Ahead of hay fever season next spring, the Forestry Agency said Oct. 31 it will investigate the extent to which radioactive cesium is transferred from cedar leaves to pollen.
Ahead of hay fever season next spring, the Forestry Agency said Oct. 31 it will investigate the extent to which radioactive cesium is transferred from cedar leaves to pollen.
The decision came after the agency received a number of inquiries on the health effects of airborne cedar pollen that travels over broad regions. There is no previous study, either domestically or overseas, on how much cesium is transferred from cedar leaves to pollen, the agency said.
Beginning in late November, surveys will be conducted at about 100 locations in Fukushima Prefecture, including cedar tree forests in the Abukuma mountains close to the Fukushima No. 1 nuclear power plant. Surveys will also be conducted in the Kanto region, agency officials said.
The study will start around the time pollen begins to form and will run through January. An interim report will be released in December.
A study by the science ministry found up to 177,600 becquerels of cesium per kilogram of cedar leaves in a district in Kawamata, Fukushima Prefecture, more than 30 kilometers from the Fukushima No. 1 nuclear plant. The district is within a designated "planned evacuation zone." A trial calculation by the Forestry Agency, based on the assumption that pollen had the same cesium concentration, produced a very low adult radiation exposure of 0.000132 microsievert per hour, even if the highest monthly airborne pollen concentration in the Kanto region over the past eight years was used, according to the agency.
"Expert radiologists have told us that, commonly speaking, there is no need to worry, but we wish to confirm the safety through our investigations," an agency official said.