The Japanese Atomic Energy Authority has online environmental radiation monitors.
The list of stations is here.
The monitoring station at O-arai is the one between Fukushima and Tokyo.
Ambient radiation levels there are 30-40 nGy per hour.
Current levels are around 300 nGy/h - ten times normal.
Acute radiation effects are seen around a dosage of a Gy,
so long way to go - currently getting close to μGy/h.
Things get serious around milliGy/h.
Watch that curve.