A"throwaway mentality" and increased packaging have amplified the consumption of paper and plastic in our society. disposable plates, cups, and utensils are convenient, sanitary, and inexpensive, and packaging preserves freshness, prevents breakage, protects against tampering, provides information to consumers, and allows shipment of products over long distances. however, paper and plastic do not degrade readily in sanitary landfills. garbologist william rathje found legible newspapers in landfills decades after disposal. because trees used to make virgin paper and petrochemicals used to make plastics may soon become depleted, source reduction is the best solution to the waste dilemma. denmark has banned the use of nonrefillable beverage containers, and mcdonald's restaurants in austria and sweden have been using biodegradable, compostable cutlery. recycling has value as well, as long as the recycling loop is closed and people purchase recycled items. bottle bills and municipal curbside collection provide recycling incentives. paper recycling is profitable if waste is properly sorted. all kinds of paper and cardboard are recyclable. food and paperboard (noncorrugated thin coated board such as cereal boxes) can contaminate collections, however, reducing their value. after processing, paper and cardboard are used to make paper towels and paperboard for packaging cereal, shoes, and toys. uncapped, washed, and flattened plastic is recycled into carpets, pillows, and new bottles. although low-density polyethylene (ldpe), from which grocery bags are made, is the most widely used plastic, beverage bottle polyethylene terephthalate, or pet(e), and high-density polyethylene, or hdpe, are the most widely recycled plastics. containers from toxic substances such as motor oil, pesticides, and solvents are not usually accepted with collected plastic because of contamination. methods to reuse and recycle polystyrene are in development, although presently, styrofoam is not collected with other plastics and is considered a contaminant as well.

closing the recycling loop refers to