A week ago in the grocery store checkout line, someone condescendingly asked me why I use cloth bags. I was surprised soI uttered something like, “I can’t throw them away and I don’t re-use them often enough.” He rolled his eyes.
I’ve heard that plastic bags take 500 to 1,00o years to degrade. What I really wanted to say was, “It’s arrogant to use plastic bags. 20 minutes of convenience to you leaves something in the landfill, possibly for centuries. When you’re dead, it’s your legacy.””
I’ve often thought about that when I leave my cloth bags at home or I buy something that can’t be recycled. Yet plastic bags have only been around for about 50 years. How do they know they last 500 years? Does trash really outlive us in a landfill?
I looked into it and found experiments that determine how fast certain substances degrade when introduced into an environment with microorganisms. The microorganisms don’t recognize man-made plastics as food so they sit there amid bananna peels and newspapers that turn back to soil in a matter of days. Plastics will photodegrade when left in the sun, and that is where the 500 to 1,000 year statistic comes from.
To make things worse, the active faces of landfills are covered in dirt everyday and the bottoms are lined so liquid waste doesn’t escape. That tends to reduce oxygen in the layers of garbage and bacteria are less likely to break down biodegradable food and paper and the light will not photodegrade plastics.
Someday the price of metals may make it viable to mine the landfills for things that were originally thrown away, but that comes with the hazards of uncovering toxic materials such as asbestos and trapped pockets of methane gas. In the meantime, make your trash truly immortal by recycling.
Will My Plastic Bag Still Be Here in 2507? from Slate.com
Why Landfill Mining Could Be the Next Big Thing from The Guardian