They take longer to switch on. Regular CFLs won't work ... if all the spent bulbs went into a landfill. Instead, the mercury in dead bulbs is reclaimed at such depots and recycled.

However, this advice is not printed on the packaging that low-energy bulbs are sold in. Toxicologist Dr David Ray, from the University of Nottingham, said about 6-8mg of mercury was present in a ...

CFLs last longer than traditional incandescent bulbs and use less electricity. But, inside each twisty tube is toxic mercury powder that can pollute huge quantities of water. Mercury is so potent ...