Inspections of radiocesium concentration levels in rice from Fukushima Prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident

Abstract

We summarize the inspections of radiocesium concentration levels in rice produced in Fukushima Prefecture, Japan, for 3 years from the nuclear accident in 2011. In 2011, three types of verifications, preliminary survey, main inspection, and emergency survey, revealed that rice with radiocesium concentration levels over 500 Bq/kg (the provisional regulation level until March 2012 in Japan) was identified in the areas north and west of the Fukushima nuclear power plant. The internal exposure of an average adult eating rice grown in the area north of the nuclear plant was estimated as 0.05 mSv/year. In 2012, Fukushima Prefecture authorities decided to investigate the radiocesium concentration levels in all rice using custom-made belt conveyor testers. Notably, rice with radiocesium concentration levels over 100 Bq/kg (the new standard since April 2012 in Japan) were detected in only 71 and 28 bags out of the total 10,338,000 in 2012 and 11,001,000 in 2013, respectively. We considered that there were almost no rice exceeding 100 Bq/kg produced in Fukushima Prefecture after 3 years from the nuclear accident, and the safety of Fukushima's rice were ensured because of the investigation of all rice.

The Effects of Radioactive Contamination on the Forestry Industry and Commercial Mushroom-Log Production in Fukushima, Japan

“…The Fukushima government abided by and implemented such a monitoring system to inspect agricultural products and protect the public from consuming excessively contaminated food. For example, rice, which is the main agricultural product in Fukushima, was inspected bag-by-bag in 2012 to allay consumer fears of contamination (Nihei et al 2015). The government initiated similar inspections at the shipment stage to ensure the safety of forest food products, including mushrooms.…”

Certified reference materials of agricultural products and foods bearing radioactivity from the Fukushima nuclear accident

“…This situation necessitated the immediate measurement of dose rates in air [1] and radioactivity in environmental materials, including food, for assessment of risk to human health [2][3][4][5][6][7]. The Ministry of Health, Labor and Welfare of Japan established an allowance of radioactivity in foodstuffs on 1 April 2012, 1 year after the FDNPP accident-the standard limit for radioactive cesium ( 134 Cs and 137 Cs) in general food was announced as 100 Bq kg -1 [8].…”

Monitoring inspection for radiocesium in agricultural, livestock, forestry and fishery products in Fukushima prefecture

“…By the end of March 2015, approximately 500 types of the foods were selected and 90,000 samples were measured in total. These results have been summarized for rice [5] and fish [6]; however, there is only limited information on other products [7][8][9][10]. Therefore, the authors selected the data to analyze the trend in the decrease in radioactivity in several categories of agricultural productions.…”