Lead is a neurotoxin. That means it attacks the nerves, causing high blood pressure in adults and learning problems in children. But lead is also good for anything with a circuit board — your computer, your HDTV, your cellphone — because without it, tin whiskers can shut them down.

Tin whiskers are sharp pointy things one-tenth as wide as a human hair. They erupt from soldering material based on tin, cadium or zinc and carry enough current to cause a short circuit. Lead is a vital ingredient in solder because it prevents tin whiskers. There are alternative solders — pure tin, tin-zinc, tin-silver-copper — but they're more expensive and less reliable.

The banning of lead from electronic products is already in effect in the European Union and being eyed in the United States. Apple went lead-free in 2004. That'll prevent lead from getting into landfills, where it pollutes groundwater, or into incinerators, which send it into the air. But recycling would accomplish the same thing.

Via The Guardian