Plastic-eating animals cannot solve global pollution

As a species, we manufacture an insane amount of plastic. According to a July 2017 study, scientists have determined the total amount of plastic ever made up to 2015: 8.3 billion metric tons (Science, “Production, Use, and Fate of All Plastics Ever Made,” 07.19.2017). To put that into perspective, the Empire State Building in New York City is 331,000 metric tons. So that means we produced 25,000 Empire State Buildings worth of plastic in just 65 years. Not only that, the rate of plastic use is rapidly increasing. Half of this total amount was created in just the past 13 years. Scientists estimate that we produced about 407 million metric tons of plastic in 2015, which is a 150 percent increase from 2010 (Science).

However, we shouldn’t be too surprised by this outcome. Plastic is very important to our society and can be found in practically everything, from computer hardware to grocery bags. What’s more disturbing is the fact that we’re barely making a dent in getting rid of it. According to the report, as of 2015, only nine percent of the 6.3 billion metric tons of plastic waste produced has been recycled and only 12 percent of it has been incinerated (Science). The remaining 79 percent has ended up in landfills or in the natural environment. Given this situation, it wouldn’t be a stretch to say that the planet is on the brink of a major plastic pollution crisis. At the current rate that the trash is accumulating, the scientists behind the 2017 study predict that about 12 billion metric tons of plastic waste will end up in landfills or in the natural environment by the end of 2050.

“Most plastics don’t biodegrade in any meaningful sense, so the plastic waste humans have generated could be with us for hundred or even thousands of years,” stated study co-author and associate professor of engineering at the University of Georgia Jenna Jambeck (Phys.org, “8.3 Billion Metric Tons: Scientists Calculate Total Amount of Plastics Ever Produced,” 07.19.2017).

Naturally, experts in various scientific fields are in a rush to find an answer to this plastic problem. Now, there has been news spreading of a possible miraculous solution: What if we breed animals that eat the plastic waste? Animals eating plastic is generally a bad sign. Animals that mistake plastic trash for food like seabirds, sea turtles and marine mammals either fatally damage their intestines, suffocate or die of starvation from a false sense of fullness (NOAA, “What is Marine Debris,” 03.14.2016).

However, scientists have found that waxworms, a species of caterpillars that develop into the common wax moth Galleria mellonella, can eat and digest plastic.

This discovery occurred when Federica Bertocchini, a researcher at the Institute of Biomedicine and Biotechnology of Cantabria in Spain, found an infestation of waxworms while taking care of her beehives (The Atlantic, “The Very Hungry Plastic-Eating Caterpillar,” 04.24.2017). Since these pests eat the wax in the honeycombs, Bertocchini placed the waxworms in a plastic bag while she cleaned out the beehives.

Yet when she returned to the bag, she saw that the waxworms simply ate their way out, making little holes in the bag. Given how the molecular bonds in plastic are often too strong to degrade naturally, it wasn’t long before she contacted biochemists Paolo Bombelli and Christopher Howe at the University of Cambridge about this new information.

“Once we saw the holes, the reaction was immediate: that is it, we need to investigate this,” said Bertocchini (The Washington Post, “These Pesky Caterpillars Seem to Digest Plastic Bags,” 04.24.2017).

Together, the three scientists conducted several tests to investigate waxworms further. In their experiment, they timed how fast these caterpillars ate the polyethylene plastic and found that each worm created an average of 2.2 holes per hour. When a hundred of them were placed on a plastic shopping bag overnight, they degraded 92 milligrams of the plastic (National Geographic, “This Bug Can Eat Plastic. But Can It Clean Up Our Mess?” 04.24.2017).

However, were the caterpillars really digesting plastic or were they just chewing holes? To find out, the researchers mushed the waxworms in a gooey paste and applied it to the polyethylene bag. After half a day, about 13 percent of the plastic had disappeared (The Atlantic). Apparently, something inside the caterpillars allowed it to digest the polyethylene in plastic and turn it into ethylene glycol as a natural byproduct.

As a result of this study, exciting speculations have been made about the possibilities with these waxworms. Perhaps one day, we could harness their power and develop an easier process to getting rid of all the plastic pollution that has accumulated so far. But is this really a viable solution? Probably not.

While using waxworms to eat our plastic waste may seem convenient, there is simply too much plastic pollution for even an entire army of waxworms to manage effectively. Remember that it took 100 worms to eat 92 milligrams of plastic in 12 hours—that’s the equivalent of four grains of rice in terms of mass. We have more than five billion metric tons of plastic waste polluting the planet (Science).

Not only that, it’s possible that the waxworms would not even completely get rid of the plastic. According to professor of chemical engineering at Michigan State University Ramani Narayan, the waxworms may end up releasing small fragments or microplastics into the environment, which would cause more harm than good (The Atlantic).

“Biodegradation isn’t a magical solution to plastics waste management,” warned Narayan.

There is just no conceivable way that we can rely on waxworms to solve for plastic pollution problems. Indeed, using waxworms or even similar plastic-eating organisms, such as Styrofoam-eating mealworms and plastic-metabolizing bacteria, can only accomplish so much in the face of overwhelming trash (The Washington Post). Although Bertocchini argues that pinpointing the molecule or enzymes involved in the plastic-degradation process and then producing it at high scale may be beneficial, the responsibility of cleaning up plastic pollution ultimately comes down to us.

We humans have to make an active effort to change our lifestyles so that we minimize the use of plastic and encourage more recycling. An easy shortcut may sound convenient, but only the combined activity of people en masse can make a significant impact in cleaning the environment. Several great ways to help include reusing your water bottle, boycotting products with microbeads like facial scrubs and weaning yourself off disposable plastics such as grocery bags, plastic cutlery and plastic straws. Only once we take the time and energy to make steps towards cleaner living can we expect the planet to slowly recover.

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