Bioaccessibility of Inorganic Arsenic in Rice: Probabilistic Estimation and Identification of Influencing Factors

ABSTRACT

Bioaccessibility, defined as the fraction of inorganic arsenic (iAs) that becomes soluble in the GI tract and ready for absorption, is one of the determining factors that impacts the iAs exposure through rice consumption. The objective of this study is to, based on published data, quantitatively characterize the bioaccessibility of iAs in rice and identify its influencing factors. A total of 256 published papers were identified and reviewed, among which eight were selected as they provide adequate data to support the analyses of bioaccessibility and influencing factors. A meta-analysis was performed to characterize the probabilistic distribution of the bioaccessibility of iAs. A general regression analysis was performed to identify the influencing factors of the bioaccessibility. A beta distribution (a = 4.91, b = 1.85) with a mean and 90^th percentile interval of 73% (43%, 95%) was estimated to adequately describe the iAs bioaccessibility in rice. The regression analysis shows that grain size (p-value < 0.001) and the inorganic-to-total proportion of arsenic (p-value < 0.001) are negatively associated with bioaccessibility, while milling status has no impact.

KEYWORDS:

• Rice
• inorganic arsenic
• bioaccessibility
• in vitro extraction
• exposure assessment
• probabilistic assessment

Acknowledgments

The study was supported by Indiana University President’s International Research Award.

Disclosure statement

The authors declare that they have no known conflict of interests that would have appeared to influence the work in this paper.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website

Additional information

Funding

This work was supported by the President's International Research Award of Indiana University.