Electronic waste is becoming an increasingly pressing problem in developing countries as sales of electronics surge and enforcement of environmental laws remains lax, a UN agency warned Monday.

A worker in China heats a circuit board to recover valuable metals at an informal e-waste recycling facility. Such sites produce toxic pollution and are also less efficient than industrial recycling operations. (StEP-EMPA) The United National Environment Program (UNEP) says developing countries like China and India risk serious consequences to the environment and human health unless they institute proper e-waste collection and recycling programs.

The report predicts that by 2020, e-waste from mobile phones in China will be about seven times greater than what it was in 2007, and waste from old computers will be up to five times greater.

The growth in India will be even higher, the report suggests, with e-waste from mobile phones in 2020 being 18 times greater than in 2007, and e-waste from computers six times greater.

The report estimates that in 2010, China will produce 2.3 million tonnes of e-waste, second only the U.S., which produces about three million tonnes.

China has banned the import of e-waste but remains a dumping ground for electronic waste from developed countries, and most of it is improperly handled.

The UNEP report says that informal e-waste recycling in China involves incinerating circuit boards and other components in backyard recyclers to recover valuable metals like gold, silver and palladium.

These small operations produce toxic pollution that is a hazard to the workers and the surrounding environment. They are also less efficient at recovering the metals than industrial recycling facilities.

Workers dismantle electronic waste at an industrial component recycling factory in China. (StEP-UNU) "This report gives new urgency to establishing ambitious, formal and regulated processes for collecting and managing e-waste via the setting up of large, efficient facilities in China," said UN under-secretary-general Achim Steiner, executive director of UNEP, in a statement.

The report said the problem is most serious in China and India but that countries in Latin America and Africa also have growing e-waste problems. Senegal and Uganda should expect e-waste from personal computers to increase four to eight times by 2020, the report said.

The amount of e-waste generated around the world is growing by about 40 million tonnes every year, the report said.

The report was written with the global think tank Solving the E-waste Problem (StEP), the Swiss research group EMPA and the United Nations University.