The city of Fukushima in northern Japan is to give radiation dosimeters to 34,000 children to measure their exposure from the crippled nuclear power plant 60km away.
All children aged between four and 15 years will wear the devices for three months from September. The data will be collected monthly.
The Fukushima Daiichi plant was badly damaged in the earthquake and tsunami on 11 March and is still leaking radioactive material.
The city is outside a 20km no-go zone around the plant, but many residents are concerned about radiation.