An in vitro assessment of bioaccessibility of arsenicals in rice and the use of this estimate within a probabilistic exposure model

作者：Trenary Heather R; Creed Patricia A; Young Andrea R; Mantha Madhavi; Schwegel Carol A; Xue Jianping; Kohan Michael J; Herbin Davis Karen; Thomas David J; Caruso Joseph A; Creed John T^*

来源：Journal of Exposure Science and Environmental Epidemiology, 2012, 22(4): 369-375.

DOI：10.1038/jes.2012.24

• rice
• arsenic
• bioaccessiblity
• exposure assessment

In this study, an in vitro synthetic gastrointestinal extraction protocol was used to estimate bioaccessibility of different arsenicals present in 17 rice samples of various grain types that were collected across the United States. The across matrix average for total arsenic was 209 ng/g +/- 153 ((x) over bar +/- 2 sigma). The bioaccessibility estimate produced an across matrix average of 61% +/- 19 ((x) over bar +/- 2 sigma). The across matrix average concentrations of inorganic arsenic (iAs) and dimethylarsinic acid (DMA) were 81 ng/g +/- 67.7 and 41 ng/g +/- 58.1 ((x) over bar +/- 2 sigma), respectively. This distribution of iAs concentrations in rice was combined with the distribution of consumption patterns (from WWEIA) in a Stochastic Human Exposure and Dose Simulator model to estimate population-based exposures. The mean consumption rate for the population as a whole was 15.7 g per day resulting in a 0.98 mu g iAs per day exposure. The mean consumption rate for children 1-2 years old was 7 g per day resulting in a 0.48 mu g iAs per day exposure. Presystemic biotransformation of DMA in rice was examined using an in vitro assay containing the anaerobic microbiota of mouse cecum. This assay indicated that DMA extracted from the rice was converted to dimethylthioarsinic acid, although a second oxygen-sulfur exchange to produce DMDTA was not observed.

• 出版日期2012-8