Bio-monitoring of Radionuclides Air Pollution Using Physiological Responses of Urban Trees

Contamination of environment by radionuclides in territories under urboecosystem conditions is an actual problem. The search for new express methods for radioactivity determination of environment is an important task of research. The present work evaluated the ability to use Eucalyptus globulus leaves to act as bio-monitor for environmental radionuclides air pollution. The accumulation features of radionuclides (226Ra, 232Th, 40K) in the leaves of camphor trees (Eucalyptus globulus Labill) growing in areas near Al-Nasr quarry for phosphate production, Upper Egypt during the physical year 2016 have been considered. The activity concentration of 226Ra, 232Th and 40K in samples of soils, plant leaves and deposited dust have been compared. These activities were measured using high resolution gamma- spectroscopy (Hyper Pure Germanium detector) with consideration for the background level. On the basis of radionuclides analysis, leaves of E. globulus exhibited different accumulation coefficients according to the distance from the quarry. The relationship between the radionuclides concentrations in leaf deposited dust and soil samples was estimated by Pearson coefficients to resolve two main mechanisms of radionuclide accumulation, atmospheric deposition, and root uptake. Differences in local conditions at the sampling sites were not significant. E. globulus physiological responses due to radionuclides stress were determined. The results of investigation recommended the use E. globulus leaves as an indicator of radioactivity air pollution.