Whole body counter assessment of internal radiocontamination in patients with end-stage renal disease living in areas affected by the Fukushima Daiichi nuclear power plant disaster: a retrospective observational study

OBJECTIVE: To assess internal radiocontamination of patients with end-stage renal disease (ESRD) who were regularly taking haemodialysis (HD) and living in areas affected by the crippled Fukushima Daiichi nuclear plant after the Great East Japan earthquake on 11 March 2011. METHODS: Internal radiocontamination in 111 patients with ESRD regularly taking HD at Jyoban Hospital in Iwaki city, Fukushima from July 2012 to November 2012 was assessed with a whole body counter (WBC). The maximum annual effective dose was calculated from the detected Cs-137 levels. Interviews concerning patient dietary preferences and outdoor activities were also conducted. RESULTS: Among the 111 patients tested, internal radiocontamination with Cs-137 was detected in two participants, but the levels were marginal and just exceeded the detection limit (250 Bq/body). The tentatively calculated maximum annual effective dose ranged from 0.008 to 0.009 mSv/year, which is far below the 1 mSv/year limit set by the government of Japan. Relative to 238 non-ESRD participants, patients with ERSD had significantly more opportunities to consume locally grown produce that was not distributed to the market (p<0.01). However, the percentage of patients with ESRD with detectable Cs (1.8%) was lower than that for non-ESRD participants (3.8%), although this difference was not significant (p=0.51). CONCLUSIONS: These findings suggest that internal radiocontamination levels and the calculated annual additional effective doses were negligible for patients with ESRD taking HD in areas affected by the crippled Fukushima nuclear plant. Although HD is suggested to promote Cs-137 excretion, continuous inspection of locally grown produce together with WBC screening for radiocontamination should be continued for patients with ESRD regularly taking HD.