexual selection, I’m told that pedantry goes
down less well.
Nickel intake
In his letter about allergies Jon Slack attributes his wife’s rash to
multi-vitamin tablets containing nickel
(15 May, p 51).
However, an additional intake of 5 micrograms a day of nickel is unlikely to
have any noticeable effect. Daily intakes of nickel have been reported to be 140
to 150 micrograms for adults in Britain, 69 to 162 in the US, and 60 to 260 in
Denmark, according to the World Health Organization report Trace Elements in
Human Nutrition (1996).
No chips off Newton
Feedback (22 May)
says that the organisers of the Ig Nobel ceremony are
looking for the descendants of famous scientists (such as Isaac Newton’s
great-great-great granddaughter, if such a person exists) to grace the stage as
authority figures during the ceremony. This could prove difficult鈥擲ir
Isaac died a virgin.
Sample collection
As a microbiology lab assistant who handles over 300 urine samples a day, I
thought that I would add something of my own research to that mentioned in
Feedback (15 May).
We supply people with pots to pee in, but they sometimes feel the need to
brighten up our dull lives by sending urine in jam jars, pots designed for other
samples (like the poo pot, which has a spoon in the lid for scooping, but when
full of urine could easily be mistaken for one of those bubble-blowing
contraptions) or even empty antibiotic bottles (which do a very good job of
killing any bugs we may be looking for).
The overwhelming evidence from my research is that it is far too difficult
for “ill” people to tighten the lids of urine containers enough to stop them
leaking all over the place before they reach us (I no longer bite my nails or
eat finger food). “Ill” people also seem unable to follow the instruction “fill
to line”.
Letter
My father is a general practitioner, and some years ago he was doing a round
of house calls. One elderly man gave him a generous urine sample in a whisky
bottle. My father left it sitting on the back seat of the car while he was doing
his other calls.
A couple of calls later, he returned to his car. He found the back window
smashed and the bottle stolen. I hope the thief knew what whisky is supposed to
smell like.
Mobile safety
We wish to respond to your editorial on mobile phone safety, “Dial F for Fear”
(10 April, p 3). As you state, an international project on cellphones and
cancer is planned. It will be coordinated by the International Agency for
Research on Cancer. Funding is presently being sought from the European Union
and national health research funding bodies.
However, while discussions are being held with mobile phone companies, no
agreement on funding has yet been made. Nor is the proposed study restricted to
Europe: there will be study centres in Australia, Canada, Israel, New Zealand,
the US and possibly Japan as well.
You also argue that there is no compelling evidence that radio frequency
radiation (RF) from cellphones is likely to cause illness and that cell phones
should be a low priority given other world health concerns.
The research on RF and cancer is mostly negative, but there have been
positive findings that cannot be readily dismissed. At present, no mechanism is
known whereby RF might cause cancer, but that may simply reflect our limited
biological understanding. There are instances elsewhere in environmental health
(for example, passive smoking and air pollution) where control measures based on
epidemiological data preceded full knowledge of disease mechanisms.
If RF is found to be a cause of cancer, the public health significance will
be enormous. Cellphones are the major source of RF exposure, are used by
hundreds of millions of people worldwide, and the number of users is rising
steeply.
The fact that the public is concerned about the safety of cellphones is not
an argument against research. Quite the opposite: it means that scientific
assessment to guide policy makers is particularly important. It is true that
investigation in this area is difficult, but this is exactly the reason for
conducting a large, carefully designed international study.
We are surprised by your comment on priorities. The international study is
being set up in response to the recommendations of the European Union and the
International EMF Project. Both groups recently reviewed the state of knowledge
in this area and recommended that research, in particular epidemiological
studies of mobile phones and head and neck tumours, be given a high priority.
Letter
Your editorial takes as axiomatic the need for GM foods and characterises the
opposition as suffering from “hysteria” and as disseminating “propaganda” rather
than science. In other words, if I raise the precautionary principle I am
hysterical, and if I express a preference to have my world designed by experts
under the control of society as a whole rather than by scientists who follow the
funding, I am a propagandist.
Major research funding is now in the gift of big firms. It used to be in the
gift of governments. Forty years ago, C. P. Snow saw scientists as on the side
of people against the big battalions. This was because the public sector, their
main employer, was then welfarist. Now, scientists regard the public as unable
to see where its interests lie, because it has been led astray by false prophets
from the environmental movement. This change of perspective is due to the shift
of funding from public to private.
In actual fact, most people are well aware that feeding the world is a matter
of distribution and production methods rather than sophisticated bioengineering.
Too many people are poor. Eating meat is a tremendous waste, because so many
more resources are needed to raise livestock than to grow crops. Potential
livestock reduction represents a huge reserve against further population
increases.
While genetic engineering can solve real medical problems, such as providing
“clean” blood plasma for haemophiliacs, it is not much more than a labour-saving
device when it comes to crops, at a time when jobs are scarcer than food.
Underlying this problem of diverging interests are the needs of the
multinational corporations. On the one hand, they want a low-paid workforce,
steadily diminishing through the application of technology. On the other, they
want an ever-increasing supply of wealthy, acquisitive consumers. Will the
scientists, perhaps through the application of cloning technology, be able to
satisfy this desire for two distinct populations in the world?
For an extended debate on GM food and a response from the editor, see
“Letters” on our website
Public fury
Once again New 杏吧原创 blindly follows a “science is always good” line
(Editorial, 22 May, p 3). To condemn the public as hysterical over
genetically modified (GM) foods is to miss the point. The public isn’t
hysterical, it is furious. It has had a dubious product forced on it and now is,
quite reasonably, demanding a choice.
Take the environmental problems due to pollen: does the reference to
“modified foods which don’t produce pollen” really mean that New
杏吧原创 thinks potato flower and cabbage flowers have no pollen? My
understanding is that both produce pollen, and brassicas are particularly
popular with bees. No wonder the public has difficulty believing scientists.
As for the idea that the dispersal of GM pollen doesn’t matter if there are
no organic crops that could be contaminated, what crops does New
杏吧原创 think are not grown organically? Certainly the main GM crops of
soya and maize are both produced organically.
The reason why it matters if tiny amounts of pollen escape is that gene
transfer is now a fact鈥攁nd once GM genes are out, we can never get them
back. You rightly identify the political aspects of this, but replace the
important ethical considerations (such as “terminator seeds”) with accusations
of emotionalism.
Science doesn’t operate in a social vacuum. Research is driven by the values,
ethics and the interests of the funders as well as the researchers. Your poll on
attitudes to animal research in the same issue
(p 26) shows exactly why it is
important to listen to the unscientific views of the public. So far the public
cannot see any benefits to GM crops and so sees no reason to take any risks with
them. It is surely reasonable to ask for labelling so we can avoid GM food if we
wish.
Just because the advance of scientific knowledge is possible, does not
necessarily mean it is a good thing for the world. Now, before it is too late,
is the time to reconsider this science from first principles.