[sten (OP)]

I  do a lot of DIY and sometimes inhale small particles unavoidably. How do the lungs clear out non-digestible debris eg small pips, pieces of tissue and metal filings, or is there some debris that stays there for life (unless you cough it up)? I read about a man who underwent surgery for lung cancer and the 'tumur' turned out to be a tiny growing fir tree from a seed he inhaled!

Thanks,

Alex

[Kerry]

I thought this sounded a bit unreal but it was reported in the Telegraph
http://www.telegraph.co.uk/news/worldnews/europe/russia/5152953/Surgeons-find-fir-tree-growing-inside-patients-lung.html [nofollow].

It does say, however

There was no independent verification of the surgeon's claims.

The Guardian
http://www.guardian.co.uk/lifeandstyle/2009/apr/16/urals-lung-operation-fir-tree [nofollow]

and Sky News
http://news.sky.com/skynews/Home/World-News/Tree-Found-In-Lung-Seed-Sprouted-Inside-Russian-Mans-Chest/Article/200904315262048?f=rss [nofollow]:

"It is absolutely impossible for a green plant to grow from this small seed inside a man's body. In order for a plant to start growing from the seed, it needs a lot of conditions - light, then water and certain temperature," said Olga Baranova, a university professor.

If anything, the 'tree' looks more like a small twig that's broken off a tree, there are no roots etc so it couldn't have 'grown' inside him could it?