Microplastics: An Invisible Threat

Authored by: Max Turtz

Art by: Camille Parisot

Every day, people consume thousands of small plastic pieces without even realizing it [Leslie et al., 2022; Amato-Lourenço et al., 2021]. These small fragments, once thought to stay in the environment, are now found within our bodies, and what used to be seen as a problem for oceans has now become a problem for us as well.

Microplastics, the name given to plastic pieces less than five millimeters in size, are abundant. They originate from plastic items, food packaging, tires, and other worn-out products. They float in the wind, drift on the ocean, and stick to food and dust. Scientists have warned governments for decades about the effects of plastic pollution on the environment, but not many have considered that it would find its way inside us. That changed when plastic particles were discovered in the human bloodstream—the first clear evidence that plastics travel through us. 

Most microplastic exposure comes from the simple aspects of daily life [Leslie et al., 2022; Amato-Lourenço et al., 2021]. Bottled water itself has hundreds of plastic particles per liter. Indoor dust and air have fibers that are shed from synthetic clothing, carpets, and furniture. We inhale them with every breath and consume them through food and beverages we drink. In 2021, scientists discovered microplastic fibers encapsulated within human lung tissue—evidence that these particles have penetrated and can persist in the body [Jenner et al., 2022]. 

Microplastics, unlike sand or dust, have the capability of interacting with the body. Microplastics can absorb and release toxic chemicals, trigger immune responses, and cause disruptions to typical cellular processes. The most dangerous are the smallest: nanoplastics. These tiny particles are virus-like in size and can penetrate into a cell and alter its function. Using new imaging techniques, Qian et al. (2024) demonstrated that nanoplastics can aggregate into structures within cells and disrupt cellular communication. Such disruption is likely to cause oxidative stress and chronic inflammation, both of which are linked with long-term disease. 

Scientists today have a keen interest in how the immune system reacts to such particles. When the immune cells attempt to engulf the microplastics, they seem to find it difficult to kill them, resulting in a cycle of chronic activation. In the long run, that may break down tissues and worsen conditions such as asthma or inflammatory bowel disease. Plastic fragments also often contain other harmful chemicals—hormone disruptors such as bisphenol A (BPA) and phthalates. Alone, or combined, they are an advanced mix of physical and chemical stressors that the body may struggle to metabolize [Prata et al., 2020; Wright & Kelly, 2017]. 

Microplastic legislation remains limited in scope despite the growing body of evidence. Plastic straw and microbead prohibition was a great starting point, but it merely scratches the surface of the plastics that have already entered the air, water, and food supply. Microplastics are quickly becoming treated as emerging contaminants, which would place them on the same level of scrutiny and risk evaluation as heavy metals or fine particulate air pollution [Hartmann et al., 2019; Sharma & Chatterjee, 2017]. 

Reducing exposure will be possible, but not easy. The best strategies involve high-impact measures, such as improving waste management and plastic production reduction, combined with small, daily choices. Drinking from glass or metal containers, bringing reusable cloth bags, and choosing natural materials can all reduce personal exposure to plastic particles [Barboza et al., 2018; Tiseo, 2023]. Large-scale change, though, will depend on global cooperation and advancements in technology. 

Microplastics have integrated into our lives that they now tell us something about ourselves as a species: our culture of convenience has reached our own biology. As it continues to come to light what these particles are doing to the human body, it is clear that the next chapter of the plastic crisis is not just environmental—it is personal.

References:

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