[Do You Know?] Humans Inhale a Credit Card of Plastic In a Week - Where Does It Go?

It's a startling revelation: humans unknowingly inhale an estimated credit card's worth of microplastic particles each week.

These minuscule fragments, produced from the breakdown of plastic products, often harbor toxic pollutants and chemicals, posing significant health risks.

Microplastics Within the Respiratory System

Recognizing the urgent need to understand the movement of these inhaled microplastics within the respiratory system, a team of researchers from various institutions, including the University of Technology Sydney and the Queensland University of Technology, developed a cutting-edge computational fluid dynamics model.

Their study sheds light on microplastic transport and deposition in the upper airway.

The surge in global microplastic production and the alarming density of microplastics in the air have raised concerns about potential respiratory health hazards.

In fact, studies in 2022 discovered microplastics deep within human airways, underscoring the urgency to address this issue.

"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," said author Mohammad S. Islam.

Their findings revealed that microplastics tended to accumulate in specific regions of the nasal cavity and oropharynx, the back of the throat. This phenomenon can be attributed to the complex anatomy of the airway and intricate flow patterns within the nasal cavity and oropharynx.

Factors such as flow speed, particle inertia, and airway asymmetry contribute to the deposition and concentration of microplastics in these areas.

Under varying breathing conditions, the research team examined how microplastics of different shapes, including spherical, tetrahedral, and cylindrical, and sizes ranging from 1.6 to 5.56 microns behaved.

Additionally, the researchers noted that both breathing conditions and the size of microplastics played a role in determining the deposition rate within the airways.

Increased flow rates were associated with decreased deposition, while larger microplastics (measuring 5.56 microns) displayed a greater deposition tendency than smaller ones.

Inhalation of Microplastics

This study emphasizes the significance of addressing the exposure to and inhalation of microplastics, especially in regions facing elevated levels of plastic pollution or industrial operations.

The researchers aspire for their findings to contribute to advancing targeted drug delivery devices and enhancing health risk assessments.

Author YuanTong Gu emphasizes the need for greater awareness surrounding microplastics' presence and potential health impacts on the air we breathe.

Looking ahead, the research team aims to extend their investigations to analyze microplastic transport in a large-scale, patient-specific whole lung model. By incorporating environmental factors such as humidity and temperature, they hope to gain a comprehensive understanding of the intricate dynamics of microplastics in the respiratory system.

The study's findings were published in the Journal of Physics of Fluids.