We have known for years that plastic pollution reaches our oceans, soil and food.
Now researchers are finding tiny plastic particles inside the human body.
Microplastics have already been detected in human blood, lungs and other tissues. A recent report drew attention to an especially troubling discovery.
Researchers tested 17 human artery samples. They found microplastics in every one.
Does this mean plastic causes heart disease?
Not necessarily. The study was small and could not prove cause and effect.
However, the findings give us another reason to reduce unnecessary plastic exposure.
What are “microplastics”?
Microplastics are plastic fragments measuring less than five millimetres across.
Some are visible to the naked eye. Others are far too small to see.
Nanoplastics are smaller still. Some are tiny enough to pass through biological barriers and enter body tissues.
These particles come from many sources.
Plastic bottles, food packaging, synthetic clothing and household dust can all release them. Larger plastic products also break down into smaller pieces as they age.
We may swallow microplastics in food and water. We may also breathe them from the air.
Once inside the body, some particles may pass through the digestive or respiratory system. Smaller particles may enter the bloodstream and travel elsewhere.
What did the artery study find?
The research was published in the Journal of Hazardous Materials in 2024.
Scientists examined 17 artery samples collected during surgery. The samples came from coronary, carotid and aortic arteries.
Microplastics appeared in all 17 samples.
The average concentration was approximately 119 micrograms per gram of tissue. Researchers identified four types of plastic.
Polyethylene terephthalate, commonly called PET, was the most abundant. It represented almost 74% of the detected plastic.
PET is widely used in:
- Disposable drink bottles
- Food containers
- Synthetic clothing
- Packaging materials
The researchers also noticed an important difference.
Coronary and carotid samples containing fatty plaque had about twice the microplastic concentration found in aortic samples without plaque.
That sounds alarming, but we must interpret it carefully.
The samples came from different artery types and different patients. The study does not prove that plastic created the fatty plaque.
It could also be that damaged or diseased artery tissue collects more particles. Other differences between patients may have influenced the results.
The researchers described their findings as useful evidence for further investigation—not proof that microplastics cause cardiovascular disease. Read the original study summary.
Could microplastics affect our arteries?
Scientists are still working this out.
Laboratory and animal studies suggest several possible pathways.
Microplastics may contribute to oxidative stress. This happens when damaging free radicals overwhelm the body’s protective systems.
The particles might also trigger immune responses and inflammation. Long-lasting inflammation plays a role in many chronic diseases, including cardiovascular disease.
Plastic particles may interfere with normal fat and energy metabolism. Some plastics also contain chemical additives that can escape from the material.
However, finding a possible biological mechanism is not the same as proving harm in people.
We need larger studies that examine exposure, particle size, plastic type and long-term health outcomes.
A larger heart study raised more questions
A separate study published in The New England Journal of Medicine examined plaque removed from the carotid arteries of 304 patients.
Researchers detected polyethylene in the plaques of 150 patients. They found polyvinyl chloride, or PVC, in 31 patients.
The researchers followed 257 participants for an average of 34 months.
People whose plaques contained microplastics or nanoplastics experienced more heart attacks, strokes and deaths than people without detectable plastic in their plaques.
This was an association. It did not prove that the particles caused those events.
People with greater plastic exposure could also differ in diet, occupation, location or general health.
Even so, the result makes the artery findings harder to dismiss. Read the cardiovascular study.
Should we worry about drinking water?
Microplastics have been detected in both bottled and tap water.
That does not mean all water contains the same amount. Concentrations vary widely between locations, products and testing methods.
The World Health Organization says available evidence remains limited. It has not established that microplastics in drinking water create a significant health risk at current measured levels.
That conclusion is not a declaration that microplastics are harmless.
It means scientists do not yet have enough reliable human evidence to calculate the risk.
The WHO continues to call for better testing methods and more health research. It also recommends reducing plastic pollution and improving water treatment. See the WHO review.
Bottled water is not automatically the safer choice.
Plastic bottles can release particles during manufacturing, transport, storage and use. Heat, sunlight and physical damage may accelerate the breakdown of plastic.
Switching entirely from tap water to bottled water could therefore increase plastic use without guaranteeing lower exposure.
Can a water filter remove microplastics?
Some filtration systems can reduce microplastic particles.
The result depends on the filter’s pore size, design, condition and flow rate. Larger particles are easier to capture than extremely small nanoplastics.
No responsible supplier should claim that every filter removes all microplastics without suitable laboratory testing.
Water treatment also needs to address established risks. These may include microbes, lead, PFAS, chlorine by-products and other contaminants found in a particular supply.
Microplastics matter, but they should form part of a complete water-quality assessment.
Take a look at the UltraStream, our ‘best way’ to minimize microplastics.
Simple ways to reduce plastic exposure
We cannot avoid every plastic particle. Plastic is now present throughout our environment.
We can still reduce unnecessary exposure.
Try these practical steps:
- Use glass or stainless-steel drink containers.
- Avoid heating food in plastic containers.
- Replace badly scratched plastic food containers.
- Reduce heavily packaged and highly processed foods.
- Do not leave plastic water bottles in hot cars.
- Vacuum and remove indoor dust regularly.
- Wash synthetic clothing gently and less often.
- Choose a properly tested water filter.
- Reduce disposable plastic wherever practical.
There is no need to panic or attempt a “plastic detox.”
No supplement, cleanse or special drink has been proven to remove microplastics from human arteries.
The sensible approach is to reduce ongoing exposure while supporting established heart-health measures. These include not smoking, exercising, eating well and managing blood pressure, cholesterol and diabetes.
What should we take from this?
Finding microplastics in every one of 17 artery samples is concerning.
It tells us that plastic pollution is no longer only an environmental issue. At least some of it is reaching human tissues.
What it does not tell us is whether these particles caused the patients’ artery disease.
Science must now answer the harder questions.
How are the particles entering artery walls? Which plastics are most harmful? Do smaller particles create greater risks? Can reducing exposure improve health?
Until we have those answers, sensible prevention costs very little.
Use less disposable plastic. Avoid heating plastic around food and water. Filter drinking water where appropriate. Support efforts to reduce plastic pollution.
We may not be able to remove plastic from modern life completely.
But we can stop treating unnecessary plastic exposure as unavoidable.