A United Nations University study into the environmental impact of personal computers, due to be published later Monday, has found that around 1.8 tons of raw material are required to manufacture the average desktop PC and monitor and that extending a machine's operational life through re-use holds a much greater potential for energy saving that recycling.

According to the study, the manufacturing of one desktop computer and 17-inch CRT (cathode ray tube) monitor requires at least 240 kilograms of fossil fuels, 22 kilograms of chemicals and 1,500 kilograms of water. In terms of weight, the total amount of materials used is about equal to that of a midsize car.

By far the best way to minimize impact on the environment from a personal computer is to extend its useful life, said Eric Williams, a researcher at UNU in Tokyo and one of the report's co-authors.

Users should think carefully about whether they really need a new computer, if upgrading their existing computer could serve the same purpose, he said. Actions such as delaying replacement and upgrading the memory or storage space or, if the machine is replaced, donating the old computer so that it may continue to be used offer potential energy savings of between five and 20 times those gained by recycling.

This is because so much of the energy required to manufacture a personal computer is used to make high-tech components like semiconductors and those components are destroyed in the recycling process to collect a small amount of raw materials. In an earlier study published in late 2002, Williams concluded that 1.7 kilograms of fossil fuels and chemicals and 32 kilograms of water are used to produce a single 2-gram 32M-byte dynamic RAM memory chip.

Seemingly endless advances in technology are encouraging people to replace their machines and falling prices are making replacement a more attractive option that upgrading and have users accustomed to a two-year to three-year upgrade cycle.

"It's a big problem," Williams said.

However, there are some encouraging signs. In the corporate market machines supplied under service contracts often have a good chance of being re-used thanks to programs offered by the equipment suppliers, such as Dell.

The vendor has seen a tremendous increase in the number of machines it receives from customers for processing before either recycling or donation to agencies such as the National Cristina Foundation, said Tod Arbogast, senior manager of asset recovery services at Dell.

The IDG News Service is a Network World affiliate.