Electronic and electrical gadgets that have reached the end of their life are expected to jump by a third in volume by 2017, a rise that poses mighty challenges for sorting and recycling, according to figures published on Sunday.

By the end of 2017, the total annual volume from refrigerators, TVs, mobile phones, electronic toys, computers, screens and other electrical or electronic castoffs will reach 65.4 million tonnes, 33 percent up on the end of 2012.

This amount "could fill a line of 40-tonne trucks end-to-end on a highway straddling three-quarters of the Equator," said Solving the E-Waste Problem Initiative, a partnership of UN organisations, grassroots groups and industry.

Last year, around 48.9 million tonnes of e-waste were produced, an average of seven kilos (15.4 pounds) for each of the seven billion people on the planet, it said.

The report found that in volume terms, China in 2012 produced the biggest amount of e-trash that was put on the market -- 11.1 million tonnes, followed by the United States at 10 million tonnes.