Consumer Reports has a piece in its June issue about recycling electronics. It's short and to the point.
"Why recycle? The cathode-ray tube in old-style TVs and computer monitors contains 4 to 8 pounds of lead, a neurotoxin. Cell phones and other electronic gadgets can contain mercury, cadmium, arsenic, and brominated flame retardants. Those toxins can leach from landfills into groundwater."