Microplastics in Brazilian aquatic ecosystems and seafood: An updated review

ABSTRACT Microplastic pollution in Brazilian aquatic ecosystems and seafood is a widespread and persistent issue affecting marine, estuarine, and freshwater environments. This review compiles data from 100 studies published between 2014 and 2025 and integrates bibliometric, spatial, and methodological analyses to provide an updated national overview. Reported microplastic concentrations vary markedly, ranging from 0.013 to over 1×10⁶ items.m⁻³ across different environmental matrices, reflecting pronounced environmental heterogeneity and strong anthropogenic influence. Fibers are the predominant particle type, followed by fragments and films, with polypropylene, polyethylene, and polyester identified as the most frequently reported polymers. Contamination hotspots include Guanabara Bay, the Santos–São Vicente Estuary, and Amazonian tributaries, while bivalves, fish, and crustaceans exhibit notable bioaccumulation, reaching up to 241,000 items.kg⁻¹ of tissue. Seasonal variability, rainfall, and mass tourism events ( e.g., Carnival) strongly influence microplastic fluxes. Methodological inconsistencies in sampling and quantification remain critical challenges, underscoring the urgent need for standardized protocols and coordinated monitoring frameworks. Addressing microplastic pollution in Brazil requires interdisciplinary collaboration and circular-economy strategies aligned with the United Nations Sustainable Development Goals (SDGs) 12 and 14 to safeguard aquatic ecosystems, food safety, and public health.