It takes much stuff to make one tiny chip. (Hidden Costs).

Despite their diminutive stature, the world's microchips levy a high toll on the environment. From an unprecedented analysis, researchers have found that the creation and use of a single 2-gram chip requires at least 72 g of chemicals, 1.6 kilograms of fossil fuel, and 32 kg of water.

Microchips' combination of small size and high value can leave the impression that they offer large benefits with little environmental impact, the scientists remark in an upcoming issue of Environmental Science & Technology. It's a misleading notion, they argue.

"The public needs to be aware that the technology is not free," says coauthor Eric Williams of the United Nations University in Tokyo. "The environmental footprint of the device is much more substantial than its small physical size would suggest."

For their analysis of the chip-making process, Williams and his coworkers collected reams of data on the production of memory chips from an unnamed semiconductor firm, industry organizations, technical literature, and other studies.

The semiconductor industry uses hundreds of chemicals to make chips, the researchers report. They calculated that 1.3 kg of fuel and chemicals go into a 2-g chip's production and another 0.4 kg into its use. These figures are conservative, says Williams. "We think the real number is maybe twice that," he adds.

Some of the chemicals--including caustic hydrogen fluoride and deadly arsine gas--are toxic, and the fossil fuel consumed contributes to global warming, says Williams. Further, manufacture of a chip requires so much water that it may strain local resources.

"The fact that a computer chip has such a short life span, because the technology turns over so quickly, exacerbates the environmental impact," Williams adds.

Analysts familiar with assessments of products' life cycles and environmental impacts may not be surprised by the large values, says H. Scott Matthews of Carnegie Mellon University in Pittsburgh. Not so for the public. "There's certainly a perception gap," Matthews says. Getting people to think about these hidden costs is the goal of such assessments, he notes.