Microplastics are a growing environmental concern due to their potential impact on ecosystems and human health. A recent study by the University of Massachusetts Amherst has revealed that rotifers, a type of microscopic zooplankton found in both fresh and ocean water, are capable of breaking down microplastics into even smaller and potentially more dangerous nanoplastics. The study found that each rotifer can create between 348,000–366,000 nanoplastic particles per day, leading to uncountable swarms of nanoparticles in our environment. In China’s Poyang Lake alone, researchers calculated that rotifers were creating 13.3 quadrillion particles every day.
Microplastics are created when plastic bottles, packaging, and parts break down into smaller pieces, which can take up to 500 years to decompose. These microplastics have been found in every corner of the globe and are altering ecosystems throughout the world. The smaller the plastic particle, the more easily they spread, and the more of them there are. Each individual microplastic could theoretically be broken down into 1,000,000,000,000,000 nanoplastic particles.
Smaller size also means more surface area, which means they are more reactive and potentially even more harmful to the health of humans and other living beings than microplastics. While there has been much attention given to microplastics, there has been far little interest in studying nanoplastics, particularly in how they’re generated, which means we don’t really know how many nanoplastics might be out there.
The study found that rotifers could produce 13.3 quadrillion nanoparticles every day in Poyang Lake alone. Scale this up to all of the ocean and fresh bodies of water where both microplastics and rotifers are present, and the number of nanoplastic particles created every day is mind-boggling.
The researchers hypothesized that rotifers, which have a specialized masticatory apparatus or “teeth,” could grind microplastics into smaller particles. After exposing both marine and freshwater species of rotifers to a variety of different plastics of different sizes, they found that all rotifers could ingest microplastics of up to 10 micrometers in size, break them down, and then excrete thousands of nanoplastics back into the environment.
The release of chemical additives in the plastic can be enhanced during and after the fragmentation, and nanoplastics can serve as carriers for other contaminants in the environment. Furthermore, nanoplastics can be potentially toxic to various organisms, making them an environmental threat that needs to be addressed.
The study highlights the urgent need to investigate other organisms on land and in water for biological fragmentation of microplastics and collaborate with toxicologists and public health researchers to determine what the impact of nanoplastics is on the environment and human health.