Environmental Research Institute, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Research Program of Toxic Substance Management in the Mining Industry, Center of Excellence on Hazardous Substance Management, Bangkok, 10330, Thailand.
Environ Geochem Health. 2019 Feb;41(1):343-356. doi: 10.1007/s10653-018-0098-8. Epub 2018 Mar 30.
Consumption of contaminated rice is a toxin exposure route in Asian populations. Since total concentrations generally overestimate health risks, the objectives of this study were to determine the levels of bioaccessible As and Cd in rice cultivated in the Mae Tao, Tak Province and evaluate their potential health impacts in local adults. In total, 59 locally grown rice samples were analyzed for their total and bioaccessible concentrations. Bioaccessible concentrations were obtained from an in vitro digestion process. Inorganic As concentrations were estimated assuming that 63.2-63.5% of the total As is inorganic As. Rice contained inorganic As (45.2% of white rice and 57.1% of sticky rice) and Cd (51.6% of white rice and 32.1% of sticky rice) levels exceeding the Codex standards. The bioaccessibilities of As (16.3-70.0%) and Cd (Null to 83.7%) in rice varied widely. The concentrations of bioaccessible As, which were 1-1.2 times greater than those of bioaccessible Cd, indicate a higher possibility of As absorption into the human body. Positive significant relationships were found between total and bioaccessible As (R = 0.568 for white rice and R = 0.704 for sticky rice) and Cd (R = 0.874 for white rice and R = 0.862 for sticky rice). The hazard quotient (HQ) of inorganic As exposure accounted for approximately 93.4% of hazard index (HI). Approximately 2-6 in 10,000 residents over a lifetime of 75 years could suffer from cancer as a result of daily rice consumption. Therefore, the consumption of the home-grown rice in this study should be limited.
食用受污染的大米是亚洲人群暴露于毒素的一种途径。由于总浓度通常会高估健康风险，因此本研究的目的是确定在泰国 Mae Tao 和 Tak 省种植的大米中生物可利用的砷和镉的水平，并评估其对当地成年人的潜在健康影响。总共分析了 59 个当地种植的大米样本，以确定其总浓度和生物可利用浓度。生物可利用浓度是通过体外消化过程获得的。假设总砷的 63.2-63.5%为无机砷，因此估算了无机砷的浓度。大米中的无机砷（白米的 45.2%和糯米的 57.1%）和镉（白米的 51.6%和糯米的 32.1%）含量超过了食典标准。大米中砷（16.3-70.0%）和镉（0 至 83.7%）的生物可利用性差异很大。生物可利用砷的浓度（比生物可利用镉的浓度高 1-1.2 倍）表明，砷被人体吸收的可能性更高。在白米中，总浓度与生物可利用浓度之间存在显著正相关关系（R=0.568），在糯米中则存在显著正相关关系（R=0.704），与镉也存在显著正相关关系（在白米中 R=0.874，在糯米中 R=0.862）。无机砷暴露的危害系数（HQ）约占危害指数（HI）的 93.4%。由于每天食用大米，大约每 10,000 名居民中有 2-6 人可能会在 75 年的生命周期中患上癌症。因此，应该限制食用本研究中种植的大米。
