EFFECTS OF SOME RADONUCLIDES ON THE ENVIRONMENT

Abstract

Twenty soil samples and its corresponding plants were collected and examined for trace elements and radionuclides content in Abu Zabala area. The obtained results of the analyzed samples from the studied area showed large variations in elemental concentrations according to its availability, presence percentage in earth crust and biological roles for plant.Ten trace and minor elements were measured in these studied samples, and the results obtained indicate that: Cadmium content rangesas; in soil samples it ranges from 0.03 to 0.63 ppm with average concentration 0.12ppm. Whereas, Cadmium concentrations in plant samples it ranged from undetected values to 0.89 with average concentration 0.21ppm. Cobalt concentration in the analyzed samples ranged from 0.1 to 13.04 ppm with average concentration 3.54ppm. The highest concentration of cobaltin plant samples reaches 1.67ppm and the lowest concentration was 0.11ppm with average concentration 0.54 ppm. Chromium concentration in soil ranged from 3.23 to 63.89 ppm with average concentration 23.64 ppm. Chromium concentrations in plant samples ranged from 8.24 ppm to 1.90 ppm with average concentration 4.44 ppm. Copper concentration in the study area ranged from 1.75 to 52.7 ppm with average concentration 19.6ppm while in plant samples the copper concentration was higher than that obtained in its soil samples. Iron percentage in soil of the studied area ranged from from1018 to 18066 ppm with an average 7407ppm. Iron concentration in plant leaves are presented in lower concentration in comparison with Fe in soil samples. The highest concentration of iron in plant samples was 2973.33ppm, while the lowest concentration was 548.30 ppm with average concentration 1220.26ppm. The lead concentration in plant samples collected from the studied area ranged from 0.55 to 8.32ppm with average concentration 3.57ppm. These concentrations are considered low in comparison with the toxic limits. The highest concentration of manganese concentration in soil was 270.33ppm and the lowest concentration was 24.02ppm with average concentration 139.17ppm. Manganese in plant samples ranged from 9.66 to 91.41ppm with average concentration 35.59ppm. Nickel in the study area ranged from 0.98 to 23.69 ppm with average concentration 9.71ppm. In plant samples it ranged from 0.55 to 6.48 ppm with average concentration 2.42ppm. Vanadium in soil of the study area found in concentration ranged from 3.80 to 35.47 ppm with average concentration 20.20ppm. Vanadium in plant samples ranged from 1.11 to 7.89 ppm with average concentration 3.08ppm. The zinc content of soils in the study area ranges from 6.72 to 642.67 ppm with a median content of 101.07 ppm. While, in plant samples it ranged from15.04 to 101.7 ppm with average concentration 40.12ppm. In general thedetected concentration of trace elements in the study area is lower than the world concentration limits presented by Cabeta Pendiace and Pendiace (1992). However, the accumulation of trace elements in plant samples differs from element to element specially in copper and vanadium which showed higher concentration in comparison with the world ranges. Four natural Radionuclides were measured in soil and plant samples, the data showed that: the concentration of Ra-226 in soil samples ranged from 9.2 ± 1.1 to 39.4 ± 3.4 Bq//Kg with average concentration 18.7 ± 2.4 Bq/Kg, the concentration of Th-232 ranged from 5.2 ± 1.1 to 23.8 ± 2.9 with average concentration 13.8 ± 1.9 Bq/Kg. K-40 concentration ranged from 78 ± 5.4 to 299 ± 13 Bq/Kg with average concentration 190 ± 1.9 Bq/Kg. The man made radionuclide Cs-137 in soil samples was found in very low concentration ranged from 0.14 ± 0.03 to 0.84 ± 0.12 Bq/Kg. The presence of Cs-137 in soil samples may be due to release from the research reactor at EAEA site which 2km far from the study area.