International microplastics measurement study being developed following 2-day workshop

A group of international experts on aquatic microplastic pollution that convened at SCCWRP for a two-day workshop in April has begun laying the groundwork to build scientific consensus around methods for monitoring microplastic particles in aquatic environments.

The experts, who hail from as far away as Germany, Norway and Canada, are helping to develop a study that aims to standardize microplastic monitoring methods worldwide, a response to recently enacted California legislation that calls for microplastics to be tracked in drinking water and the coastal ocean.

The two-year study, which could kick off as early as September, will examine precision, repeatability, cost and other issues associated with five different, commonly used technologies for measuring microplastics in aquatic environments: Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), stereoscopy, stereoscopy with staining, and Pyrolysis-GCMS (gas chromatography/mass spectrometry).

Already, more than a dozen research laboratories have signed onto the method standardization study. SCCWRP will help facilitate the study, and serve as a regional training facility for Raman spectroscopy and FTIR.

Defined as plastic particles less than 5 mm in diameter, microplastics have become ubiquitous in aquatic environments, even as scientists have relatively little understanding of how they impact the health of humans and wildlife that inadvertently ingest them.

Particularly challenging is how to track microplastics that are so small that they can’t be seen under a light microscope.

Microplastics have been documented in the guts of fish and other marine life; they’ve also been found in human feces. In aquatic environments, chemical contaminants can stick to microplastics, compounding potential health risks from ingestion.

SCCWRP and its partners have been working since fall 2018 to bring together leading microplastics scientists to develop recommendations for how California should build capacity to conduct routine microplastics monitoring.

California Senate Bill 1422, which was signed into law in September 2018, requires the State Water Board to develop plans for quantifying microplastic particles in drinking water by 2021. Similarly, California Senate Bill 1263, also signed into law in September 2018, requires the California Ocean Protection Council to adopt and implement a statewide strategy for illuminating the ecological risks of microplastics in marine environments.

Darrin Polhemus, Deputy Director for the State Water Board’s Division of Drinking Water, and Deborah Halberstadt, Executive Director of the California Ocean Protection Council, were among the more than 120 workshop attendees.

During the microplastics workshop, experts discussed the state of knowledge around different microplastics measurement methods. They also shared the most up-to-date information on approaches for monitoring microplastics in wastewater, stormwater, coastal waters and seafloor sediment, underscoring the need for a standardized method for comparing results.

For more information, contact Shelly Moore.