Caracterização e avaliação ecotoxicológica de micropartículas de espuma de poliuretano e Luffa cylindrica para uso doméstico

Abstract

The high consumption of polymeric materials, more specifically plastics, it is a relevant problem to emerging contaminants, as over time they can fragment and/or degrade, generating microparticles, whose effects are still little known in the literature for polyurethane (PU), however, there is evidence that they are harmful for the health of organisms in the short and long term. Flexible polyurethane foam (PUF) is a synthetic polymer with applications ranging from thermal insulation to scrub sponges. However, a problem that is observed in this class of polymers is that, multipurpose sponges, for example, end up generating secondary microplastics, in addition to leaching additives, which are harmful to organisms. This work aimed to study the genotoxic, mutagenic and biochemical effects (related to oxidative stress and neurotoxicity) of microparticles generated from sponge for domestic use and compare it with microparticles from vegetable loofah (Luffa cylindrica) in Oreochromis niloticus (Tilapia). In addition, the toxic potential of the leachate, PUF particles and abrasive fiber for Daphnia magna and Artemia salina was evaluated. The structural, morphological characterization and thermal behavior of the samples was carried out through analysis of spectroscopy in the infrared region with Fourier Transform, thermogravimetry, scanning electron microscopy and wide-angle X-ray diffraction. For the evaluation of the biological effects, O. niloticus fingerlings were submitted to a subchronic bioassay of 14 days with partial daily renewal of water and sample, at concentrations of 0.2 mg∙L- ¹; 1 mg∙L- ¹ and 5 mg∙L- ¹. Microcrustaceans were exposed to microparticle concentrations ranging from 20 to 200 mg∙L- ¹ for D. magna and 1 to 23 g∙L- ¹ for A. salina. After the bioassay, biochemical (acetylcholinesterase, glutathione-S-transferase, lipoperoxidation and catalase) and genetic (comet assay) biomarkers for fingerlings and the mean effective concentration of sponge particles and leachate toxicity factor for microcrustaceans were evaluated. Through these data it was possible to verify that the microparticles and the leachate from the scrub sponge showed acute toxicity for the microcrustaceans. After the bioassay with O. niloticus, it was possible to observe that all samples caused lipid peroxidation and had the potential to inhibit muscle AChE activity, while the sample of loofah stimulated brain AChE. The samples from scrub sponge had genotoxic potential and the abrasive fiber sample affected the nutritional status of fingerlings. This work brings evidence about the toxic effects caused by multipurpose sponges compared to vegetable loofah, which indicates that this material is a viable alternative from an environmental point of view, but it is not inert.