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

Area of Science:

• Environmental Science
• Food Safety
• Materials Science

Background:

• Growing global concern regarding microplastic contamination across environmental compartments.
• Limited understanding of microplastic presence and impact in human-consumed food products.
• Previous research has identified microplastics in various environmental media, but food products require further investigation.

Purpose of the Study:

• To screen popular commercial packaged food ice cubes in Mexico City for microplastic contamination.
• To quantify microplastic concentrations and identify types, sizes, and morphologies.
• To estimate the annual microplastic ingestion from ice cube consumption in Mexico City.

Main Methods:

• Analysis of 15 commercial brands of packaged food ice cubes from Mexico City.
• Microscopic examination and SEM-EDX analysis to detect and characterize microplastics.
• Calculation of microplastic concentrations (L⁻¹) and estimation of annual human ingestion.

Main Results:

• Microplastics were detected in 100% of the evaluated ice cube samples.
• Concentrations ranged from 19 ± 4 to 178 ± 78 L⁻¹, with a mean of 79 ± 47 L⁻¹.
• Predominant microplastic types included polypropylene and polyethylene; fibrous, non-colored particles < 300 μm were most prevalent. SEM-EDX revealed traces of Si, S, Ti, Ca, Al, and Na.

Conclusions:

• Packaged ice cubes in Mexico City are a significant source of microplastic contamination.
• Human ingestion of microplastics via ice cubes is substantial, estimated between 4.9 × 10² and 1 × 10⁴ particles annually.
• Urgent need for strategies to manage and eliminate microplastic contamination in food products like ice cubes.