Christchurch Pesticide Scare

The media were quick to cry “Wolf” when concerns were raised about the fungicide Benlate.

On 9 December, 1993, the people of Canterbury read an alarming headline in the Christchurch Press: “Herbicide scare after babies born with defects”. Three City Council staff “who worked with herbicides gave birth to babies with defects”. In this first report neither the nature of the defects nor a specific herbicide were mentioned.

Several comments by Council officials and others, intended to soothe public fears, were quoted in the report — “coincidence”, “a link between the defects and herbicides was unlikely”, “the substances … did not absorb well through the skin”. An occupational health expert had been asked to investigate and report urgently; a fourth parks employee of the Council, who had worked in the same area as the other mothers, had given birth to a healthy baby.

During 1993 the office of the Parliamentary Commissioner for the Environment, Helen Hughes, had been investigating the use and disposal of dangerous chemicals in New Zealand, and the report arising from these enquiries was published only a few days after the story in the Press. The Commissioner was quoted as saying that the controls recommended by her office would have been even stronger had she known of the Christchurch birth defects.

Despite the encouraging noises emerging from the Civic Offices and other official buildings, public anxiety increased almost to the level of hysteria.

Within a week the substance under suspicion had been identified as benomyl (a fungicide, not a herbicide), made by Du Pont and sold under the name “Benlate”. Sales plummeted, TV cameras were taken to garden centres to picture staff sweeping the stuff from the shelves, and only eight days after the first report, Du Pont’s New Zealand Manager was buying whole pages of advertising space in the newspapers to rebut the accusations made against his company’s product.

During the week journalists interviewed some of the people involved, and a few personal and medical details emerged. Two of the three babies were blind; the mother of one, born in 1990, was “in anguish” after slowly rebuilding her life; the parents of the other were in a more belligerent mood, threatening legal action against Du Pont. The Wellington bureaucracy was also quick to act; the Ministry for the Environment’s representative on the Pesticides Board announced she would press the Board to de-register benomyl, and recommend the Department of Health should ban its use.

Further comments intended to lessen public anxiety came from the City Council, including the announcement that Benlate was being withdrawn from use in the Parks Department. Then, less than ten days after the first report, the matter sank from public view while New Zealanders attended to the serious business of the Christmas-New Year summer holiday period. Behind the scenes, however, Dr John Alchin, Occupational Physician, was very busy. Before the issue became public, the City Council had asked him to investigate the birth defects. His report, 74 pages long, was submitted on 15 April, 1994, and reported in the Press the following day. The sub-editor’s summary of Alchin’s summary read, “Report on birth defects finds no pesticide link.”

Alchin’s investigation had been very thorough. He had examined the hospital obstetric and paediatric records, the medical and ante-natal records of the family doctors, and the notes of the obstetricians and paediatricians concerned. He had interviewed the parents at length and scrutinised City Council procedures. He instituted wide searches of two computerised medical databases, and talked to several New Zealand experts in epidemiology, environmental health, medical genetics and toxicology.

Concerning the two babies who were born blind, he noted: (1) one was born in 1990, the other in 1993; (2) their blindness resulted from two quite distinct congenital defects; (3) birth defects are not uncommon, there is roughly a 1 in 1000 chance of any two babies being born with major anomalies; (4) the two mothers had had minimal exposure to pesticides during pregnancy; and (5) other studies show no linkage of human birth defects to pesticide exposure. In view of the emphasis given to Benlate in the media reports, it is odd to note that Alchin could not confirm that either mother had been exposed to this material during pregnancy.

The third baby in the study was said in early reports to have “severe epilepsy”. Dr Alchin found he began having seizures at three or four days old, but from three months at least until nine months, had had none. His mother’s exposure, if any, had been to Roundup (glyphosate), not to Benlate. Alchin considers neonatal seizures to be common, and no evidence links their occurrence to pesticide exposure.

It seems that we have here another case of “chemophobia”, an irrational fear of exposure to chemicals, particularly synthetic, biologically active substances. What was presented initially as almost an epidemic of birth defects associated with horticultural sprays is seen on careful examination to be nothing of the kind.

Those of us who were born more or less whole, and have borne/sired healthy children, can hardly imagine the depth of pain suffered by the parents of these two blind babies, nor appreciate the handicap with which the infants start out in life. To seek some cause for such an affliction, any cause rather than no cause at all (chance), is perhaps natural. Nonetheless, to pin blame on something baselessly can in the long run only be harmful and an impediment to understanding.

Despite the thorough investigation, and Alchin’s exoneration of the pesticides, not everyone was convinced. A spokesman for the Toxins Action Group was quick (too quick even to have read the document) to label it a “whitewash”, and, at last report, the parents of one of the blind babies were continuing their legal action. Before the findings were announced, the Soil & Health Association had decided the eye defects were caused by Benlate, and was demanding its withdrawal.

The City Council emerges creditably from this affair. Its arrangements for proper handling of the wide range of horticultural materials used in our parks and gardens seem to be carefully designed with safety in mind, a thorough investigation was promptly set up as soon as an apparent problem appeared, and Council officials tried, though with little success, to counter the inappropriate public response.

As a Christchurch ratepayer, I feel my contribution to the costs of the enquiry was well worthwhile. It is good to know that this scare was unfounded; one can hope, but not with much optimism, that such scares may not occur again with so little cause.

Oh, What a Lovely World!

Late in his life, in answer to a question, Freud compared the human condition approximately to the contents of a baby’s nappy. When I first heard this story, it seemed to mark a bitter old man. That was when I was in high school in the late 1950s. Higher education was spreading in the world’s democracies. Ignorance and superstition, the plague of the human species since the caves, were on the way out. Reason, knowledge and tolerance would rule the future of the world. Or so it seemed. Does it look like that today, even to high school students? A few news items:

  • A British insurance salesman is convicted of double murder on the testimony from one of his victims, who was contacted during deliberations by three jurors using a Ouija board. Because British law normally does not allow even appeal courts to question jury deliberations, the conviction may stand.
  • Australian medical schools are being filled by significant intakes of Darwin-doubting fundamentalists, possibly 20%-25% of students. These wholesome young people will in the course of time advance, attaining places on the policy boards of hospitals, using their authority to determine health policies.
  • In South Africa a woman was forced by a mob to douse her mother in petrol and set her alight, before she and the rest of her family were killed. Her crime: being a witch. There is a steep increase in killing of witches in South Africa.
  • The Oz Skeptics have awarded their annual Bent Spoon to the Australian Attorney General, who has made it possible for workers in his department to take sick leave with a note from an iridologist, naturopath, homeopath or other alternative practitioner.
  • Freud’s doctrine of repression is itself responsible for the smell of nappy-contents that surrounds “recovered memory” therapy, probably the most vicious pseudoscientific fad ever to be adopted by the counselling industry. The fashion to blame all of life’s disappointments on “repressed” episodes of incest has caused more human suffering than any single issue to confront the New Zealand Skeptics.
  • Not that the therapists want to stop beating the drum of victimhood. When the BBC went across the Channel to give its extensive coverage to the D-Day commemorations, it made free counselling available to all its employees who might be upset by the experience. I’m not making this up. It’s more than the survivors of Omaha Beach got, but we’re so much more sensitive these days!

The meliorism of the 1950s has evaporated. Why? Some talk of abandonment of moral standards, others the rise of the nuclear threat — or the decline of the nuclear family, while others will blame it on the fall of religion — or of communism. My candidate is the degradation of education in its broadest sense — the failure of the modern democracies to give sufficient knowledge and critical, analytical abilities to young people at all levels. The dumbing down of public education, with its mantras in praise of self-esteem rather than hard-won knowledge is bad enough. But even school is being replaced by television, with all its shallowness and sentimentality, as the major enculturating force. Ignorance, prejudice, and superstitions thrive in ways that would have amazed me thirty years ago.

The next time someone tells you how much better the world is becoming with instant global communications, innovative educational methodologies, and your therapy needs covered by ACC — think skeptically!


Reasoning About Reason

Congratulations on featuring the superb contribution from Peter Münz in Skeptic 31. It seems to concur with a passage from Antony Flew I have just been reading. He says that to know something is “to believe what is in fact true, and to be rationally justified in that belief”. Like most people shivering in the postmodernist shadow, my first reaction was to draw back, thinking that all seemed a bit too definite. Surely it’s not still allowed to be definite about something?

To question the veracity of crystals, palm-reading, apocalyptic prophecy and all the rest of it has been to incur the disapproving epithet “dogmatic”, or even “fundamentalist”. Now that’s really scraping the barrel of abuse.

The warning about the morass of justifications and provisos that await the advocate of “reason” is also timely. Is it not too harsh, however, to write the process of reason off as “woolly”, given the thoughts of Karl Popper, who Münz very rightly quotes approvingly elsewhere? Does not the distinction between critical and uncritical rationalism discussed in The Open Society and its Enemies ensure that the reasoning process, while at times being tortuous, need not be woolly? This is not a rhetorical question, I’d be very interested in an opinion on this point.

Bill Cooke, Auckland

Of Postal Permits and Other Weighty Matters

Readers who take time to study the face of their Skeptic when it arrives, rather than impatiently tearing open the seal to devour the contents, will have noticed a change with this issue. Gone is the Postage Paid Permit, “Merrilands No. 2”, replaced by a Christchurch number. With this change we let go a bit of our history and the connection with our first Editor.

Keith Lockett saw the first fourteen issues through the press, and, at his local Post Office in New Plymouth, into the mail. Keith died in 1990 (see the obituary in Skeptic 16). Now, Merrilands Post Office is also dead, killed by restructuring, and a new, valid permit has had to be negotiated.

The change is one of label only, not procedure. The Secretary and his long-suffering partner will continue to hand the boxes of newsletters over the counter of their local Postshop. Groaning under a load which is heavier with each issue, we console ourselves with the thought that this reflects a growing membership.

Bernard Howard, Secretary, NZCSICOP

Hokum Locum

A Menu of Dietary Delusions

Neither Nutrasweet nor sugar-rich diets produce any change in children’s behaviour. (New England Journal of Medicine 330:301-307, 1994)

The subjects were tested in a double-blind, placebo-controlled trial. The trial was reported in the local press and produced a predictably outraged response from local nutritional quacks who have carried on regardless. Their beliefs are based on faith and are therefore not amenable to reason. For another good New Zealand review see NZ Medical Journal 27/9/89 (Diet and Behaviour) and 23/8/89 (Children’s diets: what do parents add and avoid?).

Evening primrose oil has been touted widely as a “natural” remedy for a host of conditions such as pre-menstrual tension and menopausal symptoms. The active ingredient is gamma-linolenic acid and it was tested in a randomised, double-blind, placebo-controlled trial of 56 menopausal women experiencing episodes of sweating or flushing. It was found to be no better than a placebo.

It is worth noting the value of such studies. Randomisation means that patients have an equal chance of receiving either the “test” substance (gamma-linolenic acid) or a placebo. This ensures that both wings of the trial are identical in terms of age, sex, number of smokers, etc. Double-blind means that neither the subjects nor the investigators know who was taking the “test” substance or placebo until the study has finished. It is no wonder that quacks decry such studies which remove bias, prevent cheating and usually show that quack remedies are useless. (BMJ 308: 501-503, 1994)

Smart Drinks

These are amino acids and other precursors of neurotransmitters which are being promoted among teenagers at music and cultural festivals. Smart drinks are claimed to “fire up the brain” and give the young executive an “edge”. Could there be anything more loathsome than a hyperactive yuppie? I remember reading about the smart drinks phenomenon in the US and I am not surprised that they have arrived in New Zealand. There is no evidence that smart drinks have any effect on either memory or intelligence. (NZ Doctor 31/3/94)

Sick of Work?

All that is necessary in New Zealand to get a sickness benefit ($22 per week more than the dole for those under 25 years of age) is to persuade a doctor to sign a prescribed form from the DSW.

Over the years I have seen many flagrant abuses of the SB. The best one was a young person who had been on a SB for over two years because of a perforated ear-drum. When I refused to sign the certificate she simply went to a more compliant doctor.

The court news regularly detail the activities of professional criminals and drug addicts who are described as “sickness beneficiaries”. My attempts to find out which doctors were signing these certificates were thwarted by DSW who cited “medical confidentiality”. The great irony is that at the time they were expecting doctors to inform on beneficiaries who were fiddling the system but were not prepared to put their own administration under scrutiny.

A reporter in Germany was able to obtain 41 days sick leave from five different doctors even though he told them he was perfectly well but just wanted a few days away from the office. One visit lasted four minutes, involved no examination and was worth 12 days off! (Dominion 29/3/92, Worker highlights easy access to sick leave)

This sort of abuse arises from poor ethical standards, which also extend in Germany into drug licensing (see Skeptic 27).

Laying On of Hands

The introduction of ACC around 1972 saw a great increase in both the use of physiotherapy and private physiotherapy practices. In Skeptic 29 I commented briefly on the widespread use by physiotherapists of unproven treatment modalities such as ultrasound. Ultrasound treatments have been introduced on a basis of applied experience rather than from controlled scientific study. Dr Linda Maxwell writing in the NZ Science Monthly, March 1994, has studied cellular processes at injury sites and found that ultrasound may enhance inflammation and actually cause more injury.

Physiotherapy is also traditionally used to build up muscle strength in patients with rheumatoid arthritis. A controlled trial by physiologists (New Scientist 16 Oct 1993 p17) found that this approach tended to worsen the flexion deformities seen in this condition. Work continues in the area of electrically stimulating the extensor muscles in an effort to counteract the tendency to flexion deformity.

Most injuries recover with time and I doubt whether the laying on of hands or the use of electrical gadgets by physiotherapists accelerates this process. Many of my patients become upset if they do not receive a referral for physiotherapy and few doctors will refuse in such circumstances.

It is no surprise that costs of the ACC scheme have continued to rise each year. The burden of proving that their treatments are worthwhile rests with the physiotherapy profession. ACC should not pay for any treatments unless they can be shown to be both cost effective and scientifically valid.

Alexander Technique

The “Alexander Technique” (AT) is an extreme example of the laying on of hands. To quote a recent magazine article, “…by extending the neck and opening the back, it literally makes you taller and releases the body’s natural energy flow”.

Note the typical vague language of quackery: what does “open the back” mean and just what is this “natural energy flow” that quacks keep going on about? The usual anecdotal reports are quoted by satisfied patients: “My singing has improved tremendously…I felt lighter, taller…I’ve learnt to relax by opening and lengthening the back muscles!”

The founder, Frederick Alexander, was born in Tasmania in 1869 and longed to be an actor but suffered a mysterious loss of voice. The rest is worth quoting: “Sitting alone for nine years in a room containing only mirrors and a chair, he studied his position in every detail. It took two years for Alexander to discover only the fact that when he talked he was moving his face and chin forward and contracting the vertebrae in his neck. The muscles of his neck were becoming very tight and causing obstruction in his voicebox.”

I would have described his position as ridiculous and if he found the problem after two years what did he do for the other seven years? How does one “contract the vertebrae in the neck”?

Feeling a need to inform us further about AT the author followed up with three more anecdotal reports from satisfied customers who all described how they feel “happier, more positive, less stressed”.

Quackery has many recurrent themes. The founder of AT suffered a profound illness which was clearly psychological (nine years in a room with mirrors!) and led to him feeling that he had discovered the meaning of life.

The laying on of hands is the basis for the clinical effects (essentially placebo) of most forms of physical therapy such as chiropractic, osteopathy and AT.

Massage and postural “adjustments” are pleasant procedures for patients and it is not surprising that they go away feeling empowered and improved. Unfortunately, many become dependent on therapy and I have met many people who feel it essential to consult such therapists on a regular basis for years. This of course is encouraged by such quacks because it is great for business and they are able to take advantage of people who are incapable of taking responsibility for their own lives and health.

Ischaemic Heart Disease

Ischaemic heart disease (IHD) is a serious public health issue in New Zealand and is the leading cause of death for New Zealand adults. My own father died suddenly of a heart attack while on a golf course. He was 71 years old and had no known risk factors yet autopsy showed severe coronary artery disease.

The costs of treating IHD are considerable and surgical treatment is popular. Political pressure has seen the creation in New Zealand of an absurd number of cardiac surgical units compared to similar western countries. An American study (quoted in Lancet Vol 343 p412) of 1,252 patients showed no difference in employment status after one year between comparable patients who underwent either surgical treatment (angioplasty or bypass) or medical treatment (lifestyle modification, drug treatment).

Angioplasty involves passing a fine balloon catheter into an area of blockage and inflating it, while bypass surgery involves using lengths of vein to bypass the blocked area in the coronary artery. In a subset of 72 patients the median number of days from the start of treatment to return to work was 14 days for medical treatment, 18 days for angioplasty and 54 days for bypass surgery.

Clearly surgery is not always the best option and a lot more of our health resources could be better spent on prevention of this condition by risk factor reduction.

Death or Compensation

A court in the UK awarded a Falklands War veteran $220,000 for post-traumatic stress disorder acquired as a result of serving during that campaign.

This drew a sharp response from the defence editor of the Daily Telegraph (Dominion 10/3/94) who asks how this can be taken seriously at a time when thousands of veterans are converging on Normandy to commemorate the D-Day landings. The Falklands War veteran received his award for the stress of an action over two days! Many WWII vets saw active service for five years and returned to lead happy and successful lives.

Wars are horrible experiences from which soldiers can recover without the need or right to compensation. Post-traumatic stress disorder is simply a New Age euphemism for shell shock, and an insult to all servicemen who have done their duty and returned to civilian life. This absurd monetary award is an example of Welch’s law (after Parkinson): “Whenever compensation is available conditions will emerge to take up the compensation available”.

Deliver Us From Gynaecologists?

In Skeptic 29 I referred to abuses of gynaecology. In Florida, where 25% of deliveries are by caesarean section, the state legislature has forced doctors to change their practices, wanting the rate to be less than 20% by 1997. There is a higher rate of Caesarean delivery among patients with better health insurance and higher incomes, and the rate is lowest in teaching hospitals. (BMJ Vol 308 p432)

Failing the Sex Test

This is the headline of an article which appeared in the Dominion 17/3/94, and concerns an Indian clan which murders unwanted female children. Because of the illegal dowry system, girl children are too expensive so are murdered by being either strangled or smothered soon after birth. The tribe cannot afford amniocentesis which is also abused in order to predetermine sex so that female foetuses can be aborted.

It is important that such cultural practices are highlighted and discussed. It has been interesting to see how various other equally vicious cultural practices have fared following migration to western countries. Some doctors have been de-registered for performing female circumcision and I have even seen a reference in print defending this procedure!

The Indian authorities have taken little action over these murders since the status of women in India remains low. If there are problems over the dowry after marriage, it is a traditional practice to set fire to one’s wife and make the murder look like a kitchen accident.

How far should we go in either acknowledging or accepting traditional cultural practices? Nurses in New Zealand are judged on their “cultural safety” regarding Maori traditions and customs, which fortunately do not honour such abuses as infanticide.

Paranormal Postal Service

Skeptics who’ve ordered direct from Prometheus Books will be well aware of the realities of the extra exchange and bank costs that can make a price quoted in US dollars burgeon into a massive account in New Zealand money.

Yet an alternative therapy exists, awaiting rational testing by NZCSICOP members. It’s the Humanist Bookshop, now operating from New Plymouth. And how are its impressive results achieved? We’ll give away part of the secret — the excellent discount from Prometheus, and the voluntary labour of the HSNZ Bookshop organiser. We sell to all who wish to buy from us, at basic prices, as our contribution to more critical thinking in New Zealand.

Our NZ prices usually work out at just several NZ dollars above the US dollar quoted price, plus postage.

In stock at the moment — Randi’s Faith Healers; Baker and Nickell’s Missing Pieces; Kendrick Frazier’s Science Confronts the Paranormal; Philip Klass’s UFO Abductions; several of the Paul Kurtz titles; and many, many more.

Why not conduct your own experiment? Send for an HSNZ Bookshop catalogue (price $1.00), giving prices and details of books usually in stock. Orders for anything from the Prometheus catalogue take about 2 1/2 months to arrive.

The address: Humanist Bookshop, 26a Pembroke St, New Plymouth. Organiser, Humanist and Skeptic, Jeanne van Gorkom.

Magician Appears

On 8 February 1994, Professor Clyde F. Herreid, Department of Biological Sciences, University of Buffalo, gave a talk in the Department of Zoology, University of Otago entitled “The Magician as Skeptic”. Notices were circulated to zoology staff and senior students, other university departments, and to local skeptics. Some 40 people thoroughly enjoyed the talk. Professor Herreid demonstrated, using a variety of magical tricks, how important it is that a natural explanation should always be sought for an apparently paranormal phenomenon. If such is not immediately forthcoming, any attempt at an explanation should be held in abeyance.

Maori Science

Can traditional Maori knowledge be considered scientific?

The idea of a separate indigenous science, practised by Maori before European settlement and passed on to their descendants, is an appealing one. The phrase “Maori science” has cropped up in school curriculum reform and in Museum of New Zealand planning documents. Courses on it have been taught at university level. The Department of Conservation has decided it is “highly relevant to future policies for science and research”. But does “Maori science” even exist?

At first, this seems a silly question. After all, we know that Maori possessed a huge body of knowledge about their environment, passed on orally for generations, even if today much of it has been lost. The knowledge of how to make bird snares, process karaka berries to destroy their toxins, and differentiate dozens of different varieties of harakeke surely qualify as science.

But science is more than a body of in-depth knowledge about the world. Other bodies of knowledge include history, literary theory, gardening, auto mechanics and rugby. If knowing a lot about flax is enough to make you a scientist, then so is knowing a lot about rugby. Although scientists tend to know a lot about their area of study, as astronomer Carl Sagan has said, “science is a way of thinking much more than it is a body of knowledge”.

Defining Science

The aim of science is to understand how the world really works. Not just collecting facts about the world, but questioning the mechanisms behind those facts. Knowing how to prepare karaka berries is knowledge; trying to find out why and how they are poisonous, and how your preparation is removing the poison, is science. A perfect scientist (most are mere human beings) is continually questioning, never accepting hearsay or declaring an area closed to inquiry. This aim of science, and all the methods that flow from it, is responsible for the extraordinary understanding of the natural world we have today.

Dr Ian Hawthorn of Waikato University defines science as “objective rational co-operative knowledge acquisition”. That is, it deals with the real or empirical world as opposed with subjective opinion or personal belief. It believes that the world can be understood rationally, without recourse to the supernatural, and it operates through the sharing of knowledge by scientists.

Under this definition of science, how does Maori knowledge measure up? The answer, it seems, is not very well.

Kaumatua Morris Grey has pointed out that there was no demarcation between religion and knowledge in Maori culture. Religion’s goal is not to understand the natural world, but to help people to live in it. It operates on faith and authority. However good the knowledge database possessed by Maori, questioning (“Why don’t kakapo fly? Why is the sky blue? What is a rainbow?”) would quickly bring you up against religious and supernatural explanations, which by their nature are not open to questioning.

Maori culture was not alone in this, of course. On the contrary, every society in the world until very recently operated much the same way. Society then was what we today would call authoritarian, where the authority of your elders and gods was not up for challenge. In Maori society, knowledge was not freely available, but imparted to those who were deemed worthy in a controlled environment. Knowledge was power, and had to be restricted. It was legitimised by the authority of your teacher.

A society in which science can develop needs to have people with sufficient technology and leisure time to do research. It also has to have a good communications network, and ways of reliably storing, disseminating and duplicating information. This state was nearly reached in several ancient societies, but the right conditions were only achieved a few hundred years ago in Europe, and it is only an accident of history that science began there and not in China or South America. Maori society had neither the communications network nor the social structure for collaborative research to go on between different iwi.

So Maori knowledge acquisition was neither objective (relying as it did on religious faith), rational (it mixed supernatural with mundane explanations), nor co-operative (it relied on authority rather than challenge and consensus).


It seems then that “Maori science” doesn’t qualify as science. What should it be called then? Botanist Murray Parson has suggested the useful word matauranga, one Maori term for knowledge, and one which makes no assumptions about how scientific that knowledge is.

The phrase “Maori science” is problematic in a second sense. Most scientists would agree that the universality of science is one of its strongest features. Science is only accidentally European and, more importantly, can be practised by any culture. So the terms “Pakeha science” or “Western science” do not make sense — either a practice is science or it is not, regardless of the practitioner’s culture.

Maori knowledge or matauranga seems to have concentrated more on getting along in the world than understanding what makes it tick; it has more to do with technology than science. The words science and technology are often used together or interchangeably, but biologist Lewis Wolpert has argued that until quite recently the two areas had very little to do with each other — the technology our ancestors used for hunting, farming and building houses was uninformed by science until the 19th century. So matauranga may not be science, but that is only one of the problems that would assail anyone that tried to defend it as a research method or a curriculum subject.

Demeaning Traditional Knowledge

Calling matauranga a science demeans it. Maori knowledge — a mixture of religion, mythology and observed facts — is sometimes inconsistent and often resorts to an appeal to authority to justify a statement. It has different aims and standards to science. Moreover, to contrast it with “Pakeha” science, which is wider in scope and both more detailed and more accurate in almost every case, will teach Maori children that they are heir to a “science” that is less comprehensive and often simply wrong. Scientific standards are the wrong ones to use when examining matauranga.

Consider the story quoted by early anthropologist Elsdon Best about the pukeko arriving in New Zealand on the Aotea or Horouta canoes. This is a good example of the sort of knowledge claim that might be put forward in a Maori science class. It is also empirically testable. Ornithologists will point out that although pukeko are indeed found though most of the Pacific, New Zealand pukeko belong to the Australian subspecies, not the Pacific. This is consistent with other facts, such as the ancestors of takahe being pukeko which settled here long before humans, and the number of other bird species that have arrived here from across the Tasman. It is not, however, consistent with matauranga.

Such contradictions and anomalies are not rare. If matauranga were to qualify as science, it would have to play by the rules of the game and discard its mythological and religious elements. To many, and I am sure to most Maori, this seems a ludicrous solution, one which would rob matauranga of its coherency and richness.

There is another problem with the concept of Maori science. Although some of its promoters have the laudable aim of making science more accessible to Maori children, setting up an opposition between Maori and Pakeha science will have a different effect. The message conveyed will be that “real” science, with its wide-ranging and powerful explanations, is owned by Pakeha, and that Maori own only a lesser version.

As artist Cliff Whiting has pointed out, this ignores the fact that any race and culture can practice science. Members of historically excluded groups, such as Maori and women, should be encouraged to participate in science, not taught that it is the tool of the dominant culture and that to study it is to sell out.

Why Indigenous Science?

Given that there are so many problems with the notion of indigenous science, why is it being promoted at all?

The seminal publication in this area is a paper by Liz McKinley, Pauline Waiti and Beverley Bell, published in 1992 in the International Journal of Science Education. It advocates studying the culture of Maori students to encourage their achievement in science. The proponents are not cynical and malicious, as the creationist movement in the US has been in its struggle to introduce religion into science classes. They genuinely believe that Maori knowledge is science and should be taught. The problem here is that criticising their solution could be misinterpreted as criticising the very real problem of poor Maori participation in science.

About half the paper offers constructive suggestions for making science relevant to Maori. Again and again, however, the authors slide from this point to actively defending a separate indigenous science. Their use of the term “Maori science” seems to be an attempt to legitimise matauranga in Pakeha eyes, by borrowing the cloak of science to confer some mana. As Mere Roberts, a zoologist studying kiore, has pointed out, this is a little like the situation of some decades ago, where some Maori discarded their language and culture by “trying to be Pakeha”. Why should Maori have to “legitimise” their matauranga by trying to turn it into science?

Maori science is not being talked about only in academic journals. In 1992, the Department of Conservation, in response to the debate generated over the poisoning of kiore, the Polynesian rat, gave a bicultural presentation. Roberts talked about kiore from a scientific point of view, Bradford Haami from that of matauranga (which DoC called tikanga Maori, or Maori custom/protocol). The message was that each of these “techniques” of data-gathering are of equal value when doing research, and that this approach was highly relevant to future policies for science and research.

In 1993, McKinley and Waiti are on contract to the Ministry of Education to translate the NZ Curriculum Science Statement into Maori. An interesting point made in their paper is that some scientific concepts will not be crossing the language barrier; the concepts taught in Maori may not be the same as those taught in English. Their example is that in Maori “wind” would be termed “Tawhirimatea” for the name of the Maori god of wind. They defend the inclusion of religion in a science course by pointing out that concepts of energy taught by a physics and a chemistry teacher also differ, which hardly seems a reasonable analogy even if it is true.

The idea of Maori science seems to make sense at first hearing, partly because of a vernacular but inaccurate definition of science as “a body of knowledge”, and partly because it appeals to the fairness of teachers, who genuinely want different perspectives and to tell both sides of the story. The latter appeal is misleading, and echoes creationist requests for equal time for their story. Presenting two alternative viewpoints is only appropriate if the viewpoints are genuine alternatives; that is, if they are seeking to do the same thing in different ways. Science and matauranga do not seek to do the same thing.

The transitions going on in New Zealand society at the moment mean that discussions of cultural beliefs can become emotionally polarised, with misquotation and misunderstanding running riot. Posturing, name-calling or Maori/Pakeha-“bashing” will not help answer these issues. It is vital that critical and constructive argument can occur instead.

Bruce Ames: Environmental Prophet or Apostate?

What is the link between chemicals and cancer?

Forty years ago, Bruce Ames was a young microbiologist working at NIH in the day and enjoying Scottish country dancing in the evening, when he had an inspiration: to use the rapid growth of bacteria as a method for determining whether a particular chemical was able to cause mutations. If the chemical was positive — i.e., was mutagenic — it might be considered as a possible cause of cancer. This method, soon called “the Ames test”, became widely used. It was cheap, fast, and sensitive. One of the first discoveries was that a dye commonly used in children’s pyjamas had mutagenic properties. Bruce Ames became a hero to the environmental movement when he led a successful campaign to ban such dyes.

Ames was more interested in reducing the death toll from cancer than he was in attacking new chemical technology. As more results from the Ames test accumulated, he realised that many naturally occurring chemicals were also giving positive results. Even more disturbing, the number of chemicals that seemed to be positive in high-dose tests on mice and rats was, he felt, excessive. In an extensive series of important reviews, published in prestigious journals such as Science and Proceedings of the National Academy of Sciences, he has attempted a quantitative estimate of the difference in human cancer. Because his figures show manmade chemicals in food and the environment to be quite insignificant compared to natural or self-inflicted factors, the name of Bruce Ames is now anathema to the same environmental movement that once applauded him. Nevertheless many professional scientists believe that Ames’ position is basically correct. If the inventor of the Ames test now says that most methods for detecting carcinogenicity are invalid, it is certainly not a case of sour grapes. This article is an attempt to summarise his beliefs. Those who are sufficiently interested should read some of the papers listed in the bibliography.

(1) What do we know about the incidence of cancer?

First, cancer risk increases according to the 5th power of age. That is, a 40-year-old is 100,000 times more likely to be cancerous than a 20-year-old. There are more cancer cases per 100,000 population simply because we are living longer and no longer dying of infectious diseases.

Second, the age-corrected mortality (death rate) from cancer has been declining since 1950 except in those over 84. Overall decline has been 13%. Naturally much of this decline is caused by improved detection and treatment. The only exceptions are lung and skin cancer, clearly caused by tobacco smoking and by increased exposure to sunlight. There are occasional claims that certain types of cancer are increasing slightly, but improved methods for detection are probably responsible.

Thirdly, some mostly unknown environmental factors have a major influence on the types of cancers that are likely. Japanese, for instance, have a high incidence of stomach cancer, yet Americans and Japanese-Americans have a low incidence. On the other hand, American men have much more likelihood of prostate cancer than do Japanese.

(2) What are the major known causal factors in cancer?

The single most important factor is smoking. This accounts for one-third of all US cancer deaths, not to mention one-fourth of heart disease. Each year, smoking causes 400,000 premature deaths in the US and 3 million deaths around the world.

Chronic infections contribute to about one-third of cancer on a world- wide basis. As mentioned below, any factor that causes body cells to divide increases the likelihood of cancer. Hepatitis B and C infect 500 million people, mainly in Asia and Africa. This liver infection is a major cause of “hepatocellular carcinoma”. Two different Schistosomiasis worms infect Chinese colons and Egyptian bladders, being associated with increased cancer risk in those two organs. Liver flukes cause chronic inflammation of the biliary tract, hence risk of cholangiocarcinoma. A bacterium, Helicobacter pylori, is adapted to living in the human stomach and is now believed to be a major cause of stomach cancer, ulcers and gastritis. (So much for the classical psychogenic explanation for ulcers!)

Overall about 70% of cancers might be caused by environmental factors, but pinpointing the exact causes is very difficult. There remains some 30% that cannot be ascribed to any factor other than age and bad luck.

(3) How does cancer develop?

The first requirement is that a dividing cell suffer some sort of damage to its DNA. (DNA is the basic material of our genes.) DNA damage occurs all the time, but our bodies have excellent repair mechanisms to detect and destroy damaged DNA. Based on the amount of DNA breakdown products in the urine, Ames and co-workers estimate about 10,000 “hits” on DNA every single day in an adult. These repair mechanisms are not 100% perfect, and some damaged DNA does escape.

DNA damage is mostly caused by oxidants. The oxidants in turn arise from both internal and external sources. Internal oxidants come from mitochondria, peroxisomes, cytochrome P450 enzymes, and phagocytic destruction of infected cells. The production of oxidants when infected cells are destroyed may be a factor in the connection between chronic infection and cancer. External sources of oxidants include the nitrogen oxides of tobacco smoke, iron and copper salts, and natural plant phenolics like chlorogenic and caffeic acid.

If oxidants are bad, then antioxidants should be good. They are: antioxidants protect against disease. Natural antioxidants include ascorbic acid (vitamin C) and tocopherol (vitamin E). Synthetic antioxidants are also good. One worker estimated about 5% reduction in cancer because of approved antioxidants added to our food.

The health benefits of antioxidants, provided mostly by fruits and vegetables, are statistically highly significant. The quarter of the US population with the lowest intake of fruits and vegetables has double the cancer rate of the quarter with the highest intake. This applied to “epithelial” cancers (lung, mouth, larynx, oesophagus, stomach, pancreas, cervix, bladder, and colorectal) plus ovarian cancer. Breast and prostate cancer, on the other hand, is less affected by fruit and vegetable diets. (Although there is at least a statistical link between fat/calorie intake and breast cancer.)

Persons taking daily tocopherol or ascorbate had one-third the risk of developing cataracts. In contrast, smoking and radiation (both well known oxidative stresses) are strong risk factors for cataracts. Smoking seems to destroy ascorbate: smokers need to take double or triple amounts of ascorbic acid to achieve the same blood levels as non-smokers. Incidentally, smoking by the father seems to affect sperm production and health; smoking fathers increase the risk of birth defects and childhood cancer in their offspring.

Excess food, at least in rats, is “the most striking rodent carcinogen ever discovered”. Even a 20% increase in calories over the optimal results in shorter life, with more endocrine and mammary tumours.

Excessive cell proliferation (cell division) is a very important factor in cancer production. This has been mentioned above in relation to chronic infection. Major dietary factors, such as salty pickles in the Japanese diet, have been hypothesised to be involved in the high rates of stomach cancer in this population. Even table salt, at high enough concentrations, can cause stomach cancer.

That cell proliferation predisposes to cancer is a major source of false positives in chemical screening as normally carried out. Test chemicals are repeatedly applied to animals at the “MTD” (maximum tolerated dosage). This is like chronic wounding, “which is known to be both a promoter of carcinogenesis in animals and a risk factor for cancer in humans”. Many chemicals that purportedly have caused cancer at high dose (MTD) levels, may therefore not be true carcinogens. The infamous saccharine tests are a case in point: only female mice dosed with nearly toxic levels of saccharine showed an increase in bladder tumours.

For these chemicals that “cause cancer” at high doses only by tissue irritation, a tenfold reduction of dose in a rat or mouse experiment would show much more than a tenfold reduction in risk. This seems to have been confirmed. One analysis of 52 tests showed that two-thirds of the purportedly positive results for carcinogenicity would not have been found if the dosage had been cut even by one-half! (I suspect that commercial cancer-screening laboratories get new contracts in direct relationship to how many “successes” they have had previously.)

(4) How do synthetic and natural chemicals line up as causes of cancer?

The conventional cancer-screening techniques are, as stated above, too sensitive. There are not merely a few chemicals that show up as carcinogenic. Instead, nearly one-half of all chemicals tested seem to be positive in these tests. The ratio is the same for both natural and manmade chemicals, even though very few natural chemicals have been tested. Thus we cannot generalise that natural chemicals are inherently safer or riskier than synthetic chemicals. We must look instead at the quantities of chemicals ingested.

Plants contain surprisingly large quantities of natural pesticides. One of Ames’ greatest achievements, in my opinion, has been to compile convincing evidence about how many natural chemicals have pesticidal functions. (In my youth, the question of the function of different “secondary” plant products was much debated. Some thought that products like alkaloids and lectins were mere accidents of metabolism, a plant process gone wild. I personally thought that the main role of these chemicals was to provide research material for young biochemists.) Ames pointed out that up to 5% of the fresh weight of vegetables can be natural pesticides.

The list is very long, and a sample limited just to non-toxic plants would include: the sharp flavours of mustard and other cabbage-family crops; piperine (10% of weight of black pepper); light-sensitising psoralens in parsnip and celery; chlorogenic and caffeic acid in coffee beans; nerve-poisoning alkaloids in potatoes, tomatoes and eggplants. The cat-attracting chemicals in catnip are actually very good insect repellents. The vast majority of plants are inedible by us. Even so we are at risk of poisoning if cattle or sheep graze on them. Abraham Lincoln’s mother died when she drank milk of cows that had grazed on snakeroot. A California infant was born deformed when fed milk from a goat that had been eating lupin. The concept that “natural is harmless” is simply false.

Ames has published numerous estimates of the amounts of natural pesticides that we eat every day. He calculates that we eat about 10,000 times more natural pesticides than synthetic pesticides. More usefully, he and his coworkers have attempted to estimate the relationship between the amounts of different chemicals we are exposed to, and their potency as carcinogens. After all, it is the dosage that makes the poison, to coin a phrase. Some of his calculations are shown in Table 1, rewritten from Ames et al., 1987. The last column (HERP%) is a relative risk. A 5% HERP doesn’t mean a 5% risk of cancer!

Material Carcinogen, dose to 70kg person Rodent Potency Risk (HERP%)
Tap Water Chloroform, 85 ug 90 0.001*
Contaminated Well water Trichloroethylene, 2800 ug 940 0.004
Home air Formaldehyde, 598 ug 1.5-44 0.6
PCB’s, daily PCB’s 0.2 ug (US average) 1.7-9.6 0.0002*
DDT/DDE, daily DDE, 2.2 ug (US average) 13 0.0003*
Bacon, cooked Nitrosamines, 0.4 ug 0.2 0.003-.006
Peanut butter Aflatoxin, 64 ng/sandwich 0.003 0.03
Brown mustard Allyl isothiocyanate, 5 mg 96 0.07
Mushroom, 1 raw Hydrazines 20-300 0.1
Beer, 350 ml Ethyl alcohol, 18 ml 9110 2.8*
Wine, 250 ml Ethyl alcohol, 30 ml 9110 4.7*
Comfrey-pepsin tablets, 9/day Comfrey root 626 6.2
Diet Cola, 350 ml Saccharin, 95 mg 2143 0.06*
Phenacetin pill Phenacetin, 300 mg 1246-2137 0.3**
Phenobarbital, 1 sleeping pill Phenobaribital, 60 mg 5.5 16***
Formaldehyde, industrial Formaldehyde, 6.1 mg 1.5-44 5.8
EDB, industrial exposure Ethylene dibromide, 150 mg 1.5-5.1 140

Table 1: Calculated risk factors for common chemicals.
* Material not believed to be gene-damaging; that is, acting as a carcinogen only by irritation or damage at high concentrations.
** Some evidence for increased kidney (renal) cancer after long-term use.
*** Apparently no cancer risk to people taking it for decades.

How then do these theoretical risks relate to the “real world”? A few links can be found. There have been perhaps dozens of cases of liver damage from comfrey-pepsin tablets, although this has been as “hepato-occlusive disease” rather than cancer. These comfrey-pepsin tablets have a risk factor (HERP%) of about six.

Although alcohol is a low-potency carcinogen, large quantities are consumed by some people. Alcoholics have significantly increased risk of cancer in the mouth and throat. Thus HERP’s around five seem to be genuine risks. On the other hand, the HERP value of 16 for one phenobarbital sleeping pill is apparently not connected with any risk of cancer. (Note that phenobarbital is one of the numerous so-called carcinogens that shows up as positive only at tissue-irritating concentrations.)

One interesting point is that TCDD (the dreaded “dioxin” of milk cartons and teabags) is known to cause most of its effects by reacting with an animal component called “Ah receptor”. There are chemicals in broccoli, mainly indole-carbinol, that also react with the Ah receptor. Both chemicals can protect against cancer if administered before challenge with a carcinogen. Both chemicals can promote cancer if administered after the carcinogen has already acted.

Taking potency into account, a 100 g portion of broccoli has 20,000 times more effect on the Ah receptor than a legally allowable TCDD intake of six femtograms/kg/day. (Perhaps it is not surprising, then, that experiments in which rats given a carcinogen were protected by including broccoli or cabbage in their diet. There is evidence that humans too are protected by these vegetables: People who are high-crucifer eaters are significantly less likely to wind up in cancer wards.)

(5) How pesticide regulations and chemical scares diminish public health.

Diet is one of the key routes to better health. Only 9% of the US population eats sufficient fruit and vegetables, higher consumption of these would decrease cancer as well as other diseases. There is plenty of margin to increase fruit and vegetable eating.

To discourage consumption of vegetables and fruits is to diminish public health. Excessively strict limits on harmless levels of synthetic pesticides act to increase vegetable and fruit prices, by reducing production and by increasing cost of production. Thus these regulatory restrictions may well be harming health rather than helping it.

Similar comments could be made about the attacks on Alar a few years ago, when apples disappeared from the lunchboxes of many children.

This then is one reason why Bruce Ames is hated by many “environmentalist” groups. He has shown that they are, in all likelihood, damaging public health under the guise of protecting it against non-existent or unimportant risks.


This review was inspired by an article by Dr Arthur B Robinson in Access to Energy, April 1994.


B.N. Ames. 1983. Dietary carcinogens and anticarcinogens. Science 221: 1256-1262.

B.N. Ames, R. Magaw, and L.S. Gold. 1987. Ranking possible carcinogenic hazards. Science 236: 271-280.

B.N. Ames and L.S. Gold. 1990. Environmental pollution and cancer: some misconceptions. In: Science and the Law (Ed. Peter Huber).

B.N. Ames and L.S. Gold. 1990. Too many rodent carcinogens: mitogenesis increases mutagenesis. PNAS 87: 7772-7776.

B.N. Ames, M. Profet and L.S. Gold. 1990. Dietary pesticides (99.99% all natural), mitogenesis, mutagenesis, and carcinogenesis. PNAS 87: 7777-7781.

B.N. Ames, M. Profet and L.S. Gold. 1990. Nature’s chemicals and synthetic chemicals: comparative toxicology. PNAS 87: 7782-7786.

B.N. Ames, M.K. Shigenaga and T.M. Hagen. 1993. Oxidants, antioxidants, and the degenerative diseases of aging. PNAS 90: 7915-7922.

B.N. Ames. n.d. Does current cancer risk assessment harm health? Published by The George C Marshall Institute, 1730 M Street, N. W., Suite 502, Washington, D. C. 20036-4505. ($US 5.00) [Not seen by me yet — JDM]