A new study shows how dangerous plastic particles get stuck in the nose and back of the throat.
Studies indicate that individuals are likely to breathe in close to 16.2 microplastic particles every hour, which adds up to the weight of a plastic card over the course of a week. These microplastics are minuscule fragments in the environment that form as a result of the breakdown of plastic materials and typically carry hazardous pollutants and chemicals with them.
The inhalation of microplastics can be detrimental to one’s health; therefore, comprehending their path within the respiratory tract is vital for the prevention and handling of respiratory ailments.
In a paper in Physics of Fluids by AIP Publishing, a collective effort from scholars at the University of Technology Sydney, Western Sydney University, Urmia University, Islamic Azad University, the University of Comilla, and Queensland University of Technology led to the creation of a computational fluid dynamics model that examines the movement and settling of microplastics in the upper respiratory system.
“Millions of tons of these microplastic particles have been found in water, air, and soil. Global microplastic production is surging, and the density of microplastics in the air is increasing significantly,” adds author Mohammad S. Islam. “For the first time, in 2022, studies found microplastics deep in human airways, which raises the concern of serious respiratory health hazards.”
The group investigated how microplastics of varying shapes (such as spherical, tetrahedral, and cylindrical) and sizes (1.6, 2.56, and 5.56 microns) moved under different breathing paces (slow and fast).
The study found that these microplastics often accumulated in specific regions within the nasal cavity and the oropharynx, which is the area at the rear of the throat.
“The complicated and highly asymmetric anatomical shape of the airway and complex flow behavior in the nasal cavity and oropharynx causes the microplastics to deviate from the flow pathline and deposit in those areas,” adds Islam. “The flow speed, particle inertia, and asymmetric anatomy influence the overall deposition and increase the deposition concentration in nasal cavities and the oropharynx area.”
The rate at which microplastics deposit in the airways is influenced by both the breathing conditions and the size of the microplastics. The authors found that a faster airflow resulted in less deposition, and the larger (5.56 micron) microplastics were found more frequently in the airways compared to smaller particles.
They maintain that their study underscores the serious issue of exposure to and inhalation of microplastics, especially in regions with high plastic pollution or industrial activities. They aspire that their findings could contribute to the design of precise drug delivery devices and enhance health risk evaluations.
YuanTong Gu, one of the authors, emphasizes, “This study emphasizes the need for greater awareness of the presence and potential health impacts of microplastics in the air we breathe.”
Looking ahead, the team aims to investigate the transport of microplastics on a broader scale, using a patient-specific whole lung model, and incorporating environmental variables such as humidity and temperature.
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