At Oregon State University, Stacey Harper has built a career at the intersection of cutting-edge nanotechnology and environmental health. Her research focuses on a deceptively simple question: when engineered materials shrink to the nanoscale, what happens when they encounter living systems?
“There are now all of these cool new, precisely engineered nanomaterials used in everything from energy storage to medical equipment,” said Harper, a professor of environmental engineering. “But we have no idea if they are safe for humans.”
Harper’s lab uses embryonic zebrafish as a window into human health. These tiny, transparent, fast-developing organisms allow her team to observe developmental disruptions in real time, enabling her team to rapidly screen new nanomaterials for risks.
“If manufacturers can send us a series of nanomaterials that are tweaked in one particular aspect — say surface chemistry, shape, or size — we can then evaluate each iteration’s relative toxic potential within a week or so,” Harper said.
This proactive approach helps companies avoid releasing potentially hazardous products into the market.
One key insight has been the importance of surface chemistry. “There are certain chemistries that if you add them, you can make even cellulose toxic,” Harper said. That early finding from her lab reveals that even seemingly benign materials can become harmful with the wrong chemical modifications underscores the need to evaluate not just what a material is made of, but how it’s engineered.
Nanoparticles meet the environment
Nanotechnology has become ubiquitous in consumer products, agriculture, and medicine, yet its environmental footprint remains poorly understood. Harper’s lab is tackling this gap with model microcosms — small, simplified ecosystems of algae, bacteria, daphnia (tiny water fleas), and zebrafish embryos. These models allow Harper’s team to study not just one organism, but entire communities, revealing how nanoparticles move across food webs.
Harper’s group also investigates nanotechnology-enabled pesticides, which use existing active ingredients in nanoscale formulations to alter their behavior in the environment. While these may not directly increase toxicity, Harper cautions that they can change exposure patterns for aquatic organisms in unpredictable ways.
Nanoplastics: An emerging threat
Beyond engineered nanoparticles, Harper’s group is turning to a more insidious issue: nanoplastics. Unlike engineered materials, these particles are born from the breakdown of everyday plastics. They are vanishingly small and alarmingly difficult to detect.
Recent research has revealed that nanoplastics may be even more harmful than microplastics, penetrating tissues and disrupting cellular processes in ways scientists are only beginning to understand. Harper’s lab is at the forefront of this work.
One focus has been on tire-wear particles, an overlooked but significant contributor to aquatic pollution. Harper explained that a chemical called 6PPD, widely used in tires, has been linked to mass die-offs of salmon in the Pacific Northwest. Working with the U.S. Tire Manufacturers Association, her consortium has been testing replacement chemicals and developing filtration strategies to capture toxic runoff from roadways before it reaches waterways.
Environmentally friendly alternatives?
Harper’s team is now probing biodegradable and bio-based plastics, often marketed as environmentally friendly alternatives. Early findings complicate that narrative.
“The bio-based ones degrade much faster,” Harper said. “But they make a lot more nanoscale plastics than the other ones. Once they’re at the nanoscale, it’s going to be next to impossible to remove them from an aquatic system, even a drinking water system.”
She and her students are also studying how sunlight and biofilms alter the breakdown of plastics. In some cases, light-triggered algae growth creates protective coatings that slow degradation, further compounding the problem.
A responsibility to share
Harper’s work is supported by major funders like the National Science Foundation and USDA, and she is committed to sharing her findings with both the scientific community and the public. Her lab has developed a knowledge base of nanomaterial-biological interactions to help researchers worldwide understand the risks and behaviors of these materials, paving the way for predictive models that regulators and manufacturers can use.
Ultimately, Harper’s research is driven by a sense of responsibility.
“We view all of these human health and environmental health concerns as one, because, in the end, we are part of the environment,” she said.
