Fluorescent lamps contain toxic phosphors, and even today, most contain Mercury which is now known to be an extremely hazardous material, (at school when I was a kid we used to play with it!).
Our recycling centres and disposal sites have a special container for old lamps.
I actually just have a trash can devoted to flourescent tubes. Me and my dad have no idea where to dispose of them here, but we have many years of fishkeeping left before we actually have to empty it.