BIOCHEMICAL STUDIES ON SOME ENVIRONMENTAL POLLUTANTS IN EGYPT

Abstract

The present investigation was carried out at Soil, Water and Environment Research Institute (SWERI), Agricultural Research Center (ARC), Ministry of Agriculture and Land Reclamation (MOALR), Giza, Egypt, during the period 1998 to 2000. The main objectives of this study were!­ Soil pollution:- Evaluation of heavy metal contents in different polluted locations in (Abu Rawash soils). In this study, Abu-Rawash soils, which irrigated with wastewater, were chosen as example of agricultural polluted soil in Egypt. Soil samples were randomly collected from five different locations. At the same time, control soil which irrigated with well water was collected from the same location. It was found that there increases in EC values of polluted soils which irrigated with wastewater as compared with control soil, their levels were still below salinity levels. Cations, especially Ca"+ and Na+, were relatively higher than Mg"+ and K+. Also, anionic composition was conformed the following order S042> HC03> cr, while carbonate anions did not detectable in any location of studied soils. Also, It was recorded that continuos irrigation with wastewater increased the soil contents of macronutrients (N, P and K), both total and available micronutrients i.e.; Fe, Mn, Zn and Cu and the availability of heavy metals. Levels of some elements determined in studied soil, including Pb, Ni, Co, Cd and Cr were higher than the maximum acceptable levels. In spite of some elements (Mn, Zn and Cu), their concentrations were relatively higher than of control, but their average values were below the maximum acceptable concentrations for production of healthy food in agriculture soils. 2- Plant pollution:- Effects of different concentrations (0, 0.5, 5, 20, 40, 60, 80, and 100 ppm) of lead and nickel salts on seed germination, botanical characters and chemical composition of faba bean (Vi cia faba L.) variety Giza 2. and wheat (Triticum aestivum L.) variety Sids L It was found that significant decrease of seed germination of both plants with the increasing of either Pb or Ni concentration. Significant decrease of botanical characters (roots length, shoot length, leaf area, fresh weight and dries weight) with the increasing of either Pb or Ni concentrations have been observed Macronutrients (N, P and K) were decreased with increasing the concentrations of both metals (Pb and Ni), especially in case of nickel. Decreased micronutrients (Mn, Zn, B) with increasing the concentrations of both metals (Pb and Ni), but data showed that treatments of heavy metals did not influence on iron contents of faba bean and wheat seedlings. Lead and nickel accumulation in both plants illustrated that:- The first group, heavy metals significantly increased by Pb and Ni treatments. Progressive accumulation of Ni and Pb in faba bean and wheat seedlings by Ni and Pb application have been observed, receptively. In addition, Cu content was increased under Pb and Ni stress. Second group, heavy metals significantly decreased by Pb and Ni applications, and this group included Cr alone. The third group, heavy metals did not changed their contents by Pb and Ni applications, and included Co, Cd The crude protein wat; gradually depressed with increasing the concentrations of both metals (pb and Ni) also, the irrigation of faba bean and wheat plants with wastewater did not show apparent effects on native protein and protein subunits of both seeds. Under metals-stress significant decreases of total lipid and marked alterations of fatty acid composition were observed It is obvious that total saturated fatty acids slightly increased as metal (lead or nickel) concentrations increased. On the contrary, total unsaturated fatty acids slightly decreased as metal concentrations increased. Total carbohydrate, soluble sugar, reducing sugar and non-reducing sugar contents were markedly accumulated in seedling leaves relative to control. Total chlorophyll contents of both plants (faba bean or wheat) were decreased with increasing heavy metal concentrations. Increasing the inhibition of catalase, peroxidase and amylase activities relative to control followed increases of heavy metal concentrations.