Disposing of your old lightbulbs
CFLs contain a small amount of mercury. Current legislation limits this at 2.5 mg per bulb - older CFLs may contain up to 4 mg. This is still a very low amount - less than 1% of that found in an old mercury thermometer.
The amount in one bulb is not enough to pose health risks, but on a large scale this amount of mercury shouldn't be ending up in landfill. Therefore you can't dispose of CFL lamps in your bin - these need to be recycled. As part of this process, around 95% of the materials can be recovered and used again.
CFLs can be recycled in a number of stores and public access points. Recolight is the UK's leading specialist WEEE compliance scheme for the lighting industry, and you can find your nearest recycling point on their website.
LEDs do not contain mercury, but around 80% of their components can be recycled. These can often be taken to local recycling points at the end of their life, in stores where they were purchased or at your local Recolight point.
Halogens and incandescent bulbs are not always accepted at recycling points, but do not contain any toxic materials. These can be disposed of in general household waste, taking care with the glass shell.