When you get home from work this evening, open your bathroom medicine cabinet and take a look at the creams, gels and toothpastes inside. You may find that some contain microbeads, tiny pieces of plastic used to aid exfoliation and cleaning. At approximately one millimeter long, each microbead is comparable to a grain of sand, and yet a recent report published in the journal Environmental Science & Technology claims that microbead pollution is posing a threat to the marine environment that’s entirely disproportionate to the tiny particles’ size.
Using figures from previously published papers, the authors of this recent study estimate that in the United States alone, 8 trillion microbeads make their way into lakes, rivers and estuaries every day. That’s enough to cover more than 300 tennis courts, a statistic that has caused co-author Stephanie Green to claim that “we are facing a plastic crisis and don’t even know it.” According to Green, who is a conservation research fellow at Oregon State University, the problem stems from the fact that the microbeads are too small to be filtered out by wastewater treatment plants, and consequently pass freely into our waterways.
What’s causing microbead pollution?
Microbead pollution may even be worse than the study suggests, with lead author Chelsea Rochman commenting that the 8 trillion figure is in reality a “conservative estimate.” The scientists used the data from previous studies to average the quantity of microbeads expelled in a single liter of wastewater. They then multiplied that figure according to the volume of water discharged from America’s wastewater treatment plants each day. The scientists made their calculations on the basis of each treatment plant operating at half capacity, meaning that the actual number of microbeads released into the environment could be significantly higher.
Worse still, the 8 trillion microbeads thought to enter aquatic systems directly represent just 1 percent of all microbeads washed down the sink on a daily basis. Treatment plants separate solid and liquid waste, using settling tanks to divide the two. The vast majority of microbeads settle into the resulting sludge, some of which is later used as fertilizer. When it rains, fertilizer enters rivers and lakes as run-off, before making its way to the ocean, carrying the microbeads with it. This means that instead of the 8 trillion microbeads cited in the study, as many as 800 trillion microbeads could potentially enter the marine ecosystem every day.
According to the study’s scientists, the ramifications of microbead pollution are serious. The tiny plastic particles are mistaken for food by aquatic organisms, including fish, crustaceans and mollusks. They are toxic not only due to the chemicals used to produce them, but also because they act like sponges, soaking up other pollutants in the water. As larger animals prey on smaller ones, the microbeads’ toxins are spread throughout the food chain, until eventually they make their way back onto human plates. Worse still, microbeads can cause coral death, because polyps that confuse the plastics for food are unable to digest them or take on further sustenance.
Microbeads are just a small part of the microplastic problem currently affecting our oceans, and yet the risk that they pose is serious. However, scientists claim that “the solution to this problem is simple,” and are calling for legislation that will ban the inclusion of microbeads in personal care products. The study points out that there are several biodegradable alternatives that work as well as the tiny plastic particles, including crushed nutshells and salt. Some American states have already issued a ban on microbeads, although Rochman says that strategic wording often allows for loopholes in the law.
Your role in combating microbead pollution is simple — if you do find products containing the plastic particles when you go through your bathroom, stop using them. And if you don’t, make sure to avoid them in the future.
