Let's think about this: The areas they were trying to defoliate were triple canopy jungle in the tropics. When I say "triple canopy" envision trees up to 75 feet high with understory of various type of leafy green and viney vegetation. At noon on a sunny day, if you were in the triple canopy, the light never reached the jungle floor and it was more like dusk in the light of day and you can imagine just how dark it would be at night. To penetrate this canopy, one would have needed a lot more water than a C-123 or C-130 spray plane would be capable of carrying. It was more of a feel good operation as defoliation in the worst areas was never effective. What usually happened, was they would get a bit of temporary browning on the tops and when a firefight ensued, then the real defoliation via Napalm would occur. In so doing, any residual chemical left on the foliage would be incinerated and god only knows what the by-products of burning the herbicides were. Later research has confirmed that there wasn't much all that toxic in properly manufactured 2-4-5T but if the chemical was rushed to completion and cooked too hot, then the bad stuff: Dioxin as a by-product was created.

Exposure of the "grunts" working defoliated areas was a 24/7 deal. They lived, ate, slept and lived in the areas for day after day. Troops could go as long as a month without access to water for bathing and "clean" clothes could also be a monthly occurance. Any comparison between agricultural exposure to properly manufactured herbicides and what the grunts experienced is a long way from comparable in any form.