This study investigated the effects of urbanization on the spatial distribution, sources, and levels of heavy metals pollution in urban soils of the city of Belgrade. A total of 126 composite topsoil (0–10 cm) and subsoil (10–40 cm) samples was collected within four urban zones (central, suburban, external, and rural) of Belgrade and analysed for content, spatial distribution, sources, and pollution indices using statistical methods including descriptive statistics, correlation matrix, and Principal Component Analysis (PCA). Concentration levels of zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), and nickel (Ni) in the soil of urban zones in Belgrade were found to be significantly higher in the central and suburban zones compared to the external and rural ones. The spatial variance and the general trend of heavy metals accumulation in the soil were found to be along the urban–rural gradient. The topsoil concentration levels for the same elements were higher compared to the subsoil concentration levels for the same elements in all urban zones, except for the external and the rural zones. These results indicate the need for the implementation of urban soils pollution monitoring according to specific urban zones to provide an applicable basis for the development of plans and strategies concerning urban soil use management for the purpose of the sustainable urban development.

This study assesses the potential risk of soil pollution in Belgrade by cadmium (Cd) in relation to the city’s urban development zones and different land use types. Cadmium is considered a typical anthropogenic element with toxic and carcinogenic properties. A total of 126 urban soil samples were investigated in this study. Soil pollution by Cd was evaluated based on the determined concentrations with background values (BV), maximum limit values (MLV), and remediation values (RV) established by national regulations. The contamination potential was assessed using the number and percentage of samples relative to the total number of analyzed samples, and the results were analyzed in relation to the degree of urbanization, and different land uses. The concentration of Cd was determined by atomic absorption spectroscopy (AAS) following aqua regia digestion (SRPS-ISO 14870:2005). The results indicate localized but significant risks of Cd contamination in urban soils, particularly in the central and suburban zones of Belgrade, as well as in soils of industrial complexes and traffic junctions. These findings highlight the need for systematic monitoring, targeted identification of contamination sources, and the implementation of zone-specific remediation strategies to mitigate long-term impacts on the urban environment and public health.

Greening urban ruins represents an innovative approach to the revitalization of abandoned built structures. This process merges greenery with ruins or abandoned structures, creating synergy between natural and built elements of the space. The goal of greening ruins is not only ecological but also aesthetic, as it transforms neglected buildings into green "oases" that promote biodiversity and improve microclimatic conditions in urban environments. As a part of urban green infrastructure revitalized ruins can become an effective way in adaptation cities to climate changes, especially in the terms of rainwater regulation and minimaze urban heat island. Additionally, revitalization contributes to social cohesion, creating spaces that can become gathering places for various community activities. Case studies at both European and global levels, such as the MFO Park, Qiaotou Ruin Garden, and others, provide examples of good practices that offer insights into the benefits and challenges of revitalizing abandoned structures. This paper explores the potential for revitalizing ruins through the application of plant materials, emphasizing the benefits greenery can contribute to the renewal of abandoned urban spaces, as well as analyzing various greening possibilities, including the use of different techniques such as vertical greening systems, rooftop gardens, green walls, and interior greening of buildings. Greening ruins also contributes to preserving cultural identity, as it allows old buildings, through the appropriate use of plant materials, to become integral parts of contemporary urban ecosystems. The potential for revitalization depends on the structural stability of the buildings, the maintenance and care requirements for green areas, potential legal issues, and financial considerations, which highlight the need for careful planning and implementation. Further research in this area can contribute to the understanding and making practices and specific solutions for the future revitalization of urban spaces through greening.