Microplastics: small in size, big in impact

Plastic as we know it today is not even two hundred years old. Looking at a timeline, the massive plastic industry has only been around since the early to mid twentieth century. Yet, it goes without saying that plastic has become a major issue for the Earth's health, and an even bigger market for consumers. So, I've been wondering, if this product has existed for a relatively insignificant amount of time, how has it already had such a massive impact on Earth? And to take it a step further, how are these obscene amounts of plastic on our planet affecting Earth's inhabitants—even in ways we can't see?

Microplastics on a finger

What are microplastics, and how do we ingest them?

A microplastic is a piece of plastic that is smaller than five millimeters that is found in the environment, is insoluble, and generally take centuries to break down. Zooming in even further, nanoplastics are microplastics that are found to be less than a thousand nanometers and are commonly found in animal organs and human tissues. These extremely small particles are generally the byproduct of larger plastic items that have begun to break down, but sometimes they are made intentionally, like in the case of microbeads used in toothpaste and face creams. Yes, you read that right—you are brushing your teeth with nearly invisible pieces of plastic. Keeping that slightly disturbing thought in mind, I hate to tell you that's is not even the most common form of ingestion. Many microplastics are consumed by humans in the form of food—particularly seafood as a result of the oceans' pollution. Synthetic clothing is also responsible for massive amounts of microfibers that can be found in drinking water. Microplastics are also often breathed in. The particles found in the air can come from a variety of sources such as textiles, car tires, and dust. Research has shown that humans ingest about eleven microplastic particles an hour, meaning 96,360 particles per year.

How microplastics can end up in food

Effects on Health

As you can imagine, consistently taking in this foreign, man-made substance in large quantities does have an effect on the human body. In the 1990s scientists were able to demonstrate the presence of microplastics in the lung tissue of lung cancer patients. Their research concluded that, particularly for people with lung disease, the plastic particles can stay in the lungs. The longer they remain inside, the more inflamed the tissue becomes. Particle pollution in general has been known to damage lungs and eventually lead to cancer, asthma, or other problems, so if the amount of microplastics in the air continues to grow, it is likely that the amount of individuals suffering from these health issues will too. As researchers have found that humans and animals take in microplastics, they have also seen that microplastics can be egested from our bodies. Running more tests, plastics were found in the heart, kidney, stomach, and intestines of rats. As a result of this research, researchers were able to hypothesize that human exposure to microplastics can lead to oxidative stress and DNA damage or inflammation. Different researchers performed an experiment on zebrafish exposed to high-density concentrations of polyethylene and polystyrene microplastics for twenty days. As a result, transcriptomic alterations were expressed in the immune system genes and the down-regulation of genes correlated with epithelium integrity and lipid metabolism. When the RNA sequencing occurred in the fish's liver, the liver samples came back with approximately 53 million reads per sample, and over 25,000 unigenes (sequences that appear to come from the same transcription locus) were identified. A total of 326 genes transcripts were found to be transcribed differently. These mutations can eventually lead to cancer, behavioral changes, and altered immune response. This experiment was done on a different species, at very high concentrations, but it's important to see these trends, and what may lie ahead for humans. In fact, it's not just the plastics themselves that cause harm. Their surfaces are colonized by microorganisms, which are sometimes human pathogens.

Fish with plastic-filled intestines

What can be done?

Currently, one study estimated there are about 15 to 51 trillion microplastics particles floating on the surface of the Earth's oceans. A big change that would make a large impact is replacing microplastics in personal care products with natural materials. When it really comes down to it, though, the system needs to be changed; there needs to be a fundamental shift in the way we produce, use, and dispose of plastic. For example, by increasing the use of public transport (or decreasing the use of private automobiles) we can nearly halve microplastic pollution from tires by 2040. Also, ensuring robust implementation of pellet management plans and procedures can reduce plastic pellet pollution by 80% by 2040. When it comes to textiles, redesigning fabrics to minimize microfiber shedding and installing in-line filters in washing machines can contribute to a 77% decrease in this type of pollution in the same timeframe. Taking a step away from changes that can be made in general, it's also important to look at what you can do as an individual versus what the government can do to make effective change. One step to reduce your own microfiber footprint is to change the way you do your laundry, and your overall approach to clothes. A single load of laundry can release more than a million microplastic fibers into the environment through both the wastewater generated by washing machines and exhaust from dryers. The installation of a filter in your washing machine can catch some microplastics and running the washer on a lower cycle where the clothes aren't thrown with such force. The best solution, though is buying clothes from only natural materials (such as cotton, wool, or linen), because it reduces the risk of microplastic pollution to zero. In addition, you can take steps that help with not just microplastic, but general pollution, like not using single-use plastic and increasing the use of public transportation. As much as it helps, and sends a message, to fight microplastic pollution as an individual, policies need to be changed as well. On a federal scale, the United States Environmental Protection Agency has a Trash Free Waters Program dedicated to reducing the volume of plastic in United States water ways, which will target microplastics as well. The National Oceanic and Atmospheric Administration is also conducting studies surrounding microplastics, and to measure their concentration. The New Jersey legislature has banned single-use plastic grocery bags, and in 2018 a grant allowed the Delaware Watershed Conservation Fund to monitor for microplastics and model loadings of microplastics in the upper Delaware Watershed Estuary from Trenton to the C&D Canal. More can always be done, but if we want to change, we have to start by spreading awareness. People need to be educated more on the effects of microplastics, and how prominent of an issue they are in terms of the planet's ecosystems, and when it comes to the health of living creatures.