The enormous amount of plastics that we manufacture and discard is a defining characteristic of the Anthropocene – the current geological age of human domination over climate and the environment. The same reason it is such a useful (and used a lot) and efficient material is also the reason it is problematic; which is, it is difficult to degrade.
Here are a couple of pollution facts and figures taken from sas.org that highlight in numbers how plastic is one of the largest environmental problems we are currently facing:
In 1950, the world’s population of 2.5 billion produced 1.5 million tons of plastic; in 2016, a global population of more than 7 billion people produced over 320 million tons of plastic. This is set to double by 2034.
Every day approximately 8 million pieces of plastic pollution find their way into our oceans. There may now be around 5.25 trillion macro and microplastic pieces floating in the open ocean. Weighing up to 269,000 tonnes.
For plastic to properly degrade it takes anywhere from a decade to 1000 years. This is why it is such a big problem considering the numbers mentioned above. To stop using plastic completely is an unrealistic goal, at least for a while. Therefore, a different approach, to find a way to make it degrade, would be ideal for our current situation. Interestingly enough, the answer has recently been found – a fungus that can “eat” plastic has been discovered in Pakistan.
“We decided to take samples from a rubbish dump in Islamabad, Pakistan, to see if anything was feeding on the plastic in the same way that other organisms feed on dead plant or animal matter.” –Dr Sehroon Khan of the World Agroforestry Centre and Kunming Institute of Biology
Aspergillus tubingensis is a fungus that is able to feed off of plastic by breaking down the chemical bonds in the material. In lab experiments that were published in Environmental Pollution (via ScienceDirect), the fungus was isolated, identified, and found to degrade polyurethane (PU). The scientists discovered that the mycelium of the fungus colonized polyester polyurethane plastic thus causing eventual surface degradation and scarring.
The study proved that after two months in a liquid medium, A. tubingensis had degraded a sheet of polyester polyurethane to such a degree that it had effectively completely fallen apart. Therefore, the use of such microorganisms can indeed break the plastics down and be the solution to address the growing environmental problems of plastic waste.
As amazing as this news is, there is also a scary side to it. One of the reasons that plastic is widely used is the fact that, in general, it is inert and therefore sterile. The reality that microorganisms are seemingly evolving to take advantage of this superabundant sterile resource could be something to be concerned about.
Nature has come up with a way on its own to exploit this new material we are pushing upon it in abundance. Fascinatingly, this goes to show that what we do can create completely new environments; but also that we should be careful because nature will find a way to eliminate everything eventually… which could mean us, if it must, to save the planet.