Radioactive cesium (134Cs and 137Cs) content in human placenta after the Fukushima nuclear power plant accident

Abstract

Aim The degree of contamination with radioactive cesium (134Cs and 137Cs) in the human placenta after the accident at Fukushima nuclear power plant (FNP), which occurred on 11 March 2011, has not been assessed. Material and Methods 134Cs and 137Cs contents were determined in 10 placentas from 10 women who gave birth to term singleton infants during the period between October 2011 and August 2012 using high-purity germanium detectors for gamma ray spectrometry. Five women resided within 50 km of FNP (neighbor group) and gave birth by the end of February 2012, while the other five women resided within 210-290 km of FNP (distant group) and gave birth in July and August 2012. Results All except one of the 10 placentas contained detectable levels of 134Cs and 137Cs, ranging 0.042-0.742 Bq/kg for 134Cs and 0.078-0.922 Bq/kg for 137Cs. One placenta from a woman living in Tokyo contained 0.109 Bq/kg 137Cs and no detectable level of 134Cs (<0.054 Bq/kg). 137Cs content was more than 0.2 Bq/kg in four and one placentas in the neighbor and distant groups, respectively. Conclusion Degree of contamination of the placenta with radioactive Cs was lower even in women who resided within 50 km of FNP compared to Japanese and Canadian placentas in the mid-1960s after repeated nuclear tests and in northern Italian placentas from 1986-1987 after the Chernobyl power plant accident. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.