Occurrence, toxicity and risk assessment of plastic additives in Besos river, Spain

The objective of the present study is to evaluate presence, seasonal variability and impact plastic additives along Besos river basin (Catalonia, Spain). This flows through a highly urbanized industrialized area with discharge >25 Wastewater Treatment Plants (WWTPs) large amounts floating plastics. Compounds studied included 5 phthalates, its substitutes acetyl tributyl citrate (ATBC) bis(2-ehtylhexyl) adipate, 12 long short chain alkylphenols, bisphenol A benzophenone, most them high volume production chemicals. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS) was used determine ng/L concentrations. Toxicity evaluation performed for each individual compound using Daphnia magna as test organism it found that effect concentration (EC50) decreased increasing octanol-water partition coefficients. EC50 values calculated Measured Environmental Concentrations were risk quotients. Only diethylhexylphthalate, nonylphenol octylphenol, median concentrations from 41.9 826 ng/L, caused small mostly in downstream waters 50–75% samples overpassing Quality Standards set by European Union. Seasonal variations observed higher levels summer due low water flows. WWTPs effluents leaching plastics or microplastics presumably main sources pollution.