What are the most common microplastics found in humans? 

What are the most common microplastics found in humans?

⚕️ MEDICAL DISCLAIMER: This article is for informational and educational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any changes to your health regimen, diet, or supplement use, especially if you have existing medical conditions or take medications. The information presented here should not be used to diagnose, treat, cure, or prevent any disease.

Studies have shown that microplastics of all shapes, sizes, and chemical makeup are in humans and animals. Specific polymers show up repeatedly in human tissues, each with its own exposure pathways, toxicology profile, and tissue tropism. This article maps the most frequently detected microplastics in the human body and the biological systems that they can affect. Of course, significantly more research is needed to fully understand the impact of these microplastic particles. 

What are the most common microplastics found in humans? 

Polyethylene (PE)

Polyethylene (PE), commonly used in plastic grocery bags and bottles, is the most frequently detected plastic polymer in the human body. It’s been found in blood, lung tissue, breast milk, placenta, colon samples, hair, skin, saliva, and urine [1–7]. Its widespread presence is likely tied to its prevalence in packaging, films, and textiles. Inhalation of PE fibers, ingestion via packaging leachates, and dermal contact all contribute to its tissue burden. 

Mechanistically, PE fragments and fibers can hurt cell viability, disrupt cell membrane integrity, and alter cytokine expression in epithelial tissues. This means cells may die more quickly, not function properly, or express higher levels of inflammation. In vitro and animal studies link PE to redox imbalance and proinflammatory signaling cascades [2, 4, 6]. 

Polypropylene (PP)

Polypropylene (PP), used in food containers, surgical masks, and car parts, is the second most commonly found polymer in the human body. It appears in lung tissue, breast milk, placenta, and female reproductive organs [1, 5–6, 8–11]. PP enters the body through inhalation of airborne particles and ingestion of food packaging residue. 

Once internalized, PP can disrupt tight junctions in epithelial barriers, suppress antioxidant enzyme systems, and contribute to fibrosis in respiratory and reproductive tissues. It may also serve as a carrier for phthalates and other plasticizers, which amplify its toxicity. 

Polyethylene Terephthalate (PET)

Polyethylene terephthalate (PET), is another common contaminant, regularly found in blood and lung samples [1–5, 9–10]. As the base material for most bottled water and soda containers, PET’s release of microplastics increases with heat exposure and prolonged storage.

PET particles, especially in the nanosize range, can translocate across cell membranes and interfere with oxidative phosphorylation in mitochondria. Its surface chemistry also makes it prone to adsorbing environmental toxins, which it can bring with it into the body and eventually into tissues.

Polystyrene (PS)

Polystyrene (PS), has been detected in blood, lung tissue, tumor biopsies, and epithelial fluids like saliva and skin secretions [1–2, 5, 13]. Most commonly known for its use as styrofoam or in plastic packaging, styrene, the breakdown product of polystyrene, is a known endocrine disruptor. PS fragments have demonstrated genotoxicity in multiple cell lines.

Studies show that PS particles can activate the NLRP3 inflammasome, reduce sperm viability, and promote ROS-mediated cellular senescence. 

Polyvinyl Chloride (PVC)

Polyvinyl chloride (PVC), has been found in the digestive tract, tumors, skin, and breastmilk [1, 13–14]. It is often used in construction materials, pipes, flooring, and blood bags.

Toxicologically, PVC is one of the most concerning microplastic polymers due to its high chlorine content and reliance on additives like phthalates and heavy metal stabilizers. Ingestion or inhalation of PVC particles has been linked to DNA damage, inflammatory gut injury, and hepatotoxicity.

Other Emerging Polymers in Human Tissue

Other polymers are being detected with increasing frequency, including: 

• EVA (ethylene-vinyl acetate/alcohol) – found in human blood [4]
• PA (polyamide) – present in breast milk [1]
• PU (polyurethane) – detected in placental and mammary tissue [1, 6]
• PMMA (polymethyl methacrylate) – detected in tumors and hair [1, 8]
• PLA (polylactic acid) – a “biodegradable” polymer now showing up in epithelial samples [1]
• ABS (acrylonitrile butadiene styrene) – found in blood and tumor biopsies [1, 16]
• PTFE (polytetrafluoroethylene) – present in lung tissue and blood [1, 5, 15]

Each of these plastics brings its own risks, including chemical leachates, oxidative stress, or immune disruption, depending on particle size, shape, and additives.

Size, Shape, and Tissue Penetration

Smaller microplastic particles are more likely to cross biological barriers and accumulate in blood, lymph, and organ tissue. Additionally, shape plays a role. For example fibers are more likely to get trapped in lungs or be swallowed after inhalation [1]. As another example, sharp-edged fragments cause more mechanical damage than smooth spheres.

How To Avoid Microplastics

Different microplastics take different paths throughout the body, but they all interfere with biological processes. For individuals concerned about the impact of microplastics, it’s important to implement lifestyle changes to avoid exposure and intake of microplastics. While it’s extremely difficult, if not impossible, to avoid microplastics, there are many small, simple actions that you can take each day to lower the amount of microplastics you consume. This is why we developed the Deplasto platform. 

Our platform, consisting of a scientifically-supported nutritional supplement, an app for tracking and measuring microplastic intake over time, and lifestyle recommendations is intended to help you avoid microplastics. Our nutritional supplement, that contains ingredients studied alongside microplastics, is formulated to support your body’s natural detoxification defenses, including oxidative stress management, cellular repair, and antioxidant support. Our microplastic intake app is designed to show you an estimate of your daily exposure, with every datapoint backed by scientific studies, to help you understand how you can best avoid microplastics. Lastly, given that it’s nearly impossible to completely avoid microplastic exposure, we have a plethora of lifestyle recommendations designed to help you make small changes for big impacts. 

Overall, we believe that the best way to eliminate microplastics begins with you and the changes you make to your daily life. Over time, collectively, we can make a significant difference in your health and the environment.

Sources:

1. Detection of microplastics in human tissues and organs- A scoping review
2. Micro-nanoplastics and cardiovascular diseases- evidence and perspectives
3. Microplastic particles in human blood and their association with coagulation markers
4. Microplastics in human blood- Polymer types, concentrations and characterisation using μFTIR
5. A systematic review of microplastics emissions in kitchens- Understanding the links with diseases in daily life
6. First Report on Microplastics Quantification in Poultry Chicken and Potential Human Health Risks in Pakistan
7. Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage
8. MicroRaman spectroscopy detects the presence of microplastics in human urine and kidney tissue
9. Inhalation of Microplastics-A Toxicological Complexity
10. Microplastics and nanoplastics in cardiovascular disease-a narrative review with worrying links
11. Microplastics detected in three types of female reproductive organs using micro-Raman spectroscopy
12. Integrating aggregate exposure pathway and adverse outcome pathway for micro_nanoplastics- A review on exposure, toxicokinetics, and toxicity studies
13. Detection and quantification of microplastics in various types of human tumor tissues
14. Internal and external microplastic exposure in young adults- A pilot study involving 26 college students in Changsha, China
15. Microplastics in the Human Body- Exposure, Detection, and Risk of Carcinogenesis- A State-of-the-Art Review
16. Association of mixed exposure to microplastics with sperm dysfunction- a multi-site study in China