Microplastics Are Everywhere—Even in Your Testicles

A recent study about microplastics may make you squirm in your seat. Scientists tested 70 testicles (23 from humans and 47 from dogs) and found the tiny bits of plastic in every single sample. The study, published on May 15, 2024 in Toxicological Sciences, raises concerns about the potential impact of microplastics on the human reproductive system and suggests that the presence of plastics in male gonads is lowering sperm counts.

The report is just the latest in a long line of published studies on microplastic contamination in human bodies. Plastic has also been found in breast milk, placentas, blood, and infant feces, as well as just about every major human organ including our brains, heart, lungs, and livers.

The science is undeniably clear: microplastics are floating around inside every one of us and it’s making us sick. Recent data published in the New England Journal of Medicine suggest that this is an impending health crisis, one that we can no longer ignore.

You’re not alone if the avalanche of microplastics news leaves you feeling powerless. I don’t know about you, but I tend to put my energy into tackling the problems that I feel I can help solve—hopefully through neat and quick work. And although I’ve made pretty good strides in removing plastic from many aspects of my life, eliminating it entirely is near impossible. That’s because plastic has pretty much taken over the world of consumer goods.

Don’t believe me? Try not to buy one plastic item during your next trip to the grocery store. Look in your closet and check out the clothing tags to see which items are made from synthetics (plastic). The next time you travel on a plane, see if you can go a day without touching plastic cups or food containers. The furniture we sit on, the carpets we walk on, the personal care products we use are all made in part from plastic. Much like PFAS or forever chemicals, the stuff is freaking everywhere, and we shouldn’t be surprised that it breaks down into tiny particles that find their way into us.

But now it’s in testicles? I have two sons, so naturally this is troubling news.

I tend to roller coaster between periods of intense anti-plastic action—purging my cabinets of all the plastic containers, spatulas, and cutting boards—to periods of near despair. What’s the point? I can’t escape it. 

But I always come back to my kids. And the children I hope they’ll have some day. Maybe, just maybe, we can halt this plastic epidemic. Maybe we can scream loud enough, deny the plastic pushers our dollars, and see a seismic shift in the way products are made and packaged.

I believe this can work. Historically, when large groups of people come together to demand big systemic changes, shit happens. Think about it: public outcry has ended slavery and birthed the civil rights movement. Public outcry ended the draft and won women the right to vote. Public outcry made gay marriage a reality.

To wrap my head around this accumulating microplastics evidence and seeking hope that we can solve this problem, I reached out to Paul Anastas, the director of Yale’s Center for Green Chemistry and Green Engineering. Anastas, known as “the father of green chemistry,” has been researching and writing about safer alternatives to traditional plastics for more than 20 years. I asked him some burning questions about the impact of microplastics and what we can do to make our world safer for future generations.

Are Microplastics Harmful to Humans?

I’m sure people won’t like this answer any more than I do, but right now we don’t know. And the fact that we don’t know is absurd. There are a growing number of studies that show a distinct correlation between microplastics and health impacts, like this one published in The New England Journal of Medicine. But even here, the authors go out of their way to say that while there is a correlation, there is no proven causal link. The difference between correlation and causal link are night and day and this is very important. (A correlation is a relationship between two factors; a causal link scientifically proves that one thing causes the other.)

Now, I am not one of those people that say plastics are not a health problem. But I’m a scientist and I’m saying we need to demand scientific proof. Correlations are important and they cannot be ignored, but they need to be studied. It’s absurd and just plain wrong that we’ve been swimming in synthetic plastics for decades without knowing for certain whether they are harmful and how.

Can We Remove Microplastics from Our Bodies?

The answer is yes and no.

Let’s start with the “yes.” The overwhelming majority of any plastics found in human bodies are ingested through our mouths. Our bodies recognize microplastic as a non biological (nonliving) thing and excrete the vast majority of it through urine or feces. When we ingest biological things—like food or nutrients—our bodies allow them to pass through our membranes and into our organs.

The problem with microplastics is that over time, the molecules get smaller and smaller. So small in fact, that our bodies get confused, read them as biological, and then absorb them.

And here’s where we get to the “no, we cannot remove microplastics from our bodies.” I do not know of and cannot imagine a way that we could remove these residual microplastics from our organs once they are absorbed. There’s no magic bullet that I’m aware of; no way to power flush them out like a gutter full of leaves. Only our bodies can do it. I don’t like that answer, but I believe it to be true.

Can We Escape Microplastics, or Do We Have to Accept Them?

Yes, we can escape microplastics and, no, we do not have to accept them. The solution already exists and it’s right in front of us. It’s important to remember that all plastics are not bad. Bad plastics are bad.

By bad I mean traditional plastic, which is made from the wastes created by fossil fuel companies such as toxic vinyl chloride. And we do not have to accept the bad plastics. Bioplastics (a.k.a. biological polymers) are the good plastics. They’re viable, high-performing alternatives made from agricultural waste, wood waste and even insect and shrimp shells. We already have a staggering amount of agricultural waste which could (and should) be turned into all the (bio)plastic we’ll ever need. One key driver: we should never consider growing crops or using food products to make plastics because that would be unsustainable from a life-cycle perspective.

How Effective Are Bioplastics?

You might hear that biobased plastics don’t work as well, and that nothing can beat traditional fossil fuel plastics. This is simply a lie. It’s just that traditional plastic has had a 100-year start and uses countless chemical additives to give it the performance we have come to depend on. Bioplastics can have all of the function and performance of traditional fossil plastic without all the problems as long as you use green chemistry design. Bioplastics are harmless rather than toxic, renewable rather than depleting, and degradable rather than persistent. Bioplastics are harmless to our health and environment when designed with life-cycle thinking.

The fossil fuel industry has been making plastic and shifting the responsibility to us, patting us on the head and saying ‘don’t worry about it, just recycle.’ It’s absurd for us to allow this to continue when we know the damage it’s causing and we have a solution.

How Do We Take Action Against Plastic?

Every single one of us is a consumer and in that role we have immense power. We can stop buying petroleum-based products and start demanding more bio-based plastics that are designed to degrade.

We can demand from our elected officials that more resources and funding goes to green, sustainable chemistry. We can call the EPA and the National Institute of Environmental Health Sciences and tell them to conduct studies that establish causal links. We can write to environmental nonprofits and mobilize them to start petitions.

This type of consumer pressure works. A few years ago, virtually all of our personal care products were made of petroleum. But consumer market pressure changed that. The voice of the consumer was heard loud and clear and now every major manufacturer of cosmetics and personal care products is shifting toward entirely bio-based ingredients.

All political change starts with awareness and passion, then mobilization and communication to those in power.

Looking back over two centuries of chemistry, there has always been this creative tradition of coming up with new ways of doing things that transform the quality of life. Green chemistry is building on that. It says that we can do better. It says that not only can we achieve all of that function and performance, but we can do it in a way that’s fundamentally sustainable, nontoxic, and renewable rather than degrading.

Doing right by the planet can make you happier, healthier, and—yes—wealthier. Outside’s head of sustainability, Kristin Hostetter, explores small lifestyle tweaks that can make a big impact. Sign up for her twice monthly newsletter or write to her at climateneutral-ish@outsideinc.com.