The Synthetic Fiber Of Clothing Falls Off To The Human Body, And The Toxicity Of These Plastic Particles Affects Health

A new study found that we inhale about 16.2 microplastic particles per hour. This means that our respiratory system inhales one credit card every week.

We will also eat and drink these plastic particles, because microplastics are now ubiquitous, even into our blood vessels. They exist in our tea, water and food, and more and more in the air. We cannot avoid them, nor do we understand their health effects.

"In 2022, the study found for the first time that there were microplastics in the depth of human respiratory tract, which raised concerns about serious respiratory health hazards." Mohammad Islam, an engineer at the University of Science and Technology in Sydney, said that this was their motivation for conducting the study.

Islam and colleagues from around the world have used a computational fluid dynamics model to safely explore how microplastics move in our upper respiratory tract under different respiratory conditions. This model has provided effective predictions for other forms of particles for decades.

The study found that the largest microplastics (5.56 microns) tend to stay in our upper respiratory tract, most likely in the nasal cavity or the back of the throat. The shape of the plastic dust also affects where it is deposited.

"The complex and highly asymmetric anatomical shape of the respiratory tract and the complex flow behavior of the nasal cavity and oropharynx lead to microplastics deviating from the flow path and depositing in these areas," Islam said. "Flow rate, particle inertia and asymmetric anatomy affect the total deposition amount and increase the deposition concentration in the nasal cavity and oropharynx region. Faster air flow rate leads to a decrease in the overall microplastics deposition amount, independent of their shape.

Islam and colleagues plan to next simulate how these particles move in our lungs. "Millions of tons of such microplastics particles have been found in water, air and soil. Global microplastics production is booming, and the density of microplastics in the air is also increasing significantly."

These micro plastics fall off from various plastic products around us. They may come from large-scale industrial production or daily consumer goods. One of the main sources of plastics is the clothing industry, which is constantly introducing cheaper synthetic fiber clothing.

Micro plastics will not cause immediate toxicity to us, but long-term inhalation or ingestion of these small pollutants may have adverse effects on our health, especially when they accumulate in our bodies.

In addition, plastic is also easy to absorb some harmful substances, such as drug-resistant bacteria, viruses and compounds containing flame retardants or phthalates. Therefore, it is an important step to find out where these microplastics deposit in our respiratory tract.

The study was published in Fluid Physics.