At least 1 billion cell phones have been discarded in China, where new phone models are rushed onto the market every year. However, only 2 percent of those 1 billion were recycled, according to a recent investigation.

In 2016, a total of 1,446 new phone models were released, with sales reaching 560 million phones. A 2014 survey showed that some 50 percent of cell phone users in China get a new phone after 18 months of use.

While this data indicates a booming cell phone industry, the 2-percent recycling rate is nevertheless problematic, according to Xiong Zhou, co-founder of cell phone recycling website Huishoubao.

A used cell phone can usually be resold, albeit for a sum far below its purchasing price, as long as it doesn't have any major damage. Even damaged phones can be recycled for their parts.

Zhang Xiaozhen, founder of secondhand cell phone collector Refone.com.cn, said that some 150 grams of gold can be extracted from 1 ton of discarded cell phones. Similarly, cell phones contain small amounts of silver and other precious metals.

“If properly handled, discarded cell phones can be of great use,” Zhang said. However, if improperly disposed of, the cell phones and the heavy metal they contain can contaminate water and soil.

Still, it remains a challenge to convince people to recycle their old phones, as phones often carry a great deal of personal information, which many fear could be leaked. While discarded cell phones have been added to the national regulation on electric-device recycling, a lack of detailed protocol and national funding makes the collection of used cell phones even harder.