Simulating microplastics path in human airways

Plastic is ubiquitous – easily spotted in packaging, clothing, and household items – but microplastics, just five millimeters or less in size, are even more pervasive. They can be found in water systems, accumulating in soil, and even in air. Inhaling microplastic-infested air results in microplastics reaching human lungs, but little is known about how they travel in the body or their effects on the respiratory system.

Riaz et al. developed a Computational Fluid Dynamics model to investigate microplastic movement in the lungs. They tested for different microplastic shapes inhaled by a model of a human CT scan.

“Microplastics are concerning because they can be inhaled and may accumulate in lung tissues,” said author Mohammad S. Islam. “Once in the lungs, microplastics can trigger inflammatory responses and may contribute to respiratory diseases. Moreover, the long-term effects of microplastic exposure on human health are still not fully understood, making it a topic of ongoing research and concern.”

The simulation tested different breathing intensities and microplastic shapes. The team identified deposition hotspots where microplastics gather in the airways, which can inform future targeted treatment.

“Understanding these hotspots is crucial for assessing the health risks of microplastic exposure and improving the design of drug delivery systems,” said Islam.

“Our findings not only advance our understanding of microplastic pollution’s impact on respiratory health but also hold promise for improving medical treatments. Looking ahead, it’s essential to continue investigating microplastic flow in the respiratory tract, considering factors like lung diseases and the environment, to better manage associated health risks,” said author Adnan Munir.

These findings can also help raise public awareness about microplastics. Strategies like reducing single-use plastics will help minimize microplastic exposure.

Source: “Breathing in danger: Mapping microplastic migration in the human respiratory system,” by Hafiz Hamza Riaz, Abdul Haseeb Lodhi, Adnan Munir, Ming Zhao, Umar Farooq, M. Nafees Mumtaz Qadri, and Mohammad S. Islam, Physics of Fluids (2024). The article can be accessed at https://doi.org/10.1063/5.0205303 .