Newspaper doesn't cause any health problems - most inks these days are vegetable-based anyway. I use artificial turf (from Bunnings) in some of my cages, and that works really well and is easy to clean - just take it outside, hose down thoroughly and hang in the sun to dry for a couple of days - no residual odour at all. I have duplicate pieces for each cage, and they are dedicated to particular animals. When using them for different animals, they stay outside in the sun for a couple of weeks before use, after a couple of good dousings with my favourite disinfectant Virkon S.
The main problem with newspaper is I get distracted when cleaning and just stand there and read the cage floors for hours...
Jamie.