The total number of PCs in use today has broken the one billion mark, but not enough is being done to ensure all these machines are safely broken down and recycled.

That is the conclusion of IT analyst house Gartner, which has calculated the installed base of PCs is currently expanding by around 12 per cent a year. If this continues then the number of systems will reach two billion by 2014.

"Whereas mature markets accounted for just under 60 per cent of the first billion installed PCs, we expect emerging markets to account for approximately 70 per cent of the next billion installed PCs," said Luis Anavitarte, research vice president at Gartner. "Emerging market governments are also increasingly committed to reducing the digital divide by promoting PC use among their citizens through a variety of means, including providing PCs directly to the less affluent."

Geographically mature markets in the US, Europe and Japan contain just 15 per cent of the world’s population but account for 58 per cent of the installed base of PCs. However, continually falling PC prices and better wireless communication will drive adoption in developing markets.

However, this is coming at a price to the environment. Gartner warns that not enough PCs are being recycled and this is damaging the environment.

"We forecast just over 180 million PCs - approximately 16 per cent of the existing installed base - will be replaced this year," said Meike Escherich, principal research analyst at Gartner.

"We estimate a fifth of these, or some 35 million PCs, will be dumped into landfill with little or no regard for their toxic content," she added. "It will become an even more pressing issue, especially in emerging markets, as the number of retired PCs grows with the continuing expansion of the PC installed base.”

Developing countries often suffer most as a result of poor IT disposal pra ctices. Not only are a high proportion of PCs sent straight to landfill there have been numerous investigations revealing that many old PCs shipped to countries such as India and Nigeria for re-use or recycling end up being broken down in unsafe conditions where those working on the machines are unprotected against the various hazardous chemical components. The acid used to strip out precious metals from the machines is also frequently allowed to infect the local groundwater, contributing to crop failures and high mortality rates.

Legislation such as Europe's WEEE directive has attempted to tackle the problem by making PC producers legally responsible for the safe disposal of the machines. But such rules are still relatively rare in many developing economies and there have also been reports that even where such legislation is in place it often proves difficult to police.

A version of this article first appeared at BusinessGreen.com's sister site vnunet.com