With rescue workers around Japan's stricken nuclear reactors - including reportedly two from New Zealand - exposed to radiation, experts weigh in on expected symptoms at diifferent exposure levels.
With rescue workers around Japan's stricken nuclear reactors exposed to radiation - including two USAR team members from New Zealand, who touched down by Black Hawk helicopter 20km from the exclusion zone - the Sciece Media Centre has drafted experts to weigh in on expected symptoms at diifferent exposure levels.
Today, Japan’s Health Ministry said it was raising the legal limit on the amount of radiation to which each worker could be exposed, to 250 millisieverts from 100 millisieverts (mSv), five times the maximum exposure permitted for US nuclear plant workers.
There have been conflicting reports about the level of exposure suffered by workers around the Fukushima plant; one estimate but it at 400 mSv in the early hours of the crisis.
Fukushima radiation levels are fluctuating all the time, Tokyo-based journalist Martyn Williams relayed to NBR. But "bottom line: there's no danger except when very close."
From Dr Pradip Deb is a Senior Lecturer in Medical Radiations at the School of Medical Sciences, RMIT University:
Less than 2.5 Sievert (2500 mSv) - sublethal dose
Symptoms may include: Malaise, Fatigue, Drowsiness, Weight loss, Fever, Abdominal pain, Insomnia, Restlessness, Blisters
2.5 Sv - 6.5 Sv (2500 mSv - 6500 mSv) - Potentially lethal dose
6.5 Sv - 10 Sv (6500 mSv - 10000 mSv) - supralethal dose
Acute Doses over 10 Sv (10,000 mSv)
Comparison with diagnostic x-ray exposure:
Typical effective dose for one exposure of chest x-ray is 0.1 mSv. Which is very small compared to our normal radiation acceptance level (20 mSv per year).
