Study Finds Dolphins Exhaling Microplastics Chemically Similar to Human Airway Particles — Health Impact Unknown

Microplastic pollution is now so widespread that bottlenose dolphins are exhaling microplastic fibers, a new study published in PLOS ONE reports. Researchers analyzed breath samples collected from dolphins in Barataria Bay, Louisiana, and Sarasota Bay, Florida, and found microplastic fragments whose chemical signatures closely match particles previously detected in human airways.

Chemical comparisons suggest a strong overlap between the types of microplastics present in coastal environments used by both humans and marine mammals. Scientists say this underscores how pervasive plastic contamination has become along shorelines and in nearshore waters.

How Dolphins May Inhale Microplastics

One likely exposure pathway is the "bubble burst" phenomenon: when bubbles at the ocean surface break, tiny droplets and particles — including microplastics — can be ejected into the air. Separate research estimates that bubble bursts may lift up to 110,000 tons of microplastic into the atmosphere each year. As dolphins surface to breathe, they may inhale aerosolized particles produced by wave action and bubble bursts.

Scope And Implications

The study detected microplastics in dolphins from both urbanized and more rural estuaries, but researchers note it is still unclear whether concentrations or polymer types differ consistently between habitats. Estimates suggest roughly 170 trillion microplastic pieces float in the oceans, and microplastics have been documented in rivers, mountain regions, polar areas and the deep sea.

"The impacts of plastic inhalation on dolphins' lungs are not yet known," the study authors wrote, highlighting the need for more research on health outcomes.

Because dolphins are mammals with physiological similarities to humans, scientists warn they could experience comparable risks from microplastic exposure — for example, reproductive, neurological, or respiratory effects — though long-term consequences remain unquantified. Plastic ingestion and entanglement already kill many marine animals; the International Marine Mammal Project estimates about 300,000 marine animals die each year from plastic pollution.

Solutions And Next Steps

Researchers and conservation groups advocate a combination of prevention and remediation: reducing single-use plastics, improving waste management, and adopting eco-friendlier materials are immediate steps, while new technologies — from engineered enzymes or "superproteins" that can break down plastics to large-scale cleanup systems like those developed by The Ocean Cleanup — are being tested to remove existing pollution.

Further studies are needed to measure inhalation exposure more precisely, determine whether airborne microplastics cause measurable harm to marine mammals, and identify which interventions most effectively reduce risk for both ocean life and coastal communities.