Survey: strontium widespread in Fukushima

Soil samples from around Fukushima Prefecture have revealed concentrations of radioactive strontium.

Japan's science ministry conducted a survey for radioactive substances at 11 locations in 10 municipalities from late March to mid-May.

It says strontium-90 was detected in all 11 locations.

In Namie Town, the reading stood at 250 becquerels per kilogram of soil, while in Iitate Village the reading was 120 becquerels per kilogram. The readings in the other locations were between 2 and 18 becquerels.

Strontium-90 is generated during the fission of uranium in fuel rods in reactors.

With a comparatively long half-life of 29 years, the radioactive substance poses a risk of accumulating in the bones if inhaled, because its properties are similar to those of calcium. If this happens, it could cause cancer.

The ministry says the survey revealed that strontium was detected even in the city of Fukushima about 60 kilometers from the plant, suggesting wide-spread contamination.

It says higher doses of strontium were spread northwestward from the plant, along with other radioactive substances, because of the prevailing winds.

The Nuclear Safety Commission says the detected doses of strontium were minimal, compared with those of cesium found in the region. It says the substance does not pose any immediate health threat.

Doctor Osamu Saito is a radiation expert at a hospital in Fukushima City. He says even though only small quantities of strontium-90 were detected in the survey, it still poses a high health risk because it can accumulate in the bones.

He is urging the government to increase the number of observation points throughout the prefecture, so as to help ease public anxiety.

The ministry says it is considering taking samples from additional locations in the next survey.