batteries and the environment

Over the past twenty years or so, the pro- duction and use of batteries have grown enormously. Whereas in the sixties their main use was in portable radios and torches, nowadays they are found in quartz watches, pocket calculators, hearing aids, portable computers, camera flash units, and many more. Batteries consist either of primary, i.e., non- rechargeable, or of rechargeable cells. Primary batteries may be sub-divided into zinc-carbon, alkaline manganese, mercuric oxide, silver oxide, lithium manganese diox- ide, lithium chromoxide, and zinc air types. The best known - and oldest - recharge- able battery is the lead-acid type, although nickel-cadmium batteries are catching up fast. As this article is concerned with the effect of batteries on the environment, it deals with primary batteries only, as these are disposed of by the million every day. Zinc-carbon Zinc carbon batteries are the least expens- ive, have the smallest capacity, and have a greatly varying capacity depe...