The Age of Plastic

By: Fariha Husain

With the large amounts of plastic found in our homes, landfills and the natural environment, this post discusses some of the large-scale issues surrounding ‘The Age of Plastic’.

Does plastic biodegrade?

Most plastics are derived from petroleum, the end-product of decaying ancient organisms. If petroleum-based plastics are derived from biomaterials, why aren’t they biodegradable? To answer this question, it is important to understand a fundamental step in plastic production. Petroleum-based plastics are derived from a unit chemical component of petroleum that bond and form long chains when heated. These bonds require a large amount of heat energy to form, making this very unlikely to occur in nature. Subsequently, the organisms that are responsible for the biodegradation of organic materials generally do not possess the metabolic capabilities to break down these strong bonds. Earlier this year, however, a breakthrough discovery revealed that 100 Galleria mellonella worms can consume 92 milligrams of polyethylene—the most common type of plastic – in approximately 12 hours. Although results from this study are not conclusive, these worms have the potential to reverse much of the damage caused by plastic pollution in our environment.

Exactly how much plastic exists on Earth?

Over 8300 million metric tons(Mt) of plastic have been produced to date. As of 2015, 6300 Mt of plastic waste was generated, of which 9% was recycled, 12% was incinerated and 79% resided in either landfills or the natural environment. This statistic clearly shows that if current rates of production, consumption, disposal, etc. are to continue, the amount of plastic waste stored in landfills and the natural environment is expected to rise to ~12 000 Mt by 2050.

Is this a sustainable practice?

A practice is considered sustainable if it can be maintained perpetually without causing an overall net adverse impact on the environment. As there is a direct correlation between the amount of plastic and its adverse impact on the environment, the current practice is considered unsustainable. In other words, we cannot continue to make, use, throw away, recycle and incinerate plastic waste at the current rates, without causing direct harm to the environment.

Can this be converted into a sustainable practice?

Let’s first consider the best-case scenario—imagine that the production of all new plastic was put to an end at this very moment. This would mean that there exists over 8300 Mt of plastic on Earth. To convert this into a sustainable practice, the amount of plastic that is currently in landfills and the natural environment cannot increase. Additionally, all the plastic that is currently in circulation must either be recycled or disposed of responsibly. Furthermore, the plastic that resides in landfills and the natural environment must be removed from those locations and be either systematically brought into circulation or disposed of responsibly. This model creates a circular path for the treatment of plastic waste and ensures the decline of plastic waste over time. Realistically, however, the production of new plastic will not be halted immediately and will either a) be phased-out over time or b) be decreased to a lower rate. Additionally, the rate of recycling/incineration may also increase either to a) contribute to phase-out of plastic or to b) meet current production needs. Regardless of which option is adopted, it is crucial that we reduce the amount of plastic waste in landfills and the natural environment.

What are microplastics and where are they found?

Microplastics are small pieces of plastic, 5mm or less, commonly found in oceans and lakes around the world. Microplastic pollution can be generated in a variety of different ways including:

  1. Deterioration of larger plastics into microplastics
  2. Direct-release of microparticles into waterways
  3. Leakage of raw materials during transport
  4. Discharge of sewage

How do plastics and microplastics harm the environment?

A large amount of plastic and microplastic has been detected in aquatic wildlife and birds. According to The National Oceanic and Atmospheric Administration, approximately 100 000 marine mammals, millions of seabirds, and millions of fish die due to plastic debris every year. Microplastics have also been found in the tissue of animals via ingestion and respiration. This can cause a plethora of health risks including high toxicity in the nervous system, chromosomal damage, cancer, liver and kidney damage, skin disorders and lung damage. As consumers of fish and other sea life, it is likely that this could pose major health issues in humans as well. A world-wide study that collected water samples from over 12 countries found that 83% of tap water is contaminated by plastic fibers.

What can I do?

As consumers, we can directly influence the message that we send out to plastic manufacturers and corporations based on what we choose or choose not to purchase. If we as consumers collectively boy-cot the purchase of plastics, plastic-based products and products packaged in plastic, we would put direct pressure on these manufactures to search for alternatives. To learn more about how you can reduce your plastic consumption, check out Lauren Singer of Trash is for Tossers and Bea Johnson of Zero Waste Home. Additionally, as citizens we can actively influence political movements that advocate sustainable policies.

 

For more information, check out the references below:

  1. Geyer, Jambeck, Law Sci. Adv. 2017;3: e1700782 19 July 2017
  2. https://www.livescience.com/33085-petroleum-derived-plastic-non-biodegradable.html
  3. https://www.greenfacts.org/en/marine-litter/index.htm#1
  4. https://oceanservice.noaa.gov/facts/microplastics.html
  5. https://www.rainbowlight.com/ecoguard/docs/The%20Effects%20of%20Plastic%20Waste%20on%20Animals.pdf
  6. Teuten, E L: “Transport and release of chemicals from plastics to the environment and to wildlife”, Philosophical Transactions of the Royal Society B – Biological Sciences, 364(1526), pp. 2027–2045, 2009
  7. https://www.theguardian.com/science/2017/apr/24/plastic-munching-worms-could-help-wage-war-on-waste-galleria-mellonella
  8. https://www.theguardian.com/environment/2017/sep/06/plastic-fibres-found-tap-water-around-world-study-reveals