Introduction

This research study examines the release of microplastics from containers made of three different polymer types, such as polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET).

Methods

Experiments were conducted by simulating three different conditions by which foods could be delivered. Milli-Q water at room temperature, 100 °C, and pH 4.5 were used for the experimental tests. To simulate the transport, containers were exposed for 20 minutes to milli-Q at room temperature, 100 °C Milli-Q water, and slightly acidified water with agitation at 10 rpm. Then, water solutions were filtered using a Whatmann Glass Fiber Filter, with a pore size of 1.6 µm, for microparticle recovery. Microparticles were quantified using optical microscopy. The same experimental conditions were replicated for micro-Raman analyses, using stainless-steel frits (0.2 μm), due to the low background. This approach was used to confirm the polymeric composition of the particles.

Results

The findings reveal that PET and PS containers released microplastics in varying amounts: 9 and 1 particles at room temperature, 7 and 3 in acidic conditions, and 17 and 30 at 100 °C, respectively. The detected particles measured between 13 and 32 μm. Notably, no microplastic release was observed from PP containers under any tested conditions.

Conclusions

These results highlight the significant microplastic release from PET and PS containers. These findings have great environmental implications. The release of microplastics from plastic containers raises concerns not only for direct human ingestion but also for their potential to become airborne contaminants. Microplastics in food may be subjected to evaporation, aerosolization, or mechanics, facilitating their transfer into the air. Given their small size, these particles could be inhaled, contributing to atmospheric microplastic pollution. These findings highlight the need for further research on the airborne dispersal pathways of microplastics from food packaging and their broader environmental and health implications.