Agent Orange, or "C Rations"?

On advice from friends because of possible Agent Orange exposure
I registered with the Veteran's Administration a few years back.
Now I get a pretty detailed semi-annual  physical... pee in the bottle, blood work, and "lemme have a close look in those eyeballs". The close watch on what's happening to my body is comforting.

On Facebook I've signed up for a couple Viet Nam Veteran sites-
A UH-1 Crew Chief/Door Gunner/Pilot site, and a Viet Nam Veteran site. On both there is considerable discussion about all the problems my VN Vet brethren are experiencing due to Agent Orange. Seems Agent Orange is the cause of ALL problems my 75-85 year old brothers are having.
Sigh.

Not wanting to "stir the pot", I DO NOT voice my concerns there-
Those of us old enough to remember "C Rations" will remember that the "accessory pack" included a little four-cigarette pack of cancer sticks. Since I was a non-smoker I always donated my cigs to a smoking friend. MOST of my friends smoked. It was easy to find someone that wanted my gift.
It's surprising now to realize my government was supporting the addiction of many servicemen.

But to me it sure clouds the issue.
How can we determine how many cancers and other illnesses were actually caused by Agent Orange since so many (MOST, probably) VN Vets would respond to the call "Smoke 'em if ya got 'em"?

Agent Orange was a toxic substance and I have no doubt many people are now suffering because they were exposed to it.
But nicotine and tar didn't make anyone healthier.