Scientists Warn Toxic Microplastics Now Getting Stuck in Our Airways

Microplastics are everywhere, even in the air we breathe—and we're consuming increasing amounts of them, according to scientists.

Research published in the journal Physics of Fluids on Tuesday shows that we breathe in large amounts of microplastic, which accumulate at particular spots at the back of our throats and in our nasal cavities. Humans inhale around 16.2 pieces of microplastic every hour, which adds up to about a credit card's worth across a week.

"Tiny microplastic debris is generated from the degradation of plastic products, consumer products, tire wear, and industrial breakdown. Millions of tons of these microplastic particles have been found in seas, atmospheric air and soil," paper co-author and material scientist at the University of New South Wales Sydney, Mohammad S. Islam, told Newsweek. "Global microplastic production is significantly increased these days."

Microplastics are tiny chunks of plastic, defined as being less than 5 millimeters (0.2 inches) across.

They come from a variety of plastic sources, ranging from synthetic materials, car tires, abrasion of everyday objects like shoe soles, cosmetics containing microbeads, and coatings of ships, among many others. These microplastics are released into the environment and are found in both the water and the air.

This paper found that microplastics in the air tend to accumulate in the back of the throat, in hot spots in the nasal cavity and oropharynx. The amount that collects in these areas depended on breathing conditions and microplastic size.

This is a crucial issue, due to the effects that microplastics can have on the body.

These particles can cause damage to the windpipe and to lung tissues, increasing the risk of developing lung conditions like emphysema and lung cancer, Swiss air quality tech firm IQAir reports.

Additionally, they often carry toxins on their surface, including polycyclic aromatic hydrocarbons.

"Microplastics usually contain toxic pollutants and chemicals. The toxic substances from the inhaled microplastics could potentially cause serious health hazards in the respiratory system," the authors wrote in the paper.

These microplastics, if they're small enough, can also enter the bloodstream. This can lead to build-ups in the blood vessels, leading to a hardening of the arteries called atherosclerosis.

"We usually inhale the microplastics from the atmospheric air, some of which come out of the lung through exhalation," Islam said. "Some of those trap in the nose as we have hair inside the nose. Some of those traps are in the mucus layer of the nose. They eventually come out of the airways through exhalation and dry mucus. Some fine microplastics go to the lower airways, trap in the mucus layer, and cross the submucosa and other epithelium later.

"Finally, it could enter the bloodstream of the body. Depending on the residence time, it becomes more toxic and creates different respiratory diseases, including cancer," he said.

To prevent breathing in these microplastics, Islam suggests: "Filter your indoor air, ventilate your living spaces, minimize plastic use, avoid activities that release microplastics, choose natural fibers, and be cautious during laundry."

"While these steps can help minimize exposure to microplastics, it is challenging to eliminate them completely from the environment. Thus, adopting a broader perspective towards reducing plastic pollution, in general, is essential," he said.

Reducing the amount of microplastics in the air and water requires using less of the processes and materials that generate them. One 2009 study in the journal Philosophical Transactions of the Royal Society B: Biological Sciences found that fast-decomposing materials like starch-based polymers, plant-based silvergrass, wood fiber and coconut fiber might be good replacements for plastics. Additionally, using multi-use products rather than single-use can cut plastic waste, and recycling plastics can prevent them from being ground into microplastics.

The authors hope that this study will further alert the world to the dangers of microplastic and how they affect the body.

"The results of this study could be useful for the health risk assessment under the exposure to hazardous particles topic," the authors wrote in the paper. "However, the comprehensive investigation of microplastic and its characteristic will be further studied to enhance the understanding of its effect on the human respiratory system. This includes the effect of microplastic with various shapes under the consideration of various microplastic sizes and flow rates.

"Moreover, the complex lung geometry with upper and lower lung generations will be further considered under the healthy and diseased airways conditions. The effect of environmental conditions such as humidity and temperature will be also considered in the future study."

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