Technology-critical elements (TCEs) are a non-uniformly defined group of elements with limited availability in relation to global demand. Their peculiar chemical properties make them indispensable in high-tech applications across various fields. Even though the increased use over the last decades has already been found to cause alterations in environmental backgrounds at some instances, little is still known about the exact quantities of anthropogenic releases and how these may affect ecosystems and human health. The chemical diversity of TCEs, combined with low abundance levels in environmental samples, the scarcity of background data and reference values as well as spectral interferences on some elements pose challenges to multielement approaches using inductively coupled plasma mass spectrometry (ICP-MS). This work comprises 7 publications, thereof 3 main author contributions, which extend the current state of knowledge on TCEs in the environment on multiple levels. Firstly, a fast and robust measurement procedure based on closed-vessel microwave-assisted acid digestion and ICP-tandem mass spectrometry (MS/MS) was developed, with a particular focus on the validation of TCE mass fractions in plant samples. The measurement procedure was then applied to samples from urban green and blue infrastructure to generate the first comprehensive data set on scarcely analysed elements of its kind. The study sites were located in Vienna, including two green facades, two urban gardens and two sites at the Wienfluss river. Based on the obtained data, patterns in TCE distribution depending on parameters such as plant species and tissue, season, and height above ground were explored. In the co-authored contributions, the broader scope of this work was extended to adjacent fields in various collaborative endeavours. An umbrella review on the mechanisms by which green facades improve air quality in cities through binding particulate matter (PM) provided insights into the relevance of specific leaf morphological features for PM capture, aiding the effective design of urban green infrastructure as a measure to improve air quality. Additionally, a mobile module-based wind channel was designed and constructed for in-depth studies of dust deposition on individual plant species under controlled conditions. Furthermore, current and projected TCE releases to the urban environment of Vienna were investigated through the development of a model for material flow analysis, forming a base for the discussion of potential human health impacts of TCE emissions. This PhD thesis significantly advances the environmental analysis of TCEs by providing analytical tools for future studies as well as a comprehensive dataset about the distribution of TCEs in the urban environment of a central European city. The generated data lays the groundwork for a better understanding of the impacts of anthropogenic activities on the abundance of TCEs in the environment. Ultimately, the findings aid in the assessment whether the current and expected releases of TCEs can be of concern to ecosystems and human health, and subsequently, whether prevention measures need to be implemented.