You've probably never heard of me, even though I have studied herbicides used in forests for over 50 years, all of it published in weed science literature.
However, you have heard of one famous substance I studied; Agent Orange.
Agent Orange is now known to have contained a contaminant “dioxin,” the generic name of over 70 organochlorine compounds that vary in toxicity. Agent Orange was a mixture of the well-known herbicides 2,4-D and 2,4,5-T and was put into use in Viet Nam by President John F. Kennedy, at the request of the President of South Vietnam. The goal was to defoliate the forests and gain visibility of enemy action. It was later discovered that in the synthesis of 2,4,5-T, traces of 2,3,7,8-tetrachloro-dibenzo-dioxin (TCDD) were found as by-products of that synthesis. And it is very, very toxic to most animals.
Between 1958 and 1963, I had handled diesel solutions of two dioxin-containing herbicides (2,4,5-T and 2,4,5-TP) as highly concentrated mixtures, usually at dilutions from 25% down to 4%, and often having it spread over my back as a result of leaky sprayer gaskets. Every day that I worked in the woods I would bring my oil-soaked shirts home and my wife would launder them by hand.
We couldn’t afford a washing machine then.
At that time, dioxins were unknown, their concentrations were unregulated, and high. So by 1968, when the high dioxin level was discovered, I already had had a world-class case of exposure. We now know that though it was toxic for many animals, humans seem to be extremely tolerant of it. Efforts to poison the President of Ukraine with a huge dose failed. Attempted suicides also failed, and an enormous venting of TCDD-loaded gases from a chemical plant in Seveso, Italy spread over a large urban area and killed birds and livestock, but not people.
But at the time there was concern about harm besides human death so, given my experience level, in 1972 the National Academy of Sciences asked me to investigate the persistence of Agent Orange and other defoliants used during the Vietnam War. The work was done between January and August, 1972, during which I made four trips, each a month in-country.
In a seven-month period, I applied dosages of Agent Orange and other defoliants to vegetable crops, rice paddies and forests with hand-held sprayers calibrated to approximate aerial applications. I sprayed these products using three rates of application (one-third, 1 and 3 gallons of Agents Orange and White per acre) mixed with diesel fuel and water. In all, I sprayed over 100 plots during the study, half in Vietnam.
We also had duplicate plots in the Philippines, to ensure conduct of the war would not prevent access to the work. On my way to the Philippines, the airline lost the foot locker that contained my size 15 EEEEEE boots. I doubted that Asian markets would carry such huge footgear and so I decided to spray all the plots in both countries with bare feet, exposing my legs and feet while spraying each plot except rice paddies (where dosage was diluted by flooding.)
They lost my luggage and we were losing time. Science marches on, even without boots. What you can't see are the tiny scratches and perforations after treating sixty plots in three days. Credit: Mike Newton
Yes, I waded in Agent Orange. As you might guess, my exposure level was much higher than any soldier's - if they had been present when defoliation was in progress.
But they weren't.
Defoliation missions were not done at random. The Air Force notified the Army that a defoliation mission would occur at a given time, and troops in a specified spray zone were evacuated. Helicopter gunships flew cover for the extraction operations until everyone was removed from the spray zone at least two days before spraying. No friendly troops were (supposed to be) there during the spray operations.
Another concern, eventually, was not direct exposure; it was that the spraying left residue, presumably containing dioxin. So, wouldn’t the residue contaminate troops re-entering the zones? We wanted to know, (everyone wanted to know, even the people who invented the chemicals), if it could, and if it may have caused, harm.
The elderly man standing was Geoffrey Blackman of the UK, the man who first discovered 2,4-D and its value in weed control. The person seated was the Director of the British Weed Research Organization, John Fryer. The British had used defoliation in Malaya in 1952. I took the picture in one of our “forest residue” plots. Credit: Mike Newton
What did we find? The evidence from our work and extensive study in the States said there was no physiological contact of soldiers in the field with TCDD, during or after spraying. The residue binds very quickly, within minutes, with foliage or soil. Sprayed leaf and branch litter and surface residue broke down fast in the sun, as evidenced by research done at University of California, Davis, and Oregon State University. In 2-to-6 hours in the sun, half of any dioxin deposit would already have decomposed. Once absorbed and dried, the molecules tie up firmly to that organic matter, making them very difficult to get onto clothing or penetrate skin.
The Center for Disease Control (as it was called then) found that the amount of dioxin in the blood of troops that had served in recently-sprayed areas was the same as for troops who never left the States. Indeed, it seemed that we all are exposed to tiny traces of dioxin(s) in products of combustion.
Dioxins are everywhere. And we all live with them.
In 58 years of work at Oregon State University, I have published almost 400 papers, over half of which are in refereed journals and the rest in weed science proceedings, with literally thousands of plots. Most of the time I wear shoes . . . but the bottom line is that I am a very healthy guinea pig after huge and nearly continuous exposure to herbicides, including a lot of TCDD. Since my experience in Southeast Asia, I’ve lived another 44 years, despite receiving dose after dose of 2,4-D and 2,4,5-T, each being far greater than any that could have been experienced by field troops.
Now 83 and still in perfect health, I can say definitively that at no time have I experienced any health problems that could be attributed to TCDD.
What about my wife, who hand-washed all those shirts drenched in high-dioxin herbicide for nearly two decades? She is 87, and also in perfect health!
Photo by Liz Cole, who has put up with my oversights for 35 years, and still works her butt off in our program.
NOTES:
1. It turned out banana 'trees' are not injured by Agent Orange at any dose. I sprayed the forest plots with bare feet, too, sometimes uncomfortably. We chopped down most of the cover so the applications went to organic matter, then into soil. We evaluated all the soils down to 90 cm. Weed Research Org., England, did all the analyses. About a thousand determinations.
Credit: Mike Newton
