Microplastics in Our Brains

A minimalist illustration of a human head in profile with a vintage-style anatomical drawing of a brain superimposed inside.
A conceptual illustration depicting human cognition, featuring a vintage anatomical drawing of a brain within a simple silhouette of a head.

What You Need to Know and How to Reduce Your Exposure

Did you know that tiny plastic particles—called microplastics—are in our food, water, and even the air we breathe? Every day, we are unknowingly consuming and inhaling microplastics. Scientists have now discovered something even more concerning: microplastics are making their way into human brains, and their levels are increasing.

This raises an important question: What does this mean for our health, and what can we do about it? While we may not be able to eliminate microplastics entirely, there are simple steps we can take to reduce our exposure and protect our health. In this article, we’ll break down what microplastics are, how they enter our bodies, the potential health risks, and practical ways to reduce our exposure.

What Are Microplastics?

Microplastics are tiny plastic particles, smaller than 5mm, that come from broken-down plastic waste, synthetic clothing, industrial processes, and food packaging. Because plastic never fully biodegrades, these particles remain in the environment indefinitely, breaking down into even smaller pieces over time.

Common Sources of Microplastics

Microplastics are found in everyday items, including:

  • Bottled water: Contains significantly more microplastics than tap water.

  • Seafood: Marine animals ingest microplastics from polluted oceans.

  • Processed foods: Particularly those packaged in plastic.

  • Tea bags: Some brands use plastic-based tea bags that release billions of plastic particles into hot water.

  • Air: Microplastics are floating around in household dust and city pollution.

Since we eat, drink, and breathe microplastics daily, it’s important to understand how they enter our bodies and what harm they may cause.

How Do Microplastics Get into the Human Body?

Microplastics make their way into our bodies through three primary routes:

Eating and Drinking

  • Bottled water drinkers ingest up to 90,000 microplastic particles per year, compared to 4,000 for tap water drinkers (Cox et al., 2019).

  • Seafood, processed foods, and canned goods can contain microplastics due to contamination during production and packaging.

  • Heating food in plastic containers releases billions of plastic particles into the food.

Breathing

Airborne microplastics are present in the air we breathe at home, in offices, and outdoors, particularly in urban areas. Additionally, synthetic clothing sheds plastic fibers into the air when it is washed or worn, further contributing to the inhalation of these particles.

Household Exposure

Cooking and storing food in plastic can cause microplastics to leach into the food we eat. Similarly, plastic tea bags and coffee pods release billions of tiny plastic particles into hot liquids, increasing overall exposure.

Because these tiny particles are everywhere, scientists are now studying how they affect our health—especially our brains.

Are Microplastics Harmful to Our Health?

While research is still ongoing, several studies have raised serious concerns about microplastics in the human body. Here’s what scientists have found so far:

Microplastics in the Brain

A recent study found microplastics in human brain tissue, with levels 3–5 times higher in people with dementia (Nihart et al., 2025). Scientists are unsure whether dementia weakens the brain’s defense, allowing more plastic in, or if microplastics contribute to cognitive decline.

Heart Disease Risk

A study found that people with plastic particles in their arteries had a higher risk of heart attacks and strokes (Marfella et al., 2024).

Gut Health Concerns

People with inflammatory bowel disease (IBD) had 1.5 times more microplastics in their stool compared to healthy individuals (Yan et al., 2022). Microplastics may disrupt gut bacteria and contribute to inflammation.

Other Potential Effects

Scientists suspect microplastics may also contribute to:

  • Hormone disruption: some plastics contain chemicals that interfere with the endocrine system.

  • Lung irritation: from inhaling airborne microplastics.

  • Long-term health risks: still being studied.

Since avoiding microplastics completely is impossible, the next best step is reducing exposure where we can.

Easy Ways to Reduce Microplastic Exposure

While plastic is everywhere, simple daily changes can significantly lower the amount of microplastics we ingest and inhale.

  • Switch to Tap Water: Drinking tap water instead of bottled water can reduce microplastic intake by over 90%. Use a water filter if concerned about contaminants.

  • Avoid Heating Food in Plastic: Use glass or stainless steel containers instead of plastic. Never microwave food in plastic containers.

  • Choose Fresh or Frozen Foods Over Canned: Canned foods can release chemicals like BPA, which is linked to hormone disruption. Opt for fresh, frozen, or glass-packaged alternatives.

  • Use Cloth or Metal Tea Strainers: Avoid plastic tea bags—opt for loose-leaf tea with a stainless steel infuser.

  • Improve Air Quality: Use a HEPA air filter at home to remove airborne microplastics. Vacuum regularly to reduce plastic dust indoors.

These small changes can make a big difference in reducing everyday exposure.

Can Microplastics Be Removed from the Body?

Right now, scientists don’t know if microplastics can be fully removed from the human body, but some early research suggests:

  • Sweating may help: Some studies suggest that sweating (through exercise or sauna use) can help excrete plastic-related chemicals like BPA.

  • Healthy lifestyle choices: Staying hydrated, eating fiber-rich foods, and regular exercise may help the body naturally eliminate toxins.

  • Long-term exposure reduction: The best strategy is reducing intake in the first place.

More research is needed, but reducing microplastic exposure now is the safest approach.

Small Changes Make a Big Difference

Microplastics are everywhere, and while we can’t avoid them completely, we can take practical steps to limit exposure and protect our health. By making the choices we suggested above, you can help protect your health while also reducing plastic pollution in the environment.

It’s crucial to hold local, state, and national elected officials accountable for policies that protect your health and the well-being of your loved ones. Be mindful of who you vote for, and once they are in office, advocate for strong regulations that reduce plastic pollution and safeguard public health. Your voice matters—demand action.


Sources: Nihart et al., 2025 – Study on microplastics in the human brain (Nature Medicine). Marfella et al., 2024 – Microplastics and heart disease (New England Journal of Medicine). Cox et al., 2019 – Microplastic consumption (Environmental Science & Technology).

The Hidden Cost of Climate Change: How Air Pollution Impacts Eye Health

Image of irritated eye on left with
Air Pollution Impacts Eye Health. Credit: activist360

How Air Pollution from Climate Change is Taking a Toll on Our Eyes—and What We Can Do About It

Climate change is often discussed in terms of rising sea levels and extreme weather, but did you know it could also be affecting your eyes? Recent research has found a striking link between air pollution—a byproduct of climate change—and eye health issues like irritation and allergies. For example, high levels of air pollution can double the likelihood of needing treatment for conditions like dry eye syndrome.

Understanding the Science

What is Particulate Matter (PM)?

Particulate matter, or PM, is a mix of tiny particles and droplets in the air that come from sources like vehicle exhaust, industrial emissions, and even wildfires. The two main types, PM10 (particles smaller than 10 micrometers) and PM2.5 (smaller than 2.5 micrometers), are small enough to be inhaled or settle on the surface of your eyes. These pollutants are closely tied to human activities that drive climate change, such as burning fossil fuels.

How Does PM Affect Eye Health?

Your eyes are directly exposed to the environment, making them especially vulnerable to pollution. Particles can irritate the surface of the eyes, causing redness, itching, dryness, and even long-term conditions like dry eye syndrome. When exposed to high levels of particulate matter, the protective tear film on the eyes can break down, leading to discomfort and inflammation.

Key Findings from Recent Research

A study conducted in the Denver Metropolitan Area found significant connections between air pollution and eye health:

  • Higher Pollution, More Doctor Visits: Visits for eye irritation and allergies increased as pollution levels rose. For example, five days of exposure to PM10 at 110 µg/m³ made patients over twice as likely to seek treatment compared to lower pollution levels.

  • PM10 vs. PM2.5: While both types of particulate matter were linked to eye issues, PM10 had a stronger impact, especially during colder temperatures.

  • Beyond EPA Limits: Eye health effects were observed even at pollution levels below those considered harmful by the Environmental Protection Agency.

These findings align with broader studies that link air pollution to respiratory and cardiovascular conditions, highlighting air quality as a serious health concern.

Broader Implications

Climate Change as a Health Crisis

This study underscores how climate change is not just an environmental issue—it’s a public health emergency. The pollutants contributing to global warming are also causing immediate harm to our bodies, including our eyes.

Eye Health as an Overlooked Area

While much attention is given to the respiratory and cardiovascular effects of pollution, the impact on eye health often goes unnoticed. This gap in awareness means millions of people could be suffering unnecessarily.

What Can You Do?

While collective action to hold polluters accountable is essential, here are some practical steps you can take to protect yourself and advocate for meaningful change.

Protect Yourself

  • Indoors: Use air purifiers to reduce indoor pollution levels.

  • Outdoors: Wear protective glasses and avoid outdoor activities on days with poor air quality.

  • Stay Informed: Check local air quality advisories and adjust your plans accordingly.

Advocate for Change

  • Support local and national politicians and policies that reduce emissions and improve air quality, such as stricter vehicle emissions standards and renewable energy initiatives.

  • Join or support organizations fighting for clean air and climate solutions.

Routine Eye Care

  • Schedule regular eye exams, especially if you live in areas with frequent air pollution.

  • Discuss symptoms like dryness or irritation with your eye doctor, as early treatment can prevent more serious issues.

Summing Up

The link between air pollution and eye health is clear: the higher the pollution, the greater the risk. But this isn’t just about statistics—it’s about our quality of life. By taking steps to protect yourself and advocating for cleaner air, you’re not just preserving your vision but contributing to a healthier, more sustainable world. Remember, protecting our planet isn’t just about saving the environment—it’s about protecting our health, including our eyes!


References:

Patnaik, J. L., Dye-Robinson, A., James, K. A., & Kahook, M. Y. (2024). Association Between Particulate Matter Pollutants and Ophthalmology Visits for Ocular Surface Irritation and Allergy. Clinical Ophthalmology, 18, 3263–3270. https://doi.org/10.2147/OPTH.S485199

Are gas stoves bad for your health? Here’s why the federal government is considering new safety regulations

Gas stove. Photo by Andrea Piacquadio.
Gas stove. Photo by Andrea Piacquadio.

By Jonathan Levy, The Conversation

Cooks love their gadgets, from countertop slow cookers to instant-read thermometers. Now, there’s increasing interest in magnetic induction cooktops – surfaces that cook much faster than conventional stoves, without igniting a flame or heating an electric coil.

Some of this attention is overdue: Induction has long been popular in Europe and Asia, and it is more energy-efficient than standard stoves. But recent studies have also raised concerns about indoor air emissions from gas stoves.

Academic researchers and agencies such as the California Air Resources Board have reported that gas stoves can release hazardous air pollutants while they’re operating, and even when they’re turned off. A 2022 study by U.S. and Australian researchers estimates that nearly 13% of current childhood asthma cases in the U.S. are attributable to gas stove use.

Dozens of U.S. cities have adopted or are considering regulations that bar natural gas hookups in new-construction homes after specified dates to speed a transition away from fossil fuels. At the same time, at least 20 states have adopted laws or regulations that prohibit bans on natural gas.

On Jan. 9, 2023, the U.S. Consumer Product Safety Commission announced that it will consider measures to regulate hazardous emissions from gas stoves. The agency has not proposed specific steps yet, and said that any regulation will “involve a lengthy process.” On Jan. 11, CPSC Chair Alexander Hoehn-Saric further clarified that the agency was looking for ways to reduce indoor air quality hazards, but did not plan to ban gas stoves.

As an environmental health researcher who does work on housing and indoor air, I have participated in studies that measured air pollution in homes and built models to predict how indoor sources would contribute to air pollution in different home types. Here is some perspective on how gas stoves can contribute to indoor air pollution, and whether you should consider shifting away from gas.

Natural gas has long been marketed as a clean fuel, but research on its health and environmental effects is calling that idea into question.

Respiratory effects

One of the main air pollutants commonly associated with using gas stoves is nitrogen dioxide, or NO₂, which is a byproduct of fuel combustion. Nitrogen dioxide exposures in homes have been associated with more severe asthma and increased use of rescue inhalers in children. This gas can also affect asthmatic adults, and it contributes to both the development and exacerbation of chronic obstructive pulmonary disease.

Nitrogen dioxide in homes comes both from outdoor air that infiltrates indoors and from indoor sources. Road traffic is the most significant outdoor source; unsurprisingly, levels are higher close to major roadways. Gas stoves often are the most substantial indoor source, with a greater contribution from large burners that run longer.

The gas industry’s position is that gas stoves are a minor source of indoor air pollutants. This is true in some homes, especially with respect to exposures averaged over months or years.

But there are many homes in which gas stoves contribute more to indoor nitrogen dioxide levels than pollution from outdoor sources does, especially for short-term “peak” exposures during cooking time. For example, a study in Southern California showed that around half of homes exceeded a health standard based on the highest hour of nitrogen dioxide concentrations, almost entirely because of indoor emissions.

How can one gas stove contribute more to your exposure than an entire highway full of vehicles? The answer is that outdoor pollution disperses over a large area, while indoor pollution concentrates in a small space.

Ventilation is an essential tool for improving indoor air quality in homes.

How much indoor pollution you get from a gas stove is affected by the structure of your home, which means that indoor environmental exposures to NO₂ are higher for some people than for others. People who live in larger homes, have working range hoods that vent to the outdoors and have well-ventilated homes in general will be less exposed than those in smaller homes with poorer ventilation.

But even larger homes can be affected by gas stove usage, especially since the air in the kitchen does not immediately mix with cleaner air elsewhere in the home. Using a range hood when cooking, or other ventilation strategies such as opening kitchen windows, can bring down concentrations dramatically.

Methane and hazardous air pollutants

Nitrogen dioxide is not the only pollutant of concern from gas stoves. Some pollution with potential impacts on human health and Earth’s climate occurs when stoves aren’t even running.

A 2022 study estimated that U.S. gas stoves not in use emit methane – a colorless, odorless gas that is the main component of natural gas – at a level that traps as much heat in the atmosphere as about 400,000 cars.

Some of these leaks can go undetected. Although gas distributors add an odorant to natural gas to ensure that people will smell leaks before there is an explosion risk, the smell may not be strong enough for residents to notice small leaks.

Some people also have a much stronger sense of smell than others. In particular, those who have lost their sense of smell – whether from COVID-19 or other causes – may not smell even large leaks. One recent study found that 5% of homes had leaks that owners had not detected that were large enough to require repair.

This same study showed that leaking natural gas contained multiple hazardous air pollutants, including benzene, a cancer-causing agent. While measured concentrations of benzene did not reach health thresholds of concern, the presence of these hazardous air pollutants could be problematic in homes with substantial leaks and poor ventilation.

Methane leaks from natural gas at all stages of production and use. UC Santa Barbara, CC BY-ND
Methane leaks from natural gas at all stages of production and use. UC Santa Barbara, CC BY-ND

Reasons to switch: Health and climate

So, if you live in a home with a gas stove, what should you do and when should you worry? First, do what you can to improve ventilation, such as running a range hood that vents to the outdoors and opening kitchen windows while cooking. This will help, but it won’t eliminate exposures, especially for household members who are in the kitchen while cooking takes place.

If you live in a smaller home or one with a smaller closed kitchen, and if someone in your home has a respiratory disease like asthma or chronic obstructive pulmonary disease, exposures may still be concerning even with good ventilation. Swapping out a gas stove for one that uses magnetic induction would eliminate this exposure while also providing climate benefits.

There are multiple incentive programs to support gas stove changeovers, given their importance for slowing climate change. For example, the recently signed Inflation Reduction Act of 2022, which includes many provisions to address climate change, offers rebates for the purchase of high-efficiency electric appliances such as stoves.

Moving away from gas stoves is especially important if you are investing in home energy efficiency measures, whether you are doing it to take advantage of incentives, reduce energy costs or shrink your carbon footprint. Some weatherization steps can reduce air leakage to the outdoors, which in turn can increase indoor air pollution concentrations if residents don’t also improve kitchen ventilation.

In my view, even if you’re not driven to reduce your carbon footprint – or you’re just seeking ways to cook pasta faster – the opportunity to have cleaner air inside your home may be a strong motivator to make the switch.

This article has been updated to reflect the Jan. 11, 2023 statement from the Consumer Product Safety Commission that the agency has no plans to ban gas stoves.