E-Waste is the waste that comes from discarded electronic equipment such as computers, mobile phones, mp3 players, televisions, and other electronic equipment. When these items end up in landfills or get burned in an incinerator toxic substances like lead, mercury and cadmium end up contaminating the land we live on, the water we drink, and the air we breath.
It's only been recently that there have been recycling programs for these items, and there are decades and decades of car stereos, old TV's, walkmans, pagers and other obsolete electronics buried in the earth. Even today, with the recycling programs that exist, not everyone recycles items that are no longer obsolete, just last year's models.
Before throwing away an electronic item, think of another way to dispose of it that is environmentally friendly. Cell phones can be turned in where you buy a new phone or donated to a charity who will recycle them for profit. The same with printer cartridges. Old computers can be donated to schools (especially private schools who often don't have budgets for technology) or given to a family who doesn't have a computer yet. And of course, you can always Freecyle any of your old electronics.
If you can't find any other way to recycle your E-Waste, most counties have recycling programs for E-Waste that are separate from their regular curb side recycling programs. Contact your county to find out where to take old electronics so they can be disposed of safely.