Natural Radionuclides and Heavy Metal Contents in the Olive (Olea europaea L.) Groves of Northwestern Anatolia

The objective of this study was to examine the content of heavy metal (Cd, Pb, Ni, Cr, Al) and natural radionuclide (238U, 232Th, 40K) contents of the olive groves around the highway from Alia？a to Ezine. In general, findings showed that total heavy metal contents were more in the subsurface soils. In this regard, total Ni contents of the soils changed between 11-69 mg/kg. It is considered the only threatening heavy metal which exceeded 30 mg/kg critical level especially in the soils of the olive groves in Alia？a Soma, Ayval？k, Edremit and Ezine. Bergama region differed in this regard. The highest of total Pb, Cr and Cd contents in the soils of Alia？a region were found 44.59 mg/kg, 60 mg/kg and 0.81 mg/kg, respectively. These findings are found very close to the reference limit values (50, 100 and 1 mg/kg) reported by different scientists. Natural radioactivities of 226Ra, 232Th and 40K in the soils were also measured and found 37.45 and 410 Bq/kg respectivelly which were slightly above the cited limit values (226Ra:35 Bq/kg, 232Th:30 Bq/kg ve 40K:400 Bg/kg). Results in relation to olive leaves indicated that trees were not threatened by the heavy metals in the soils, only in some cases Cr (0.19-0.99 mg/kg) was found over the limit value (0.60 mg/kg). It could be concluded that this risky region with high contamination potential should be studied periodically before it is too late