What are Microplastics?

No other man-made material may be more ubiquitous than plastic. Even though more and more plastic-free options are available, plastic is still so prevalent. It trashes our oceans and Great Lakes. And it's even in the air we breathe!

Photo by Jasmin Sessler on Unsplash  

But what we want to know about are microplastics. What exactly are they? And what harm can they pose?

Microplastic (MP) is a term based on the size of plastic waste: plastic particles that are 5 mm in dimension (about the size of a sesame seed) or smaller. There are no distinctions about the composition - microplastic is defined based on size only. There's even a smaller type called nanoplastics, defined as particles from 1 nm ≤ x ≤ 1 μm. Both are considered plastic particles that emanate from plastic products.

Where Microplastics Come From

There are different sources of microplastics. One is large plastic products (e.g., containers) that have degraded through the years and turned into smaller pieces. Another source is synthetic textile like polyester. Production and use of these fabrics ultimately release fibrous microplastics into the air. And the third source is plastic microbeads - this is a type of polyethylene commonly used in makeup, cleansers, and toothpaste.

Among these three sources of microplastic, only microbeads is purposely manufactured to be that small. And it goes unchanged, sort of, even as it goes into water and land. There's much more worrying stuff about microplastics that come from degraded plastic. After all, there are different dyes, pigments, and plasticizers that leach off these particles.

For example, if you wash a polyester shirt, some of those synthetic fibers get frayed and release into the wash. And repeated laundering of polyester fabrics results in plastic particles washing off into our marine systems. All plastic materials and synthetic fabrics wear out. And their smaller fragments, in turn, chemically decompose and turn into these microplastic and nanoplastic particles.

Microplastics are also in the very air we breathe. In fact, the majority of fibrous microplastic is polypropylene, and studies show that these are ever-present in our atmosphere - both outdoor and indoor air.

Basically, there will be plastic particles released when all plastic products degrade. But the problem is, that these plastic particles do not ever go away. Even if they partly decompose, they just turn into microplastics (MPs) and nanoplastics (NPs).

And this issue is nothing new. Evidently, microplastics have been around since 50 years ago, with microbeads being used in personal care products in lieu of other natural ingredients. But only recently has the clamor for preventing microplastics become louder than ever.

Are Microplastics Harmful?

Right now, we have yet to collect a large mass of scientific evidence about the effects of microplastics. There are a number of research finding out certain risks, but we still have a long way to go knowing the true extent of microplastic effects.

But the most recent finding is astonishing: microplastics can enter and travel in our bloodstream! 

According to this latest research, 77% of donors (17 out of 22 participants ) had plastic particles in their blood. The most common type was polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), and poly(methyl methacrylate) (PMMA). These micro- and nanoplastics are most likely ingested through food or inhaled in the air. These modes of entry are far likelier than the particles penetrating our skin. Previous findings, like this 2017 paper, also cite that ultrafine particles can actually accumulate in the lungs.

According to this current research, plastic particles that enter the bloodstream can potentially come from our air, water, food, clothing, tattoo ink residue, and personal products like makeup and toothpaste. And with regards to food, people who consume large amounts of sugar and seafood might ingest more microplastics.

How does the body react to microplastics?

There is evidence that our biliary tract (liver, gall bladder, and bile ducts) as well as the kidneys flush out some microplastics. Take note: some. That means we literally have plastic particles still running through our bloodstreams even with our body's natural cleaning systems. 

It's also worth noting that while much of microplastics are inhaled, not all are respirated or go through the lungs. But of course, the smaller particles are found to still be able to bypass the mucociliary clearing mechanism of the lungs - especially in people who have compromised respiratory health.

Seems like there's no escaping microplastics after all!

Microplastics Potential Health Issues

With so much microplastics in our environment, you'd wonder, "how will all the microplastics impact my health?"

Foreign Matter Inside Our Bodies

There's no definitive answer to that question, not yet at least concerning plastic in our blood.

But it's certainly worrisome. How good can foreign particles be inside our bloodstream?

What's more, animal studies about microplastics show aren't good, either. In one study for instance, scientists examined how microplastics affect the kidneys in mice. Results showed that MPs caused mice weight loss, increased death rate, and significantly damaged their kidney. And prolonged exposure to plastic particles, whether it's micro or nanoplastic, caused cellular damage.  

Phthalates in Plastics

Another critical issue with microplastics are phthalates. Now, these are known to affect human health. There are scientific findings concerning these plasticizers. Phthalates are a class of chemicals used in plastics to make them flexible, durable, more plastic-y. Like what we've learned in this article, phthalates have been linked to genital dysmorphia in males, lower testosterone, and propensity to obesity.

Other Contaminants

Plastic will always contain numerous dyes, pigments, phthalates, and other additives that could cause health issues. As mentioned, effects on reproductive health is already established. But aside from that, plastic could also be carcinogenic. For example, house dust that contains polybrominated diphenyl ethers (a kind of plastic common in fire retardant electronics, textile and furniture) is linked to cancers, neurodevelopmental deficits, and hormonal disruptions.

Microplastics Everywhere: What Now?

With much of the world enveloped in both visible and invisible plastic, what can we do?

The best course of action is to reduce and be as plastic-free as possible. If there are any accessible alternatives for usual plastic products, you may want to use those. The less we rely on plastic, the more we could cultivate a plastic-free environment.

Again, we don't have the scientific proof yet that microplastics can directly cause health problems, but we've seen how plastic's very composition makes it a vehicle for many toxic ingredients. And all these things will likely have serious long-term effects.