Occurrence of Microplastics and Potentially Toxic Elements in Red Sea Crab (Portunus pelagicus) and Squid (Uroteuthis spp.): Contamination and Food-Safety Concerns

Abstract

Microplastics (MPs) and potentially toxic elements (PTEs) are co-occurring marine contaminants, yet integrated assessments of Red Sea seafood remain limited. This study evaluated MP contamination, PTE bioaccumulation, and dietary health risks in Portunus pelagicus (n = 281) and Uroteuthis spp. (n = 159) from Yanbu, Rabigh, and Umluj. A standardized subset of 180 specimens was examined for MPs using stereomicroscopy, yielding 508 suspected particles. All 508 particles were examined by FTIR, of which 260 (51.2%) were spectroscopically confirmed as polyethylene (PE), while 248 (48.8%) remained unconfirmed. Crabs showed approximately 10–89-fold higher suspected-particle burdens than squid (0.742–1.683 vs. 0.008–0.167 particles/g wet weight). Eleven PTEs were quantified in edible muscle by ICP-MS. Squid contained approximately 17–24-fold higher Fe and 5–7-fold higher Cd, whereas crabs contained 11–13-fold higher total As and higher Zn. Non-carcinogenic risk remained below the conventional threshold (HI < 1) across all scenarios, whereas estimated arsenic-related carcinogenic risk exceeded 1 × 10−4 in some crab-consumption scenarios under the assumed 7% inorganic-As fraction. Exploratory MP–PTE associations were strongly influenced by species identity and cannot establish MP-mediated PTE transfer.