Effort underway to more than double size of microplastics toxicity database

SCCWRP and its partners have begun working to nearly double the size of a public, web-based repository of toxicity data that summarizes the health effects of microplastics exposure on humans and aquatic life – a major expansion that reflects the key role the Toxicity of Microplastics Explorer (ToMEx) is playing in advancing California’s microplastics management strategy.

During a four-part SCCWRP workshop series that kicked off in February and concludes in May, about 70 microplastics researchers from 14 nations have been discussing how to evaluate microplastics toxicity studies and decide if and how to add the data from these studies to the ToMEx database. Scoring criteria are being used to decide which studies are not of sufficient quality.

ToMEx, which was originally unveiled last year, is serving as a key resource for microplastics toxicity experts as they develop health thresholds that define for California managers the exposure levels at which microplastics can be expected to trigger adverse biological effects. Preliminary thresholds already have been derived for aquatic life; work is ongoing to amass sufficient data to develop human health thresholds.

The 150+ new toxicity studies that are being added to ToMEx will help researchers refine preliminary aquatic life thresholds that were originally developed in 2021.