Microplastics affect reproductive organs and other systems and cells

Although these microscopic particles were measured in mice, they are probably affecting humans, too.

I tried to pick up a plastic bucket while working in my greenhouse. The bucket had been filled with sand and had been sitting in a corner for several years. As I grabbed the handle, it snapped and the bucket cracked into a thousand pieces all over the ground.

The bucket had simply become old and increasingly brittle with age. It had also been in a sunny spot, and sunlight ages everything more quickly. I did my best to clean up the mess, noting that many of the cracked pieces were very, very small.

The fate of that bucket is the fate of all plastic, from grocery bags to garden hoses, aging and falling apart into smaller and smaller pieces. As time goes on, that bucket will disintegrate more and more. Ultimately, it will become thousands of microplastics, which are defined as particles smaller than five millimeters long, or about the size of a sesame seed, down to the microscopic level.

Microplastics come from plastic things falling apart. They are also intentionally manufactured for products such as toothpaste and beauty supplies. They have been found everywhere. Every ocean in the world has microplastics floating among its fish and seabirds. Microplastics have even been found on the icy summit of Mount Everest.

Without realizing it, we are awash in tiny plastic bits. A Canadian study from 2019 found that people might consume between 39,000 - 52,000 particles of plastic in a year’s time. A 2022 study conducted in the Netherlands found microplastics in the bloodstreams of all individuals who volunteered for the project.

Microplastics and health

Researchers have recently looked into how all this plastic might affect our health. In one study, scientists gave laboratory mice drinking water containing microplastics. They were naturally expecting to find plastic bits in the digestive tracts of the mice—the stomach, liver, and intestines that come in direct contact with the ingested plastic—but to their surprise they found microplastics in every tissue of every organ, including the brains of the mice.

Researchers also observed the mice and how they behaved in different environments. They found that mice exposed to microplastics exhibited symptoms similar to dementia in humans. Fortunately (so far), despite all of the microplastics we consume, there doesn’t seem to be a corresponding increase in human dementia. In fact, rates of dementia seem to be declining.

As plastic ages, it breaks down into smaller and smaller parts, ultimately becoming microplastics. Chemically, plastic is resistant to breaking down. Those little bits of broken down Legos and straws are going to be around a long, long, time. Photo: Friends of the Earth foe.org

In a study conducted in China, scientists gave water containing microplastics to mice for four weeks. They later compared the testes of these mice to a cohort of control mice who drank untainted water. Compared with the control group, the testicles of the microplastics group showed signs of premature aging: In addition to their sperm counts being much lower, the spermatogenic cells, those that generate the sperm, were “loosely arranged,” as might be expected in older individuals. Testicular tissue also showed signs of inflammation and fibrosis or internal scarring. Additionally, many of the animals’ testicles had developed unexpected hollow spaces.

Looking more deeply, cells throughout the mice exposed to microplastics were less likely to go through the normal cell division that characterizes healthy cells. The microplastics also appeared to reduce the cells’ ability to detoxify. Given this evidence, it’s no surprise that the scientists even noted DNA damage in the cells.

Your exposure and your health

We have made plastic ubiquitous, but you can limit your exposure. Drink tap water and avoid bottled water. The longer water remains in a bottle, the more plastic it accumulates. I know a lot of folks think bottled water is safer, but in the U.S., the safety standards for tap water are higher than for bottled water. You might also consider filtering your drinking water.

Whatever you do, don’t use toothpaste or cosmetics that have microplastics in them! You can also keep plastic out of your mouth by using a natural fiber toothbrush. You can get one with a handle made of bamboo and bristles from the castor bean plant.

Wear clothing made of natural fiber, like cotton or linen. Fabric such as polyester can slough off plastic microfibers through use and laundering. The same can be said of bedsheets. A lot of carpeting is made of synthetic fibers that produce microplastics during normal wear and cleaning. You can replace them with affordable rugs made of natural fibers. Whether you have natural fiber rugs or rugs made of synthetic material, vacuuming regularly is a big help to reduce microplastics in your home. If you want to be hard-core about it, you can get a vacuum with a high-efficiency particulate air filter that can trap some of the smallest dust and dirt.

For more information on plastics and human health, check out these previous Green Dispatch posts:

Bottled water: we pay a high price for it in more ways than one, January 13, 2023

Plastics: From lingerie to Legos they are everywhere, May 3, 2021

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