First-ever study uncovers microplastic contamination in Nepalese table salt.

Area of Science:

• Environmental Science
• Food Safety
• Analytical Chemistry

Background:

• Microplastic contamination is a global concern, yet data on Nepalese table salt is scarce.
• Table salt is a ubiquitous food ingredient, making it a potential vector for microplastic ingestion.

Purpose of the Study:

• To investigate and quantify microplastic contamination in table salt samples from Nepal.
• To characterize the types, shapes, and polymer composition of microplastics found in Nepalese table salt.
• To estimate the annual microplastic intake from salt consumption for the Nepalese population.

Main Methods:

• Salt samples were collected from seven provincial zones across Nepal.
• Microplastics were extracted using Fenton's reagent digestion and visualized using digital and stereomicroscopes.
• Fourier-transform infrared (FTIR) spectroscopy was employed for polymer identification.

Main Results:

• 100% of analyzed table salt samples (Nepalese and Indian brands) contained microplastics.
• Microplastic abundance ranged from 80 to 1040 particles/kg, with an average of 381 ± 219 particles/kg.
• Fibers (56%) were the predominant shape, and polyethylene and polypropylene were the identified polymers.
• Estimated annual ingestion of microplastics from salt consumption was 1853 particles per person.

Conclusions:

• Nepalese table salt is significantly contaminated with microplastics, posing a public health concern.
• Manufacturing processes, rather than storage or packaging, appear to be the primary source of contamination.
• Improvements in raw material sourcing and salt purification methods are crucial to mitigate microplastic pollution.