Biomonitoring of 137Cs, 40K, 232Th, and 238U using oak bark in Belgrade forest, Istanbul, Turkey

Abstract

In the present study, the bark of oak trees (Quercus petraea Liebl.) was collected from Belgrade Forest northwest of Istanbul for determination of 137Cs, 40K, 232Th, and 238U activity. A gamma spectrometer equipped with high-purity germanium detector was used for radioactivity measurement. Bark samples were collected from the northern and southern sides of trees at a height of 1.5 m above the ground in order to see the effects of rainfall and wind; and they were also collected from the northern side at a height of 0.5 m above the ground to assess the effect of soil splash. The activity concentrations of 137Cs, 40K, 232Th, and 238U in the bark samples were found to vary in the range of 1.40-27.50, 45.0-221.2, 0.92-9.64, and 4.04-36.10 Bq/kg, respectively. The elevated activity of 238U in bark samples could be attributed to a large amount of coal combustion in the region until the 1990s. According to one-way ANOVA, a significant difference was not found in bark samples collected at a height of 0.5 m and 1.5 m above the ground in terms of radionuclide activity. There was also no significant variation regarding radionuclide accumulation between northern and southern sides

Radionuclides’ content in forest ecosystem located in southwestern part of Serbia

“…In or der to un der stand the dis tri bu tion of radionuclides in dif fer ent parts of woods (trees), radionuclide con tent in tree stems of dif fer ent trees, leaves or nee dles, de tri tus (tree floor) and soil in the forest eco sys tem of south-west ern Ser bia has been in ves tigated. Moss and bark are known as a good biomonitors [9,10] and it is of in ter est to de ter mine whether some other parts of trees could be used as biomonitors as well.…”

Extraction of 137Cs from moss using solutions similar to acid rain

“…If moss sorbs a cer tain sub stance (for ex am ple 137 Cs) it be comes pol luted with it [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. When moss is then sub merged in wa ter or is pe ri od i cally soaked with so lu tions not con tain ing the sorbed sub stance, this substance will be ex tracted.…”