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DaVinci, respirometry and a sip from a plastic water bottle …

A few weeks ago, an article mentioned that if Leonardo DaVinci drank from a plastic water bottle and then set it on a counter, that bottle would still be intact today. Of course, I can’t remember, nor could find, the source.

It’s a metaphor nonetheless on the outsized lifespan of plastic and its hyper-proportional impact on the environment.


Simply put, plastic in its many forms does not go away quickly or easily. In fact, it never truly biodegrades or vanishes – nothing in nature is predisposed to consume it.

Still, no one really knows for certain how long plastics and polystyrenes (Styrofoam) stick around. It’s a mixture of scientific finding and estimation – along with some conjecture.

Much of that educated guesswork is based on respirometry tests. Intended to plot the biodegradation of materials in wastewater treatment, the process is among several also put to use to gauge the potential biodegradation rates of non-organics; i.e. plastics.

Plastics are virtually impervious to the environmental influences that degrade organic matter; air, water and sun. For example, when scientists test generic plastic bags, nothing happens – there’s no CO2 production and no decomposition. Why? The most common type of plastic shopping bag – the kind you get at supermarkets – is made of polyethalene, a man-made polymer that microorganisms don’t recognize as food.

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If this plastic water bottle remained in place, the sun would eventually deteriorate it yet the plastic particulates would never really leave our environment.

Yet while standard polyethylene bags don’t biodegrade, they do photodegrade. When exposed to ultraviolet radiation from sunlight, polyethylene’s polymer chains become brittle and start to crack. But even in degraded form, plastic remains with us even in microscopic form. There are insideous environmental impacts: when tiny organisms ingest small plastic particulates, those organisms in turn are eaten by larger organisms – thereby introducing plastics into the bodies of larger animals.

This list is a composite list from several sources of the expected lifespan of various materials:

  • Aluminum can: 200-500 years
  • Disposable diapers: 550 years
  • Plastic bags : 20-1,000 years
  • Plasitic water bottle: 450 – 1,000 years
  • Plastic jug: 1 million years
  • Monfiliment fishing line: 650 years
  • Glass: 1-2 million years
  • Styrofoam: 1-plus million years

(Cited or paraphrased for this post: csuohio.edu, ebsbiowizard.com, goecopure.com, des.nh.gov.)

About Dave Bradley (259 Articles)
I'm the one behind two totally unrelated blogs; one on 15 years of writing a weekly letter to my kids (plus other recipients), the other on my localized environmental responsibility. I'm a writer by trade and both endeavors are accepted practice for me. As for the letters, my adult children Ellen and Reid may have seen letters as corny at one point, but it's accepted practice for them, too, to find something in their mailbox other than bills and junk mail. Email and texting don't do a lot for me for a lot of different reasons. Snail mail has its place in the communicative world so as long as they keep selling stamps, I'm buying. As for 'Pick Up Your Path' and the environment, I advocate what citizens can do themselves to take a direct hand in their neighborhood environment. But Pick Up Your Path is also a general environmental blog. It may be largely about litter and trash, but both of those are just one element of the total environmental picture.

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