By Shion Choe
Abstract
With approximately 79% of 8.3 billion tons of plastic within the environment, human exposure to microplastic and nanoplastics is now seeminglessly inevitable. This paper explores how plastic particles disrupt systemic human health through three mechanisms. Each of these include a biomolecular disguise evading the immune system, causing organelle stress build up leading to cell function failure, and a trojan horse vector to spread disruptive chemicals. This paper aims to address these cellular and microscopic plastic disruptions to shift the generalized focus on environmental pollution toward an unrecognized urgent clinical issue of cellular health within humans.
Introduction
For a very long time, plastics have mainly been recognized and seen as a threat to the ecosystem. Images and findings of marine animals harmed by plastic waste have gone viral in the past and public awareness of environmental pollution became a major issue (BBC News, 2020). Out of the varying sizes and types of plastics, microplastics are plastic particles ranging in size from 5 millimeters, which is about the size of a pencil eraser, to 1 nanometer. Considering that a strand of human hair is about 80,000 nanometers wide, most of these plastics are invisible to the human eye (Environmental Protection Agency, n.d.). Microplastics can either be intentionally manufactured in small sizes for consumer products, or degrade into smaller pieces from larger plastic products (EPA, n.d.). However, they cannot be biodegraded, and can only be fragmented into smaller pieces, eventually becoming microscopic or even smaller nanoplastics. During the process, the plastics are exposed to contamination, including various chemicals and environmental toxins, later releasing it as pollutants at its location. (National Oceanic and Atmospheric Administration, 2019). Due to these characteristics, small plastic particles can cause critical disruptions to ecosystem health, being a major factor of environmental pollution and can be easily consumed by animals. Still, despite the existing awareness of the environmental impacts of microplastics, the specific disruptions in a human body including inflammation and toxicity caused by accumulation of plastic particles are yet unrecognized. This review aims to propose how long-term exposure to microplastics and nanoplastics contribute to health such as immune responses and inflammation in a few different ways.
Literature review
Geyer et al. (2017) conducted a global flow analysis to quantify all of the manufactured plastics around the globe and their disposal. The global data was collected from 1950 to 2015, combining statistics across industrial sectors.Their observations concluded that approximately 8.3 billion metric tons of plastics has been produced since then. However, only 9% of manufactured plastics have been recycled, while 79% has been accumulated in the environment.
The review by Hernández et al. (2025) evaluated the impacts of microplastics and nanoplastics within human body parts at a cellular level and their navigation through the immune system. By integrating evidence from recent human biomonitoring studies, they mapped out how plastic particles can interact with biological systems and simulated the movement. Their study of internal exposure of plastic particles suggested that these wastes can cause disruptions in biological barriers of key organs such as guts and lungs. Due to the various chemicals on the particle’s surface, they can trigger oxidative stress and chronic inflammation in humans. The study also explained how plastics navigate the human body, by coming in contact with biological fluids thus forming a biomolecule corona made of proteins and lipids around its surface. This disguises the plastic as a biological molecule, giving it the ability to remain undetected and reaching human organs to settle for long periods.
Lee et al. (2023) focused on the human regulatory system impacted by microplastics. They collected data of different microplastic concentrations and sizes in the region of South Korea and compared individuals that would regularly consume microplastics in different sizes and shapes. Out of those observations, they suggested that macromolecular size level plastics after consumption alter their biological characteristics, mimicking natural hormones and leaching onto receptor sites. This causes false signals throughout the body, leading to dysfunction and metabolic disorders.
This paper by Bishop et al. (2025) looked into inflammation due to the presence of plastic particles. By extracting types of microplastics and exposing it to human cell lines and blood immune cells, observations in their interaction was made. Their results showed a response from inflammatory cytokines, showing that plastic accumulation eventually triggers an immune response causing swelling and redness within the body.
In the article by Sobarathne et al. (2025), the direct physical and oxidative harm of plastic particles were experimented. The experiment used a human stem cell, exposing it to various concentrations of polystyrene microplastic particles. In conclusion, the plastic particles were found to mainly accumulate in the lysosomes acting as a recycling center. Further observations revealed lysosomal storage stress build up and function decline.
Tyc et al. (2025) analyzed the role of plastic particles as carriers of disruptive chemicals. Their research synthesized data from recent toxicological and epidemiological studies related to microplastic impacts on key hormonal regulatory axes. The study concluded microplastics as vectors to carry and transport various chemicals on its surface. However, these chemicals include bisphenol A and phthalates as well as numerous unknown substances. Coming in contact with these chemicals from plastic consumption leads to dysregulation of reproductive functions, hormone production, and metabolic health.
In the article of Segovia et al. (2025) reviewed how the chemical components of microplastics can influence early child development. The study focused on perinatal exposure, looking at how disruptive chemicals from plastic bits can interact with human biological pathways. They discovered that early life accumulation is particularly critical because the developing hormonal and immune system is highly sensitive to fragmented polymers, ultimately causing stress in the body's immune response and disrupting hormonal balance.
Analysis
Because 79% of plastic waste around the world remains as a part of the ecosystem (Geyer et al., 2017), there is a constant risk of human exposure through inhalation or ingestion. This immense volume of plastics and their ability to avoid biological systems causes an unavoidable infiltration of plastic particles within human tissues. (Lee et al., 2021; Hernández et al., 2025). The global inevitability of plastic consumption has led to a direct cellular impact throughout.
Plastic particle navigation through the human body is supported by a biomolecule corona outer layer. By coating themselves in a bodily protein and lipid layer, these particles mimic biological components of the human body and surpass the immune system. This delays the immune response, allowing plastics to reach key tissue organs without being previously excreted and trigger late inflammation after accumulation has already happened throughout (Hernández et al., 2025; Bishop et al., 2025).
The quiet build up of particles leads to mechanical failure. Plastics are not biodegradable nor digested through human systems, eventually gathering within cells. Within the lysosome, the cell’s recycling center, plastic build up causes lysosomal storage stress and malfunction of waste production. The internal stress has a possibility of worsening through disruptive chemicals coated on microplastics, suggesting severe organelle damage leading to overall function decline and cell death (Sobarathne et al., 2025; Tyc et al., 2025).
Beyond irritation, microplastics act as a trojan horse for chemical toxicity. Plastic particles within human bodies serve as vectors for disruptive chemicals, leaching on to hormone receptors once settled in human tissue. Dysfunction of the receptors can potentially disturb the entire regulatory system, leading to metabolic issues. This plastic chemical interference can even begin in the utero, suggesting disturbance even during early life hormonal system development (Tyc et al., 2025; Segovia et al., 2020).
Limitations
While the evidence of cellular disruption from microplastics do exist, several concerns about its actual effect must be acknowledged. First, a major limitation is that while microplastics are frequently found in diseased human tissues, it is difficult to definitively prove that the plastic was the actual cause of the disease. There is a possibility that those plastics were just there due to being disguised from the immune system and flowing into body tissues. Technological problems, specifically regarding the detection and quantifying of extremely small nanoplastics is another constraint. Some plastic particles are microscopical, but there are still even smaller, potentially severely harmful plastic particles. Furthermore, much of the existing data testing toxicity cannot accurately reflect actual human exposure or concentration level of particles due to the mentioned technological issues and small size. Finally, because human exposure to plastics is universal, even within infants, it would be nearly impossible to find and compare people unexposed to any source of plastics. This lack of a standard control group makes it difficult to differentiate health impacts of microplastics from other environmental factors such as air pollution or heavy metals.
Discussion
The evidence of this review suggests that microplastics should no longer be an environmental issue, as the biological invisibility and disguise of plastic particles represent a threat to the immune system. By shifting the focus from ecosystems to the cellular environment, it becomes more clear that the human body can experience stress due to these plastic particles. The ability of these particles to acquire a biomolecule corona and induce lysosomal storage stress indicates that plastics can be a permanent and systemic pollutant that acts as both a physical irritant and a chemical vector. This camouflaging characteristic can suggest a reason that microplastics may be a hidden variable in metabolic and endocrine disorders. Overall, these findings are relevant to the fields of toxicology and immunology, stating microplastics as a major driver of unrecognized inflammation. However, there is a need for standardized clinical detection methods, as current technology often fails to distinguish and detect nanoplastics. Future studies should prioritize longitudinal human tracking to correlate plastic bioaccumulation with specific inflammatory reactions over years or possibly decades, which can also investigate the transgenerational effects and how it leads to early-life exposure.
Conclusion
The synthesis of these microplastics in physical and chemical pathways addresses the invisibility of plastic accumulation disrupting the human body system. While global awareness has mainly focused on the ecological impacts of plastic waste, the biological evidence presented reveals a more unrecognized part of its capabilities. By bypassing biological defenses through molecule disguises and inducing internal failures through lysosomal stress, it suggests that these particles are active drivers of systemic pathology. This transition from environmental waste to cellular toxicity suggests that long term exposure significantly influences health, such as inflammation and hormonal unbalance. Ultimately, understanding these specific, microscopical disruptions of plastic particles is essential to recognize not only their impact in the ecosystem, but also their lasting changes in our internal biological system.
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