I COLLECT CDs, I don't throw them away.

Given what complicated beasts CDs and DVDs are — products with thin layers of different materials mixed together are nearly impossible to recycle — most municipal recycling program won't accept them, leaving consumers to fend for themselves in figuring out how to dispose of them. As a result, most discarded discs end up in the trash.

These difficult-to-recycle materials can pollute groundwater and, in turn, contribute to a whole host of human health problems. But the low cost of producing such top-selling consumer items means that replacing them with something greener is not likely anytime soon.

Research has shown that polylactic acid (PLA), a biodegradable plastic-substitute derived from corn and other agricultural wastes, could replace plastic polycarbonate as a disc's main substrate, but the present high cost of using such a material makes it unlikely to catch on any time soon.

As for jewel cases, most are made out of polyvinyl chloride (PVC), an inexpensive petrochemical-based plastic that is notoriously difficult to recycle and has been linked to elevated cancer rates among workers and neighbors where it's manufactured. Furthermore, when PVC is thrown in with regular recyclables it can contaminate entire batches, ruin equipment and cause human health problems. While cardboard and paper jewel cases may be all the rage among a few record labels — Warner Music Group's U.S. division, for example, has been using 30 percent post-recycled paper for packaging in all of its CDs and DVDs since 2005 — the high cost and low durability of such alternatives have kept them largely out of the mainstream.

Don't forget about the carbon footprint of shipping the between manufacturing to distribution, to the record shop, and then to your home.

Please go digital.