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標題: | 主要食米國家人口食用食米之砷暴露健康風險探討 Health Risk Assessment for Rice Arsenic Intake for Countries with Rice as Staple Food |
作者: | Szu-Chi Lai 賴思齊 |
指導教授: | 黃耀輝 |
關鍵字: | 食米,無機砷,砷暴露,健康風險評估,管制標準, rice,inorganic arsenic,arsenic exposure,health risk assessment,regulation, |
出版年 : | 2018 |
學位: | 碩士 |
摘要: | 世界上將近一半人口攝食食米,然而食米含有高濃度的砷,甚至高於其他穀類約10倍。米粒中主要的砷物種是三價和五價的無機砷,而無機砷又被世界衛生組織列為人類致癌物,因此探討攝食食米引起砷暴露之健康風險是重要的議題。目前較少有研究探討不同國家攝食食米的潛在健康風險,因此本研究蒐集整理各主要食米國家食米中砷濃度和食米攝食量的資料,推估不同國家攝食食米之砷暴露健康風險值。
本研究以PubMed、Toxline和Web of Science等資料庫蒐集整理各主要食米國家的食米無機砷濃度、食米攝食量及國民體重資料等風險評估相關參數。再運用蒙地卡羅模擬方法進行十萬次模擬運算,推估各國攝食食米之砷暴露健康風險值。 研究結果顯示12個亞洲國家地區和6個歐美國家地區終生平均每日砷暴露劑量(LADD)中位數值各國分布範圍分別為1.79×10-5-1.42×10-3 µg/g/day和1.91×10-5-1.15×10-4 µg/g/day;致癌風險中位數值各國分布範圍分別為2.68×10-5-2.13×10-3和2.86×10-5-1.73×10-4;危害商數(HQ)中位數值各國分布範圍分別為0.06-4.73和0.06-0.38。此外,訂定食米無機砷濃度管制標準為0.200 µg/g、0.150 µg/g、0.100 µg/g和0.050 µg/g情況下,大部分國家食米中砷濃度合格率分別為90-100%、80-100 %、0-60 % 和0-10 %。在上述四種不同食米無機砷管制標準情況下,攝食食米之無機砷暴露致癌風險中位數值與未設管制標準情況下相比所降低的致癌風險中位數值(降低百分比)分別為0.0-5.58×10-5(0.0-7.4 %)、4.25×10-6-6.23×10-4(10.5-48.5 %)、8.30×10-6-8.72×10-4(25.5-62.2 %)、1.51×10-5-1.38×10-3(28.1-79.0 %)。同時在這四種不同食米無機砷濃度管制標準下,符合1×10-4可接受健康風險值的各國人口比例分別為0.0-92.1 %、0.0-93.3 %、0.0-96.3 %、0.0-99.9 %;但符合1×10-5和1×10-6可接受健康風險條件下的人口百分比則僅為0.0-44.0 %。 本研究結果顯示大部分國家攝食食米的健康風險值超出1×10-4可接受健康風險值,各國應重視攝食食米無機砷暴露的議題,並對超出可接受健康風險值的情況應採取相關應對改善措施。另從管制標準的角度來看,訂定食米砷濃度管制標準為0.200 µg/g和0.150 µg/g時,可改善降低攝食食米砷暴露致癌風險中位數值達10-20 %。對公共衛生來說,更嚴格地管制食米中砷濃度將可使更多人口免於因攝食食米導致無機砷暴露而造成額外的致癌風險。但推動更嚴格管制標準可能會受到技術、經濟、人力、時間和社會成本等限制,因此如何在管制標準可行性和公共衛生健康保障上取得平衡,還需視各國食米無機砷濃度、食米攝食量等參數差異情形再來審慎評估。 Rice is staple food for more than half of the world population. However, arsenic level in rice is about ten folds higher than that in other kinds of grain, and arsenic content in rice is mostly composed of inorganic arsenic, which is classified as human carcinogen by World Health Organization. It is an important issue to explore the potential health risk of rice arsenic intake. Therefore, the objective of this study was to assess the rice arsenic exposure and the potential health risk impact through rice comsumption for countries with rice as staple food. PubMed, Toxline and Web of Science were used as databases to collect information on rice arsenic level, rice intake rate and body weight for the study countries. With these information, lifetime average daily dose(LADD) for inorganic arsenic were calculated with Monte Carlo simulation, which was in turn used to characterize the potential cancer risk and Hazard Quotients with probalistic risk assessment. Results show that the median LADDs, the median cancer risk and the median Hazard Quotient ranged from 1.79×10-5 to 1.42×10-3 µg/g/day, from 2.68×10-5 to 2.13×10-3 and from 0.06 to 4.73, respectively, for the 12 Asian countries, while those for the 6 American and European coutries ranged from 1.91×10-5 to 1.15×10-4 µg/g/day, from 2.86×10-5 to 1.73×10-4 and from 0.06 to 0.38, respectively. Given the maximum limits for arsenic level in rice being set at 0.20, 0.15, 0.10 and 0.050 µg/g, the corresponding percentages of qualified rice were 90-100 %, 80-100 %, 0-60 % and 0-10 %, respectively, for most of the study countries. Meanwile, as compared to that without maximum limit being set, the median cancer risk could be reduced across the study countries by varying from 0.0 to 5.58×10-5( or from 0.0 % to 7.4 %), from 4.25×10-6 to 6.23×10-4 (or from 10.5 % to 48.5 %), from 8.30×10-6 to 8.72×10-4 (or from 25.5 % to 62.2 %), and from 1.51×10-5 to 1.38×10-3 (or from 28.1 % to 79.0 %), respectively, as the maximum limits for arsenic level in rice were set at the aforementioned four different values. In consequence, in the study countries the percentages of people with health risk less than 1×10-4 ranged from 0.0 % to 92.1 %, from 0.0 % to 93.3 %, from 0.0 % to 96.3 % and from 0.0 % to 99.9 %, respectively, as the maximum limits for arsenic level in rice were set at these four different levels. Meanwhile, the percentages of people with health risk less than 1×10-5 or 1×10-6 only varied from only 0.0 to 44.0 % for the study countries, no matter what level of maximum limit for arsenic level in rice is applied. Study results indicated that the health risk imposed by rice arsenic intake exceeded the 1×10-4 acceptable health risk for most of the study countries. The governments should pay attention to the issue of exposure to inorganic arsenic in rice, and take necessary measures to alleviate the situation for people at exposure level beyond the acceptable health risk. Median cancer risk is expected to be reduced by 10 to 20 % given the maximum limit for rice arsenic in level was set at 0.200 or 0.150 µg/g. For public health viewpoint, the more strickter regulatory limit on rice arsenic level, the more population is out of the cancer risk for rice arsenic intake. However, the regulatory limit might be comprised by technical, economic, and social costs. Balance between the regulatory limits and the public health concerns heavily depends on the inorganic arsenic level and the rice intake rate in each country. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/21968 |
DOI: | 10.6342/NTU201803588 |
全文授權: | 未授權 |
顯示於系所單位: | 職業醫學與工業衛生研究所 |
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