Role of microplastics as vector for pharmaceuticals in aquatic environment
The presence of contaminants of emerging concern (CECs) in aquatic environment represents the risk due to potential adverse effects on both human health and the environment. The term CECs does not only apply to chemical contaminants but to the microplastics (MPs) as well. As MP may interact with the co-pollutants present in water through sorption, it may serve as a vector for accumulated chemicals, altering their environmental behavior and overall toxicity. We investigated adsorption behaviour of pharmaceutical by pristine and aged MPs. The study is aimed at establishing correlation between structural characteristics of MPs and adsorption capacity at varied conditions. For that purpose, polyethhylene teraphthalate (PET) MPs were used as the most abundant type in aquatic environment in the combination with diclofenac as the representative of widely used pharmaceuticals. The adsorption experiments were performed according to the statistical planning, whereas the level of MPs aging, as well as pH and temperature were used as influential factors. The results were modelled using the principles of response surface methodology and the corresponding adsorption isotherms were established. The toxicity of MPs/diclofenac was assessed using freshwater green algae Selenastrum capricornutum according to the standard method ISO 8692:1989.