Do microplastics harm humans?

Do Microplastics Harm 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.

Look around you. Do any of the plastic items around you hurt you? Has your plastic water bottle ever harmed you? Your polyester shirt? The bag that your chips came in? The couch that you’re sitting on? Because we’re so accustomed to them, we don’t view plastics as harmful. The same is said for microplastics. We know that they’re in us, but what’s the big deal? 

Well, on a molecular level, microplastics harm our cells. From the bloodstream to the lungs, and from placentas to digestive tracts, they are showing up everywhere in the human body. Microplastics enter our bodies through air, food, and water and, once inside, they interact with cells, disrupt immune systems, and may even promote cancer. This article explores the pathways, mechanisms, and health effects of microplastic exposure in humans.

How Microplastics Enter the Body

Humans are exposed to microplastics through ingestion, inhalation, and sometimes skin contact [1]. They’ve been found in biological samples including blood, lung tissue, stool, and placental tissue, pointing to widespread bodily distribution and potential bioaccumulation [4–7].

Ingestion

Microplastics are present in seafood, table salt, processed foods, fruits and vegetables, beer, and more. They’re often there as a result of contamination during processing or packaging [2, 8–9]. Drinking water is another consistent source, with both bottled and tap water, and plastic and glass containers, testing positive for plastic particles [10–12]. Filters can only remove so much. 

Inhalation

Airborne microplastics also present a serious concern. This is especially true in urban and indoor environments, although they’ve been found in the air even in remote mountaintops. These microplastic particles can be inhaled into the lung tissue, where they have been detected postmortem in human samples [4, 6, 7, 9, 19, 24–26]. The sources of these airborne microplastics include synthetic textiles, like polyester clothing, industrial emissions, and degraded plastics [13–23].

Skin Contact 

Skin exposure remains less studied, but plausible. Microplastics can transfer through handling plastic-laden consumer products or via contaminated water sources, with mobile phone cases and household surfaces identified as points of contact [1, 27]. Nevertheless, most studies don’t list this as a primary method for microplastics to enter our bodies. 

How Microplastics Harm Our Health

Microplastics may impact human health through a combination of mechanical, chemical, and immunological mechanisms. For example, they may cause physical damage. Irregularly shaped and sharp edged microplastics have been shown to injure epithelial linings in the lungs and gut [28]. Microplastic can also leach endocrine disrupting chemicals and additives like phthalates and flame retardants, or adsorbed pollutants such as PAHs and heavy metals. All of these can cause damage to tissues [1, 4, 22, 27, 29–30]. Additionally, microplastics naturally active immune responses and drive inflammation in affected tissues [3, 19, 26, 31–32]. Lastly, but not exhaustively, microplastics can disrupt the gut microbiota and compromise digestion, immunity, and nutrient signaling [1, 21, 32].

Potential Microplastic-Driven Health Effects Across Human Systems

Respiratory System

Inhaled microplastics can cause respiratory irritation, worsen asthma, and embed in lung tissue [4, 12, 19, 24–26]. Their interaction with lung surfactants could impair gas exchange and amplify inflammation [33]. However, significantly more research is needed to fully understand the impact of microplastics on the respiratory system. 

Cardiovascular System

Microplastics have been found in human atheromas and linked to vascular inflammation and clotting irregularities [3, 12, 31]. They may alter blood rheology and promote coagulation abnormalities, as confirmed by thromboelastography studies [34–35]. As with the respiratory system, the full effects of microplastics on the cardiovascular system needs to be further characterized. 

Digestive System

Gut exposure to microplastics triggers oxidative stress, mucosal damage, and gut microbiome shifts that undermine intestinal health [21, 23, 32]. 

Nervous System

Microplastics have been detected in the human olfactory bulb, likely via the nasal route, and are linked to neuroinflammation, mitochondrial damage, and changes in brain energy metabolism [7, 19, 36].

Reproductive System

Microplastics impair reproductive function by damaging sperm, reducing motility, and disrupting testicular architecture. Long-term exposure accelerates testicular aging and may affect hormone regulation [10, 28, 37–38]. 

Immune System

Microplastics impact both innate and adaptive immunity. Studies show they skew cytokine balance, suppress immune cell function, and increase susceptibility to infection or autoimmune dysfunction [3, 19, 26, 31–32, 39]. 

Liver and Kidney

Animal models show liver inflammation, lipid dysregulation, and renal function disruption following microplastic exposure [40–41]. Although human data are limited, the toxicokinetics appear conserved across mammalian models.

Endocrine System

Microplastics and their chemical additives interfere with hormonal signaling, impacting everything from thyroid function to reproductive hormone balance. These effects may contribute to developmental delays, menstrual irregularities, and fertility issues [22, 42].

Cancer Risk

Microplastics are implicated in cancer development via chronic inflammation, DNA damage, and oxidative stress. Their ability to carry mutagenic pollutants further elevates this risk [2, 4].

What Makes Microplastics More Dangerous?

Several factors influence the severity of microplastic toxicity. One of which is their size and shape, as smaller particles penetrate tissues more easily, while irregular shapes cause more physical abrasion [9, 28, 43]. Another factor is polymer type. For example, materials like polystyrene and PVC show greater biological reactivity than polyethylene or polypropylene [2, 4]. Additionally, the chemical load matters, as plastics that carry additives or other pollutants cause compounded toxic effects [1, 4, 22, 27, 29–30].

The Evidence Suggests Microplastics Harm Humans

Studies show that microplastics can harm humans across multiple organ systems. They have pro-inflammatory, oxidative, and endocrine-disrupting effects, making them more than just an environmental contaminant. As research accelerates, a vital next step is developing mitigation strategies to reduce exposure at both the personal and societal levels. 

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-backed wellness supplement, a microplastic intake calculator, and lifestyle recommendations is intended to help you avoid microplastics. Our supplement 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.

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