Exploring the environmental impact of textile polymer photodegradation through a multianalytical approach

Recent studies have demonstrated that microplastics (MPs) exert adverse physiological and ecological effects on aquatic organisms. Similarly, synthetic microfibers (MFs) have attracted growing scientific attention regarding their environmental distribution, degradation pathways, and biological impacts. This study investigated the release of polymer degradation products following UV induced photoaging. To isolate polymer-specific effects, only additive-free materials were used. A selection of natural and synthetic fibers was tested before and after photoaging. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses revealed surface oxidation and structural defects in photoaged polymers, which were absent in pristine samples. These findings confirmed the physicochemical changes induced by photoaging. However, not all materials exhibited detectable surface modifications. To comprehensively assess the molecules released into the environment, we employed two complementary extraction techniques, solid-phase microextraction (SPME) and liquid–liquid extraction (LLE), combined with gas chromatography–mass spectrometry (GC–MS) for leachate analyses. Both techniques were applied in untargeted mode to maximize the number of detected compounds. This approach generated a large dataset, subsequently processed with advanced machine learning tools that enhanced spectral annotation, ensuring higher accuracy and reducing the rate of mismatches. As expected, for most compounds aged materials showed a release higher than pristine ones (at 95% confidence level), in particular for specific molecular classes such as ketones, carboxylic acids, and aldehydes. These findings underscore the environmental relevance of microfiber aging, suggesting that photo-induced degradation products may contribute to the overall toxicity of fibrous pollutants in aquatic ecosystems.