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The Creepy Crawlies Helping Us Break Down Medical Plastics

by Silas Fernandes

Imagine that you are a sea turtle making your way through the Pacific Ocean, exhausted from migration and in search of a snack to maintain the energy needed to complete your journey. You see something in the water just ahead of you that looks like it might be something you eat: a jellyfish, a sea sponge, maybe even algae. When you bite into it, however, you are met with an unpleasant surprise—plastic. Ingesting just one piece gives you a 22% chance of dying.

Sea turtles aren’t the only animals suffering from plastic waste pollution. About 1,500 species, both marine and terrestrial, are known to ingest plastic waste. Humans, though we may not knowingly be eating plastic, have been found to have microplastics in our livers, kidneys, and placentas. More research is needed on how these microplastics affect our bodies, but early studies have suggested microplastic inhalation is correlated with inflammatory bowel disease symptoms and respiratory complications. Additionally, 4,200 of the 16,000+ chemicals used to make plastics are associated with health risks such as infertility, obesity, diabetes, cancer, thyroid complications, and more.

The ideal solution to this would seem to be eliminating plastics (especially single-use plastics) entirely. Organizations like Break Free From Plastic, the Plastic Pollution Coalition, and the Alliance to End Plastic Waste are all working towards an increasingly plastic-free world. However, there are some instances in which these plastics are necessary and life-saving. This is especially true in the medical field, where harms of spreading infectious diseases to already vulnerable patients are too great to risk cross-contamination through the reuse of materials. So, even if we are successful in reducing all other plastics, what do we do about the ones we need?

Researchers at the University of British Columbia (UBC) have begun making progress on this by offering microplastics to a species of mealworm, Tenebrio molitor, that is common in the United States and Europe, but also found on all other continents except for Antarctica. The researchers sourced the microplastics from two different types of face masks, with the primary plastic components of each being either the common plastic polypropylene (PP) or the plant-based bioplastic polylactic acid (PLA). They wanted to see whether mealworms would be able to successfully break down plastic face masks, and whether the type of plastic in the mask affected their efficiency in doing so. In order to simulate natural foraging conditions, the microplastics were mixed in with wheat bran to offer the mealworms an alternative food source. At the end of the experiment, the researchers discovered that the mealworms had consumed approximately 53% of the microplastics they were fed. Mealworms exposed to PP ate about the same amount of microplastics as the mealworms exposed to PLA, indicating that the type of plastic they were offered did not affect their feeding efficiency. For the most part, these microplastics were biodegraded, though a small proportion of microplastics were also egested without being completely broken down. Finally, the study showed no difference in survival or development (pupation) between the mealworms fed microplastics and those that were not, implying that this was a safe way of decomposing the face masks. No noticeable harm was caused to the mealworms.

Though research on the degradation of plastics by insects is extremely limited, a number of studies have revealed the underlying mechanisms in several species. Through saliva analysis, researchers have determined that larvae of the wax moth Galleria mellonella are able to break down polyethylene—the most widely produced plastic across the globe—using three storage proteins that make up the bulk of their spit. In the same species of mealworm used in the UBC study, we know that bacteria in its gut are at least partially responsible for their ability to degrade plastic. A 2024 study has also suggested that these mealworms may also contain enzymes capable of helping break down plastic molecules into smaller components. Both of these case studies, in addition to explaining potential mechanisms for plastic biodegradation, reveal potential biological solutions to breaking down microplastics that can be applied even outside of their host systems.

As exciting as all of this sounds, there are also major limitations on the ability of insects to break down plastics. The researchers in charge of the UBC study estimated that it would take 100 mealworms about four and a half months to completely break down a single face mask. Given that the United States is estimated to produce over 1.5 million metric tons of medical plastics annually, it is unrealistic to expect that mealworms will solve all of our problems. Instead, plastic-degrading insects should be used as a supplementary solution for the breakdown of necessary plastics while we put most of our energy into phasing out unnecessary plastics. Though biodegradation of plastic by insects is happening almost exclusively in research labs, this could, in the future, be expanded through the construction of biodegradation facilities. These facilities would house and rear mealworms, which would then be used to degrade medical plastics collected from nearby hospitals.

There are many ways in which you can help mitigate the plastics crisis. Though it sounds elementary, following the principles of reduce-reuse-recycle is a fantastic start at the individual level. Reduce your plastic consumption as much as possible, reuse the plastics you do have if you can, and recycle what waste you are able. In Pittsburgh, you can even save money on single-use plastic bags by carrying around a reusable one instead to do your shopping. If you have a plastic item that is no longer in sufficient condition for its original use, see if you’re able to repair it or repurpose it for something else before throwing it away.

In addition to making changes to your own lifestyle, consider ways to bring your community together to make larger impacts. Influence those around you to reduce their own plastic consumption. Organize or join a plastic clean-up in your community, donate your used plastics to members of your community who can use them, or participate in events such as clothing swaps to prevent your plastic items from ending up in a landfill.

On a greater scale, the best way to reduce plastic production is through policy. Make sure to keep up-to-date with local, state, and national legislation to see what is being done to reduce plastic pollution and where you would like to see improvement. You should also vote in every election to improve environmental legislation both locally and across the country. Connect with members of your local government to show them that you care about plastic pollution. You can do this by calling or emailing your local representatives and attending public council meetings. You can also contribute on a wider scale by supporting national and global organizations that are working to directly influence policy to reduce plastic production, especially by regulating unnecessary single-use plastics produced by large corporations.

You don’t need to do everything; any step towards plastic reduction is a good one. We all have unique skills that, when put together, can improve the circumstances of thousands of animal species worldwide. If insects can do their part, so can we.