The book "Dangerous Pollutants (Xenobiotics) in Urban Water Cycle" offers a comprehensive analysis of the challenges posed by hazardous pollutants in the urban water cycle. With the growth of the population and rising living standards, the pressure on water supply and the quality of drinking water is increasing. The work highlights the effects of xenobiotics, including heavy metals, organic compounds, and endocrine disruptors, which are often inadequately removed by wastewater treatment plants. These pollutants can have significant impacts on aquatic ecosystems and represent a growing concern. The authors, including Petr Hlavinek and Ongjen Bonacci, discuss the need for an interdisciplinary approach to assess the impacts of these pollutants throughout the urban water cycle and emphasize the importance of rainwater utilization and wastewater recycling.