Avaliação toxicocinética e caracterização de microplásticos em tecidos de corvinas (Micropogonias furnieri) no litoral do Rio de Janeiro

Abstract

Plastic is a widely used material due to its versatility and low cost. However, its high persistence in the environment favors the formation of microplastics (MPs), affecting different organisms. In this context, this study investigated the presence and translocation of MPs in Micropogonias furnieri by analyzing the gastrointestinal tract, gills, liver, and gonads of individuals collected in Itaipu and Barra da Tijuca (Rio de Janeiro, Brazil). The results indicated a predominance of juveniles in summer and adults in winter, with similar δ¹³C and δ¹⁵N trophic patterns among ontogenetic stages, confirming the generalist feeding behavior of the species. Regarding elemental composition, adults showed higher %N values, while juveniles presented higher C:N ratios, indicating greater lipid content. Two MP extraction protocols were compared; the method using 10% KOH and NaI proved to be more efficient than 15% H₂O₂ and NaCl, while µFTIR with FPA detector stood out as an advanced analytical technique for MPs. Our results recorded 491 particles in the 36 analyzed gastrointestinal tracts (13.6 ± 7.03 part/ind), with fibers predominating (77%) and higher concentrations of potential MPs in juveniles (56.2%), indicating biodilution throughout growth. Most ingested particles were transparent (30.5%) and blue (29.9%), mainly ranging from 1000 to <500 µm (37.1%). Regarding synthetic polymers, Itaipu showed PET (12.6% in winter and 29.4% in summer) and PVC (4.6% in winter), while Barra da Tijuca presented only PP (3.2%) and PS (3.2%) in winter and a single occurrence of PP in summer. In the gills, MPs were identified in all analyzed samples, totaling 280 particles in 12 individuals (23.1 ± 46.5 part/ind), with adults showing higher concentrations (44.6 ± 60.9 part/ind). Particles between 10 and <50 µm predominated (88.9%), and PP was the most abundant polymer (48.1%). These findings reinforce the role of gills as a target organ for MP retention in fish. Finally, MPs were also detected in internal organs, indicating possible translocation. In the liver, 66.7% of individuals presented MPs, with predominance of PP (95.4%) and particles between 10 and <50 µm (95.6%). In the gonads, 83.3% of individuals contained MPs, with higher occurrence in juveniles, predominance of PP (62.5%), and particles between 10 and <50 µm (87.8%). These results demonstrate the ability of MPs to reach internal tissues, especially in smaller size classes, indicating the risk of transfer along the trophic chain. From a One Health perspective, this contamination may impact environmental, animal, and human health, reinforcing the need for public policies and specific regulations, such as those by ANVISA, for the control of MPs in food.