THE obvious is oftentimes incorrect.
It's "obvious," for example, that plastics are bad for the environment. Plastics don't biodegrade, many argue, and they choke our landfills. In fact, plastic rather than paper is often the best choice for the environment.
While paper is often thought of as biodegradable, its rate of degradation in most landfills is unacceptably slow. Excavations of landfills yield paper products three decades old.
The production of paper is "dirty work" in the environmental sense, requiring hefty amounts of energy and producing lye, sulfur dioxide, and other harsh effluents that pollute streams.
Trees - which convert carbon dioxide back to oxygen and thus combat the greenhouse effect - are sacrificed in growing numbers to produce paper. When harvesting is carried out on a sustainable basis, one acre of woodland yields 500-600 pounds of paper, according to University of Toronto researcher James Guillet. He notes that a one-year subscription to the Toronto Star requires one acre of natural forest.
If all plastic packaging were eliminated and replaced by either paper or cellulose-based products, some 82 billion pounds of additional paper would have to be produced per year, Mr. Guillet calculates. That would require an additional 162 million acres of forest land devoted to paper production - an area comparable to six times the size of Tennessee.
The environmental impact of that would be felt around the world. The greenhouse effect would be stepped up, and the loss of habitat and the harsh effluents from paper production would have far-reaching consequences for plants and animals.
Plastics provide several advantages over paper. For example, polystyrene "clamshells" used by take-out restaurants require 30 percent less energy to produce than paperboard containers. Its manufacturing results in 46 percent less air pollution, and 42 percent less water pollution than paperboard, according to a study by Franklin Associates.
The plastic most often used for bags is polyethylene. While made from petroleum, less than 2 percent of the petroleum produced is used for polyethylene production.
LIKE most plastics, polyethylene can be used as "white coal" by being burned cleanly and efficiently in an incineration system to produce power. We can use the plastic first for bags and containers and then get about the same amount of energy out of it as if we had burned the petroleum in the first place. These two-step applications "obviously represent a considerable conservation of energy and raw materials," Guillet adds.
Plastics can be recycled rather easily and efficiently, relying on the initiative of private entrepreneurs. Paper recycling, on the other hand, often needs governmental underwriting because of the costs involved and the relative low demand for the finished product. Also, harsh chemicals are involved in the process of "de-inking" newspaper. Some paper products - like resin-coated clamshells - cannot be recycled because their components cannot be economically separated.
The pace for recycling plastics is quickening. As the percentage of plastics used in automobiles increases, firms like BMW, General Motors, and Ford are investigating ways to efficiently recycle their vehicles. BMW has initiated a test program in the United States, offering $500 off of a new or used BMW to owners who turn in an old BMW to a recycling center. Upwards of 30 percent of all the plastic produced worldwide could be recycled.
Also, use of plastics can be reduced by at least 10 percent using innovative approaches. Proctor & Gamble redesigned Crisco oil bottles to use 28 percent less plastic, and now sells superconcentrated detergents requiring 15 percent less packaging.
A promising development is the formation of intrinsically biodegradable polymers by the thermoforming of starch. The material is economical to produce and has very promising uses, such as for containers used aboard ships. It may be possible to use biodegradable plastics in disposable diapers. Under the proper conditions, such materials could be composted rather than sent to landfills.
A substantial percentage of the plastics produced annually can find useful "second lives" through an integrated approach using recycling, incineration to produce power, and composting. These developments are promising for the future because plastics are environmentally safe and user-friendly.