Recently, several readers, including my dad, have forwarded me articles about a group of Yale students who discovered an Amazonian fungus (pestalotiopsis microspora) that can not only eat polyurethane plastic, but can actually survive on it as its sole source of carbon. Could a fungus be the solution to our plastic pollution problem? And what does it mean in terms of the kinds of plastics we see littered every day?
Let’s stop and think it through.
There are many different types of plastic polymers. In general, single-use disposable products, the kind that make up the bulk of municipal plastic waste, are made from polyethylene terephthalate, high and low density polyethylene, polyvinyl chloride, polypropylene, or polystyrene. Not polyurethane. Polyurethane is used as foam for furniture cushions, car seats, and mattresses; garden hoses; footwear; liquid varnishes; and a whole host of other durable products–not the kind that are routinely littered. So a fungus that eats polyurethane is not going to affect most of the plastic waste that ends up in the landfill or incinerator or environment.
But perhaps this organism is just one of many to be discovered that will break down other kinds of plastics. In 2008, a Canadian high school student discovered a type of bacteria that could break down polyethylene bags. Musing on the ramifications of his discovery back then, I wrote:
But does this mean that plastic bags are now off the hook and that plastic packaging has been redeemed? Can we continue to use as much of it as we want guilt-free? Plastic is still made from non-renewable fossil resources. It’s manufacture uses energy and creates pollution in the form of pre-production plastic pellets, aka nurdles, that can escape and cause harm to the marine environment. And unlike paper bags which biodegrade easily and naturally when exposed to the elements, plastic bags will need to be processed in a controlled way at a temperature of 37°C (99°F) because the microbes that break them down don’t exist in abundance in the natural world, certainly not in the cold ocean.
Using microbes to dispose of waste is otherwise known as composting. We compost food scraps and some bio-based plastics now, and perhaps some day, we will be able to compost fossil-based plastics using bacteria, fungi, and other organisms. But we need to keep in mind that composting is simply a method of waste management. It’s better than landfilling and incinerating, but it does nothing to reduce the amount of new plastic being produced in the first place. It doesn’t address the massive amounts of plastic polluting the ocean and other areas of our planet. And it certainly doesn’t mitigate the toxicity of the chemicals used to make plastics and plastic products.
While it’s useful to find “natural” methods to deal with the plastic waste that already exists, the real solution is reducing the amount of plastic we use in the first place by refusing single-use disposable plastics and lowering our consumption of other plastic products. If news of these new technologies gives consumers the impression that it’s okay to consume plastic as usual, is it possible that this information could do more harm than good?