Nanoplastics Detected in Commercial Sea Salt

Abstract

People of all ages consume salt every day, but is it really just salt? Plastic nanoparticles (nanoplastics) polluting the oceans and the atmosphere are posing an increasing environmental threat and have begun to contaminate everyday salt in consumer goods. Herein, we developed a combined Surface Enhanced Raman Scattering (SERS) and Stimulated Raman Scattering (SRS) approach that can simultaneously realize the filtration, enrichment, and detection of nanoplastics in commercial salt. SERS was used to explore the potential types of nanoplastic contaminants in salts. SRS was used to conduct imaging and to quantify the presence of nanoplastics. Nanoplastics in sea salts produced from different sources were studied, with the following nanoplastics detected: polystyrene (PS), polyethylene (PE), polypropylene (PP). We estimate that, depending on location, an average person could be ingesting as many as 63,100 nanoplastics per year through the consumption of sea salt alone. Nanoplastics can readily adsorb organic matter and heavy metal particles, so the potential harm to human health should not be underestimated.