Evaluation of the migration potential of printed plastic films into the aquatic environment

Abstract This study aimed to evaluate the degree of contamination of water matrices (deionised water, spring water, tap water) in a 14-week experiment using film samples from commercial bags printed with water- and solvent-based inks. The effect of different lighting conditions on leaching and ecotoxicity was also investigated. Samples were exposed for 24 hours to natural sunlight and to no light in a darkroom. A significant increase in contaminants in the aqueous matrices was observed in the 12-week leaching potential of the components from the films in all the lighting variants and aqueous matrices analysed: an increase in dissolved organic carbon (DOC), total organic carbon (TOC) and total suspended solids (TSS). Based on the procedures carried out, the relationship between lighting conditions and the amount of constituents released into the aqueous matrices was not confirmed. The concentration of total organic carbon in all samples peaked between weeks 6 and 9 of the study, followed by a gradual reduction in leaching. This phenomenon could be linked to the gradual depletion of the substances present in the samples or to the achievement of a concentration equilibrium between the aqueous matrix and the sample and/or to the formation of deposits on the surface of the films, which hindered the migration of substances into solutions. Ecotoxicity tests performed between 7 and 14 weeks showed most samples' toxic and highly toxic effects on the growth of Lemna minor fronds and Sinapis alba/Lepidium sativum roots. In contrast, no toxic effects were observed in most samples in screening mortality tests on Daphnia magna and Artemia salina. The study highlights the need for further research into the effects of plastic pollution on the aquatic environment.