Microplastic contamination in commercial salt: An issue for their sampling and quantification

Food Chem. 2023 Mar 15;404(Pt B):134682. doi: 10.1016/j.foodchem.2022.134682. Epub 2022 Oct 20.

Abstract

Sea salt can be considered as a vector of microplastics in the human body. In this work, the sea salts collected from three Italian salterns has been solubilized in MilliQ water and filtered to extract microplastics. The visual quantification of microplastics with a stereomicroscope was carried out on the bases of their size, followed by a classification taking into account their physical characteristics. ATR-FTIR and Raman spectroscopy were used to identify the polymeric type of microplastics. Their significant presence has been revealed: 1653 ± 29 microplastics/kg of sea salt. In total, 80.6 % of microplastics have a fiber shape, 18.9 % a fragmented shape and 2.7 % are sphere. The size of microplastics has been analysed, indicating that the most frequent is between 0 and 500 µm. Polypropylene, polyamide and polyethylene were identified as the most frequent types of polymers. This research could be of global relevance given the significant export of Italian salt to foreign countries.

Keywords: Edible sea salt; Human health; Mediterranean Sea; Microplastics; Pollution.

MeSH terms

  • Environmental Monitoring / methods
  • Humans
  • Microplastics*
  • Plastics / analysis
  • Polyethylene
  • Sodium Chloride, Dietary / analysis
  • Water Pollutants, Chemical* / analysis

Substances

  • Microplastics
  • Plastics
  • Water Pollutants, Chemical
  • Polyethylene
  • Sodium Chloride, Dietary