+ 0 Votes Fan-cooled Notebook PCs are particle traps yonian 1 year ago If a fan is running very much of the time, particles in the air will come to be concentrated in the cooling pathways. If you have Radon in your house you might be surprised to find how strongly a Geiger counter responds to it. After Ireland banned smoking in pubs ten years ago, musical instrument repair shops found that their business fell off sharply because instruments didn't get contaminated as much. Cigarette smoke is much more harmful to all sorts of things than most smokers realize. That's not a moral judgment, it's an observable fact.