Microplastics in commercial food products from the United Kingdom market: Implications for human exposure

The widespread use and disposal of plastics have led to the pervasive accumulation of microplastics (MPs) in the environment, raising concern over their potential risk to human health. This study assessed the presence, abundance, particle size, and polymer types of MPs in commonly consumed food and beverage items purchased from local markets in Birmingham, United Kingdom. The sampled items included table salt, sugar, honey, vinegar, soy sauce, lime concentrate, milk and cooking oil. MPs were detected in all analysed samples. Table salt exhibited the highest mean concentration (173 ± 94 MPs/kg), followed by honey (101 ± 73 MPs/kg) and sugar (94 ± 17 MPs/kg). Moderate levels were observed in lime concentrate (58 ± 18 MPs/L) and soy sauce (53 ± 39 MPs/L), while lower concentrations were found in cooking oils (25 ± 5 MPs/L), vinegar (19 ± 9 MPs/L), and milk (19 ± 6 MPs/L). Detected particle sizes ranged from 44 – 516 μm. μ-FTIR analysis revealed the predominant polymers were polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET). Estimated exposure of different UK age groups to MPs via the studied food items ranged between 118 – 343 MPs/kg BW /year from salt intake (highest), to 4 – 5 MPs/kg BW /year from soy sauce (lowest). This study provides first experimental evidence of MPs contamination in commonly consumed dietary products in the UK, highlighting packaging as a major contributor to MPs concentrations and polymer types in some food items. Our findings highlight the urgent need for safer packaging materials, and further comprehensive assessment of dietary exposure of UK population to MPs and the health risk arising from such exposure. • MPs detected in all samples of studied UK food items • Highest MPs found in salt and honey while lowest in cooking oils, vinegar and milk • Plastic packaging contributed substantially to MPs contamination • Plastic grinders increased MPs concentration in salts • Children had higher MP exposure per kg body weight than adults