In 1970, I was in the “cut up” room of the New Zealand Herald catching up on what had been happening whilst I was away on my first tour of South Vietnam.

Naturally, I was drawn to the Vietnam file and after a brief glance placed it back in it position on the bookshelf when I noticed a very slim supplementary file. I can’t remember the title but do remember that it was in there that I first read the word “defoliant” in relation to South Vietnam.

The prompt for the file was the then recently published report by the Bionetics Laboratory’s claim of birth defects and malformations in mice tests using 245T.

If that file had been allowed to run to it full conclusion it would been many times greater in size than the Vietnam file.

Unfortunately I had left school before Dr DK Sewell of Ivon Watkins Dow in New Plymouth had written on the manufacture of 245T for the science curriculum. Nor was it covered in my Certificate of Science course prior to joining the Army. So it became a hunt through the science and toxicology texts of the time to identify the actions of a defoliant.  


The object of a defoliant was to drop the leaves off the plant to aid cultivation or harvesting.

In South Vietnam the object was also to drop the leaves but in much greater numbers and on different species of plants requiring very high concentrations of the chemicals used. Agent Orange was applied raw without dilution but occasionally using oils as an adjunct to aid dispersal.

Ironically this military use was identified during an US Senate hearing on the “Effects of 245T on man and the Environment” in 1970, prompted by the Bionetics results, but the significance of the military composition was not debated.

I wasn’t privy to that information and it would not be until 1992 I would realise that Agent Orange was a military specific oil soluble formulation with no domestic equivalent and had Joe Cole an US Veteran raise my concerns in BRAVO Veterans Outlook magazine.

On return to South Vietnam on my second tour I witnessed the change in the area where defoliation had occurred on my earlier tour and I astounded by the destruction.

After returning to New Zealand until I left the Army unknown to me science was beginning to investigate aspects of the defoliation program or the individual chemicals.

The individual chemicals 245T and 24D were cleared by science of the time and the focus was now on the contaminate TCDD or dioxin. The toxicology evidence that 24D was a severe eye irritant was no longer important.

The investigators ranged from the National Academy of Sciences, the USAF, aerial applicators of the product s on behalf of the South Vietnamese Government, to the manufacturers of the products.

Getting rid of the evidence

Also during this time the US military had to find a solution for disposal of stocks of Agent Orange held after application was curtailed in South Vietnam in 1970.

Of course the simplest would be to simply sell it to domestic users after dilution. Fortunately science had passed them by and new dioxin thresholds would not allow it. Amazingly there was a proposal to plough it into the ground in mile long swathes in South Vietnam and allow natural breakdown of the chemicals. Thankfully that never happened. When it was decided to burn it at sea there was objection from the Hawaii environmental scientists who were advocating recovery of components from the products. The science of dioxin health affects was in its infancy.

All stocks for destruction were examined using the new testing techniques and those results combined with a very limited number of historical samples held by the USAF to produce what would be the mean of dioxin in Agent Orange of 2ppm.  But on examination in reality it only showed the mean for Agent Orange stocks produced after the industry had put in place measures to reduce the impurity in the finished product much of which never went to South Vietnam. Sure there was an evaluation of some stocks ex Vietnam at Johnson Island but in the main most were of recent manufacture. Perhaps the most interesting was the claim that high dioxin stocks were from the occasional old Agent Purple drums because there was iso octyl ester in the soil at Johnson. No consideration given to the hundreds of drums of Agent Orange II the iso octy version produced because of a shortage of butyl esters .

None the less from that point on a bias against exposure of troops was introduced to science.

There were a number of models used to discount exposure and the majority used the 2ppm mean. This mean would be referenced in all future scientific publications including the National Academy of Sciences.

Some years later there had been some media reporting of Agent Orange and Vietnam Veterans but this didn’t really tell me anything. 

Health questionnaires

In 1980 I along with other Vietnam Veterans received a medical-in- confidence questionnaire from Defence Headquarters with some real obscure questions. I didn’t have any children and couldn’t answer the question “Do any of your children suffer a deforrity?”  Deforrity what the hell is that? Did my godchild, alive of sorts at that time fit in that category? The parent’s doctor said it was either drugs or chemicals but I never saw him or others of his ilk demand an inquiry.

“Do you think you were exposed to Agent Orange or other defoliants?” was another question. It would be three decades before I would be able to answer that with any surety.

The questionnaire was a waste of time eventually been considered inconclusive because the authorities did not know when the spraying program finished. Last I heard the completed questionnaires remain in a locked cabinet in Defence Headquarters. Unfortunately the Privacy Act is not retrospective. 

Australian & US reports

But they did acquire the information they needed within two years. The Australians had bowed to Vietnam Veteran pressure and initiated an enquiry on chemical use in South Vietnam. The Australian Army was commissioned to research the subject and by the middle of 1982 was ready to present its report to the Government. A copy was sent to NZ Army Headquarters but it could not be reported on as it was embargoed until it has passed through the Australian Parliament.  Remarkably here was evidence of all the Ranch Hand missions in Phuoc Tuy province where the majority of New Zealanders served but it was never utilised until three decades later to establish exposure of NZ troops to defoliants.

All those years of veterans claiming they were sprayed with Agent Orange could have been proven or discounted with that document that lay gathering dust with the rest of the NZ Defence chemical warfare files.

In May 1983 The Government Cabinet Committee concluded that “there were insufficient Vietnam Veterans in New Zealand to justify and inquiry in this country”. From that point on we would have to watch what was going on in other countries with their Vietnam veterans. Two the Government would be watching was Australia and its Royal Commission and the US Ranch Hand studies of crew who flew the defoliant aircraft. It had been speculated that these crew would be the most exposed of all who served in South Vietnam.

Perhaps the most humorous comment was the claim that “The Minister of Health saw a need for caution in handling the situation and this was based on the nature of epidemiological study, a feature of which was the care taken to avoid what was often the temptation to link evidence to possible causes.” Years later to enable a political solution this advice was disregarded.

But in those days I wasn’t privy to any of that information and within a few years I was asking why there wasn’t a study of Vietnam Veterans children.

Some of the earlier generation of soldiers were free with their comments claiming it was a result of sexual diseases. In their day no association could be drawn because science wasn’t advanced enough but by the 1970’s there was sufficient retrospective studies to identify those congenital conditions that were associated with syphilis and the like. These were not the conditions reported by Vietnam Veterans.

To be fair not all previous generation soldiers were judgemental. An ex RNZAF WWII doctor who saw many Vietnam Veterans on their return did make an observation that there appeared to be more offspring health problems than he encountered with his generation in a letter published in the New York Academy of Sciences.

In reply to my request the predecessor to Veterans Affairs bluntly said “why don’t you apply to the Research Trust with a proposal.” I asked a couple of medic’s and they were adamant an epidemiological study was required.

Once again I was into self-taught science mode and the previous toxicology investigations had nothing on epidemiology. I was becoming jealous of the Officer ilk and their taxpayer sponsored education.  What with chance, bias, cofounding and self-reporting, cohort size and study protocols been thrown into the epidemiological mix it was looking impossible with the numbers of children involved.

This was further complicated when I was given a summary on the issue published by some Aussie journalists. A paediatrician commented that majority of conditions six months from service in Vietnam were more likely to be mutagenic in nature than teratogenic.  With infantry usually transiting though Singapore for 6 month before return to New Zealand this was an additional restriction to any study.

It quickly became apparent to me that epidemiology was not going to find the answers yet studies continued without any definitive results. All were seeking evidence of teratogenic events.

I didn’t pursue the issue any further but I did learn a lesson how trustworthy some Vietnam Veterans were when the journalist book I had borrowed from another veteran never came back to me to return to the originator.  The generational “information is power and yah don’t share” was alive and well in some parts of the Vietnam Veteran community.

Decade’s later conditions on the NAS IOM matrix listing an association but not causality would speed the acceptance of War Disablement Pensions for some Veterans and ex gratia payments for a very small number of children.

 Later in 1984 another myth around Agent Orange was formulated. A thesis on the USAF Ranch Hand missions was published and at that time the myth that the name Ranch Hand had been used to disguise the real name of “Hades” to describe the defoliation missions appeared.  As every soldier knows mission code names are there to disguise the mission from those who should not know and be immediately recognisable by those who should. Ranch Hand was one of many names with a Texas ranch component that identified 7th USAF missions on behalf of SE Asian nations. Hades with its three arms of crop destruction, defoliation and perimeter clearance identified the total US chemical mission whilst Orion, the Australian mission was for perimeter clearance only.

In January 1984 a legal notice”  to all persons who served in or near Vietnam as member of the armed forces of the United States, Australia and New Zealand” was notified  by the United States District Court of New York. They must a lost mine because I never received anything.

The result in September 1985 was the out of court settlement with the American Chemical companies. They were not settling as an admission of culpability but to prevent further legal challenges from Veterans. They were not successful as history would show.

0.2 percent of the total settlement was for New Zealand Vietnam Veterans.

I was a work when the announcement was made. A fellow employee came up and said “all you Vets are going to be millionaires.”  Another pulled me aside and said “do not get your hopes up the only people who make anything substantive from tort litigation is the lawyers.” How prophetic that turned out to be.

Eventually the money was put into a Trust to be issued on the basis of need not exposure to chemicals.  Much later another Trust negotiated with the NZ Government who was acknowledging the “toxic environment “Vietnam Veterans served in would have the same conditions in the guise of “poverty” or “hardship”.

In 1986 a special article “The Agent Orange controversy after the Evatt Royal Commission” by Wayne Hall was published in the Medical Journal of Australia claiming the Commission’s report  “has authoritatively  rejected the claims by” Australian Vietnam Veterans on exposure to phenoxy herbicides. Fundamental to that claim was “the Commission called several toxicologist’s to provide opinions on the likely level of exposure”. “The calculations were….well below the safe no effect levels for 245T and 24D and for TCDD.” That 2ppm mean was in play again.

Whilst the outcome was treated with contempt by Australian Vietnam Veterans it was not without detractors from the scientific community.

The University of Sydney Centre for Human Aspects of Science and Technology (C.H.A.S.T) published an interpretation of the scientific evidence by a number of contributors in different areas of science.

The issues raised were enough to convince me to take the findings of the Evatt Royal Commission with “a pinch of salt.” 

With the Australian Royal Commission perceived as offering no supporting evidence to Vietnam Veterans claims by authorities in New Zealand eyes were now focused on the US. Whilst the Ranch Hand results were some years away the National Academy of Sciences Institute of Medicine was tasked to find the answers.

At that time there was no definitive way to ascertain the dioxin levels in individual servicemen and its relevance to Vietnam service.  The Australian Institute of Health considered an adequate exposure index insurmountable. With no exposure methodology available the NAS used as a surrogate meta epidemiological data coupled with biological plausibility that a condition could be associated with dioxin was to be used.

The results were classified in three categories of potential association.

In 1996 the evidence for teratogenic conditions was elevated when a Ranch Hand study suggested an association with spina bifida. There was dissent but not from the medical fraternity but the Cato Institute, a liberation think tank, who claimed the results, had a weak association and was more probably the result of data dredging.   

Reeves Report

Whilst the US and Australian accepted the first NAS IOM findings the New Zealand Government was more cautious.  But changed it mind after a New Zealand enquiry in 1999 initiating what was to be called the “Reeves Report”.   

Most interesting in the terms of reference was the requirement to “Examine the records of the exposure environment…and whether exposure might have occurred.”

The Committee did a “roadshow” and when it arrived at Papakura I went along to listen.

They weren’t giving much away so I suggested that exposure was going to be problem.  A nod suggested this was accepted by no detail how they were going to do it. Eventually asking the question different ways elicited a response that they had all the information they required.

When the report was published it included the statement “Because of the difficulty in establishing which if any (personnel) were exposed” and as a result they had made a number of assumptions.

I wrote to the Committee with a please explain. Because the Committee was wound up it was forwarded to the Chair who did reply identifying what evidence they had sighted but no mention of the Australian Army report which was gathering more dust.

Later when it was uplifted to be used for the first time it would be revealed that no one serving the Reeves Committee had signed it out.

With the possibility of an association of spina bifida the Committee deferred to an expert who studied the association of spina bifida with folate deficiency in the mother.  He concluded the condition was more probably the result of that effect than chemical exposure. 

Regardless  the Reeves Commission formally introduced the NAS IOM matrix as the benchmark for conditions related to service in South Vietnam and New Zealand could now follow the US and Australia.

For the other conditions potentially of paternally induced mutagenic origin the opinion of the experts was “In most instances the questions have not been designed in a way that the data reported are comparable to the available sources of expected numbers.” Back to the future…1980!

In 2000 the Chemical companies out of court settlement came back to bite them when two US Veterans who had developed cancers after the time of the earlier settlement choice to re litigate.

They lost not because they didn’t have a case but because of the now familiar “contractor defence” copout. “They made us make it”. Later Vietnamese claimants would be stymied by the same mechanism although I never understood why the lawyers didn’t seek out claimants who were exposed before the appropriate enforcement legislation was enacted. To me the outcome was predictable yet the media was expressing dismay. Over the years I have often wondered if the media has any knowledge of the history of this subject at all.

At the dawn of a new century I had a discussion with some Australians who were pushing for an investigation of Vietnam Veterans children.  When they got to the protocol stage they informed me that the process would be an epidemiological investigation. Whilst accepting that Australia had a much larger cohort then New Zealand I groaned inwardly of the use of epidemiology.

McLeod Report

The next year 2001 saw the results of a meta study of epidemiological literature on chemicals and children of Vietnam Veterans contracted by Veterans Affairs NZ. The conclusions identified the limitations of epidemiology in reaching conclusions, but I found that out decades earlier, with a caveat that “Interpreting this data in a New Zealand context must take into account the very limited potential New Zealand troops had for exposure to Agent Orange. The information available to the authors was that ANZAC Forces generally served in Phuoc Tuy province where there was no aerial spraying.”

Once again the Australian report with its many pages of defoliant mission data was been denied to researchers contracted to the Government of the day. By an organisation that claims all veterans are members of their whanau.

Whilst the study was an informative appraisal of the difficulty of measuring birth defects and cancers in Vietnam Veterans children using epidemiology, something I had identified for myself years earlier, it was the incorrect assertion on exposure that was to earn the wrath of a number of Vietnam Veterans in emails to the author of the what was to be labelled the “McLeod Report”. But the report was considered definitive by Veterans Affairs because like its predecessor the "Reeves" it formally introduced other childrens' conditions, albeit with much less confidence than spina bifida, to the prescribed list.

It was the possibility that all this angst been directed at Dr McLeod could be perceived as reflecting on all Vietnam Veterans that the officer ilk finally came on board and started politically organising another investigation.

The subsequent Select Health Committee terms of reference included “Identify and examine evidence that defence personnel were exposed to Agent Orange and other chemical defoliants during the Vietnam War including new evidence recently brought to public attention…”

This was later to called the “Master’s Map” When it was eventually made public I recognised it straight away. It was a large scale general purpose map of known hazards in the ANZAC TAOR showing a wide range hazards such as the signals main transmitter field at Nui Dat. Because of its general nature the defoliant information it was of little value for establishing exposure. But it was a nice political totem as indicated when the Minister asked if it was authentic given the tear from the corner.  To have his question and the reply of Officers present that it was “only the South China Sea that was missing” circulated to Vietnam Veterans blogs. No one told him it was of no use for identifying individual exposure. That dust gathering Australian report could do that.

And at last it was. Two officers finally dusted it off and using it, the Herbs tapes Mercator coordinates and commanders diaries, but not the “Masters Map” were able to give a reasonable facsimile of where NZ soldiers had traversed previously defoliated areas.

The New Zealand Herald of December 15 2004 said it all. “Vietnam war veterans were “exposed to a toxic environment”. I suspect by this date the old cut up room no longer existed and that slim file was now in some digital archive somewhere.

 For me I received confirmation four years earlier when I was forwarded the logs of the USARV Surgeon Generals Office. On return from an inspection of US facilities at Vung Tau they were alerted by the duty officer of a defoliation mission over the potable water supply. After failing to acquire information from the Chemical Corps in country they were forced to seek clarification from the US. One of the roles of that unit was epidemiology. If they had not been deflected by Washington they could very well have conducted the first epidemiology study of Agent Orange.

“Toxic environment “ was to become the New Zealand equivalent of “boots on the ground” used by the US to determine exposure.

Also at this time a pilot study on New Zealand Vietnam Veterans suggested that genetic damage was more pronounced amongst those who served compared to those who did not. Mutagenic conditions are more likely to present as a range of conditions as opposed to an elevated single condition isolated by epidemiology. Because TCDD was in scientific focus this was suggested as a potential association but there were many other mutagens of Vietnam service.

The Government of the day initiated a Joint Working Group on concerns of Vietnam Veterans.

Joint Working Group

Once more it was back to Papakura RSA for another meeting. Listening to the verbal submissions of other Vietnam Veterans was enlightening and at time humorous.  At one point someone suggested there should be a monetary compensation for the lack of duty of care over the years.

He suggested 10.000 dollars to every surviving veteran. After a round table of banter this was raised to 2million. Joking aside it did look that there might be something tangible this time.

One of the issues for some, although I was initially nonplussed was the issue of a new medal to replace the Aussie one disguised under a New Zealand Royal Warrant. The more I thought about it I realised given the small numbers it could be attractive to collectors and hence a tangible asset for ones Tamariki in the future. But it was too much of a ask. Although the Joint Working Group recommendation was that “a bar to an existing medal and retention of the existing medal would be a sop to the principle” that is what veterans got.

Veterans were in the dark until the Government had received the report and commented on it.

But the press did comment. It was published that Vietnam Veterans were going to receive a 40,000 dollar pay-out. Back to the future…1984.  People were now saying all Vietnam Veterans were to be compensated and the issue was finalised. A myth believed by many to be true today.

Been wary from the earlier experience I emailed the journalist for a clarification but he would not.

Given that the Officers of the Working Group had maintained that fellow Vietnam Veterans would not be privy to the recommendations until the Government responded I wasn’t happy. But as I was to find out the whole shebang was conducted out of the Prime Minister’s office and was not subjected to Parliamentary Privilege so there was no way of confirming the journalists claim.

Later in the media the Minister did respond by saying there would be no universal compensation to Vietnam Veterans.

When the recommendations were eventually released I wasn’t surprised that the pay-out was only for a few veterans with limited conditions and later when I received Cabinet Papers it was obvious that it was known at the outset that only small numbers of Vietnam Veterans and their children would receive any tangible benefit.

I guess I had become somewhat cynical over the years and it wasn’t unexpected.

But I was incensed at the political elevation of a small number of children’s conditions to a scientific level to enable small numbers of ex-gratia payments in line with the Vietnam Veterans pay-outs.

I believe it would have best to have compensated all or none given the uncertainty of epidemiological evidence and new evidence on mutagenicity of veterans.

Given there were claims that they would keep a watching brief of further NAS IOM decisions I took that to mean if other conditions reached the same level of scientific evidence as those accepted by the MoU they would be compensated equally.

Not so.

Much later with the public release of a Defence Select Committee report investigating the War Pensions system they would state that:

The MOU provided for ex gratia payments of up to $30,000 to children of Vietnam veterans who suffered from one of five accepted conditions. Both of these decisions were made by the Government of the day and did not set a precedent for the entitlements to be extended at any time in the future.

It was a politically gimmick after all.

Some people have questioned why the Government relented after all the years of procrastination and denial. When I looked at it from a New Zealand/Canada perspective the reason became apparent.

Agent Orange was a military specific product and was not registered in either country. There was a duty of care. Perhaps the Canadians were the most generous for although their ex gratia pay-outs were individually less than New Zealand they covered many more medical conditions than those on the small Kiwi prescribed list.

The Australian Vietnam Veterans Family Study was eventually published and found no evidence of an association with those children’s accepted on the NAS IOM matrix. Not unexpected given it was epidemiologically based. The NAS contract expires in 2016 so I guess that is the end to any further epidemiological investigations of Vietnam Veterans children.

But the Australian study, which is said to have included data from the New Zealand register, did offer one insight. Post-Traumatic Stress Disorder in the Vietnam Veteran does lead to ill health in veteran’s children.  Service in war does have a deleterious outcome for the off spring of veterans. 

The Australian study was to have an unexpected sting. In April 2015, the Repatriation Medical Authority revoked the SOP on spina bifida claiming that it "did not have any factors which can be "related to service" as defined in the Act."


It was the late Allan Stuart who alerted me to the facts surrounding the Australian Army report. A simple letter to the Australian Parliamentary Archives resulted in my been privy to a document that had the potential to be available to any New Zealand researcher since 1982.

Rest in peace Allan. 


Noel Benefield

How to cite this page: 'Observing Agent Orange', URL:, (Ministry for Culture and Heritage), updated 22-Oct-2015