Sophia Scott, Source Water Protection Coordinator, Maine CDC Drinking Water Program
A version of this article first appeared in the Drinking Water Program’s quarterly newsletter, the Service Connection (Volume 26, Issue 3).
Concern over plastic pollution is not breaking news. Plastic use is so widespread that some have dubbed our current era as the “Plastic Age.” Global production is roughly 300 million tons annually and estimates suggest that 8 billion tons of plastics have been created since the 1950s.
Plastics provide many conveniences to people across the globe. We use and rely on plastics every day. However, unsustainable use and improper waste management have created catastrophic pollution worldwide. One infamous example of plastic pollution is the Great Pacific Garbage Patch. This floating mass of plastic debris is roughly the size of Texas.
Plastic pollution can come in many sizes. We have all seen plastic litter: a plastic bottle, cellophane wrappers, cigarette butts. These items are examples of macroplastic pollution. Microplastic pollution is less obvious but just as prevalent. Microplastics are defined as plastic debris under 5 millimeters in size, which includes plastics the size of a pencil eraser to particles that can only be seen under a microscope. These tiny plastic pieces have been found virtually everywhere: air, soil, salt water, brackish water, fresh water, bottled water, and tap water. Tiny plastic particles have been found in Arctic sea ice, a remote Mongolian lake, and the Gulf of Maine.
These contaminants enter the environment as primary or secondary microplastics. Primary microplastics are manufactured plastic particles. Secondary microplastics are created when larger pieces of plastic waste break down into smaller particles. Microplastics do not biodegrade and they remain in the environment for centuries. Some microplastics can release harmful chemicals into the environment. Others attract chemicals and act as vectors for pollutants. Despite their wide distribution, very little is known about the human health implications of microplastic pollution.
From a drinking water standpoint, microplastics have been found in both bottled and tap water across the globe. In the first study of its kind, researchers in the Czech Republic looked at how three water treatment plants performed in microplastic removal. Systems removed between 70% and 85% of microplastic particles. The details of the study are in the table below.
Does this mean we’ll see regulation for microplastics in the future? As we say here in Maine, “Hard tellin’, not knowin’.” Despite this uncertainty, it is a safe bet to say that we’re a ways off from any microplastic regulations in drinking water. Microplastics are not listed on the most recent Contaminant Candidate List and research on the implications of microplastic pollution in drinking water is only just beginning.