By Rivka Shapiro
Life in plastic is not so fantastic, and nowadays, we certainly do live life in plastic. From medical paraphernalia and disposable food containers to construction materials and electronic components, plastic is an incredibly useful material that has permeated every aspect of our lives. But we often forget to consider what happens to plastics as they age, or after we “dispose” of them. A category of complex polymers, plastic is not biodegradable, meaning the compounds cannot break down into other chemicals. Rather, plastic products simply break into smaller and smaller pieces over time, eventually becoming what scientists refer to as micro and nano plastics. Often invisible to the human eye, these particles have contaminated oceans, rivers, and other water sources. They also pollute the air, and can be aerosolized through combustion, like from the burning which occurs in garbage dumps. According to the American Chemistry Society, humans consume an average of 74,000 individual microplastics per year.
But what exactly is so bad about microplastics? Surely something so ubiquitous, so essential to our modern lives, would be safe. Environmental researchers at the University of Copenhagen set out to discover the potential dangers of microplastics. They took food containers made out of a specific plastic polymer called polyethylene (PET) and ground them to a fine dust, to mimic the particles which might occur naturally. Cultured human tissue exposed to the PET was then tested for various indicators of damage. The scientists found two different types of DNA damage in these cells, demonstrating that microplastics have the ability to seriously endanger human DNA.
Another group of scientists from the Chinese State Laboratory of Pollution Control found exposure to a different microplastic, polystyrene, also caused DNA damage in plants. Not only that, but the plants’ growth was greatly diminished after exposure to high concentrations of the microplastic. While humans certainly aren’t plants, these findings do not bode well for the long-term effects of microplastic exposure for living organisms.
It’s not just DNA damage that we have to worry about. Ingestion of microplastics can cause serious gastrointestinal distress. Humans have a necessary population of microorganisms living in their gut called a microbiome, which aids in the digestion and absorption of essential nutrients. Scientists in Germany discovered that the presence of microplastics disrupts the microbiome, leading to nutrient deficiency and digestive issues, and unfortunately, humans ingest microplastics all too often. Microplastics can enter your diet from degrading or low-quality plastic dishes, containers, and utensils, or through consuming fish which live in contaminated waters.
Microplastics can also over-activate our immune systems. As a foreign particle entering the body, the immune system is likely to send out a heavy response to microplastics. While it is good to have a strong and defensive immune system, over-activation can lead to unnecessary inflammation and symptoms of illness. Not only that, but if microplastics end up evading the immune system, more dangerous pathogens may “hitch a ride” with the microplastics and invade the body unfettered.
We don’t fully know what the long term effects of microplastic exposure will be. Plastics only started to become household items in the 1950s, and microplastics have only been studied in depth in the last thirty years. However, it may still be wise to limit your exposures by being careful with the products and foods you consume, and making a conscious effort to recycle and contribute to environmental cleanup. After all, most humans aren’t Barbie.