First evidence of microplastic contamination in ready-to-use packaged food ice cubes

Concern over microplastics has grown tremendously, and they have been found in all environmental compart-ments; yet, much remains unknown regarding their impact on a variety of human-consuming food products. Here, we contribute to ongoing research by screening the 15 most popular commercial brands of packaged food ice cubes in Mexico City for microplastics. Microplastics were detected in 100% of the samples evaluated, with concentrations ranging from 19 +/- 4 to 178 +/- 78 L-1. There was a significant difference in the microplastic concentration across samples. The mean microplastic concentration was 79 +/- 47 L-1, and the main types were polypropylene, polyethylene, polyvinyl alcohol, tygon polymer, sealing ring gardena 2824 large, polyamide 6, and cellophane. Moreover, microplastics that are fibrous (87%), non-colored (54%), and less than 300 mu m in size (63%), were found to be more prevalent. The SEM-EDX analysis showed heterogeneous structural and morphological characteristics of microplastics, as well as traces of Si, S, Ti, Ca, Al, and Na. Furthermore, we estimate that ice cube consumption in Mexico City can result in the inadvertent ingestion of 4.9 x 102 +/- 3.4 x 102-1 x 104 +/- 7.2 x 103 microplastics annually. The findings of the study revealed that microplastics were identified in ice cubes and can be conveyed to humans, stressing the need of managing and eradicating such contamination from our food.

Automated summary

Microplastics were detected in 100% of the evaluated ice cube samples, with concentrations ranging from 19 to 178 L-1. The microplastic concentration varied significantly across samples, and the main types found were polypropylene, polyethylene, polyvinyl alcohol, tygon polymer, sealing ring gardena 2824 large, polyamide 6, and cellophane. The study estimated that ice cube consumption in Mexico City could lead to the inadvertent ingestion of a large number of microplastics annually, highlighting the need for management and eradication of this contamination in our food.