Only 9.4% of Americans who bought new mobile phones last quarter recycled their old handsets, a survey from iSuppli Corp’s consumerTrak service says. This is double the number of phones recycled in the third quarter of 2007 but well below the numbers hoped for.

“iSuppli’s fourth-quarter survey indicated that while U.S. consumers increasingly are recycling their old handsets, there’s still plenty of room for improvement,” said Greg Sheppard, chief development officer for iSuppli.

“More U.S. consumers were motivated to recycle their handsets by the rising awareness of green issues when it comes to disposal of electronic waste. Wireless companies are promoting the recycling of old phones, making it easier for consumers to do so. For example, Verizon Wireless’ HopeLine program collects old phones at its stores and then refurbishes them for sale, or recycles them in an environmentally responsible way.”

You may be asking yourself, “What is being done with all those old mobile phones?”

“More than one third of all old handsets, 36.8 percent to be precise, were stored away in the fourth quarter of 2007, and now are collecting dust in closets throughout America,” Sheppard noted. “Consumers keep their old phones because they perceive them to have some residual value. However, all too often, those handsets end up in the trash when spring cleaning comes.”

The survey indicates that 15.5% of U.S. consumers gave away old handsets to friends or family members in the fourth quarter. Around 8.5% of consumers donated their handsets to charities, while 5.7% returned their old mobile phones to the retailers where they bought them.

Just over 10% of those surveyed said they either threw away their old handsets, or had them stolen or lost. Sheppard thinks this may create an environmental hazard.

“Simply throwing away a mobile handset is not an environmentally responsible action,” Sheppard noted. “Mobile handsets include hazardous materials, including mercury and lead. The U.S. Environmental Protection Agency (EPA) estimates Americans discard 125 million phones each year, creating 65,000 tons of waste. All this toxic waste can pollute air and groundwater.”

If you are interested in recycling your mobile phone, ask the place you bought it from whether they participate in a recycling project. At least eleven companies — AT&T, Best Buy, LG Electronics, Motorola, Nokia, Office Depot, Samsung, Sony Ericsson, Sprint, Staples and T-Mobile, have all promised to collect mobile phones and hold recycling events. The EPA has a list of cellphone drop-off centers at EPA.gov.