Monitoring of Air Pollutants Using Plants and Co-Located Soil – Egypt: Characteristics, Pollution, and Toxicity Impact

Abstract

\n The present work was conducted to characterize and monitor the air quality in terms of pollution and toxicity impact using two evergreen tree leaves, Eucalyptus globulus Labill and Ficus benjamina L. 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 and atomic absorption spectrometer. Bivariate and multivariate statistical analysis 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 leaves in urban Greater Cairo and rural Menoufia Governorate show that the major elements are slightly higher in F. benjamina than in E. globulus. Likewise, the mean values of elements in soil from Greater Cairo and Menoufia Governorate show no significant difference except for major elements (Fe, Al, Mg, K, Na, and Ti) in Menoufia Governorate. The normalized concentrations of tree species and soil show that the accumulated elements by F. benjamina is slightly higher than in E. globulus in Greater Cairo GC and Menoufia Governorate MG. While in terms of the investigated area, the concentrations of elements in MG is considerably higher than in GC. 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. PER was significant for As in Soil and for As and Cd for 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.