Bioaccumulation and human risk assessment of inorganic nanoparticles in aquaculture species

Abstract

The escalating use of inorganic nanoparticles (NPs) in various applications raises concerns regarding their potential environmental release and subsequent bioaccumulation in the food chain, posing a risk to human health. This study aimed to assess the bioaccumulation potential of titanium dioxide (TiO₂) and silver (Ag) NPs in three commercially relevant aquatic species: sea bream, sea bass, and Japanese carpet shell, and evaluate the associated human health risks through dietary exposure. Bioaccumulation patterns were evaluated in target organs (liver, kidney, and muscle) of sea bream and sea bass following dietary exposure to varying concentrations of NPs (0.25–1.5 mg kg⁻¹) for extended durations (up to 90 days). While moderate bioaccumulation was observed in non-edible organs like kidneys and livers, no significant accumulation was detected in the muscle tissue, even at high exposure levels. Conversely, bioaccumulation of both TiO₂ and Ag NPs was evident in the soft tissues of Japanese carpet shell (maximum concentrations: 2.5 × 10¹⁰ g⁻¹ for Ag NPs and 8.0 × 10⁶ g⁻¹ for TiO₂ NPs). In vitro studies utilizing the Caco-2 human intestinal model revealed limited transcellular transport of NPs from both fish and shellfish muscle tissue (less than 34% for TiO₂ NPs in sea bream and less than 61% and 4% for TiO₂ NPs and Ag NPs, respectively, in Japanese carpet shell). These findings suggest that, while bioaccumulation may occur in certain species and organs, the human health risk associated with dietary exposure to NPs from commonly consumed fish appears to be low due to limited intestinal uptake. However, further research is necessary to elucidate the long-term consequences of chronic exposure and potential health effects.