Particle and mass-based microplastic burden, additive screening, and surface elemental signatures in commercial shrimp (Penaeus indicus) from Gresik industrialized coast, Indonesia: implications for human dietary exposure.

Microplastics contamination in seafood has emerged as a growing concern for environmental exposure and food safety. This study characterizes microplastics in commercially harvested Penaeus indicus from the industrialized Gresik coast, Indonesia, combining particle-based quantification under a Poisson-based LCg/MDA quality-control framework; particle-to-mass conversion based on measured length, shape, and density distributions of the particles; GC-MS additive screening, and SEM-EDX surface elemental analysis. Shrimp contained a mean microplastics burden of 0.0487 ± 0.0734 particles per gram whole-body wet weight, equivalent to 1,919 ± 8,025 ng per gram whole-body wet weight. Particles were predominantly black (70.3%) and fibrous (66.3%), with polymer composition dominated by polypropylene (65.3%) and polyethylene (26.7%). Based on national shrimp consumption rates, the estimated dietary exposure was 769.6 particles per person per year (≈36.9 mg per year). GC-MS analysis detected seven plastic-associated compounds, with 2,4-di-tert-butylphenol and 2-butoxyethanol as dominant additives, showing the highest relative peak-area contributions within the chromatograms. SEM revealed weathered particle morphologies characterized by surface cracking and adhered debris, while EDX indicated the presence of toxic metals, with Hg showing the most prominent signal in localized hotspots.