State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, China.
China-Russia Joint Laboratory of Plasma Technologies, Laser Institute of Shandong Academy of Sciences , Jining 27000, China.
Environ Sci Technol. 2017 Apr 18;51(8):4689-4696. doi: 10.1021/acs.est.7b00495. Epub 2017 Mar 28.
A steady-state mouse model was developed to determine arsenic (As) relative bioavailability (RBA) in rice to refine As exposure in humans. Fifty-five rice samples from 15 provinces of China were analyzed for total As, with 11 cooked for As speciation and bioavailability assessment. Arsenic concentrations were 38-335 μg kg, averaging 133 μg kg, with As being dominant (36-79%), followed by DMA (18-58%) and As (0.5-16%). Following oral doses of individual As species to mice at low As exposure (2.5-15 μg As per mouse) over a 7-d period, strong linear correlations (R = 0.99) were observed between As urinary excretion and cumulative As intake, suggesting the suitability and sensitivity of the mouse bioassay to measure As-RBA in rice. Urinary excretion factor for DMA (0.46) was less than inorganic As (0.63-0.69). As-RBA in cooked rice ranged from 13.2 ± 2.2% to 53.6 ± 11.1% (averaging 27.0 ± 12.2%) for DMA and 26.2 ± 7.0% to 49.5 ± 4.7% (averaging 39.9 ± 8.3%) for inorganic As. Calculation of inorganic As intake based on total inorganic As in rice overestimated As exposure by 2.0-3.7 fold compared to that based on bioavailable inorganic As. For accurate assessment of the health risk associated with rice consumption, it is important to consider As bioavailability especially inorganic As in rice.
建立了一个稳定状态的小鼠模型，以确定大米中砷（As）的相对生物利用度（RBA），从而细化人类对砷暴露的评估。分析了来自中国 15 个省份的 55 个大米样本中的总砷含量，其中 11 个样本用于砷形态和生物利用度评估。砷浓度为 38-335μg/kg，平均为 133μg/kg，其中砷占主导地位（36-79%），其次是 DMA（18-58%）和 As（0.5-16%）。在低砷暴露（每只小鼠 2.5-15μg As）条件下，连续 7 天经口给予小鼠各砷物种后，观察到尿液中砷排泄量与累积砷摄入量之间存在强烈的线性关系（R=0.99），表明该小鼠生物测定法适用于测量大米中的砷-RBA，且具有较高的灵敏度。DMA 的尿排泄因子（0.46）小于无机砷（0.63-0.69）。烹饪大米中的 DMA 的 As-RBA 范围为 13.2±2.2%至 53.6±11.1%（平均值为 27.0±12.2%），无机砷的 As-RBA 范围为 26.2±7.0%至 49.5±4.7%（平均值为 39.9±8.3%）。与基于大米中总无机砷相比，基于生物可利用无机砷计算的无机砷摄入量高估了砷暴露量 2.0-3.7 倍。为了准确评估与食用大米相关的健康风险，必须考虑砷的生物利用度，尤其是大米中的无机砷。
