Nanoplastics Detected in Commercial Sea Salt

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Plastic nanoparticles (NPs) are an emerging environmental contaminant.
• NPs have been detected in various consumer goods, including table salt.
• The extent of NP contamination in salt and its implications are not fully understood.

Purpose of the Study:

• To develop a method for detecting and quantifying nanoplastics in commercial salt.
• To assess the prevalence of nanoplastics in sea salt from different global regions.
• To estimate the annual human ingestion of nanoplastics through sea salt consumption.

Main Methods:

• A combined surface-enhanced Raman scattering (SERS) and stimulated Raman scattering (SRS) approach was developed.
• Anodic alumina oxide substrates loaded with gold nanoparticles were used for SERS.
• SRS microscopy was employed for imaging and quantification of NPs based on hydrocarbon group identification.

Main Results:

• The SERS-SRS method successfully identified and quantified nanoplastics in commercial sea salt.
• Nanoplastic contamination was found in sea salts from Asia, Australasia, Europe, and the Atlantic.
• Estimated annual ingestion of nanoplastics via sea salt consumption ranges up to 6 million particles per person.

Conclusions:

• The developed SERS-SRS technique is effective for NP detection and quantification in salt.
• Sea salt represents a significant source of nanoplastic ingestion for humans.
• The potential health risks associated with nanoplastic ingestion warrant further investigation.