🍼 Plastic in My Chicken Nugget? What Parents Need to Know About Microplastics
By Dr. Pete, Emergency Physician, Professor, and Relentlessly Practical Dad
I used to think the biggest threat hiding in my pantry was expired ranch dressing. Then I read a headline that made me spit out my coffee: researchers are finding microplastics—tiny particles of plastic—in everything from bottled water to baby formula to human blood. Excuse me? We’re seasoning our kids with polyethylene?
Welcome to the age of plastic confetti—so small you can't see it, but it’s likely swimming in your water, floating in your air, and possibly taking up long-term residence in your spleen. This article breaks down what we actually know (and don’t) about microplastics, and how to reduce your family’s exposure—without selling your house to buy a water buffalo and a lifetime supply of glass containers.
🧪 What Are Microplastics?
Microplastics are plastic particles smaller than 5 millimeters—roughly the size of a sesame seed, if that seed had a grudge against human biology.
They come in two main types:
Primary microplastics: Manufactured small from the start (e.g., microbeads once used in face scrubs before being banned).
Secondary microplastics: Formed when larger plastic items like bags or bottles break down due to sunlight, wind, and water (GESAMP, 2015, IMO/FAO/UNEP).
These particles have been detected in tap water, bottled water, seafood, honey, beer, indoor air, and household dust. More unsettling: microplastics have been found in human blood (Leslie et al., 2022, Environ Int), placental tissue (Ragusa et al., 2021, Environ Int), breast milk, and brain samples (Campen et al., 2025, UNM Health Sciences).
No need to panic. But maybe reconsider that habit of chewing pen caps.
⚠️ The Risks (And the Big Fat Asterisk of Uncertainty)
The science is still developing, but here’s what researchers are starting to uncover—along with the many questions that remain.
🚨 Known or Emerging Health Concerns
Cardiovascular risk: A 2024 New England Journal of Medicine study found that patients with plastic particles embedded in carotid artery plaques were over 4 times more likely to suffer a heart attack, stroke, or death over three years than those without plastic-laden plaques (Marfella et al., 2024, NEJM).
Hormonal disruption: Microplastics carry chemicals like phthalates and bisphenol A (BPA), which are known endocrine disruptors that can affect reproductive and metabolic systems (Demeneix & Slama, 2019, WHO/UNEP).
Gut inflammation: In mouse models, microplastics have been shown to damage intestinal barriers, disrupt gut microbiota, and trigger inflammation (Jin et al., 2019, Sci Total Environ).
Brain infiltration: Researchers recently detected microplastics in every human brain sample they tested, particularly polyethylene—the same plastic used in bags and bottles (Campen et al., 2025, UNM Health Sciences).
Immune suppression: Inhaled microplastics can impair lung macrophages, the immune system’s cleanup crew. A 2024 study showed reduced ability of these cells to fight bacteria (Soloff et al., 2024, ATS Conference).
🤔 What We Still Don’t Know
Causality: While some findings—especially in cardiovascular research—are concerning, many others are based on animal studies or observational data. Definitive proof in humans is still lacking.
Safe exposure levels: There’s currently no official threshold for “acceptable” microplastic exposure. We don’t know what dose is harmless—or if one even exists.
Long-term health impact: Do microplastics contribute to chronic disease over decades? Might they interact with other environmental or genetic risk factors? We’re only beginning to ask these questions (Bucci et al., 2020, Environ Sci Technol).
In short: this is what scientists call a “low-certainty, high-concern” public health issue. Not unlike parenting a tween with Wi-Fi access.
🧻 Where Are They Coming From?
Here are the main sources of microplastic exposure—most of them hiding in plain sight:
Tap and bottled water: Bottled water, in particular, often contains significantly more microplastics, due to the bottling process and plastic packaging (Mason et al., 2018, Front Chem).
Synthetic clothing: Fleece, polyester, and nylon shed microfibers in every wash cycle.
Plastic containers: Especially when heated. “BPA-free” does not mean “microplastic-free.” Heat causes plastic to degrade and release particles (Huat et al., 2023, J Hazard Mater).
Tire wear: As tires degrade on roads, they release microplastics that end up in stormwater and waterways (Knight et al., 2020, Environ Pollut).
Indoor air and dust: Textiles, carpets, and synthetic furniture fibers contribute to airborne microplastics in our homes (Vianello et al., 2019, Environ Int).
🛡️ How to Reduce Exposure (Without Going Off-Grid)
No, you don’t need to move into a yurt. Here are science-backed steps you can actually take:
Don’t microwave plastic. Heat speeds up the release of both microplastics and endocrine-disrupting chemicals. Use glass or ceramic containers instead (Yang et al., 2022, Environ Sci Technol).
Filter your water. Reverse osmosis filters are most effective, but even common pitcher filters reduce microplastic levels (Schymanski et al., 2018, Water Res).
Wear natural fibers. Cotton, wool, linen, and hemp shed biodegradable fibers, not plastic.
Use a laundry filter. Guppyfriend bags or filters like Lint LUV-R capture microfibers before they enter wastewater systems.
Avoid single-use plastics. Switch to stainless steel bottles, beeswax wraps, and reusable containers.
Choose better personal care products. Avoid items with polyethylene or polypropylene. Use the Beat the Microbead website to check labels.
Ventilate your home. Open windows regularly to help remove airborne microplastic dust.
🎯 Final Thoughts: Don’t Panic, Just Pivot
Microplastics are likely not “the next asbestos.” But recent studies—especially those linking them to cardiovascular disease—suggest they’re more than just a quirky ocean pollution story.
The good news? You don’t have to overhaul your life. With just a few tweaks, you can meaningfully reduce exposure while teaching your kids that yes, sometimes science really is stranger than fiction.
Because when it comes to your family’s health, “probably fine” doesn’t quite cut it.
📚 References
Beat the Microbead. (2024). Campaign against microplastic ingredients in cosmetics.
https://www.beatthemicrobead.org
Bucci, K. et al. (2020). Plastics and the human body: a review of the key knowledge gaps. Environ Sci Technol.
Campen, M. et al. (2025). UNM researchers find high levels of microplastics in human brains. UNM Health Sciences Newsroom.
Demeneix, B., & Slama, R. (2019). Endocrine disruptors: evidence to human health protection. WHO/UNEP.
GESAMP. (2015). Sources, fate and effects of microplastics in the marine environment. IMO/FAO/UNEP.
Huat, T. L. et al. (2023). Microplastics released from food containers at high temperatures. J Hazard Mater.
Jin, Y. et al. (2019). Polystyrene microplastics induce gut barrier dysfunction in mice. Sci Total Environ, 691, 516–525.
Knight, L. et al. (2020). Tire wear particles as a source of microplastics. Environ Pollut, 258.
Leslie, H. A. et al. (2022). Discovery of microplastics in human blood. Environ Int, 163, 107199.
Marfella, R. et al. (2024). Microplastics in atheromas and cardiovascular events. N Engl J Med, 390(10), 900–910.
Mason, S. A. et al. (2018). Synthetic polymer contamination in bottled water. Front Chem, 6, 407.
Ragusa, A. et al. (2021). Plasticenta: microplastics in human placenta. Environ Int, 146, 106274.
Schymanski, D. et al. (2018). Analysis of microplastics in drinking water. Water Res, 129, 154–162.
Soloff, A. et al. (2024). Inhaled microplastics impair immune cell function. Presented at ATS 2024, Univ. of Pittsburgh School of Public Health.
Vianello, A. et al. (2019). Airborne microplastics in indoor environments. Environ Int, 132, 105099.
Yang, C. et al. (2022). Microplastics from infant bottles: release and risk. Environ Sci Technol, 56(18), 13346–13354.
Thanks for reading ParentRounds! Subscribe for free to receive new posts and support my work.
Author’s Note on Content Creation
I use AI tools like ChatGPT and Gemini in an iterative workflow to help with reference cross-checking, fact validation, and initial drafts. The final tone, structure, humor, and all opinions remain my own as an emergency physician, educator, and parent. These articles reflect my writing, my judgment, and my voice—with a little help from the robots.