- Food and Cooking»
- Dietary Restrictions
The Problem With Indestructable Plastic Bags
If you are still taking home your new purchases in single-use polyethelene plastic bags, it's time to reconsider your habit - and build a new one.
While the US Environmental Protection Agency argues that the common plastic shopping bag take less energy to manufacture, recycle and ship than the traditional paper bag, an environmental disaster is afoot. Those same plastic bags are made of a substance that is virtually indestructable. Although the bags may no longer serve a useful purpose because of rips and tears - and are thrown out or abandoned by the millions across the globe every year - the plastic itself persists.
The issue is that polyethylene - the polymer that makes up plastic - never dies. It may break into smaller pieces, right down to the individual polyethylene molecules, but it simply doesn't fully degrade.
Dr. Anthony Andrady, a research scientist and author of Plastics in the Environment, said, "Except for a small amount that’s been incinerated, every bit of plastic manufactured in the world for the last fifty years or so still remains. It’s somewhere in the environment." This doesn't just mean plastic bags - it means every bit of plastic that you've purchased and thrown away, from the clear wrap on your meat purchase to the plastic spout on your juice carton to the bubble wrap on that new piece of electronics.
This is where the problem becomes serious. We've been producing artificial plastic polymers for about half a century. In that time period, our estimated total production has now surpassed 1 billion tons.
Which brings us back to plastic bags. What sense can it make to use a virtually indestructable material for "single use" functions?
A Short History Of The Plastic Shopping Bag
The word "plastic" entered the modern lexicon in 1909. It was originally coined to describe Bakelite, the first fully synthetic resin. The unique aspect of "plastic" was that when heated it could be molded but it retained its shape when cooled. This property was highly desirable for all sorts of industries - and plastic started on the road to becoming a common and pervasive part of our lives.
The modern plastic bag was not possible until the accidental discovery of the first industrially practical method of polyethylene synthesis in 1933. From 1933 to today, the uses and manufacture of polyethylene have grown exponentially. As much as 4 per cent of the world's petroleum may be converted into ethylene - the basic material of any plastic bag, from the bag you get from the grocers to the bag your drycleaning comes in.
Plastic bags became the bag of choice for shoppers beginning in the early 80's, as large supermarket chains Safeway and Kroger began to offer them. The oft-heard question, "Paper or plastic" was the beginning of a sea change in how consumers would carry home their purchases. However, economics was behind the efforts of businesses to convert consumers to plastic - it driven by the fact that cheap oil made cheap plastic. The ligher plastic bags were cheaper to ship, store and manage. So, while the environmental groups pushed for us to quit using so much paper, the plastic bag industry quietly stepped into the breach.
It's been less than 30 years since the introduction of the plastic bag. Experts estimate that our current use of plastic bags is 500 million to 1 trillion per year.
Killing US Softly
While it's not just bags that cause problems, they are perhaps the most evident of our plastic garbage. We even jokingly refer to them as urban tumbleweeds, after the familiar site of a plastic bag, caught by the wind and tumbling end over end down the street.
But plastic goes much further than this. In fact, it ends up in our oceans in alarming quantities.
One of these regions is the Pacific Gyre. The Gyre is created by a combination of large-scale wind and ocean currents that create an immense, swirling formation of air and ocean. The gyre effectively traps what lands within it - which is one reason that ancient sea mariners avoided them. They were hard to get out of.
The Pacific Gyre has now received the unofficial name of the Great Pacific Garbage Patch. Some estimates have the amount of floating debris - the majority of which is plastic - as 100 million tons.
At issue is that this debris kills wildlife of all kinds, with additional unknown effects on the environment.
Plastic on the surface of the ocean "photodegrades", leaving plastic molecules suspended in the water to be fed on by microscopic sea life. Larger plastic pieces are often eaten by sea birds and turtles, killing them through slow starvation or blockage of their digestive tracts.
The existence of the Pacific Garbage Patch was predicted in 1988 by the US National Oceanic and Atmospheric Administration. By 2009, it is a grim reality that is twice the size of Texas.
Some Good News
No problem, you say. We'll find a way to break it down and properly degrade it so that our environment will not be overwhelmed. Well, the bad news is that science has tried, and to date, mostly failed.
Dr. Andrady is aware of research that attempted to find out how long it will take polyethylene to biodegrade by incubating a sample in a live bacteria culture. He reports that after one full year, less than one per cent of the original sample had been degraded. Andrady says that this isn't good news: the bacteria only broke the most easily disturbed connections between the polymer chains, and that means that all the plastic was still there. It was just in smaller pieces.
Those smaller pieces become the plastic that builds up in the guts of wildlife.
However, in 2008 there was another experiment performed by a Canadian student that proved nature might still have a trick up her sleeve. Daniel Burd, a teenager from Waterloo, discovered a combination of microbes that can break down plastic bags. With the right microbes and the right conditions, Burd achieved a 43 per cent reduction in a piece of plastic bag in a 6 week period. We are yet to know if this has an application in the real world or if this process will only work in the lab.
It isn't necessarily the answer to large scale plastic pollution in the oceans. There, we still have a huge cleanup on our hands.
Buy Or Make Reusable Bags
What We Can Do
The right steps are simple, as they are in most environmental issues:
- Carry your own reusable bags when you go shopping. Your best bet is reusable cloth bags: while reusing paper bags is better than taking that plastic bag at the check-out, paper bags are often made from newly cut trees. If you are going to use paper, look for bags made from recycled paper.
- Take home your produce without taking that extra clear plastic bag to hold it. That's how our grandparents did it. Most produce will travel safely without the extra bag.
- Avoid packaging! The less packaging, the less you have to carry home and the less bags you need. It also means less of other types of plastic going into our landfills, with the same problems that we have with polyethylene. (See my article on avoiding packaging and saving money.)
- Write to your local politician as well as your federal representatives. These people need to understand the issues and take action to move industry in new directions. While plastic manufacturers may complain about restrictions or regulation, human ingenuity will be stimulated by a legislative environment that favors our environment. Without that kind of push, industry will tend to continue in the path of least resistance.
- Buy local. There's no better way to avoid plastic than to buy food that has never seen plastic. The farmers' market is a great place to both support your local farmer and get fresh, healthy food without plastic.
- Want more inspiration on reducing plastic? Read my hub Living Life Without Plastic.
Want to know more on this issue? Check out these links for additional information: