Disposing of Nickel-Cadmium Batteries
(contributed by John Rogers; email: jrogers@email.unc.edu)
Nickel-cadmium batteries are the most popular source of power for cellular phones and many other portable electronic devices. This may not last much longer, however, and they will probably soon be replaced by other batteries.
The problem is that cadmium is a very toxic, potentially carcinogenic, metal, and ingesting even small amounts causes damage to a number of organs. Many of the difficulties stem from the very similar chemical reactions of cadmium and lead (geologists say that the two elements are "isochemical"). Thus, almost no naturally occurring processes can separate cadmium from lead, and all lead ores contain very small amounts of cadmium. Because cadmium is so much less abundant than lead, however, its dangers were recognized only recently, and we have generally neglected cadmium poisoning while we have made largely successful efforts to remove lead from the environment.
But while we still have the batteries, we have to do something with them when they wear out, are damaged, or are simply no longer needed. Purchasers of the batteries now receive printed warnings that they should not be discarded into landfills and, particularly, should never be burned. Some companies operate non-profit recycling plants and have open collection sites, and many state and local governments have strict rules about disposition.
So, be very careful with nickel-cadmium batteries. Follow all instructions about their use and disposition, and do not let any of the cadmium loose in the environment.