Microplastics (MPs) are tiny fragments of plastic measuring less than five millimeters. These ubiquitous particles, formed from the breakdown of larger plastic waste, have recently been confirmed to circulate within the human body. Scientists first reported the detection of plastic polymers in human blood in a 2022 study, finding these particles in nearly 80% of tested subjects. This finding demonstrates that MPs are absorbed and transported throughout the body via the bloodstream. While the long-term health consequences of this internal exposure are still under intense investigation, the discovery validates growing concerns about plastic pollution’s direct impact on human physiology.
Sources and Entry Points into the Body
The primary ways microplastics enter the human body are through ingestion and inhalation. Ingesting microplastics occurs through contaminated food and water sources, including both tap and bottled water. Food items like seafood and commercial products such as table salt contribute to daily intake. The degradation of plastic packaging, especially when food is heated or stored in plastic containers, causes microplastics to leach directly into meals.
Inhalation represents another significant pathway, as airborne microplastic fibers are shed constantly from synthetic textiles like polyester and nylon clothing. Urban dust, tire wear, and general air pollution release these tiny particles, which are then breathed in, especially indoors where concentrations can be higher. Once inhaled, these particles can settle in the respiratory tract.
A third, less significant route is through dermal contact, where microplastics, particularly nanoplastics, may pass through the skin barrier. Personal care products containing microbeads or creams with minute plastic components offer a path for this entry. However, the digestive and respiratory systems remain the main portals for microplastic entry into the body’s internal systems.
Circulation and Biological Retention
Once microplastics enter the body, they must cross biological membranes to reach the bloodstream, a process dependent on particle size and composition. Particles absorbed through the digestive tract and lungs must be small enough to pass through the epithelial lining. Particles generally smaller than 5 to 10 micrometers are believed to be the most capable of translocating from the gut or the deep lung alveoli into the circulatory system.
The blood then functions as a transport system, distributing these foreign particles, which are treated as xenobiotics, throughout the body. Evidence indicates that MPs are carried to various organs, including the liver, kidneys, spleen, lungs, and even the placenta. In the liver and spleen, the particles may be intercepted by the body’s filtration and immune cells.
However, the body’s natural clearance mechanisms struggle to fully eliminate these particles. The kidneys, which filter waste from the blood, are designed to excrete soluble compounds, making them ineffective against solid plastic fragments. Particles larger than the diameter of microcapillaries, approximately 5 to 8 micrometers, can cause localized obstruction and potentially lead to accumulation in tissues. While some microplastics are excreted through feces, a fraction of the smallest particles are retained, leading to their persistence in various tissues over time.
Current Limitations in Medical Removal
There are currently no established, standardized medical treatments for removing microplastics already circulating in the blood. Conventional medical procedures, such as specialized dialysis or chelation therapy used for heavy metals, have not been approved or widely adopted for safe and effective microplastic extraction. The complex nature of MPs—varying widely in size, shape, and chemical composition—makes a single targeted treatment challenging.
Research is focused on repurposing existing medical technologies for this new challenge. One promising area of study involves therapeutic apheresis, an established blood filtration technique similar to dialysis. This procedure draws blood, filters it through specialized membranes to remove targeted components, and then returns the cleaned blood to the patient. Initial experimental evidence suggests that apheresis can successfully remove microplastic-like particles from human blood samples.
However, apheresis is a specialized, time-consuming, and expensive treatment, not a casual detoxification method. Even if this technique proves effective and safe for broader use, the problem of continuous re-exposure remains. Without addressing the root cause of the influx, the body would quickly become recontaminated. Therefore, while experimental treatments offer a future possibility, the current, most effective strategy remains preventing further accumulation.
Lifestyle Strategies to Reduce Exposure
Since direct medical removal of microplastics from the blood is not yet a reality, the most actionable step individuals can take is to minimize the daily intake of new particles. Targeting water sources is a foundational strategy, given the high concentration of MPs found in both tap and bottled water. Installing a high-quality water filter, such as a reverse osmosis system or a filter with a block of activated carbon, can significantly reduce the number of microplastics consumed. Additionally, simply boiling tap water has been shown to remove a large percentage of potential micro- and nanoplastics.
In the kitchen, reducing contact with plastic during food preparation and storage is a tangible step. Heating plastic, particularly in a microwave, accelerates the release of microplastics and associated chemicals directly into the food. Switching to glass, stainless steel, or ceramic containers for all food storage and reheating is a simple but effective substitution. Consumers should also choose non-plastic cutting boards, such as those made of wood or glass, as plastic boards can shed millions of fragments during chopping.
Managing indoor air quality is another impactful preventative measure, as airborne fibers from synthetic fabrics are a major source of inhalation exposure. Using a vacuum cleaner equipped with a High-Efficiency Particulate Air (HEPA) filter helps to capture fine dust particles containing microplastics. Furthermore, choosing clothing and home textiles made from natural fibers, such as cotton, wool, or linen, reduces the shedding of synthetic microfibers into the indoor air. These consistent, daily habits represent the current best defense against the accumulation of microplastics in the body.