Hijiki seaweed consumption elevates levels of inorganic arsenic intake in Japanese children and pregnant women

ABSTRACT

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.

GRAPHICAL ABSTRACT

KEYWORDS:

• Inorganic arsenic
• oral exposure
• hijiki
• seaweed

Acknowledgments

We thank Masami Yoneda, Yumiko Tateno, Akiko Higashimoto and Yuko Hosoi for their technical assistance on recruiting the participants and on preparing the food duplicate samples. We also thank to Dr. Michael J. DiNovi for his critical reading the manuscript. This work was supported by a Grant-in-Aid for Food Safety Research from Ministry of Health, Labor and Welfare of Japan (H25-Food-General-006) and JSPS KAKENHI Grant Number 15K06912.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary Material

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Additional information

Funding

This work was supported by the Grant-in-Aid for Food Safety Research from Ministry of Health, Labor and Welfare of Japan [H25-Food-General-006]; JSPS KAKENHI [15K06912].