New studies reveal the ubiquitous nature of microplastics while the California State Water Resources Control Board adopts a first-of-its-kind definition.
Stemming from the requirements outlined in California Senate Bill 1422, on June 16, 2020, the California State Water Resources Control Board (“Board”) adopted this groundbreaking definition of microplastics in drinking water:
‘Microplastics in Drinking Water’ are defined as solid polymeric materials to which chemical additives or other substances may have been added, which are particles which have at least three dimensions that are greater than 1nm and less than 5,000 micrometers (µm)3. Polymers that are derived in nature that have not been chemically modified (other than by hydrolysis) are excluded.State Water Resources Control Board (link)
While this is the first time microplastics in drinking water has been defined (not only in the United States but also internationally), it’s not a micro issue. A recent review of over 50 studies on plastic ingestion found that on average (globally) we could be ingesting approximately 5 grams of microplastic every week—the equivalent weight of a credit card—from the food we eat, air we breathe and water we drink. Another recent study found microplastics present in every human organ that was tested. While the health implications of microplastics are still unclear, microplastics can persist and accumulate in human tissues once ingested.
Defining microplastics in drinking water is a critical first step in addressing its prevalence in our water supplies. Next steps for the Board, which must be completed by July 1, 2021, include: (1) adopting a standard methodology to test drinking water for microplastics; (2) setting requirements for microplastics reporting; (3) considering the issuance of quantitative guidelines to assist consumer understanding of results; and (4) accrediting qualified California laboratories to analyze microplastics in drinking water.
How did we get here? In an effort to reduce reliance on natural resources, World War II drove the production of synthetic alternatives, which resulted in a 300% increase in plastic production in the U.S. Although plastic has been mass produced for nearly 70 years, the proliferation of use has increased exponentially. Half of all plastic has been produced in the last decade: “In product after product, market after market, plastics challenged traditional materials and won” (and beyond that is hailed as critical in “most of the lifesaving advances of modern medicine”).
While plastics have profoundly shaped modern society, there’s no such thing as a free lunch. It’s estimated that only 9% of all plastic has been recycled and when it is, plastic is almost never recycled more than once. A third of plastic waste ends up in nature as microplastic from many sources including: larger plastic debris breaking down over time, nurdle (a very small pellet of plastic) spills, polyester released while washing clothes, and microbeads (note: in 2015, the Microbead-Free Waters Act of 2015 banned the manufacturing, packaging and distribution of rinse-off cosmetics containing plastic microbeads in the United States). Today, “microplastics are ubiquitous environmental contaminants leading to inevitable human exposure.” Microplastics circulate the globe in the atmosphere and ocean currents and therefore are even present in remote Arctic sea ice and snowpack. They exist throughout our food chain and environment leaving humans and other organisms to absorb them by ingestion, dermal contact and inhalation. While at one point some were optimistic microplastics would pass through biological systems as “unnatural fiber,” a study on mussels in 2008 revealed that this was not the case and instead found microplastic accumulation in the organisms. Moreover, microplastic particles can attract, carry and give off other contaminants. The long-term impact of this exposure is not yet known but may impact the immune system and increase inflammation.
While the Board’s definition and coming steps to test and report microplastics are constrained to California’s drinking water, this is expected to have broader implications. California’s Ocean Protection Council is working toward implementing a Statewide Microplastics Strategy mandated through SB 1263 that must be completed by 2025. This collaboration between the Board, the Ocean Protection Council and the Southern California Coastal Water Research Program is part of an international study to standardize methods for monitoring microplastics in aquatic environments, surface water, sediment and fish tissue. First you define it, then you measure it, and finally you attempt to address and mitigate it. And like so many issues of our time, this one knows no jurisdictional boundaries.
 Susan Freinkel, Plastics: A Toxic Love Story (New York: Henry Holt, 2011), p. 4.