Microplastic pollution in commercial salt for human consumption: A review

Microplastics (MPs) are plastic particles with less than 5 mm in size that are considered global environmental pollutants. The MPs present in the environment result from the successive breakdown of larger plastic pieces or from the direct input of micro- and nano-sized particles used in various industries and products available to consumers. Such MPs have been found in several wild species and other natural resources, including some consumed as food by humans, with possible adverse effects on ecosystem and human health. The central aim of this work was to review the published literature regarding the contamination of sea commercial salts (sea and terrestrial origins) and its possible impacts on human health. Moreover, to lead to a comprehensive understanding of the paradigm, a short introduction and revision of the environmental contamination by MPs and its effects are included. MPs have been found in commercial salts from 128 brands, from 38 different countries spanning over five continents. The concentration of MPs found in the samples analysed is lower than the concentrations of MPs reported in other resources, such as blue mussels. However, as commercial salts are used every day and by all humans, they constitute a long-term exposure route for the general population in addition to others (e.g., animals consumed as food by humans, water, air). Therefore, commercial salts contaminated with MPs may contribute to the potential long-term adverse effects resulting from human exposure to these particles.