U.S. researchers have discovered microplastic particles in the exhaled air of wild bottlenose dolphins, indicating that inhalation might be a significant way for these potentially harmful pollutants to enter their bodies.
U.S. researchers have discovered microplastic particles in the exhaled air of wild bottlenose dolphins, indicating that inhalation might be a significant way for these potentially harmful pollutants to enter their bodies. Miranda Dziobak of the College of Charleston in South Carolina, U.S., and her team shared these findings in the open-access journal PLOS ONE on October 16, 2024.
People and many animals around the globe are coming into contact with tiny plastic particles known as microplastics. In humans and rodents, exposure to these microplastics has been associated with negative health effects, such as oxidative stress and inflammation. Consuming food that contains microplastics is a principal way both humans and wildlife encounter these particles, and inhaling airborne microplastics has also been connected to health issues in humans.
Despite this, there has been limited research on how inhalation may serve as a source of microplastic exposure in wildlife. This research team collected exhaled air samples from five bottlenose dolphins in Sarasota Bay, Florida, and six bottlenose dolphins in Barataria Bay, Louisiana, during health assessments conducted on a catch-and-release basis. They captured the exhaled air by holding a collection surface just above each dolphin’s blowhole as it breathed out.
Analysis of the samples revealed that all 11 dolphins exhaled at least one suspected microplastic particle. Further inspection of these particles indicated they were a mix of fibers and fragments, comprising various types of plastics, such as polyethylene terephthalate (PET), polyester, polyamide, polybutylene terephthalate, and poly(methyl methacrylate), known as PMMA.
For comparison purposes, the research team also collected air samples from the environment surrounding the dolphins, demonstrating that the identified microplastics were indeed exhaled air and not merely airborne particles near the blowhole.
These findings support the hypothesis that inhalation might be an essential method of microplastic exposure for dolphins, in addition to ingestion. Nevertheless, the authors caution that these findings are initial and that more studies are necessary to accurately assess how much microplastic exposure occurs via inhalation in bottlenose dolphins and to understand the potential health implications, such as lung damage.
The authors express: “We know that microplastics are present in the air, so we expected to find them in breath samples. What we found is concerning because dolphins have large lung capacities and take deep breaths, raising worries about the potential effects of these plastics on their lungs.”
