The 90s party-favorite song by Aqua would have you believe life in plastic is fantastic. While this may be Barbie’s reality, plastic has crept into almost every facet of our life—including our drinking water—and as scientists are beginning to discover, that’s not a good thing. 

Since John Wesley Hyatt first combined cotton cellulose and camphor to create an ivory substitute to make billiard balls, the world has become reliant upon the synthetic polymers commonly called plastics. Hyatt’s discovery in 1869 heralded a modern age full of chemically manufactured plastics and polymer materials that substitute for natural materials such as cotton, rubber, and wood. The huge societal benefits gained through the invention and use of plastics in everyday life have come at a cost as discarded plastic materials have polluted the environment.  Increasingly, concerned citizens wonder about the long-term consequences of these man-made materials and scientists have turned their attention to understanding the many different effects plastic waste may have on public health and the environment.

One microcosm of this public health concern has been the presence of microplastics in the environment, and the potential for these tiny particles to make their way into our food and water. Microplastics fall into two main categories—those that are manufactured as additives or for use in manufacturing and those that come from the degradation or breakdown of larger plastic particles. And there’s good cause for concern as they are ubiquitous, having been found at the bottom of the ocean and in the most remote geographic locations.

Microplastics are being dispersed in a variety of ways, many of them related to the decomposition of plastic bags, bottles, and other plastic items which find their way into rivers, lakes, estuaries, and oceans. Not surprisingly, tire wear is estimated to contribute as much as 28% of the microplastics now polluting the ocean. Particles present in stormwater runoff make their way to the ocean, entering the food chain of the shellfish and fish we consume. Researchers are still trying to understand the prevalence and impact of this phenomenon.

Unraveling the scope of this problem begs the question: If microplastics are in our food, then are they also in the water we drink? How much concern is warranted?

The World Health Organization published a report in 2019 concluding that although microplastics have been reported in drinking water and certainly appear to be ubiquitous in the environment, there are no apparent human health effects. However, the report encouraged further research to advance our understanding.

California’s State Water Resources Control Board (SWRCB) is doing just that, anticipating the need for an investigation into the prevalence of microplastics in drinking water and in response to Senate Bill 1422. The bill, which passed in late 2018, first identified the need for consensus on the definition of a microplastic, and required the SWRCB to adopt said definition by July 1st of this year. The bill further requires the Board to adopt a method of analysis for the determination of microplastics, accredit laboratories to perform the method, and establish the framework for a four-year drinking water study to collect data and make it public by July 1, 2021.

Environmental Toxicologist Dr. Scott Coffin has spent the past year leading the Board’s efforts to work with an Expert Review Panel to establish a definition. While many organizations and previous researchers have defined microplastics in different contexts related to their purposes, California will be the first governmental entity in the world to establish a regulatory definition for drinking water. The definition, published on March 19, 2020, has been specifically created to address the substance, state, and dimensions of a microplastic. It defines a microplastic as a solid polymeric material with at least two dimensions between 1 and 5,000 micrometers. The complete definition, which excludes naturally occurring polymers that haven’t been chemically altered, can be found on the State website, along with the complete staff report.

Adoption of the definition brings California one step closer to discovering the prevalence microplastics in our water and gaining insight into the quality of “life in plastic.”