In vivo assessment of arsenic bioavailability in rice and its significance for human health risk assessment

Albert L. Juhasz, Euan Smith, John Weber, Matthew Rees, Allan Rofe, Tim Kuchel, Lloyd Sansom, Ravi Naidu

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    198 Citations (Scopus)

    Abstract

    Background: Millions of people worldwide consume arsenic-contaminated rice; however, little is known about the uptake and bioavailability of arsenic species after arsenic-contaminated rice ingestion. Objectives: In this study, we assessed arsenic speciation in greenhouse-grown and supermarket-bought rice, and determined arsenic bioavailability in cooked rice using an in vivo swine model. Results: In supermarket-bought rice, arsenic was present entirely in the inorganic form compared to greenhouse-grown rice (using irrigation water contaminated with sodium arsenate), where most (∼ 86%) arsenic was present as dimethylarsinic acid (organic arsenic). Because of the low absolute bioavailability of dimethylarsinic acid and the high proportion of dimethylarsinic acid in greenhouse-grown rice, only 33 ± 3% (mean ± SD) of the total rice-bound arsenic was bioavailable. Conversely, in supermarket-bought rice cooked in water contaminated with sodium arsenate, arsenic was present entirely in the inorganic form, and bioavailability was high (89 ± 9%). Conclusions: These results indicate that arsenic bioavailability in rice is highly dependent on arsenic speciation, which in turn can vary depending on rice cultivar, arsenic in irrigation water, and the presence and nature of arsenic speciation in cooking water. Arsenic speciation and bioavailability are therefore critical parameters for reducing uncertainties when estimating exposure from the consumption of rice grown and cooked using arsenic-contaminated water.

    Original languageEnglish
    Pages (from-to)1826-1831
    Number of pages6
    JournalEnvironmental Health Perspectives
    Volume114
    Issue number12
    DOIs
    Publication statusPublished or Issued - Dec 2006

    Keywords

    • Arsenic
    • Arsenic daily intake values
    • Bioavailability
    • In vivo
    • Maximum tolerable daily intake
    • Rice
    • Risk assessment speciation

    ASJC Scopus subject areas

    • Public Health, Environmental and Occupational Health
    • Health, Toxicology and Mutagenesis

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