Assessing Risks of Microplastics in Drinking Water: Insights From California's Expert Workshop
Channel: Scott Coffin
Date: 2021-11-01

Dr. Scott Coffin's presentation at SETAC North America 2021.
More information:https://www.sccwrp.org/about/research-areas/additional-research-areas/trash-pollution/microplastics-health-effects-webinar-series/
Slides: https://www.researchgate.net/publication/355827871_Assessing_Risks_of_Microplastics_in_Drinking_Water_for_Humans_Insights_From_California's_Expert_Workshop
Abstract:
Recent findings of microplastics in drinking water prompted concern amongst scientists and policymakers due to the potential harm towards humans. In 2018, the California legislature passed Senate Bill 1422 requiring the California State Water Resources Control Board to (1) define microplastics, (2) develop a standardized method to monitor in drinking water and accredit laboratories, (3) monitor for microplastics in drinking water for four years, and (4) provide consumers with guidance regarding health impacts. Despite being studied since 1961, the human health effects of microplastics remain poorly understood, especially through the ingestion route of exposure. However, the exponential increase in the number of mammalian toxicity studies since 2019 allows for preliminary insights into potential human health effects. To assess the available evidence for human health hazards of microplastics in drinking water, we convened an inter-sector expert workshop, and conducted a systematic literature search. Studies were screened for quality criteria, including particle characterization, experimental design, and applicability for risk assessment prior to undergoing additional expert evaluation. In vivo and in vitro studies suggest microplastics may cause adverse effects in model mammalian organisms to various target organs through oxidative stress and inflammatory pathways, however significant uncertainties remain for both hazard identification and exposure assessment. Challenges in estimating risks from exposure to microplastics include a relative lack of studies on polymers and shapes other than polystyrene spheres, uncertainties with measured apical endpoints, and missing exposure information. Insights from the expert elicitation process, quality scoring tool, and key findings from the available toxicity studies will be presented.