Actually, I was watching the Darker than Black anime (around episode...5, I think?)

But near the beginning, the character November mentions that a cigarette, when inhaled directly contains, i think, 5-65 [insert appropriate unit of measurement here...] of nitrosamines, but when exhaled afterwards, contains about 600 [units of above chemical]. I was just curious to the more technical circumstances to this.

I've been trying to look this up on google and wikipedia, but can somebody shed some more light on why exhaled smoke contains more of this chemical?

U mean second hand smoking?
if that is the case, people say second hand is worse than first hand smoking, but think this way, first hand you have a filter, i guess

I assume it's because of the filter in the cigarette, but I'm not a smoker, and I don't know the anatomy of a cigarette... so I'm not sure.

Smoking is bad, never do it, I hate people who do.

First of all, I know that I might stand on a lone place in this dicussion because I'm a smoker. I know that it is unhealthy and that I might die earlier as non-smokers.

Second, I don't take this personal what longbow said but hating a person just because he/she is smoking is a childish way for me. I have a lot of friends who don't smoke and even trust and accept me although I'm smoking. I always try not to smoke when non-smokers are around because I know that second hand smoking is very dangerous.

About the question of hofodomo:

It's hard to explain it for me in english but I will try.
I think that this is a wrong information. I've read some articles in the net and there was nowhere any explanation about this. It's a bit unlogical because I think about this:

You inhale the smoke to your lungs. The lung has the function of gaschanging (hope this makes sence in english). So if you inhale the smoke the lung will "clean" it and absorbe most of the poisening stuff. That's why you can get cancer from smoking: some parts of the stuff in a cigarette are carcinogenic. The lung filters it out and the carcinogenic stuff is remaining in the lung.

What's most dangerous is the smoke of a burning cigeratte: the environmental tobacco smoke. It's like a fire which is burning, than nearly stopping and than burning again. Also the environmental tobacco smoke is given up by a temperature of 500°C and so most of the carcinogenic stuff will not be burned like in the main smoke (burns with nearly 900°C)

So, I hope this helps you to shed some more light into this.
I'm not an expert or a doc so this might be wrong but if you really are interested in getting a good and right answer I would suggest to ask a doctor ^___^