Branko Petrinec
Institute for Medical Research and Occupational Health, Croatia
Title: 137Cs in soil and milk in the region of Zagreb, Croatia
Biography
Biography: Branko Petrinec
Abstract
At the Institute for Medical Research and Occupational Health in Zagreb, Croatia, research on environmental radioactivity has been carried out over a number of years. Aft er the Fukushima accident in March of 2011, we have paid a special attention to its possible impact on the radioactivity of soil and precipitation in Northwest Croatia (Zagreb region). Before and after the accident, we determined the activity concentrations of 137Cs (A) in soil samples taken from 3 adjacent surface layers (depths of 0-5 cm, 5-10 cm and 10-15 cm) as well as in samples of milk. Before the accident, A in the soil was nearly uniform, only slightly increasing with increasing depth. Shortly aft er the accident, we observed an increase of A in the topmost layer, which was in agreement with the values of A measured in fallout. In subsequent years, we have detected both the penetration of 137Cs deeper into the soil and the overall decrease in A. In 2010, the values of A in milk were quite uniform over the months, amounting to about 35 Bqm-3. In 2011, this increased to 199 Bqm-3 in average, mainly due to the large values measured in the summer months; we attribute this eff ect to the infl ux of the radioactive matter from Fukushima. In consequence of the increased presence of 137Cs, the estimated yearly eff ective dose due to the intake of 137Cs via milk in 2011 was 200 nSv, which
can be compared with 73 nSv in the period of 2010-2015.
