Department of Environmental and Occupational Health, School of Public Health - Bloomington, Indiana University, Bloomington, IN, 47405, USA.
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China.
Environ Pollut. 2020 Aug;263(Pt A):114397. doi: 10.1016/j.envpol.2020.114397. Epub 2020 Mar 17.
Rice intake is a major route of oral exposure to inorganic arsenic (iAs), a known human carcinogen. The recent risk assessment on iAs in rice conducted by the US Food & Drug Administration (FDA) didn't propose an action level for iAs in rice mainly because of the relatively low consumption rate in the general US population. However, this decision may not be applicable to high rice-intake populations, such as the Chinese population.
The objective of this study was to probabilistically characterize the exposure of iAs via rice intake in Chinese population with a focus on the urban population.
With the consideration of bioaccessibility of iAs in rice, iAs exposure is mainly determined by rice intake rate and iAs concentration in rice. To estimate the daily rice consumption, a dietary survey consisting of 1873 subjects was conducted in three major Chinese cities (Beijing, Guangzhou, and Hangzhou). Speciated As concentration in rice was measured using 480 rice samples collected from markets in these three cities. Monte Carlo simulation approach was applied to distributionally estimate the average daily dose (ADD) of iAs through rice intake.
The estimated distribution of daily iAs exposure of the study population has a mean of 10.5 μg/day with a 95th percentile interval from 0.1 to 75.3 μg/day. The estimated distribution of ADD has a mean of 0.179 μg/kg/day with a 95th percentile interval from 0.001 to 1.224 μg/kg/day. Greater level of iAs exposure (due to higher rice intake) was observed in males than females, and in summer than other seasons with lower temperature. Geographically, the ADD of iAs exposure from rice intake reduces from south to north.
About 13% of the Chinese urban population are exposed to iAs via rice intake higher than the Reference Dose (RfD) level.
摄入大米是人体接触无机砷（iAs）的主要途径，iAs 是一种已知的人类致癌物。美国食品药品监督管理局（FDA）最近对大米中的 iAs 进行的风险评估主要由于美国普通人群的相对低摄入量，并未提出大米中 iAs 的行动水平。然而，这一决定可能不适用于高大米摄入量人群，如中国人群。
本研究旨在概率描述中国人群通过摄入大米接触 iAs 的情况，重点关注城市人群。
考虑到大米中 iAs 的生物可利用性，iAs 暴露主要取决于大米摄入量和大米中的 iAs 浓度。为了估计每日大米摄入量，在三个中国主要城市（北京、广州和杭州）进行了一项包含 1873 名受试者的膳食调查。使用从这三个城市市场采集的 480 个大米样本测量了大米中砷的形态浓度。采用蒙特卡罗模拟方法分布估计通过摄入大米摄入 iAs 的平均日剂量（ADD）。
研究人群的 iAs 暴露日分布的平均值为 10.5μg/天，95%置信区间为 0.1-75.3μg/天。ADD 的估计分布平均值为 0.179μg/kg/天，95%置信区间为 0.001-1.224μg/kg/天。男性比女性、夏季比其他温度较低的季节摄入更多的 iAs（由于摄入更多的大米）。从地理上看，摄入大米导致的 iAs 暴露的 ADD 从南向北逐渐降低。
约 13%的中国城市人口通过摄入大米接触的 iAs 高于参考剂量（RfD）水平。
