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Although exposure to inorganic arsenic is a health concern, especially in developing foetuses and children, dietary exposure levels among pregnant women and children have not been extensively studied in Japan. To address this shortcoming, we completed a 3-day duplicate diet study for 104 children and 101 pregnant women in two cities, Shimotsuke, Tochigi and Asahikawa, Hokkaido. The levels of intake of total and inorganic arsenic were estimated using the concentrations of total and inorganic arsenic in food and drinking water measured by inductively coupled plasma-mass spectrometry. Estimated intakes of total and inorganic arsenic were 8.46 ± 3.02 [µg/kg BW/week] and 1.74 ± 1.07 [µg/kg BW/week] in pregnant women and 20.07 ± 3.53 [µg/kg BW/week] and 8.46 ± 3.02 [µg/kg BW/week] in children, respectively. Weekly arsenic exposure per kg body weight was significantly higher in children than in pregnant women. Concentrations of total arsenic were generally very low in collected drinking water samples with a small number of exceptions, and drinking water was not considered as a major source of inorganic arsenic exposure in Japan. We found that total and inorganic arsenic intake were higher among frequent consumers of hijiki seaweed, in both pregnant women and children. Although rice and rice products that are staple foods of the Japanese have been reported to be major sources of inorganic arsenic exposure in Japan, our results indicate that hijiki consumption elevates levels of inorganic arsenic in Japanese children and pregnant women. More efforts are necessary to reduce the risk of exposure to inorganic arsenic in populations highly sensitive to environmental pollutants.

適正な維持透析を施行していく上で, 塩分・水分摂取制限の継続は重要である. しかし, 透析患者では塩分味覚閾値が高く, 塩分味覚が鈍感になっている事が知られている. 今回, 透析患者における塩分味覚と塩分・水分摂取に伴う透析間の体重増加との関連を, 試食法とアンケート調査で検討した. 安定期血液透析患者61例を対象として塩分量を一週毎に1.5g, 2.0g, 3.0gと変化させたカレーライスを昼食時に試食させた結果から, 塩分味覚正常群, 塩分味覚鈍麻群, 塩分味覚障害群の3群に分類し, さらに, アンケート調査によって透析導入後の味覚変化を自覚している群, 自覚していない群, どちらとも判断できない不明群の3群に分類し, 体重増加率との関係を検討した. 結果は塩分味覚鈍麻群 (14例), 障害群 (38例) と両群が85.2%を占めており, 患者の多くに塩分味覚の異常が認められた. 塩分味覚障害がみられ透析導入後の味覚変化を自覚していない群は5.9±0.1%と最も透析間の体重増加率が高く, これらの患者の多くは自らの味覚変化に気づかずに徐々に塩味の「こい」食事に移行してしまう可能性が考えられた. 一方, 塩分味覚障害がみられるにもかかわらず味覚変化を自覚している群は体重増加率が低く, これらの患者では自らの努力によって味覚障害を克服している事が示唆された. これらの事実は透析患者の塩分・水分管理の上で参考になるだけでなく, 高血圧, 心不全, 肝硬変, 腎疾患患者などに対して減塩食療法を指導する際にも参考になると思われる.