Why I’m not that worried about microplastics (yet)

There’s a credit card’s worth of plastic in your brain.

How’d it get there?

From something that’s everywhere, invisible, and according to some people, going to kill us all

Microplastics.

If you’re reading this then you probably already know that microplastics are in our food, water, and air.

You probably also know that there’s alcohol in bananas, but we still feed bananas to our kids.

Why?

Cause the dose makes the poison.

While I’m sure we all agree that plastic in our body isn’t a good thing, if the amount of microplastics we consume is small enough to not cause serious health effects, then it’s not a good use of time and effort to go to crazy lengths to remove plastic 100% from our lives.

So the goal of this blog post isn’t to scare you about microplastics or tell you that you need to rearrange your life to avoid them.

The questions I want the answers to are:

And most importantly, can I blame microplastics for all my health issues while taking no personal accountability for poor lifestyle decisions?

(sarcastic laugh)

To explain my questions a little better, if microplastics are not that harmful – then removing plastic say, 30-50% from our lives could be a worthwhile action for our health and the environment without taking too much-added effort.

This would include easy lifestyle changes like not drinking from plastic bottles, avoiding paper receipts, or using plastic Tupperware. 

But if microplastics are the root cause of all cancer, death, disease, and everything bad in the world as one side of the internet claims – then removing plastic 99% from our lives would be worth the serious mental and physical effort, time, and inconvenience that takes.

Those extreme lifestyle changes include never ordering takeout food or paper coffee cups, only wearing clothes made from cotton, wool, and silk, and avoiding seafood entirely.

The answer of course, is somewhere in the middle. So let’s find the truth on microplastics – and I’ll be sure to sprinkle a healthy dose of my opinion on top 😉

Part 1: Microplastics for dummies

A microplastic is just a baby plastic 👶🏻

What do you think the deepest trenches of the ocean, highest mountain peaks in the world, and the air we breathe all around us have in common? 1.

Microplastic particles are there (and pretty much everywhere else).

The size of microplsatic particles ranges from 5 millimeters to 100 nanometers 2.

They come from…everywhere

“Where do microplastics come from Josh?” From the breakdown of larger plastics.

For example, when a plastic water bottle ends up in the ocean, it degrades, over time into smaller pieces, which are microplastics. 

Then fish eat that microplastic -> that fish ends up on your dinner plate – > microplastics end up in you.

Plastic waste in the ground also degrades down into microplastics, which end up in the air, in plants, and in animals (and then the people who eat those plants and animals).

They come from plenty of other place too.

For example, car tire wear is actually one of the larger sources of atmosphere microplastics. 

* It’s important to mention that a lot of microplastic detection technology is still in development. For example, the exact amount of microplastics in the air is difficult to measure. Ian Mudway, an expert in respiratory toxicology says, “The only stuff we can measure in the air is the big particles, and then we assume we are inhaling smaller particles” 3.

And of course, microplastics are found in food, water, and all the other stuff that comes packaged in plastic.

One study found that people who drink water from plastic bottles consume 90,000 microplastics annually. People who drank tap water only consumed 4,000 4.

Plastic food containers (Tupperware) also release microplastics, especially when they’re heated 5.

A well known study heated plastic containers in the microwave for 3 minutes and found that they released as many as 4.22 million microplastic and 2.11 billion nanoplastic particles from only one square centimeter of plastic area.

That study found that even refrigerator and room-temperature storage of food in plastic containers releases microplastics.

Plastic cutting boards are also a known microplastic source 6. And synthetic fabrics like polyester or nylon clothing release microplastics into the water supply and air when you wash them.

And inside you of course

So plastic is everywhere, it sheds microplastics constantly, and through our food, water, and air they end up inside our bodies.

So far, scientists have found microplastics in human blood, lungs, placentas, breast milk, livers, brains, and testicles.

One popular study you may know about claims that the amount of microplastics we consume every week is equal to a credit card’s worth of plastic 7. 

According to a study by Professor Matthew Campen at the University of New Mexico, the adult human brain has 5-10g of plastic in it (that’s the size of a plastic spoon) 8.

Another study found microplastics in 100% of human testicle samples that they looked at 9.

Part 2: Health effects

So what?

Alright, scary stuff. But before we freak out, Let’s remember that just because microplastics are found in our bodies doesn’t mean that they’re going to kill us.

The next question we have to answer is:

Is the level of microplastics in our body proven to cause harm? Or is having some amount of plastic in our brains and balls no biggie?

The mechanisms through which microplastics may harm the body are:

1. Physical damage
2. Chemical toxicity
3. Carrier effect

Physical damage means inflammation and tissue damage.

Chemical toxicity comes from the additives in plastic like phthalates and bisphenols (more on those in a sec) which are known endocrine disruptors.

The carrier effect just means that microplastics absorb and transport other environmental pollutants.

So that’s the theory.

But what does the science say about microplastics‘ health effects?

Well as you could guess, science says that at high doses, plastic inside you is bad.

But spoiler alert: There aren’t any studies that prove microplastics to be harmful to human health at environmental exposure levels.

Most human studies don’t even address health, they just find microplastics.

“Yep, they’re in there!”

And then there are animal studies that test the health effects, but they’re at super high plastic doses

Like, “Let’s make these mice drink a plastic smoothie and see what happens”

Animal studies

Mice drink water with microplastics, get dementia 🧠

A recent study by University of Rhode Island researchers gave mice microplastics in their drinking water for three weeks 10.

After the 3 weeks, microplastics were found in the gut, liver, kidneys, lungs, spleen, heart, and brain (crossing the blood-brain barrier). They even led to changes in the mice’s behavior, with them showing symptoms similar to dementia in humans.

This study begins a conversation on the harms of high-dose microplastics and shows the possibility that they travel from the water in our GI tract to other organs in the body and even past the blood-brain barrier and into the brain.

But, as an animal study, we’re not sure how it applies to humans. Only 50% of rodent studies end up translating over.

It’s also unknown what the concentration of microplastics in the water given to the mice was and how it compares to the amount of microplastics we are exposed to every day.

Microplastics hurt immune cells

A study by UNM researchers looked at the effects of polystyrene microplastics on a type of cell called a macrophage (an immune system cell) 11.

The study found that when macrophages swallowed microplastic particles, it changed how the cells worked. They started using energy differently, relying more on a process called glycolysis and less on their usual, more efficient energy-producing process (mitochondria).

The macrophages with plastic in them also released inflammatory chemicals.

This study suggests that microplastics may interfere with how our immune system normally functions

If that’s the case, microplastics could be a large cause of the skyrocketing rates of autoimmune diseases 11.

The criticisms of this study are:

While it gives some insight into how microplastics affect immune cells in petri dishes… petri dishes aren’t people.

As an in vitro (petri dish) study, it’s unknown how the findings apply to in vivo (living organism) conditions.

The study also doesn’t specify the concentration of microplastics used and the short-term response leaves questions about microplastics’ long-term effects and how the body may adapt to them over time.

Mice exposed to microplastics have lower sperm count & testosterone 🍒

Mice exposed to polystyrene microplastics for 28 days were found to have decreased sperm quality, lower testosterone levels, and inflammation in the testes 12.

The microplastics also caused increased sperm malformation rates and damage to reproductive structures.

The authors of this study take these findings and throw out the idea that microplastics may be partially to blame for the rising rates of male infertility and lowering semen quality (with obesity, diet, and pollution as other factors).

Not joking here, this study has me genuinely considering throwing out my polyester underwear.

Plastic kills kidney cells

The below screenshot is from a study that demonstrated how high levels of plastic kill kidney cells 13.

However, the amount of microplastics used in this study is at a high dose that we would never experience it.

Human studies

Ok, those were animals and petri dish studies. Let’s talk about a few of the most popular human microplastic studies.

Microplastics double risk of heart attack and stroke

This 2024 found that heart disease patients with microplastics in their carotid arteries were twice as likely to suffer a heart attack or stroke 14.

This study is concerning and for sure a good jumping-off point for future research, but I’m not sure the takeaway is “microplastics double your risk of heart attack.”

For one, the study did not quantify the exact dosage of microplastics found, which makes it impossible to compare to average exposure levels.

And as we all know, correlation does not equal causation.

Maybe, instead of the microplastics causing more cardiovascular issues, it could be that people with higher levels of microplastics in their arteries have other lifestyle factors or environmental exposures that contribute to their increased risk

For example, people with microplastics in their blood are probably more likely to eat foods packaged in plastic, which are processed, fatty, unnutritious foods that cause heart disease and stroke.

For other skeptics out there, there is also a potential explanation of reverse causality.

The disease process of plaques building up in arteries could cause an increased surface area to catch microplastics in the artery, so the microplastic accumulation comes after the disease rather than before.

Microplastics found in human placentas

This widely cited study found 12 microplastic fragments (ranging from 5 to 10 μm in size) on the fetal and maternal sides of the placenta and in the chorioamniotic membranes 15.

No direct health effects were measured; so it’s unknown how this level of microplastics affects fetal development.

While this study is a popular one to point to (we all can get behind healthy babies) I think the strongest argument against its findings is the high risk of microplastics contaminating the sample during collection or analysis.

Since microplastics are in the air (especially in a hospital environment with lots of single-use plastics) it’s very possible that they were not actually in the placentas and instead got into these samples during collection and transport to the lab.

Microplastics found in human stool 💩

Another study found an average of 20 microplastic particles per 10g of human stool 16.

This confirms that we ingest and pass microplastics through our digestive systems.

No direct health effects were measured or linked to this finding and like the placenta study, there is potential for sample contamination during collection or analysis.

It’s also important to note that the sample size was only 8 participants.

Microplastics found in human blood 💉

This study found microplastics in 17 out of 22 human blood samples, with an average of 1.6 μg/ml 17.

No health effects were measured and again there is the potential for sample contamination.

Plastic industry workers develop lung disease

There are many known cases of workers in plastic factories developing respiratory diseases at a much higher rate than the general population.

In one case, a 28-year-old businessman developed asthma after exposure to thermoplastics used in 3D printing 18.

In another a 66-year-old patient developed hypersensitivity pneumonitis after working in the Polyethylene terephthalate (PET) production industry 19.

In a Baltimore plastic injection molding facility, five employees were confirmed to have developed Legionnaires’ Disease, with one worker dying 20.

While these add to the proof of the danger of plastics, they don’t provide clear, dose-dependent evidence of harm at exposure levels outside of plastic factories. 

Part 3: Additives

While the evidence for microplastics harming our health is still being collected, it seems that the additives in plastic like BPA, phthalates, and Pfas, (found both in microplastics and large plastics) are a lot more conclusively dangerous.

“BPA Free” is meaningless

BPA is probably the most well-known plastic additive.

While doing the research for this article I learned that the proudly labeled “BPA-free” plastic water bottles and tupperware I own are just as dangerous as plastics with BPA.

Why?  

In BPA-free plastics, the BPA compound (fancy name = Bisphenol A) is just replaced with BPS (Bisphenol S) which is equally as toxic. 

Professor Joseph Allen of Harvard School of Public Health calls this process “chemical whack a mole” or “regrettable substitution” 21.

“BPA-free means the product lacks BPA, not that it’s free from other toxic chemicals,” says Dr. Rhonda Patrick

Also, the tag “microwave safe” only means that the plastic won’t melt in the microwave, not that it’s free of toxic chemicals or is safe to heat up and eat off of.

Health effects of BPA, BPS, and Phthalates

Plastic additives are known to cause health problems. Like:

Studies suggest that prenatal and early-life exposure may affect brain development, potentially leading to behavioral issues like hyperactivity, anxiety, and depression in children 22.

BPA and phthalates have been associated with altered reproductive function, including effects on fertility, prostate health, and mammary gland development 23.

Some research indicates a possible link between these chemicals and increased risk of obesity, type 2 diabetes, and cardiovascular disease 24.

Animal studies have shown that BPA exposure may suppress immune function 25.

While more research is needed, some studies suggest a potential link between these chemicals and certain types of cancer, including breast and prostate cancer 26.

Human studies have found associations between higher urinary levels of these chemicals and disrupted hormone function. For example, one study showed that consuming canned soup for five days led to a significant increase in urinary BPA levels, with measurable changes in hormone levels6. However, it’s important to note that while these associations exist, establishing direct causality is challenging.

Part 4: Takeaways

Are microplastics really our biggest health problem?

Okay, microplastics and plastic additives are everywhere, they’re inside of us, and they’re not good for us.

But, the jury is still out on how bad for us they are and at what level. Because there are no studies proving how our current level of microplastic ingestion affects health outcomes.

So without any evidence that our current level of microplastic consumption harms our bodies, how much of our lives should we change around to avoid them?

I mean the next time you’re in your kitchen and at the grocery store, try to avoid buying food packaged in plastic. It’s not possible.

Meanwhile…

Heart disease is out there claiming one in three Americans, and 90% of those cases could be prevented with lifestyle changes.

Air pollution contributes to 4.2 million premature deaths worldwide each year.

2/3 of Americans are diabetic or prediabetic, most are overweight or obese, and 70% of food in grocery stores is ultra-processed.

Are microplastics even our biggest plastic problem? 🌎💨♻️

You could argue that microplastics aren’t even our biggest plastic problem.

Dr. Ian Mudway who’s an expert in respiratory toxicology, says that there are 2 more pressing and well-established problems related to plastics that should get our immediate attention:

1. Waste
2. Pollution

Globally, we’re producing over 300 million tons of plastic annually, with only about 9% recycled. The rest is piling up in landfills or being incinerated.

There’s now more man-made material on Earth than biological material. This includes bacteria, flora, fauna, and all other living organisms.

Dr. Mudway points out, “If we are really going to be worried about the health effects of microplastics, I would be starting in Indonesia and the Philippines and in the countries where we are shifting huge plastic waste and where much of it is actually being burnt in open fires to get rid of it.”

The health impacts of burning plastics are well-documented and severe. It releases a cocktail of harmful chemicals into the air, including dioxins, furans, mercury, and PCBs. These toxins cause immediate respiratory issues and long-term health problems.

So while microplastics are a concern that warrants research, the more immediate and severe impacts of plastic waste, burning pollution, and overall plastic production I think are more urgent. Because these issues have clear, documented effects on human health and the environment.

How you can limit plastic in your life

That being said, plastic in our bodies isn’t making us healthier, some of these human and animal studies are seriously concerning and plastic waste in the environment isn’t making our world a better place.

So after learning what I have while writing this article, I am going to take some easy precautions to limit the plastic in my life.

Kitchen

I’m gonna stop heating any food in plastic containers and use glass bowls and containers for all reheating.

I’m also going to use glass containers for as much food storage as I can, and then fill in the gaps with plastic tupperware.

I don’t currently drink much water from plastic bottles but I used to. From now on I’m going to avoid plastic water bottles whenever I can and only use non-plastic reusable water bottles.

Coffee ☕

I also am going to make an effort to bring my yeti coffee mug with me when I go to coffee shops to avoid disposable “paper” coffee cups (coated in plastic) since heat and plastic seem to be a smart combo to avoid. Also reduces waste and keeps my coffee hot longer.

Underwear

After seeing the mouse study with microplastics seriously affecting testosterone and sperm health, along with the societal rates of plummeting male fertility, I think I’m going to switch away from my polyester underwear to something else.

Conclusion

What We Know:

1. Microplastics are in our food, water, air, and yes, even in our bodies.
2. At high doses, plastics and their additives can cause harm.
3. We’re exposed to a lot of plastic, and that exposure is increasing.

What We Don’t Know:

1. Whether the current levels of microplastic exposure are actually harmful to human health.
2. The long-term effects of chronic, low-dose exposure to microplastics.

Here’s the thing: while microplastics are a concern, they’re swimming in a sea of other, more well-established health threats. Heart disease, obesity, air pollution – these are the heavyweights in the ring of public health, and we know how to fight them.

As the World Health Organization pointed out in 2019, there’s not enough evidence to say that microplastics in drinking water pose a risk at current levels. That doesn’t mean we should ignore the issue, but it does suggest we might want to prioritize our health concerns.

It’s also important to remember how much the invention of plastic has helped our world and allowed for the cheaper production of so many things in healthcare, food safety, and countless other areas of our lives. The goal isn’t to eliminate all plastic – it’s to use it wisely and reduce unnecessary exposure.

So, what’s the takeaway?

The science on microplastics is still evolving. Keep an eye on new research, but don’t try too hard to avoid plastic, it’s everywhere and you’ll go crazy.

Apply the precautionary principle while we wait for more conclusive evidence, it’s wise to take steps to reduce our plastic exposure where we can, without going to extremes.

The plastic waste crisis and the pollution from plastic production and incineration are immediate, well-documented problems. Supporting efforts to address these issues might be the most effective way to tackle the plastic problem.

While we wait for science to catch up, let’s not lose our minds over every plastic water bottle. Instead, make some easy swaps where you can and focus on the health stuff we know works – like not eating junk food and getting off the couch once in a while.

Stress kills too, so don’t let microplastic panic keep you up at night. Stay balanced, and maybe give your plastic spoon collection a side-eye.

– Josh