Snorting - Snorting MDMA, how much is too much?

[Synesthesiac]

swim has a friend that has taken recently to sniffing his mdma instead of bombing it. swim never does this as he cant bare the strong chemical taste, but is a bit worried about his mate using this method all the time. He does have an on and off habit wth mdma, he'll go through phases of using mdma about three times a week, and due to this he has to snort quite a lot to get a decent buzz. Averagely he will snort 0.5g in a night, and always pure mdma, never pills. Which seems to me to be a hell of a lot to be snorting in one night.

I'm sure that this has been discussed before, but what are the dangers he is in by doing this? I'm not sure how tollerant our lungs are to mdma, but I would have thought it puts a much higher strain on them than sniffing coke or other compounds. But then again this is only based on swims own painful experiences of doing this, swim assumed that the higher the pain the more damage was being caused, but this may not be strictly true.