How is California doing with recycling cell phones?

Cell phones have become a common item to most Americans. Most cell phones contain toxic metals (such as lead and cadmium) that may create environmental harm when disposed of. These devices must be handled as a hazardous waste and not thrown away in the municipal landfill.
To encourage the recycling of cell phones, the Legislature passed and the Governor signed The California Cell Phone Recycling Act of 2004, which requires retailers to accept all cellular phones from consumers for recycling. In order to determine how effective the program is, DTSC publishes the recycling rate on this page for each year.
Recycling rate for the year 2010
Phones returned for recycling (reported) 3.7 million = 21
Phones sold in California (est.) 18 million
What do the numbers mean?
DTSC calculated California’s estimated cell phone recycling rate using information gathered from retailers, recyclers, national sales figures for cell phones, and California’s percentage of those sales. Retailer and recycler take-back programs collected approximately 3.7 million units. DTSC obtained 2010 United States smartphone sales data (number of units sold) from the Gartner Group. We then used the estimated percentage of smartphones sold in the U.S.(40-50% as provided by nielsonwire) to estimate the total sales in the U.S. for 2010. Furthermore, we estimate that California’s sales represented approximately 12% of the total sales, as census data indicate California’s population is approximately 12% that of the United States. Therefore, we estimate that approximately 18 million cell phones were sold in California in 2010.
The estimated recycling rate has decreased for the first time since 2007 (when recycling data was first collected for the purpose of the Cell Phone Recycling Act of 2004), as illustrated by the following chart:

There are limitations to the accuracy of these recycling rates. California law does not require cell phone collectors to report the number of cell phones collected for recycling in the state of California, nor does it require manufacturers to report cell phone sales data for California. Improving how the industry counts phones will increase the accuracy in the reported values.
While retailers and manufacturers of cell phones are concerned in protecting our environment, new incentives and more publicity about the Take-Back programs will help motivate the public to get those phones out of the drawers and into the right hands.
*This is the preliminary estimate of the cell phone recycling rate for 2010.