Understanding Microplastics: What Recent Research Reveals

Almost everyone has heard of microplastics in some way or another. This is likely due to the fact that they are now found in our oceans, soil, air, food, water and even in our own bodies. As the topic has gained attention from the public, scientists have begun answering an important question that many people are asking:

Are microplastics harmful to human health?

Recent peer-reviewed research doesn’t provide us with every answer, but it does confirm something significant: microplastics are entering the human body, and they are not harmless.

What Are Microplastics?

Microplastics are plastic particles smaller than 5 millimeters. Some are created intentionally (like microbeads once used in cosmetics), while others form when larger plastic items break down over time.

Today, exposure appears widespread. Researchers have identified:

Microplastics in tap water
Microplastics in bottled water (plastic bottles and glass bottles)
Airborne synthetic fibers in indoor air
Plastic particles in crops and seafood

Because plastic does not easily break down, these particles persist in the environment and in the human body.

Microplastics Found in Human Blood

In 2022, researchers published a groundbreaking study in Environment International detecting microplastics in human blood for the first time (Leslie et al., 2022).

Out of 22 healthy adults tested:

(77%) or 17 of 22 participants had measurable plastic particles in their bloodstream
The blood samples contained plastic polymers including polyethylene terephthalate (PET)
The blood samples also showed polymers of styrene, which comes from polystyrene plastics

This research is concerning because particles circulating in the blood may travel to organs throughout the body. This discovery shifted microplastics research from an environmental issue to a human exposure issue.

Microplastics Found in Human Lungs

In 2022, a study published in Science of the Total Environment (Jenner et al., 2022) provided the first strong evidence that microplastics are present in living human lung tissue.

Researchers analyzed lung samples taken from 13 patients undergoing surgery. Using advanced spectroscopy techniques to identify plastic polymers, they detected microplastics in 11 of the 13 samples. In total, 39 individual microplastic particles were identified.

The types of plastic found included:

Polypropylene (commonly used in food packaging and textiles)
Polyethylene terephthalate (PET) (often used in bottled water containers)
Resins commonly used in industrial applications

This alarming study demonstrated that microplastics can be inhaled during everyday activities. Wearing synthetic clothing, vacuuming, or simply spending time indoors. All of these seemingly harmless aspects of our daily lives are secretly exposing us to airborne plastic fibers with little to no warning signs.

Nanoplastics and the Blood–Brain Barrier

In 2020, a peer-reviewed review published in the International Journal of Environmental Research and Public Health(Yong et al., 2020) examined emerging evidence on how microplastics and nanoplastics interact with mammalian tissues, including the brain.

Drawing from controlled animal studies, the authors summarized experiments in which polystyrene nanoplastics were orally administered to rodents. Researchers later detected these particles in brain tissue, demonstrating that extremely small plastic particles were able to cross the blood–brain barrier, a protective membrane designed to shield the brain from harmful substances circulating in the bloodstream.

In these animal models, brain exposure to nanoplastics was associated with:

Oxidative stress (an imbalance between free radicals and antioxidants)
Neuroinflammatory responses
Alterations in neurotransmitter levels

The authors emphasized that most current evidence comes from animal research, not human trials. However, the ability of nanoplastics to bypass the body’s protective barriers and accumulate in brain tissue raises important concerns. If similar translocation occurs in humans, chronic exposure could potentially influence neurological health through inflammation and cellular stress mechanisms—areas that researchers say urgently require further study.

How to Reduce Microplastic Exposure

While completely eliminating microplastic exposure isn’t realistic, there are practical steps that can help lower daily intake. Limiting bottled water, avoiding heating food in plastic containers, and storing food and drinks in glass or stainless steel can reduce plastic shedding. Improving indoor air quality by vacuuming with a HEPA filter and wet mopping can help decrease airborne synthetic fibers. Choosing natural fiber clothing when possible and reducing single use plastics may also lower both personal exposure and environmental contamination. Small and consistent changes in high frequency areas like drinking water, food storage, and indoor air, can meaningfully reduce cumulative exposure over time.