Abstract:
ABSTRACTIn the last escalation of hostilities in Gaza (2014), Israeli occupation forces dropped about 36,000 tons of artillery shells (AS) and air force bombs (AFB) on Gaza Strip from 7th of July to 28th of August. As a result of using such massive amount of munitions 7,473 impact craters in agricultural and non-urbanized areas were recognized, as well as, two million tons of buildings rubbles were produced. Forty-five top soil and five rubble multi-increment composite samples were collected using systematic-random system from targeted soils and households, as well as 10 control, and two bar samples were collected from untargeted agricultural and isolated areas respectively, to assess the impact of the military activities on soil and rubbles pollution by metals in targeted locations. Digestion of samples was performed using Strong Acid Leachable Metals (SALM) digestion method. Concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were detected using atomic absorption spectrometer (AAS), while concentration of aluminum was detected using UV/VIS Spectrophotometer. Soil properties (Soil texture, CEC and pH) were measured in order to predict the behavior of the metals in the soil profile of the targeted areas. The soil samples were grouped into categories. The T-test was used to compare the mean concentration of each metal among the different categories of soil in order to investigate the different aspects of the effect of the military activities on targeted soils. The mean concentration of the bar samples was considered as a normal limit of the natural contribution of the environment while, the mean concentration of the control samples was used as a normal limit for agricultural activities. The result showed that, the agricultural activities enriched the Gaza soils with, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn, while the content of Al is likely to be affected by the environmental contribution. Although military activities introduced significant amounts of of Cd, Co, Cr, Cu, Mn, Ni, and Al in targeted soils, only Cd in (26.67%) and Cr in (20%) of the targeted soil samples were found with concentrations higher than the MACs of Chemical Constituents in Uncontaminated Soil listed by USEPA. The metals contents in targeted soil samples were not affected by the used type of munition (AFB and AS) except for Cu, where its content in samples collected from areas subjected to AS is significantly higher than that of samples collected from areas subjected to AFB. Although, the high sand content, as well as the low CEC values of Gaza soils increase the possibility of downward migration of metals in soil profile via soil solution, the slightly alkaline to moderately alkaline values of the soil pH decrease this possibility. Accordingly, relevant institutions should establish research programs to investigate the fate of metals and other explosive residuals in deep soil, groundwater and plants, as well as soil and rubble contamination with other metals, explosive residuals and radioactive materials should be investigated. The results also revealed that, only in terms of the investigated metals, rubble can be used in construction purposes or as a filling material, since their concentrations in rubble samples are lower than MACs of Chemical Constituents in Uncontaminated Soil Used as Fill Material listed by USEPA.