Maria Hayder was staring at a vial of wastewater in her Amsterdam lab when she realized the tools to measure the tiniest plastic particles—nanoplastics—were failing science. At less than a micrometer wide, these invisible pollutants slip through standard detection methods, leaving researchers blind to their true spread. Now, in a breakthrough that could reshape how we understand plastic pollution, Hayder has combined two analytical techniques to create a far more accurate way of identifying and quantifying nanoplastics in water and the environment. On June 24, she will defend her Ph.D. dissertation at the University of Amsterdam, marking a pivotal step toward clearer, comparable data on one of the most urgent environmental health questions of our time.
Plastic waste, with over 400 million metric tonnes produced globally each year, breaks down into microplastics and, eventually, nanoplastics. While microplastics (1 micrometer to 5 millimeters) have been widely studied, nanoplastics—ranging from 1 nanometer to 1 micrometer—are far more elusive. Their size allows them to infiltrate food, water, and even human tissues, raising alarms about long-term health effects. Yet without reliable measurement, risk assessment stalls. Hayder’s method bridges this gap by pairing size-based separation with chemical identification, enabling precise detection of nanoplastics in complex environmental samples like wastewater.
Using this new approach, Hayder and her team exposed common plastics to fresh and seawater over years, simulating natural degradation. Contrary to expectations, the breakdown didn’t follow a simple pattern of progressively smaller fragments. Instead, nanoplastics emerged in a wide range of sizes and were found throughout the water column—even particles denser than water remained suspended at various depths. This challenges previous assumptions about how and where these particles accumulate.
Hayder also reviewed current knowledge on plastic in food, finding that while seafood has been heavily studied, crops like fruits, vegetables, and grains—key components of daily diets—remain under-researched. Yet estimates suggest these foods may contribute the highest daily intake of plastic particles. In lab simulations of the human digestive tract, she discovered that small nanoplastics tend to clump together due to digestive enzymes, forming larger aggregates. This could reduce their ability to cross the intestinal wall, potentially lowering their bioavailability—but significant uncertainties remain.
"Currently, measurement methods vary widely between laboratories, making results difficult to compare. This hinders not only scientific research but also policy regarding plastic use and pollution," Hayder warns. Her method isn’t perfect, but it’s a critical leap toward standardization. As governments and industries grapple with plastic regulation, having reliable, reproducible data will be essential. With nanoplastics now coming into sharper focus, science is finally catching up to the invisible crisis we’ve been swallowing for decades.