Increasing world population has led to an inevitable increase in the amount of garbage produced by society. Conventional disposal methods, such as burial in a landfill, have proven inadequate to handle the growing waste problem. One solution to this problem is the reuse of discarded materials through recycling. Although scrap metals and other materials have been reused in manufacturing processes for some time, true recycling is a broad-based, household-by-household effort. The increasing pollution generated by industry and consumerism, added to the depletion of natural resources, make the re-use of materials less a concern of efficiency and more as one of necessity for the survival of the human species. Not only does the recycling of waste materials prevent the unwanted build-up of garbage, it saves energy and slows the depletion of natural resources such as trees and petroleum products.