From Sea to Self: Stanford Researchers Trace Microplastics Through Oceans, Wildlife, and Human Health

Microplastics—tiny fragments of plastic smaller than a sesame seed—have become one of the most pervasive pollutants on Earth.

phys.org

Found in oceans, rivers, soil, food, and even human tissue, their movement and impact remain poorly understood. A new wave of Stanford-led research, stretching from Monterey Bay to medical labs, is uncovering how these particles travel through ecosystems and into our bodies, and what risks they may pose to both the environment and human health.

1. Microplastics are everywhere – from alpine peaks to deep-sea trenches, and increasingly inside human bodies, where their long-term effects are still unknown.
2. Monterey Bay serves as a living laboratory – with its rich biodiversity and decades of ecological data, it provides a unique setting to trace how plastics move through marine ecosystems.
3. Fieldwork reveals ubiquity – researchers have collected microplastics from beaches, rivers, coastal waters, krill, and whales, confirming their spread across multiple habitats.
4. The ocean surface paradox – while vast amounts of plastic enter the sea, only a fraction is found floating. Models suggest much of it sinks through processes such as aggregation into “marine snow.”
5. Deep-sea accumulation – oceanographers link microplastics to the carbon cycle, as sinking particles can carry both plastic and carbon into the deep ocean, altering ecological processes.
6. Microscopic mapping – Stanford’s Manu Prakash and team now detect microplastics even a kilometer below the surface, finding them in every single sample of ocean water.
7. From whales to humans – whales ingest millions of microplastic-laden prey daily, and similar exposure pathways are seen in humans through seafood, meat, and plant-based foods.
8. Emerging health concerns – early studies show microplastics in blood, lungs, placenta, and breast milk, with potential links to inflammation, oxidative stress, and toxic chemical exposure.
9. Innovations in detection – researchers are developing faster and more accessible methods, such as Raman spectroscopy, to measure micro- and nanoplastics in tissues, food, and water.
10. Systemic problem, systemic solutions – while individuals can reduce single-use plastics, experts stress that real change requires stronger regulations, safer materials, and global reductions in plastic waste.