Microplastics in Brains and Air
- Michael Chevalier
- Nov 8
- 4 min read
Microplastics—tiny plastic particles less than 5mm in size—are now found in virtually every part of the environment, from the depths of the ocean to the air we breathe. Recent studies suggest that trees play a crucial role in intercepting airborne microplastics, potentially reducing human exposure. However, alarming discoveries have also shown that microplastics are present in human brains, raising serious concerns about their neurological impact. Compounding this issue, research indicates that microplastics are being transported globally through ocean spray, further increasing human and environmental exposure. This article explores these findings and their implications.
Trees as Microplastic Interceptors
A study conducted in Chengdu, China, provides compelling evidence that urban trees can trap airborne microplastics. Researchers collected air samples from open rooftops and beneath trees, discovering that trees intercepted a significant amount of airborne microplastics. Key findings include:
Trees intercepted 16.3% of airborne microplastics in the study area.
An estimated 347.69 kg of microplastics were captured by urban forests in Chengdu over the course of a year.
Fibers were the most common type of microplastic captured, indicating that textiles are a major source of microplastic pollution.
Tree canopies and leaf structures played a role in trapping particles.
This study highlights the potential of urban forests to act as a barrier against airborne microplastic pollution, improving air quality and reducing human inhalation exposure.
UNM College of Pharmacy study
Study a team led by toxicologist Matthew Campen, PhD, Distinguished and Regents’ Professor in the UNM College of Pharmacy, reported that plastic concentrations in the brain appeared higher than in the liver or kidney, and higher than previous reports for placentas and testes.
A recent study published in Nature Medicine provides strong evidence of microplastic and nanoplastic (MNP) bioaccumulation in human organs, including the brain. Using advanced detection techniques such as pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), Fourier transform infrared spectroscopy, and electron microscopy, researchers identified microplastics in postmortem human liver, kidney, and brain tissues. The study found that polyethylene was the most prevalent polymer, with the highest concentrations detected in the brain. Notably, microplastic accumulation in brain samples increased significantly between 2016 and 2024, suggesting rising environmental exposure. Even more concerning, brain samples from individuals with dementia exhibited far greater microplastic concentrations, with notable deposition along cerebrovascular walls and immune cells. These findings highlight the urgent need to investigate the pathways through which microplastics enter the brain and their potential role in neurodegenerative diseases. The study underscores the growing health risks posed by environmental plastic pollution and the necessity of mitigating human exposure to these persistent contaminants.
Article;
Microplastics in Ocean Spray: A Global Transport Mechanism
While trees can help trap airborne microplastics in urban settings, another major pathway for microplastic exposure has emerged—ocean spray. Research has shown that:
Microplastics from the ocean can be aerosolized into the atmosphere through breaking waves, sea spray, and bubble bursting.
These particles can travel vast distances via wind currents, carrying plastic pollution from the ocean back to coastal and even inland areas.
Marine ecosystems are a major sink for microplastics, but ocean spray is now redistributing these particles into the air, potentially increasing human exposure.
Coastal populations may be at higher risk of inhaling microplastics due to ocean-driven atmospheric deposition.
This discovery suggests that even in areas far from urban pollution sources, people may still be breathing in microplastics carried from the sea.
New Study: The Ocean Is Emitting Millions of Pounds of Plastic Into the Atmosphere
Microplastics Found in Human Brains
Perhaps the most concerning recent finding is the detection of microplastics in human brains.
Studies indicate that:
Microplastics can cross the blood-brain barrier, potentially leading to inflammation and neurological effects.
Inhaled and ingested microplastics can travel through the bloodstream, reaching the brain and other organs.
Animal studies have linked microplastic exposure to cognitive decline, oxidative stress, and behavioral changes.
Certain plastic additives, such as phthalates and bisphenol A (BPA), may exacerbate neurological toxicity.
The presence of microplastics in the brain raises urgent concerns about their long-term health effects, including possible links to neurodegenerative diseases like Alzheimer’s and Parkinson’s.
The Connection Between Trees, Air Quality, and Brain Health
Given that trees can trap airborne microplastics, preserving and expanding urban forests may be a crucial step in reducing human exposure especially in coastal regions. At the same time, the presence of microplastics in ocean spray suggests that atmospheric plastic pollution is more pervasive than previously thought. Addressing this issue requires a multifaceted approach:
Reducing plastic pollution at the source by limiting single-use plastics and improving waste management.
Expanding urban forests to act as natural filters for airborne microplastics.
Studying the impact of ocean-derived microplastics on human health to understand their full effects.
Importance of Tree Canopy
Reducing tree canopy coverage from 30% to 15% could significantly increase human exposure to airborne microplastics, as trees play a vital role in filtering these pollutants from the atmosphere. Studies suggest that urban forests can intercept 16-20% of airborne microplastics, meaning a 50% reduction in canopy coverage could lead to a proportional decrease in filtration capacity. This decline would result in more microplastics remaining in the air, increasing the likelihood of human inhalation and absorption into the bloodstream, lungs, and even the brain. For coastal and urban communities, where microplastics are already abundant due to ocean spray and industrial pollution, such a decrease in tree coverage could exacerbate health risks, particularly for vulnerable populations like seniors
Conclusion
The discovery that trees can intercept airborne microplastics is an encouraging development in combating plastic pollution. However, the detection of microplastics in human brains and their prevalence in ocean spray highlights an escalating crisis. As scientists continue to investigate these threats, proactive measures—such as reducing plastic waste, restoring natural filtration systems, and monitoring microplastic exposure—will be critical to protecting both environmental and human health.
Preserving trees and expanding tree canopy coverage is essential for protecting public health on coastal communities, especially for seniors, who are more vulnerable to environmental pollutants. As research increasingly shows that trees can intercept airborne microplastics, maintaining and restoring urban forests can serve as a crucial line of defense against these harmful particles. Seniors, who often have weaker respiratory systems and are at higher risk for neurodegenerative diseases, benefit significantly from cleaner air and reduced exposure to airborne toxins. A thriving tree canopy not only filters pollutants but also provides cooling shade, reducing heat-related stress and promoting overall well-being in communities. Investing in tree preservation and urban reforestation efforts is not just an environmental priority but a public health necessity, ensuring that vulnerable populations, including older adults, can breathe cleaner air and lead healthier lives.
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