Geographical and vertical distribution of radiocesium levels in coniferous forest soils in Izmir

Preliminary picture of ¹³⁷Cs radioactivity levels in forested areas in and around Izmir is illustrated. Both activity concentrations and activity depositions of ¹³⁷Cs in soil samples were determined. Their values varied from 8.29±0.27 to 445±3.16 Bq.kg⁻¹ (d.w.) and 0.63±0.01 to 11.6±0.08 kBq.m^–2 (d.w.), respectively. It was found that while activity deposition of ¹³⁷Cs is normally distributed, activity concentration of ¹³⁷Cs is log-normally distributed in forest soils and the activity deposition is less variable than the activity concentration. Cesium-137 activities in soils increase with increasing elevation, annual average rainfall and soil organic matter.