For many of us, plastic pollution means the debris we can see. Bottles, bags, and bits of larger items float in accumulating amounts through our oceans and lakes, affecting people, plants, and animals. More recently though, scientists have turned their attention to microplastics—tiny, mostly microscopic pellets that come from the gradual breakdown of larger plastics. You might have even rubbed some of these pellets on your face this morning—one of the most obvious ways microplastics are used is as microbeads in cosmetics.
Microbeads are too small to be caught in sewage treatment plants, and as a result they’re polluting our oceans, lakes, and even Arctic ice, attracting the attention of scientists, activists, and legislators. Just this week, Illinois banned cosmetics containing microbeads, with similar legislation in the works in California and New York. Companies like Unilever recently phased out its use of microbeads at the urging of activists. And while the research on how microplastics affect human and animal health is still underway, early findings are prompting some scientists to create biodegradable alternatives for cosmetics.
Kirk Havens, a researcher at the Virginia Institute of Marine Science, is one of those scientists. He recently received federal funding to research PHA (polyhydroxyalkanoate), a bioplastic made through bacterial fermentation. It’s physically similar to the synthetic plastics used to make microbeads, but less environmentally damaging.
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Unlike some types of plastic, the majority of microplastics tend to float, which means they move readily from your shower drain, through wastewater treatment plants, and into waterways. “It’s like the saying from Finding Nemo,” explains Havens. “All drains lead to the ocean.”
PHA, on the other hand, is denser than water, and thus sinks to the bottom. When it sinks, it’s buried with other sediment or consumed by salt or freshwater bacteria. This is an improvement over synthetic microplastics, which are more likely to be eaten by microorganisms that mistake the tiny pellets for food. But if bacteria consume PHA, they break the substance down into water, carbon dioxide, biomass, and naturally occurring small molecules after a few months. These substances are relatively harmless compared to longer-living man-made plastics like polyethylene.
The chemicals that make up microplastic can also create “a potentially poison pill” for the organisms that eat them, says Chelsea Rochman, a marine ecologist from the University of California at Davis. Microplastics stick to other non-degradable pollutants like the insecticide DDT and polychlorinated biphenyls (PCB’s), both of which have been banned for decades but remain in traces in the environment. DDT, PCBs, and others have been shown to cause cancer, nervous system damage, and hormonal changes, according to Rochman. PHA, on the other hand, is assumed not to cause these issues.
And because PHA is made of bacteria, it’s biodegradable. Worms and amphipods, along with other animals, use or bury the pellets, which Havens observed after preliminary experiments. He believes the borrowing to be particularly advantageous, as it keeps the pellets from being re-suspended in the water and sets them up to be more quickly consumed by microorganisms, he tells The Daily Beast.
Another critical aspect of PHA microbead development is whether they are easily captured and disposed of in wastewater treatment plants. If they are, that would make them superior to small synthetic plastics, which float through the treatment plants and into our waterways. They can’t yet say for sure that PHA will work in this way, but Havens is assessing this at the Hampton Roads Sanitation District, a treatment plant serving 1.6 million people in Virginia.
Havens is optimistic that if PHA beads could be used successfully in cosmetics without losing their ability to scrub. That’s because PHA requires bacteria to be broken down, and many soaps and washes include antibacterial components to keep the products from going bad on the shelves, Havens says.
But it won’t be easy. Further development of PHA cosmetic microbeads could be stymied by developing legislation, which is meant to protect against man-made synthetic plastics, not necessarily bioplastics. That’s because some states, like California, define a microbead as any plastic less than 5 millimeters in size, made from linking small molecules together through a chemical reaction. Technically, PHA falls under this definition, though Jason McDevitt, a technology transfer director for the Virginia Institute of Marine Science, hopes that the language will be amended before the bill is potentially passed and made into law. The Illinois legislation does not include bioplastics like PHA, defining the banned microplastics to be of the synthetic type.
Costs are a potential issue, too. Havens thinks that the cost differences for consumers will be minuscule, according to rough model calculations. But on a larger scale, companies that buy the beads in large quantities will have to pay more for the PHA in bulk. Some companies may embrace the chance to have their brand be associated with less harmful microbeads despite the price uptick, but it's another unknown for the project.
In the meantime, anti-plastic advocates are helping to influence further industry changes. And other scientists are researching the effects microplastics have on the food web and our health.
In any case, the anti-plastics movement is likely to gather steam in the next few years. Havens and his team are working on getting a patent and then licensing their PHA, though you can be on the lookout for further biodegradable developments. Also, advocacy organizations will continue their work, like the Plastic Soup Foundation, who released an app to help consumers determine whether their cosmetics contain microbeads. “Just having a greater understanding of all these synthetic things we use every day” can start us on better behaviors limiting our use of plastics, says Courtney Arthur of NOAA.
Food for thought, the next time you wash up.
