The continual growth in city populations leads to an inevitable increase in garbage. Eventually, existing landfills and garbage dumps are filled, forcing new dumping sites to be established. This leads to the gradual but steady destruction of the local environment. To reverse this problem, many areas have established recycling centers, where much of the garbage is sorted and reduced to reusable components through various means. These components are then used to manufacture new products. In this way, much of the trash produced is turned into raw materials for production, rather than contributing to the ever-increasing pollution problem.