These days, it's often cheaper and more convenient to buy a new PC than to upgrade an old one. But what happens to those old computers once they've been abandoned for newer models? The refuse from discarded electronics products, also known as e-waste, often ends up in landfills or incinerators instead of being recycled. And that means toxic substances like lead; cadmium and mercury that are commonly used in these products can contaminate the land, water and air. The United States generates more e-waste than any other nation according to the Environmental Protection Agency. More than 4.6 million tons of it entered U.S. landfills in 2000, and that amount is projected to grow fourfold in the next few years. Some of that waste is recycled. For example, steel, aluminum and copper are often stripped from outdated machines and reused in newer models.

E-waste has become the fastest growing kind of waste in the world, due to both the recent meteoric growth rate experienced in the electronic industry, and to the built-in obsolescence of these products. Because e-waste contains Printed Circuit Board more than 1000 different chemical compounds, it is one of the most polluting industrial products of our time. Hazardous substances found in e-waste include cadmium, copper, beryllium, lead, and brominates flame-retardants. Since the United States is the world's principal producer and consumer of e-appliances, the problems associated with e-waste disposal, storage, and recycling are much larger and more pressing here than in other parts of the world.

In 1998 about 20 million computers were already obsolete in the US. The overall weight of the e-waste for that year is estimated to have been between 5 and 7 million tons. A study conducted in 1999 by Stanford Resources, Inc. on behalf of the National Safety Council projected that, by 2001, more than 40 million computers would become obsolete in the US. In California alone, more than 6000 computers become obsolete every day. Experts estimate that in the ten-year period between 1997and 2007 the number of discarded computers will surpass 500 million.

Japan and the European Union have adopted progressive e-waste recycling laws. The European parliament recently approved two legislative Cathode Ray Tube Waste mandates to require manufacturers to cover the recycling and collection costs for their own take-back programs. Europe's Restrictions on Hazardous Substances (Ro HS) directive and Waste Electrical and Electronic Equipment directive are setting the global standard for computer recycling, Smith said. Under the Ro HS initiative, any manufacturer who wants to do business in Europe has to produce lead-free products.

The U.S. Environmental Protection Agency (EPA) estimates that electronics waste accounts for about 1% of the nation's 210 million tons of solid waste each year. Other reports have estimated that e-waste constitutes as much as 2-5% of the US municipal solid waste stream and continues to grow rapidly. E-waste is continually on the rise—an average of 220 tons of computers and other e-waste are dumped in landfills and incinerators every year in the US. Municipal incineration is the largest source of dioxin into the US and Canadian environments and among the largest point source of heavy metal contaminations of the atmosphere.