*deleted*

Tobacco use in young adults is a very high statistic

By this I think you mean that tobacco use is highly prevalent in young adults, or the statistics are surprising, but you kind of muddle those two ideas together.

Many teens around me smoke or chew tobacco; damaging their lungs, teeth, and even their brains with the harmful substances.

You do not need (or want) the word "the" before "harmful substances."

In general, I have come to suggest to most writers (especially in professional settings), that the easiest way to quickly upgrade a work is to avoid the Egregious "P"s:
Particles (the, so, however, nevertheless, and, than - more here: http://en.wikipedia.org/wiki/Grammatical_particle)

Platitudes (common sayings; idiomatic expressions. As in "in terms of -" which may be the most egregious platitude of all)

Prepositions (that, then, there, before, behind, by... detailed list here: http://www.englishclub.com/grammar/prep ... s-list.htm)

So I will not point too many more egregious "p"s, but know they are often lurking.

For some reason, teens around me are fascinated by the image of smoking, and by the idea. The fact is,

The first sentence could be reworded (and shortened) to say "In my experience, teens..."
"The fact is" doesn't add anything to the work - it's kind of an egregious p.

that is more harmful to your body even more...

This is redundant.

The effects of withdrawal, however, is the scariest thing to most young adults.

Tense agreement error: "effects... is."

It is a difficult thing to pretend not to notice the craving long enough to rid your body of it, and most teenagers struggle to ignore it for that long of a period.

Remove "thing" - it is another egregious "p."
Remove "and" as well. You can rewrite this to shorten and strengthen it.
"pretend not to" may be better as "pretend to not" - bringing "not" closer to the action it negates.

Approximately 396,000 smokers who started in their teens die each year from smoking related diseases. Of the every 6,000 teenagers that start smoking every day, 2,000 will become addicted and continue smoking. Teens become addicted faster and on lower levels of nicotine than adults.

This is a very interesting factual paragraph, and the prose is pretty strong.
However, you do not have any inline citations - whether laziness or not required, I don't know. But it could help your argument to seem more credible.

It is a thing now, in public schools, to smoke, just to look cool.

This sentence is overly complex, and has not any backing (no reference, nothing).
Either you can back it up with a statistic, or delete it.

'invincibility syndrome'

This is fascinating - an interesting idea, and one which you could thread through your work and explore as a possible explanation for teen smoking, but you do not really elaborate on this. And your parenthetical explanation leaves something to be desired.

Another glamorous reason to use tobacco, in teenager’s heads, is the fact that the drugs calm you down and make you focus.

Bring your actor closer to the beginning of the sentence. The subject is displaced. For instance, "To teens, tobacco is made glamorous and desirable by..." and so on.

from the ballerina side of things

Egregiousness!
"from the... side of things." Avoid using platitudes like this one - they detract from the individuality of your work.

many professional dancers smoke

Says who? You should back this claim - as it is, it stands empty and opinionated.

depending on how long you have been smoking, the quicker your recovery will be

This is nonsensical. I think I understand what you are saying, but you need to seriously reword it to get around its grammatical problems.

many teens that want to quit, cannot because of the hardcore cravings.

Comma splice. This is all one sentence.

Not many people realize all the diseases you can acquire, along with the symptoms of smoking or chewing tobacco. Smoking can result in hearing and vision loss, arthritis, chronic coughing, tooth decay, decrease in energy levels and attentiveness, bad breath, kidney and liver damage, pancreatic cancer, bladder cancer, and most dangerous and possible of all, lung cancer.

Intimidating. But remove "and possible" - it does not help to add anything to your statement, and, if anything, convolutes your sentence.

It is hard to resist tobacco.

In a poetic or fictional work, a simple sentence can make a strong statement. But here, it floats emptily, and is actually detracting from your argument.

Because of the aforementioned invincibility syndrome

You bring invincibility back up, but still never explore it - a fleeting mention and momentary recall do not a memorable point make. But I think you can tie it together, and make this a very full sentence (because it has been a theme in your work, or it has been discussed in detail, etc.).

All I know...

Never, ever, ever second-guess yourself in an argumentative essay. And you may not see this as second-guessing, but to suggest that your knowledge of the topic is limited is perhaps the greatest mistake one can make in argument (even though your knowledge necessarily is limited).

Overall
Altogether, a very good argument (although slightly trite), and rather good organization. It's the nuts and bolts - the tightening and oiling and testing - that you still have before you.

Also, what if I should argue retardation may not be caused by smoking? You should make sure you draw a serious line between correlation and causation, and you should be sure (at least in passing, if not with exact citations) to back up all your claims with the writings/publications/etc of others. (I don't know for sure that this is the case, but studies show that... blah blah blah).

Take with a grain of salt; mind the edges.

~Skorlir