Experts are raising serious concerns about the potential public health crisis linked to rising microplastic levels in the human body. Microplastics, tiny plastic particles smaller than five millimeters, have infiltrated every corner of the globe – from Mount Everest to the ocean’s deepest trenches. These particles have been discovered in 1,300 animal species and are now showing up in human organs, including the lungs, blood, liver, and even the brain. As the presence of microplastics grows, scientists are increasingly worried about their impact on human health.
The Growing Threat of Microplastics
Microplastics are found everywhere: in our food, water, air, and even in bottled water and seafood. It is estimated that 10 to 40 million tonnes of microplastics enter the environment annually, a figure expected to double by 2040. These particles have now been detected in the human body, including organs like the lungs, liver, testicles, and breast milk. Studies show that we inhale, ingest, and even swallow microplastics daily. This constant exposure raises questions about the long-term health implications.
Microplastics in the Brain: A New Concern
One of the most alarming findings in recent years comes from a 2024 study in Nature Medicine, which found that human brains may contain as much as seven grams of microplastics. This is roughly the equivalent weight of a plastic spoon. This concentration is significantly higher than the levels found in other organs like the liver or kidneys. Additionally, research indicates that microplastic levels in the brain have been rising over the past eight years, increasing by about 50% between 2016 and 2024.
Recent studies have shown higher levels of microplastics in the brains of people diagnosed with dementia, though these findings are not conclusive. “The rise in brain microplastic concentrations over the past few years is particularly concerning,” says Nicholas Fabiano from the University of Ottawa, the lead author of a recent study. “This mirrors the exponential increase in environmental microplastic levels.” Scientists are particularly concerned about particles smaller than 200 nanometers, which are small enough to potentially cross the blood-brain barrier, a protective layer of cells that guards the brain against harmful substances.
Are Microplastics Linked to Dementia and Other Health Issues?
The connection between microplastics and health remains unclear, but the growing body of research is increasingly concerning. For instance, lab studies on animals have shown that exposure to microplastics can disrupt the gut biome, cause inflammation, and even lower sperm quality and testosterone levels. In vitro studies on human lung tissue have revealed that microplastic exposure could inhibit the growth of airways, potentially contributing to respiratory problems.
In a broader review published in 2024, researchers concluded that microplastics could cause oxidative stress, inflammation, immune dysfunction, and even cancer in animals. These findings have raised alarms, especially given the increasing levels of microplastics in humans. Yet, much of the research involves non-human subjects, and the effects on human health remain largely speculative at this point.
Early Signs of Microplastics’ Impact on Human Health
While definitive answers remain elusive, some studies have already linked microplastic exposure to serious health risks. A 2024 study found that individuals with microplastics in their blood were 4.5 times more likely to experience heart attacks, strokes, or death compared to those without. Similarly, a study published in Environmental Science & Technology revealed that people with inflammatory bowel disease had significantly higher levels of microplastics in their stool samples compared to healthy individuals.
Further research has also found microplastics in the urinary tract, with 54% of urine samples, 70% of kidney samples, and 68% of bladder cancer cases containing microplastic particles. While these studies show associations rather than causation, the potential for microplastics to contribute to chronic diseases like cancer, kidney disease, and urinary tract infections is a growing concern.
Microplastics and Disabilities: A New Link?
In an intriguing 2024 study, researchers found that coastal communities with higher levels of microplastics in their water had higher rates of cognitive and mobility disabilities. For instance, 15.2% of individuals in areas with high microplastic levels had memory and thinking disabilities, compared to 13.9% in regions with low levels. Although the study does not prove that microplastics cause disabilities, the correlation is noteworthy. According to Sarju Ganatra of Lahey Hospital, “Higher microplastic exposure may contribute to disabilities that affect thinking, memory, movement, and independent living.”
What Can We Do to Protect Ourselves?
While the long-term effects of microplastics on human health are still being studied, experts suggest a few strategies to reduce exposure. One of the simplest ways to cut down on microplastic intake is to switch from bottled water to tap water. Studies indicate that bottled water may expose people to nearly as many microplastic particles annually as all other sources combined.
Experts also recommend reducing consumption of seafood, processed foods, and beverages in plastic containers, as these are significant sources of microplastics. Avoiding plastic packaging for food storage and switching to alternatives like glass or stainless steel can also help minimize exposure.
Researchers like Brandon Luu from the University of Toronto further emphasize the importance of avoiding plastic containers for heating food, especially in the microwave. The heating process can release harmful microplastics into food. Additionally, regular home ventilation and vacuuming can reduce airborne microplastics in household dust.
The Need for Action and Research
Despite these precautions, much more research is needed to fully understand the impact of microplastics on human health. Monitoring projects and large-scale research efforts are already underway in some regions, such as the CUSP collaboration in Europe. However, governments must also take action on a policy level to address microplastic pollution.
California recently became the first state to test drinking water for microplastics, setting an example for other regions. In Australia, researchers have called for clearer definitions of microplastics, better regulation of industries that produce plastic waste, and increased funding for microplastics research.
As David Puder, a co-author of a recent Brain Medicine paper, concludes, “We need more research to understand the effects of microplastics. This could be one of the biggest environmental crises that most people never saw coming.”
While the full extent of the health risks posed by microplastics remains unclear, there is no doubt that they are becoming an increasing presence in our lives and bodies. With more research, better public policies, and a shift towards reducing plastic consumption, it’s possible to mitigate the damage. For now, experts are calling for greater awareness and continued vigilance as we navigate this growing environmental and public health issue.
For more in-depth coverage on the environmental impact of microplastics, visit Issue N Fact.
