since the air gets very dry because of central heating, i have got a humidifier, the kind you put water in and it throws out a fine cold mist into the air.
what it is doing is putting a fine white dust on everything especially the television which normally attracts a lot of dust anyway (due to static i guess).
since we are in a hard water area (north london u.k.) would that be as somebody has suggested the chalk in the water or is it something else? it seems to like settling on the computer also in the cd tray etc, could this be harmful? thanks for any advice