A simplified questionnaire was developed to assess inorganic arsenic (iAs) intake level in a Japanese population. The two page questionnaire included photographs of single serving sizes of rice and cooked hijiki (Hizikia fusiforme: brown algae), and asked subjects about the number of servings of rice and cooked hijiki, two predominant dietary sources of iAs in Japan, they consume in a day. Daily intake of iAs was estimated for 72 Japanese subjects using the questionnaire together with data of iAs content in rice and hijiki seaweed, and the estimated intakes were compared with actual iAs intakes of the subjects as measured for a duplicate diet using liquid chromatography-inductively coupled plasma mass spectrometry. A highly significant correlation was found between the estimated and measured intakes (r = 0.65, p < 0.001); however, the slope of regression indicated a systematic error in the intake estimation. Possible sources of error are discussed herein. It was concluded that this approach is promising if minor improvements are made to the questionnaire.
Keywords: daily intake; hijiki; inorganic arsenic; questionnaire; rice.