The increased use of cosmetic products, in particular UV filter compounds, results with their introduction in significant amounts in to aquatic ecosystems. Thus, the study and understanding of these substances in the environment is of major importance because of their potential to bioaccumulate and consequent toxicity, which may have a negative impact on the receiving environment, especially for biota, or even humans. Moreover, the contamination of these compounds is further aggravated in urban ecosystems, as fallout of population pressure and human activities. This master project seeks to analyze the impact of these substances in urban environments by having the city of Barcelona and its surroundings as a case study. To accomplish this, first an extensive literature review on characteristics, environmental and toxicity levels of UV filter compounds was performed. Secondly, water samples from rivers and WWTPs from the urban surroundings of Barcelona were analyzed so as to check the levels of mentioned substances, as well as to calculate the removal efficiency of the treatment stations and the potential risk posed by levels audited