Paper or plastic? (Environmental Watch).

Paper or plastic? You hear this very question every time you go to the grocery store. Which should one choose? While some might prefer the moisture-proof nature of plastic or the straight-edged neatness of paper, we all know that the question is an environmental one. The fact is that most of us don't actually know which is the more environmentally friendly choice.

If people recycled both materials, the choice of one over the other would have less environmental significance. The sad truth is that both of these materials are mostly just thrown away. Many choose paper thinking that it's the better environmental choice. After all, paper is based on a renewable resource--trees--while petroleum-plastic is not. By that simple comparison, paper seems the better choice.

Right now, according to Biocycle magazine, Americans are generating more waste every year: increasing from 340 million tons in 1997 to 390 million tons in 1999--a fifty million ton increase in just two years. Understanding what kind of waste makes it into our landfills can help us answer the paper versus plastic question.

Finding out what we have been throwing away is the job of Bill Rathje, a University of Arizona archaeologist. By boring ninety-foot-deep shafts into old landfills, Rathje and his team can collect samples and study how well waste is decomposing.

Since the pressure of tons of trash above it typically doesn't flatten paper, it is common for newspapers to take up 14 percent of a landfill. Newspapers buried for ten or even twenty years very often remain readable, helping Rathje figure out when the trash was buried. This shows us that the decomposition process is a long one.

Plastic is different from paper in that it does well in landfills. Even though it doesn't decompose, it is easily crushed by the pressure of trash piled on top of it, leaving it flat. Consequently, it takes up less space than paper, and space is one of the key considerations in a landfill.

In fact, since today's plastics are lighter in weight than ever before, they take up even less space in landfills than they used to. Soda bottles made of polyethylene terephthalate (PET) plastic weighed sixty-seven grams in 1974; today they weigh forty-eight grams. Plastic grocery bags were thirty microns thick in the 1970s; now they are just as strong but only eighteen microns.

If the question of paper or plastic is about conserving our landfills so there is room for rubbish long into the future, plastic would seem to be the best choice. However, so far there is no shortage of suitable landfill space, so this probably shouldn't be the determining factor.

If pollution of groundwater near landfills is the environmental issue we should be concerned about, there is a problem with both paper and plastic. Both contain inks that are bad for the environment. The inks used to print on both materials commonly are petroleum- and solvent-based, allowing them to dry very quickly but also producing wastes that don't easily decompose. Once in landfills, the inks often break down into poisonous materials that seep into groundwater.

Recycling is a good way to conserve our resources. The use of nonrenewable resources may not be a significant disadvantage if a sufficient percentage of the material can be recycled.

The form of plastic used in grocery bags is low-density polyethylene (LDPE), which is very flexible, making it ideal for carrying groceries. This plastic has to be sorted by hand because there are so many variations of color. The old bags are then run through special grinders that can grind very fine plastics. Finally, the recycled plastic is washed and reused for its original purpose.

Recycling paper can benefit us as well. In fact, recycled paper can be better than new paper because it is more opaque, dense, and flexible. Recycled paper benefits the environment by reclaiming resources and cutting down energy consumption. Harvesting trees requires tools (such as chain saws, mills, and trucks) and labor. This wastes fossil fuels as well as money for workers. By contrast, recycling takes five times less labor and emits 74 percent less air pollution. It also consumes 58 percent less water and produces 35 percent less water pollution.

Certainly paper bags are renewable, but why use them? It takes approximately seventeen trees to make a ton of paper. Due to current recycling efforts, more than 200 million trees are saved each year. That number would be much higher if we all recycled. To produce one ton of wood pulp (the material that is used to make paper), it takes 16,320 kilowatt hours (kwh). To get one ton of paper from recycled wood pulp takes only 5,919 kwh--a 64 percent advantage. Considering Americans use 67 million tons of paper a year, recycling makes a huge difference.

All too often people who claim paper is better than plastic have simply jumped on the bandwagon without doing any investigation of their own. The solution to the dilemma of paper or plastic is recycling. Grocery companies could organize recycling programs, rewarding customers who bring back their old bags. Then by removing all printing ink from bags--plastic and paper--we could close the loop on recycling.

Sam Lien is a sixteen-year-old student from Edina, Minnesota. This essay received "honorable mention "in the thirteen-to-seventeen category of the 2001 Humanist Essay Contest for Young Women and Men of North America.