Plastic doesn’t readily degrade or decompose. That’s why plastic pollution presents such a serious problem.
Nothing like plastic existed until the middle of the nineteenth century. The manufacture of true plastics began in the early twentieth century. It soon became a flood, as industry developed more and more different kinds of plastic. And almost all of it still exists in one form or another.
Waste management techniques such as incineration or pyrolysis destroy some of it. Scientists have discovered some plastic-eating bacteria. Apparently, sunlight degrades polystyrene into its component parts. It’s not strictly true that plastic lasts forever. But for all practical purposes, it might as well.
Chemically, plastics are enormous strings of molecules called polymers. Even natural polymers take a long time to decompose. Plastics and their building blocks don’t exist in nature. Nature hasn’t figured out how to degrade them. All it can do is tear plastics into smaller and smaller pieces––microplastics. They remain the same unnatural substance.
Plastic’s advantages and disadvantages
Half a century ago, plastic seemed like a cheap and inferior substitute for natural materials. It didn’t get a lot of respect. Since then plastic has turned out to be a superior material for some products. Personal computers, cell phones, and other modern gadgets have never been made from metal, glass, or wood.
Plastic bottles have all but replaced glass. They’re much lighter. They don’t break as easily. When they do, the pieces are larger and less dangerous to pick up than glass shards. Plastic shopping bags are sturdier and easier to carry than paper.
Disposable plastic has become a huge pollution problem, however. In a single year, Americans alone use a hundred billion plastic bags and tens of billions of plastic bottles. Those figures don’t begin to summarize all of the various kinds of packaging, pens, razors, and other disposable products that we buy and discard every year. The rest of the world adds to that total.
And nearly all of it still exists. A small fraction gets recycled or burned. The rest of it never decomposes or degrades.
When we properly dispose of plastic waste, most municipalities put trash in landfills. Others incinerate it. Both methods have negative effects on the environment, but not nearly as bad as what happens when litterbugs foul the landscape with it. Plastic pollution harms wildlife. Lighter plastics make their way into streams, where they increase flooding. Or into sewers, where they cause trouble at wastewater treatment plants.
The menace of plastic pollution in the oceans
Much of that plastic pollution eventually winds up in the ocean. It’s lightweight. It floats. And, of course, neither sunlight nor saltwater causes plastic decomposition. It gets into streams, which eventually reach the sea. Not all plastic that gets into a stream makes it all the way to the ocean, but when it does, it gets caught up in ocean currents.
Plastic washes up on beaches and gets in the way of swimming and other beach activities. What’s worse, rotating currents encircle vast gyres or vortexes. And one gyre contains the Great Pacific Garbage Patch—one of at least five such swirls of plastic in the oceans.
By the time plastic pollution reaches the gyre, natural forces have broken it into smaller pieces. Fish and birds can eat it but can’t digest it.
At best, their digestive systems will leach out some of the chemicals from the plastic before their bodies eliminate the rest. Those chemicals enter body tissues, along with the nutrients the animals get from whatever real food they eat. And they stay there. Predators eat animals contaminated with plastic. which accumulates in their own bodies
By the way, Americans eat a lot of fish from the Pacific. So we have plastic in our bodies.
At worst, the pieces of plastic are small enough for a bird or fish to swallow, but too large to pass through their bodies. They remain in the stomach, taking space. As the bird or fish ingests more and more plastic, eventually it has no capacity to receive or digest food. It starves.
What we can do about plastic pollution
All plastic is recyclable in principle. That is, any kind of waste plastic can be used to make some kind of new product. Technology can’t handle it all, though. Not sorting equipment, not manufacturing processes. Regarding plastic, therefore, a green lifestyle requires that at the very least we
- Reduce our personal consumption of disposable plastic
- Participate fully in as many recycling collection programs as we can. (For example, grocery stores accept plastic bags for recycling that municipal recycling equipment can’t handle.)
- Purchase products made from recycled plastic in order to encourage demand for waste plastic as a resource. Releve™, for example, is one brand of polyester made from plastic bottles.
- Keep at least one plastic bag and put it to good use: collect litter in it and dispose of it properly. When other people notice, it affects their own behavior. At the very least, they’ll be less likely to litter for a while.
These steps are not enough to eliminate plastic pollution, of course. Government and business––and society in general––need to undergo systemic changes. But if enough individual households make all the changes they can, larger changes will become more likely.