Bird Lungs Are Filled with Microplastics, UT Arlington Research Shows, Suggesting Risks to Humans
Large quantities of microplastics and nanoplastics that increasingly saturate the air we breathe are lodging in birds' lungs and making them sick, according to new research authored by a biologist from University of Texas at Arlington alongside collaborators in China.
These bits of plastic that can be invisible to the naked eye have increasingly filled the environment as plastic waste fragments into tiny particles, sparking fear over their potential to impact human and animal health. Plastics are manufactured by the petrochemical industry and can be highly resistant to degradation.
The new study, published in the Journal of Hazardous Materials earlier this year, provides the first evidence of dangerous microplastic contamination in wild bird lungs. Researchers quantified the plastic contamination inhaled by dozens of bird species using laser imaging, then used a calculation called the Polymer Hazard Index to determine its health impacts.
"Results suggest that most bird lungs in the study are at elevated risk of harm from microplastics exposure, which could potentially damage bird physiological functions and ecological balance," the academic paper said.
The research focused on birds as bioindicators because they are found across the world in the same environments as humans, according to Shane DuBay, an assistant professor at UT Arlington and the U.S.-based collaborator on the study.
"Birds serve as important indicators of environmental conditions," DuBay said. "Our research highlights an urgent need to address plastic pollution in our environments, as these contaminants can have far-reaching impacts on ecosystem health, as well as human health."
In humans, high concentrations of microplastics and nanoplastics are connected to inflammation, cancer and fertility problems, along with heart, lung, digestive and neurological illnesses.
To complete their analysis, study authors collected samples at China's Chengdu Tianfu International Airport between March and May 2024. They found an average of over 400 microplastic particles per gram of lung in the birds they analyzed. Most of the plastic particles they identified were about the size of a human skin cell (20-50 micrometers). The most prevalent plastic types were chlorinated polyethylene, used in cable and rubber industries, and synthetic butadiene rubber used in tire manufacturing.
The researchers also discovered that certain species were more heavily impacted than others: "terrestrial birds, carnivorous species and larger-bodied birds exhibited a greater burden" from the microplastics they inhaled, the paper said.