Radioactivity analysis following the Fukushima Dai-ichi nuclear accident

• 118 samples were analyzed using HPGe γ spectrometry.
• Trace amount of 131I was detected in rain and surface soil samples.
• No 131I was detected in milk, drinking water, seawater or marine biota samples.
• Result indicate it pose no threat to public health.

A total of 118 samples were analyzed using HPGe γ-spectrometry. 131I, 134Cs, 137Cs and 136Cs were detected in aerosol air samples that were collected 22 days after the accident with values of 1720 µBq m−³, 247 µBq m−³, 289 µBq m−³ and 23 µBq m−³, respectively. 131I was detected in rainwater and soil samples and was also measurable in vegetables collected between April 2 and 13, 2011, with values ranging from 0.55 Bq kg−1 to 2.68 Bq kg−1. No 131I was detected in milk, drinking water, seawater or marine biota samples.