It’s become second nature to sort rubbish into plastics, paper and ‘other’ for curbside recycling. But could we soon have a worm-assisted compost heap for plastics at home in the same way you might have a wormery for kitchen scraps? It’s a real possibility after the discovery by a Chinese-US research team that tiny mealworms—the larval form of the darkling beetle—can eat plastic and recycle it into ‘biodegraded fragments.’
In a series of experiments, researchers at Beihang University, BGI-Shenzhen and Stanford University discovered that one mealworm can happily chew through a pill-sized piece of Styrofoam a day—significant because, until now, Styrofoam was thought to be non-biodegradable and therefore a problem for the environment.
The worms converted about half the Styrofoam into carbon dioxide, which is normal, apparently, regardless of what they eat (grains or leaf litter). A day later, after microorganisms in the worms’ guts got to work, they pooped out the rest as mini droppings that are safe enough to use as soil for crops. The lab mealworms thrived on their steady diet of junk food with no noticeable ill effects.
The research is a breakthrough on many levels as it suggests a practical, low-tech method of dealing with plastic waste that doesn’t involve landfills or incineration. Currently, less than 10 percent of the 33 million tons of plastic thrown away in the US gets recycled; the equivalent figures for the UK and Australia are 24 percent of 5 million tons and 46 percent of 1.3 million tons, respectively.
‘Our findings have opened a new door to solve the global plastic pollution problem,’ says Wei-Min Wu, senior research engineer at Stanford and a co-author with Jun Yang of Beihang University of two companion studies published in Environmental Science and Technology.
Wu and his co-researchers had already discovered that waxworms, the larvae of Indian mealmoths, have gut microorganisms that can break down thin plastic packaging. New avenues for research include seeing whether mealworms and other insects can biodegrade the microbeads (used in some toothpastes and exfoliants) that are currently wreaking havoc on marine life, or polypropylene (used in products ranging from textiles to cars).
In the end, though, the best way to deal with the plastic waste problem is to not use so much of it. Or to start building that mealworm compost heap.
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