The pollution before the flood: Microplastics and PAHs in water, sediment and fish from Júcar River basin (E Spain)

In October 2024, Júcar River and its tributary, Magro, were responsible for the fatal floods in the south of the province of Valencia. There is general concern about the environmental pollution by microplastics (MPs) due to their possible adverse effects on organisms and their ability to accumulate various types of contaminants, such as polycyclic aromatic hydrocarbons (PAHs). Thus, the co-occurrence of MPs and PAHs was investigated in superficial water, sediment and fish samples from the Júcar River basin (E Spain) to set the benchmark of pollution before the flood. Extraction protocols were optimized according to matrix and analyte type. MPs were determined by micro-FTIR (μFTIR) and Pyrolysis coupled with Gas Chromatography-Mass Spectrometry (Py-GC-MS), while PAHs were quantified using GC-MS. Ecological and human health risk was, also, estimated by different indexes. Both MPs and PAHs were detected in the majority of samples with higher concentrations near the river mouth that coincides with the metropolitan area of Valencia and an industrialized zone. A potential ecological and cancer risk would be possible due to exposure to MPs and PAHs. This study provides helpful insight into pollutants and their associated risk a few months before the rivers overflowed.