I pulled an older pair of jeans out of the wash the other day and saw that some of the plastic decoration on the back pockets was starting to come off, and I wondered where it went and what impact it might have. After a quick search on the web, I discovered that "microplastics" in wastewater are a problem and one that is actively being looked into.
There are two main sources of microplastics that are found in wastewater. The first is from cosmetic products. Referred to as microbeads, they are used in toothpaste, shower gels and personal care products. These tiny plastic pieces are used to produce a mechanical cleaning effect. A second source of microscopic plastic originates from our washing machines when some synthetic textiles are laundered.
Microplastics, according to the National Oceanic and Atmospheric Administration, are small plastic pieces less than 5 millimeters in length, which is about the size of a sesame seed, and they do not dissolve in water.
Both municipal wastewater treatment systems and onsite wastewater treatment systems have issues and concerns with microplastics. As they can build up, the microplastics will block and even damage how well the system functions. Microplastics that are discharged in treated water enter river ecosystems or they can build up in the soil profile if they're from an onsite system and eventually find their way to a receiving water body.
The oceans, unfortunately, contain significant amounts of debris and plastic. This debris is documented to cause harm to the health of the ocean waters and the animals that call it home. Until recently, little consideration has been given to microplastics in freshwater bodies, such as rivers, and their impact on river ecosystems.
Rivers are often the drinking water source for communities in addition to providing a habitat for fish and drinking water for wildlife. The concern comes when fish and invertebrates, such as crayfish and snails, eat the tiny pieces of plastic and then are consumed by other creatures as part of the food chain. As the microplastics in smaller creatures goes up the food chain, they can potentially end up in our food.
Dr. Timothy Hoellein at Loyola University Chicago found that water downstream from a wastewater treatment plant had a higher concentration of microplastics than water upstream of the treatment plant. His research also found that the tiny plastic from the treatment plant contained bacterial communities that were not consistent with naturally occurring bacterial communities found in the studied rivers.
While wastewater treatment plants do a good job of removing major pathogens and excess chemicals like carbon and nitrogen before releasing the treated water, these systems are not designed to filter or remove tiny plastic particles. Once the microplastics are in the river ecosystems, they remain there for a long time and can travel significant distances from their point of origin.
At the March 2018 International Marine Debris Conference, microplastics and synthetic fibers were discussed. It was suggested that microfiltration was needed to remove these particles to protect the environment, yet this was still problematic, as treatment plants deal with large volumes and some microplastics might still be discharged.
In 2015, the United States placed a ban that stopped the production of personal care products and cosmetics containing plastic microbeads. This federal law, designed to protect the nation’s waterways, also banned the sale of cosmetics containing microbeads beginning July 2018 and over-the-counter drugs containing these plastic particles by July 2019.
If you have not already done so, now is a good time to see what products you may have on hand and start making the switch to microbead-free or mircoplastic-free products. Also, when purchasing clothing items, consider what embellishments they might contain and what type of textile you are purchasing. These and future decisions will help to protect the wastewater treatment system you are using, as well as the environment both locally and globally.