Occurrence and exposure to microplastics in salt for human consumption, present on the Lebanese market

Plastics are versatile and pervasive materials, useful in countless applications and industries. Nevertheless, their high disposal and environmental stability are raising concerns and microplastics are now considered emerging food contaminants by moving all the way up the food chain. High level of uncertainty remains regarding the risks derived from human dietary exposure to microplastics. The aims of the study were to assess the occurrence of microplastics in salt for human consumption found on the Lebanese market, to estimate the Lebanese dietary exposure to microplastics from salt intake, and to suggest techniques that would ensure reduction of these microparticles in this commodity. All salt brands (n = 16) for human consumption present on the Lebanese market were collected and analyzed on two separate dates (n = 27), between September 2019 and December 2020. The presence of different types of microplastics was determined using the Fourier-Transform Infrared (FTIR) technique. Results showed that 81.3% of the assessed brands (n = 16) and 55.6% of the total samples (n = 27) were contaminated with microplastics. Moreover, all (100%) samples and replicates were contaminated with either microplastics or other foreign matter. The packed and coarse sea salt were more likely to be contaminated than those sold in bulk or the fine salt. The types of microplastics identified included polypropylene, thermoplastic elastomers, polyester and polyethylene. Plasticized rubber, benzyl butyl phthalate and other plasticizers were also detected by the FTIR in addition to hair, ant, human skin among others. It is estimated that each Lebanese adult would be exposed to 2372 microplastic particles. Year 1 through salt intake. While the environmental impact of microplastics has received much attention, it is yet early to draw conclusions on the effect of long-term human exposure to dietary microplastics as more research and risk assessment are required. There is however, a pressing need to adopt novel techniques during salt production to minimize human exposure to these emerging contaminants.