Microplastics in solar salt: baseline contamination assessment from Goa, India

Area of Science:

• Environmental Science
• Food Safety
• Analytical Chemistry

Background:

• Microplastic (MP) contamination in food is a growing concern for human health.
• Limited data exists on MP occurrence in natural solar salt, especially from estuarine environments.

Purpose of the Study:

• To assess microplastic contamination in solar salt harvested from the Mandovi estuary, Goa, India.
• To characterize the types, sizes, and polymer composition of detected MPs.
• To evaluate the ecological risk and potential human intake of MPs from salt consumption.

Main Methods:

• Collection of eight solar salt samples from salt pans.
• Analysis using density separation, filtration, and Fourier-Transform Infrared (FTIR) spectroscopy.
• Calculation of pollution load index and polymer risk index.

Main Results:

• Microplastics were detected in all samples, ranging from 64.00 to 106.67 particles/100g.
• Fibers (90.40%) in the 0.1-0.3 mm size range (49.21%) were predominant, mostly colorless (64.30%).
• Polyethylene, polyester, and polypropylene were the dominant polymer types; high ecological hazard (Level V) and estimated annual intake of 2,457.8 particles/person were reported.

Conclusions:

• Natural solar salt from the Mandovi estuary is contaminated with microplastics.
• The identified MPs pose a significant ecological risk.
• Mitigation strategies are crucial to minimize human exposure to microplastics through salt consumption.