Microplastics Pose an Inhalation Risk

Microplastics and nanoplastics are one of the “new” pollution concerns.  Like “forever chemicals” and pesticides, once again there is a concern about contaminants we can’t even see!   Microplastics are tiny plastic pieces less than or equal to 5 mm, small microplastics are less than or equal to 20 micrometers or microns, and nanoplastics are less than or equal to 1 micron. Exactly how do these get into our bodies?  Here are some routes being researched:

• Eating foods contaminated with microplastics: one 2025 study found that Indonesians eat about 15 grams of microplastics per month—more than any other country—with the majority of plastic particles coming from aquatic sources such as seafood.

• Drinking contaminated water or other beverages: milk, water, tea and coffee, and bottled beverages can all contain microplastics

• Inhaling microplastics from degrading plastics in the environment: Again, Asian countries topped the list: Residents of China and Mongolia breathe in more than 2.8 million particles per month, while U.S. residents inhale about 300,000 particles per month. (Study maps human uptake of microplastics across 109 countries)

Because HypoAir focuses on air quality, we’d like to look at where in the environment they come from, and how these microplastics get into our bodies via inhalation. 

Where do the particles come from?  The primary sources of microplastics are intentionally manufactured and placed in cosmetics and personal care products such as toothpaste.  Obviously toothpaste is swallowed, not inhaled, but creams and lotions that dry on the skin can flake off and be inhaled.

The secondary sources of microplastics are fragments derived from the degradation of larger plastic products, such as water bottles, food containers and clothes.  Synthetic textiles are a principal source of indoor airborne plastic particles, while a multitude of sources contaminate the outdoor environment from aerosols from the ocean to particles originating from wastewater treatment (which also contaminate the ocean when there’s a sewage spill, which is more common than most realize).  (Every breath you take: Following the journey of inhaled plastic particle pollution)  There are incredibly high numbers of microplastics in sewage.  A 2025 study in Plymouth, UK showed that within a two-year period, sewage spills into the sea coincided with onshore winds of at least 14.5 mph on at least 178 days (that’s almost 25% of those 2 years!)   These stronger onshore winds can aerosolize plastic particles from the sewage-contaminated water and float them over the city, not only presenting problems from the plastics but also sewage microbes that stick to the plastics (yuck!).

 Of course, humans inhale air via the nasal passages and trachea (windpipe), and depending on the size of particles, they can get lodged/accumulate at different points along the way, all the way to the deepest parts of our lungs (alveoli), where nanoplastics can cross the air/blood barrier.  

A 2025 study used computer models of breathing rates along with particle size and shape to determine where in the respiratory system plastic particles would be deposited. (Every breath you take: Following the journey of inhaled plastic particle pollution).  According to Senior Lecturer of Mechanical Engineering Dr. Suvash Saha, of the University of Technology Sydney,  "Faster breathing rates led to heightened deposition in the upper respiratory tract, particularly for larger microplastics, whereas slower breathing facilitated deeper penetration and deposition of smaller nanoplastic particles. Particle shape was another factor, with non-spherical microplastic particles showing a propensity for deeper lung penetration compared to spherical microplastics and nanoplastics, potentially leading to different health outcomes.” 

In addition to the blood barrier in the lungs, there is a vulnerable spot in our noses where microplastics may be able to get into the brain.  There are special nerves called the olfactory nerves, that detect smells.  These run from the inside of the nose, through the skull, and then directly into part of the brain called the olfactory bulb.  Somehow microplastics may get transported along these nerves into the brain.   Researchers from the Freie Universität Berlin and the University of São Paulo analyzed the olfactory bulbs of 15 residents of São Paulo who had died. Eight out of the 15 brains studied had microplastics in their olfactory bulbs (but, comfortingly, these eight samples had only 16 microplastic particles between them).  The 16 plastic particles included fragments, spheres and fibers made of polypropylene, nylon and other plastics, some of which could have come from clothing. Laundering clothes made from synthetic fibers is a significant source of microplastics in the environment.  These individuals did not die from the particles, however nanoplastics have been shown to kill cells in animal embryos, which can lead to birth defects in animals if the embryo is exposed to a high dose of nanoparticles.  (Breathing may introduce microplastics to the brain—new study) 

Plastic pollution is going to be a problem for decades to come.   However, with information about where it’s coming from, we can be more careful about not breathing it in.  We think the following tips could help:

• Synthetic clothing and home furnishings are a source of microplastics, so we might, first of all, evaluate what we buy in light of how it can damage our bodies and the environment.  Secondly, dispose of overly-worn synthetic clothing (microfiber sheets, synthetic fleece, nylon clothing, etc.) into a landfill instead of continuing to use and launder them, which releases particles into the air and water.  The same applies to old plastic containers and bags that are degrading.

• The ultrafine particles that come from tires also contain microplastics, therefore it’s another reason to consider where you live, work and go to school in relation to heavy traffic areas and wind patterns.  If you do live in these polluted areas, try to filter as much of the air you breathe outside and inside as possible! (Tires Shed Millions Of Tonnes Of Microplastics Into The Environment)

• Consider installing a nanoparticle lint trap such as Filtrol, PlanetCare, CleanR or Lint LUV-R in your washing machine drain. 

• Alternatively, you can catch the laundry particles in devices such as a Guppyfriend Washing Bag (no installations required) and dispose of them into a landfill.

• Beware of spending time at urban waterways when there are high winds as these may pick up microplastics from the water (which emanate from sewage spills). 

• Stop microwaving and dishwashing plastics: Microwaving them releases microplastics into your food, and washing plastic containers in the dishwasher can release up to 920,000 micro- and nanoplastic particles per load. (Running plastic dishes through the dishwasher adds millions of microplastics to wastewater each year)  When you can, store and heat your food in non-plastic containers, like glass or ceramics (that don’t also contain lead), and handwash plastic containers or replace them with glass or ceramic. 

• Clean your home’s floors with a wet mop or HEPA vacuum-mop, since microplastics love to cling to dust (and are an inhalation problem for everyone in the home, especially children who play on the floor). 

Photo by John Cameron on Unsplash