Influence of the residence time of street trees and their soils on trace element contamination in Paris (France)

Monitoring of air pollutants using plants and co-located soil-Egypt: characteristics, pollution, and toxicity impact

The present work was conducted to evaluate the air quality in terms of inorganic pollutants and toxicity impact using two evergreen tree leaves, Eucalyptus globulus Labill (E. globulus) and Ficus microcarpa L.f., Suppl. Pl. 442 (1782) (F. microcarpa) as biomonitors. Thirty tree leaves and an equal number of co-located soil samples from different regions of Egypt (urban Greater Cairo Metropolitan (GC) and rural Menoufia Governorate (MG)) were collected. The concentrations of 34 and 40 elements were determined using instrumental neutron activation analysis (INNA) and atomic absorption spectrometry (AAS) in tree leaves and soils, respectively. Bivariate and multivariate statistical analyses were implemented. The air pollution was assessed using enrichment factor, pollution load index, potential ecological risk, and risk index. In addition, human and ecotoxicity were evaluated based on the ReCiPe method. The mean concentration values of the obtained elements in tree leave in urban Greater Cairo and rural Menoufia Governorate show that the major elements are slightly higher in F. microcarpa than in E. globulus. Likewise, the mean values of elements in soil from GC and MG show no significant difference except for major elements (Fe, Al, Mg, K, Na, and Ti) in MG. The normalized concentrations of tree leave and soil show that the accumulated elements by F. macrocarpa are slightly higher than in E. globulus in GC and MG. While in terms of the investigated area, the concentrations of elements in MG are considerably higher than in GC. Pollution load index (PLI) spatial distribution over investigated areas showed that despite high population density, heavy traffic, and urban pollution, the Cairo samples exhibit significantly lower values as compared to those from Menoufia, which is most likely due to the uncontrolled industrial and domestic waste disposal outside Cairo. Potential ecological risk (PER) was significant for As in soil and for As and Cd in tree species. Human toxicity shows higher values in urban locations. Contrariwise, in the terrestrial ecotoxicity aspect, the rural locations are much higher than in urban ones.

Urban areas, human health and technosols for the green deal

Authors aim to carry out a bibliographic review as an initial approach to state of the art related to the quality of urban soils, as well as its possible link with human health. This concern arises from the need to highlight the consequences that soil could face, derived from the growth and aging of the population, as well as its predicted preference for urban settlement. Urban development may pose a challenge to the health of urban soils, due to degradative processes that it entails, such as land take, sealing, contamination or compaction. A healthy soil is the one which maintains the capacity to support ecosystem services, so it can provide numerous benefits to human health and well-being (carbon sequestration, protection against flooding, retention and immobilization of pollutants and a growth media for vegetation and food production). This article addresses threats facing urban soils, the strategies put forward by the European Union to deal with them, as well as the issues that require further attention. Greening cities could be a consensual solution, so authors analyze whether soils of cities are ready for that challenge and what resources need to maintain soil ecosystem functions. This review proposes to use made by waste Technosols for a sustainable green city. Although the use of Technosols as a type of soil is very recent, the interest of the scientific community in this field continues to grow.