Table 1 Ambient dose rates along the hiking trail on Mt Okura in Tomioka Town, Fukushima Prefecture, during October to December 2019 (see Supplementary S1).

From: Radiocesium levels in contaminated forests has remained stable, even after heavy rains due to typhoons and localized downpours

Date (dd/mm/yy)

Device

Average (µSv/h)

Range (µSv/h)

Median (µSv/h)

External exposure dose (mSv/y)

Proportion of 137Cs sites (% (pts/pts))

10/10/19

RADI-PROBE

0.51

0.19–1.1a

0.48 (0.67)b

4.2c

4.7 (52/1110)d

D-SHUTTLE

0.34e

0.16f

–

17/10/19

RADI-PROBE

0.47

0.17–0.96

0.45 (0.63)

3.9

1.4 (12/880)

D-SHUTTLE

0.21

0.10

–

24/10/19

RADI-PROBE

0.47

0.20–1.1

0.45 (0.60)

3.9

1.1 (11/1037)

D-SHUTTLE

N/A

N/A

–

05/12/19

RADI-PROBE

0.49

0.19–1.1

0.47 (0.64)

4.1

2.4 (26/1105)

D-SHUTTLE

0.23

0.11

–

  1. aMinimum–maximum (maximum values were measured at the same location).
  2. b90th percentile.
  3. cEstimated annual dose rate (µSv/h × 24 h × 365 d × 0.001) based on median dose rate using the RADI-PROBE system.
  4. dProportion of measurement sites where 137Cs was detected using a RADI-PROBE. The values inside the brackets shows monitoring points where 137Cs was detected per all monitoring points.
  5. eIndividual dose rate for the entire time spent hiking measured using a D-SHUTTLE dosimeter (Hp(10)).
  6. fEstimated annual dose rate assuming that the average leisure time of Japanese on weekends is 10 h (i.e., 480 h/year) measured using a D-SHUTTLE dosimeter.
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