Microplastics and their impact on our body
We live in a world where plastic is inescapable. From food packaging to clothing and cosmetics, plastic plays a role in many aspects of our lives. But what if these plastics don't just stay in our environment, but also enter our bodies? Research shows that micro- and nanoplastics are making their way into our organs, blood, and even our brains. What does this mean for our health? And what can we do to reduce our exposure? In this blog, I’ll walk you through the science behind micro- and nanoplastics and share what you need to know to protect your health.
In This Article You’ll Learn…
..the difference between microplastics (MP) and nanoplastics (NP).
..how plastic spreads and enters our bodies.
..what plastic does to your brain, hormones, nerves, and reproduction.
..practical ways to reduce plastic exposure.
..why avoiding plastic completely isn’t possible, but conscious choices can help.
Essential Knowledge About Plastics
What is Plastic?
Plastic is a synthetic material, and most plastics are produced from fossil fuels, mainly petroleum and natural gas.
A Brief History of Plastic
In 1950, large-scale plastic production began. Many factories that had been used during World War II for producing materials and equipment were repurposed after the war to manufacture consumer goods. There was a significant demand for relatively cheap, practical, and quickly produced materials. Plastic fit this need perfectly, often replacing more expensive or scarce raw materials.
Possible Short vs. Long-Term effects
Short-Term Effects
• Irritation and inflammation in the intestines or other tissues
• Disruption of gut flora
• Nervous system disturbances
Long-Term Effects
• Hormonal disruption
• Increased risk of chronic diseases
• Fertility issues
• Accumulation and tissue damage
• Greater risk of blood clots
Key Harmful Substances
Terms You May Have Heard Before
You may have heard that BPA-free products are good because BPA is harmful. Or you might recognize the term PET bottle. There are also terms you may not have heard before, like Phenol or PFAS.
What’s the Connection Between These Chemicals?
All these chemicals have one thing in common: they are used in plastics and consumer products and can have harmful effects on our health.
BPA (Bisphenol A): A synthetic chemical found in plastic bottles, food containers, can linings, and receipts.
BPS (Bisphenol S): A replacement for BPA, often used in “BPA-free” products but just as harmful.
PET (Polyethylene Terephthalate): A commonly used plastic for water bottles, soda bottles, and food packaging. Considered safe but can release microplastics and chemicals when heated.
Phenol: An organic chemical used in the production of plastics, adhesives, and disinfectants. BPA is a type of phenol.
Phthalates: Additives that make plastic flexible and soft. Found in packaging, PVC products, toys, cosmetics, perfumes, carpets, and medical equipment.
PFAS (Per- and Polyfluoroalkyl Substances) – The "Forever Chemicals": A group of thousands of chemicals with water-, grease-, and stain-resistant properties. Found in non-stick pans (Teflon), waterproof clothing, fast-food packaging, fire-fighting foam, and cosmetics.
The Difference Between Nanoplastics and Microplastics
The primary difference between microplastics and nanoplastics is their size, which affects how deeply they can penetrate the body.
Microplastics (MPs): 1 micrometer (1 µm) to 5 millimeters (5 mm), about the size of a grain of sand. They break down from larger plastic objects.
Nanoplastics (NPs): Smaller than 1 micrometer (1 µm), less than 1/1000th of a millimeter, formed by the further breakdown of microplastics. For comparison, mitochondria (the “powerhouses” of the cell) are about 0.5 to 1 micrometer in diameter and 1-2 micrometers in length.
Plastic in Our Bodies
You may have heard claims that humans ingest the equivalent of a credit card (5 grams) every two weeks. This came from early research assuming the highest possible intake.
Later studies show this estimate was too high. In reality, intake ranges from 1 milligram to a few hundred milligrams per week. However, even 1 mg of plastic could contain thousands of microplastics or trillions of nanoplastics.
“Microplastics are often called a ‘cocktail of contaminants’ because various harmful chemicals stick to them.”
Once Inside, What Does It Do?
The Olfactory Bulb is a nerve cluster in the brain (located near the nose) responsible for our sense of smell.
Researchers who examined 15 deceased individuals found several microplastic particles in this part of the brain. This means that these plastic particles had crossed the Blood-Brain Barrier (BBB)—a barrier designed to keep harmful substances out while allowing beneficial ones to pass through.
Micro- or nanoplastics that manage to penetrate this barrier could cause damage, potentially leading to paralysis or loss of function. In another study, researchers found that micro- or nanoplastics in the brain could make us more susceptible to Alzheimer's and Parkinson's diseases.
During Pregnancy
Micro- and nanoplastics may be able to cross the placental barrier (a barrier that, like the BBB, is supposed to block harmful substances), potentially reaching the fetus.
The placental barrier normally functions to keep harmful substances out, but if plastic particles manage to penetrate it, there is a risk that the development of the unborn child could be disrupted.
Some researchers suspect that this could lead to growth abnormalities or hormonal changes in the baby.
The Endocrine System
The endocrine system regulates our hormones and controls essential processes such as growth, metabolism, and mood. Micro- and nanoplastics can disrupt this system, particularly affecting testosterone.
Research shows that micro- and nanoplastics can alter testosterone levels in both men and women. Among the study participants, the most significant changes in testosterone were observed in women aged 40-60 and boys aged 6-12.
Testosterone plays a vital role in reproduction, muscle growth, and overall health. Prolonged exposure to these plastics may lead to fertility problems or other health issues.
Reproduction
Micro- and nanoplastics may affect reproduction by accumulating in the testes, potentially leading to a reduction in sperm count.
Additionally, they could negatively impact the quality of egg cells and sperm cells.
While more research is needed to confirm this, scientists are concerned that plastic particles could harm fertility in the long term.
The Gut
A large part of our immune system is located in the digestive tract. Research indicates that micro- and nanoplastics may irritate the intestinal lining and alter the composition of gut flora.
This is particularly relevant for people with IBS (Irritable Bowel Syndrome), as their intestines are often more sensitive and vulnerable. If microplastics exacerbate existing inflammation or disrupt the gut flora balance, it can lead to increased or more severe symptoms.
Although research is still in its early stages, initial findings suggest that exposure to microplastics may play a role in worsening gut issues.
The Nervous System
Micro- and nanoplastics can disrupt certain enzymes in the nervous system. These enzymes are essential for transmitting signals throughout the body.
When these enzymes don’t function properly, it can lead to motor impairments (problems with movement) and cognitive disorders (problems with thinking and memory).
Although this has primarily been studied in laboratory settings so far, researchers remain cautious about the potential effects on humans.
In the Arteries
Micro- and nanoplastics can also enter the bloodstream. Researchers have investigated the formation of atheromas (plaque buildup in the blood vessel walls), which can lead to atherosclerosis (hardening of the arteries).
The concern is that these tiny plastic particles may trigger inflammatory reactions in the vessel walls, causing plaques to form more quickly or worsen. This increases the risk of cardiovascular problems, such as heart attacks or strokes.
Although this link has not yet been fully proven, the initial research findings are concerning enough to warrant further investigation into the exact impact of micro- and nanoplastics on heart and vascular health.
Keeping plastics outside of our body
Completely keeping plastic out of our bodies seems impossible, but we can certainly reduce the amount we ingest by making the right choices.
Food products
Pre-packaged ready meals: Plastic packaging can release microplastics when heated (for example, in the microwave).
Plastic water bottles (PET bottles): Bottled water often contains more microplastics than tap water. At warm temperatures or when exposed to sunlight, even more microplastics can be released into the water.
Fish and shellfish: These often contain microplastics in their stomach and intestines. The amount we ingest varies by species and region. Rinse and clean these products thoroughly, or choose alternative protein sources when possible.
Tip: Opt for fresh, unpackaged foods—buy fruits and vegetables loose. Use glass or stainless steel containers for storage, and avoid heating food in plastic containers.
Clothing
Synthetic Fabrics (Polyester, Nylon, Acrylic):
These fabrics can release thousands of microfibers with every wash, which end up in the water system and eventually in the food chain. Additionally, your skin can absorb particles while wearing these clothes, especially in sensitive areas like the vulva.
Natural Fibers (Cotton, Wool, Linen, Hemp): These do not release plastic fibers.
Tip: Use a washing bag or filter for synthetic clothing to catch plastic fibers in the washing machine. Air-dry clothes instead of using a dryer to reduce fiber shedding.
Products to avoid/ replace
Cosmetics and Personal Care Products with Microplastics
Scrubs, toothpaste, and makeup containing plastic particles often wash directly into the sewage system, eventually ending up in rivers and oceans. Choose products with natural exfoliants and look for labels like ‘microplastic-free’.
Plastic Tea Bags
Some tea bags have a thin plastic layer that can dissolve at high temperatures, releasing microplastics. Loose leaf tea or paper bags made from natural fibers are more sustainable alternatives.
Plastic Kitchenware (Cutting Boards, Spatulas, etc.)
When cutting or stirring, plastic spatulas and cutting boards can release microscopic plastic particles, especially when exposed to heat. Opt for wood, bamboo, or stainless steel kitchenware to avoid micro- and nanoplastics.
Plastic Bottles and Drinking Cups
Plastic bottles can wear down over time and release microplastics, particularly with repeated use or heat exposure. Reusable bottles made from stainless steel or glass are safer and more eco-friendly alternatives.
To-Go Cups
Many disposable cups have a plastic coating that releases nanoplastics when exposed to heat (from tea or coffee). Reusable thermos cups made from stainless steel, glass, or bamboo offer a sustainable and stylish alternative.
How Micro- en Nanoplastics spread
Evaporation
As water evaporates from oceans and lakes, ultrafine plastic particles can rise into the atmosphere. These particles attach to dust and spread over long distances.
Snow
Once in the air, micro- and nanoplastics bind to snowflakes and fall back to the ground. When the snow melts, they enter rivers, groundwater, and the soil. Researchers have even found microplastics in snow samples from Antarctica.
Breaking Waves
When waves break, tiny water droplets are released, carrying plastic particles into the air. Through sea spray, microplastics are dispersed across large areas.
Rain
During rain showers, plastic particles fall from the atmosphere onto land and water. This leads to further distribution in ecosystems and can eventually end up in our drinking water.
Kerosene – Fine Particles from Airplanes
In addition to CO₂, airplanes emit fine particles and kerosene residues, which can act as carriers for micro- and nanoplastics. These particles spread in the upper atmosphere and settle in areas far from flight paths.
Challenges in Research
Micro- and Nanoplastics (MPs and NPs) are difficult to measure due to their extremely small size and varied compositions.
As a result, there are currently no universal standards for detecting and analyzing these particles consistently. At the same time, the exact impact on human health and the environment remains unclear, highlighting the need for further research.
Challenges
• The lack of standardized measurement methods.
• The wide variation in shape, size, and chemical composition of the particles.
• The high cost and complexity of advanced analytical techniques.
• The limited ability to reliably isolate very small (nano) particles.
• Incomplete knowledge about the long-term effects on humans and the environment.
Conclusion
Micro- and nanoplastics are infiltrating both our environment and our bodies, and in the short term, they can cause inflammation or mild disruptions.
The potential long-term risks—such as hormonal imbalances, cardiovascular diseases, and fertility issues are still being investigated.
While there’s no need for immediate alarm, becoming more mindful about plastic use, reducing plastic packaging and washing synthetic clothing more carefully can help limit our exposure and reduce potential risks.
Sources
Check out the articles used for this blog below to get an even deeper insight and understanding of the topic.
Estimation of the mass of microplastics ingested – A pivotal first step towards human health risk assessment (Journal of Hazardous Materials)
Ingested microplastics: Do humans eat one credit card per week? (Journal of Hazardous Materials Letters)
Microplastics in the Olfactory Bulb of the Human Brain (JAMA Network Open)
Microplastic presence in dog and human testis and its potential association with sperm count and weights of testis and epididymis (Toxicological Sciences)
Detection of microplastics in human lung tissue using μFTIR spectroscopy (Science of The Total Environment)
Plasticenta: First evidence of microplastics in human placenta (Environment International)
Detection of various microplastics in placentas, meconium, infant feces, breastmilk and infant formula: A pilot prospective study (Science of The Total Environment)
Rapid single-particle chemical imaging of nanoplastics by SRS microscopy (Proceedings of the National Academy of Sciences)
Microplastics in European sea salts – An example of exposure through consumer choice and of interstudy methodological discrepancies (Ecotoxicology and Environmental Safety)
Canned Soup Consumption and Urinary Bisphenol A: A Randomized Crossover Trial (JAMA)
Microplastics and other harmful substances released from disposable paper cups into hot water (Journal of Hazardous Materials)
Microplastics and other harmful substances released from disposable paper cups into hot water (Journal of Hazardous Materials)
Urinary Phthalate Metabolites Are Associated With Decreased Serum Testosterone in Men, Women, and Children From NHANES 2011–2012 (The Journal of Clinical Endocrinology & Metabolism)
Microplastics and Nanoplastics in Atheromas and Cardiovascular Events (The New England Journal of Medicine)
The plastic brain: neurotoxicity of micro- and nanoplastics (Particle and Fibre Toxicology)
