Do we need another 20 years?

I keep hearing "We don't know what the effects will be in 20, 30 years." Do we need that long? 

I was fascinated by a youtube video showing - in very broad terms - the massive differences in Formaldehyde generation between ecigs and smoked lit tobacco (there'll be a link at the bottom). During the course of said excellent work the statement (paraphrased) "We don't really know what the long-term risks are, and we won't for another 20 or 30 years" was used, and it rankled me a little. Here's why:

The state of the art in science is pretty well advanced these days. We know what the long term effects of all kinds of substances and behaviours are. Indeed, such is the knowledge that scientists can reliably predict ongoing changes in state from the changes that have occurred thus far, and, these days give pretty accurate timescales for various of these changes to occur. 

So it is that I've been asking questions for the last six years, trying to get an answer - even a ballpark one. The simplest of these is "What is the earliest point in a smoker's smoking career are the first signs of damage evident?", followed by "and what are those signs or symptoms, and what is the prognosis and/or treatment regimen that would mitigate them?" 

On numerous occasions I've asked acknowledged experts, and even activists that are 100% sure that their pronouncements are hyper-accurate (like, as of today, 2/3rds of all smokers will suffer premature death etc etc etc) the first one. 

Guess what? 

I've never got an answer. It's always "We can't say - there are no figures." 

I call BS. 

If we are so certain that smoking causes A,B,C and D, and we know as much as we claim to about the progression of them, then it absolutely must be possible to put even ballpark timescales on such things. If that's not the case, then, it seems to me, we're actually guessing about causality. Now that's a bit of a side issue here, so I'll just park it and leave it to you to decide what it actually means.

But in terms of "We just don't know", it makes little sense. 

Let's take just Formaldehyde, as an example. It's a Class 1 Carcinogen. One would assume that its status has been derived from lots of study and research, and that its carcinogenic action can be described in quite some level of detail - as it would have to be in order to be able to produce medicines to treat its effects. 

On that basis, one would also assume that "they" would be able to say something along the lines of "repeated exposure above 100 parts per billion in a volume of X litres of air/water/milk over a period of Y weeks/days/minutes produces Z effect in 100% of cases".

You'd think, eh? Given that there's an occupational exposure limit and so on, surely, they must know these things? 

So, it necessarily follows that they must be aware of timescales. 

And if so, why on earth won't they answer my question? Why? 

The reason I ask it is very simple. If they were to come back and say "We'd expect to see Formaldehyde-caused excess bright purple sputum at four years into a smoking career" (obviously an exaggerated example) then we, as vapers, would have a benchmark. We'd be able to say things like "After seven years of vaping, not one vaper has exhibited these signs". We'd be able to make the kind of comparisons that would blow the "we just don't know" arguments so far out of the water that "they" would be made to look daft.

Or, alternatively, if we saw those signs, we'd be warned - we'd be able to turn to those folks that say "ecigs are no better than fags" and say "Yes, you were right. Sorry for being a dick". 

However, I don't think the second scenario will ever come to pass. We know too much. It's not us being dicks... 

Here's that video: 

https://m.youtube.com/watch?v=bxuFSGjZeBg