Coal, steel, oil - we think of these old-economy industries, and we picture pollution. Smoggy skies, fouled rivers, toxic waste. As we make the transition to a new economy, we imagine that industrial pollution will become a thing of the past. Mobile phones, laptops, MP3 players - they conjure images of spotless semiconductor factories and the eternal summer of Silicon Valley where the digital economy was born.
But the tech industry has a dirty little secret: it has toxic waste of its own. Phones and computers contain dangerous metals like lead, cadmium and mercury, which can contaminate the air and water when those products are dumped. It's called electronic waste, or e-waste, and the world produces a lot of it: 20 to 50 million tons a year, according to the UN - enough to load a train that would stretch around the world.