攝食米食之砷、鎘、鉛、銅暴露健康風險評估──以桃園、彰化、台中稻米樣本為例

Assessment of the health risks of arsenic, cadmium, lead, and copper exposure through rice consumption: using rice samples from Taoyuan, Changhua, and Taichung as examples

本研究利用國內桃園、彰化、台中等地稻米樣本實地資料為例進行健康風險評估，以瞭解攝取米食的潛在重金屬暴露風險等級。方法：本研究在桃園與彰化/台中兩地區分別採集167筆與200筆稻米樣本，以感應耦合電漿質譜儀測定銅、砷、鎘及鉛等金屬含量。再結合蒙地卡羅模擬分析法評估健康風險。結果：研究結果顯示，國人經米食攝取金屬之非致癌風險值最高為砷暴露，0.518（5％, 95％百分位：0.166, 1.663）。另外，攝取米食之砷暴露致癌風險值中位數為2.33×10-4（7.48×10-5, 7.48×10-4）。再以無機砷為例，若米食中濃度管制標準分別設在0.20、0.15、0.10 µg/g，國人經米食攝取之砷暴露致癌風險值中位數降低幅度分別為4.3％、13.3％與31.8％，健康風險值小於1×10-4的人口比例則分別為12.1％、14.3％、22.7％。結論：利用健康風險評估過程可檢視國人體重、米食攝食量、金屬種類與濃度、致癌或非致癌性風險參考係數等因素對健康風險值的影響程度，推估不同管制標準對改善健康風險的幅度，做為米食安全政策評估的重要參考依據。

This study investigated data of rice samples from Taoyuan, Changhua, and Taichung to rank the potential health risks of heavy metal exposure through rice consumption. Methods: In this study, 167 rice samples were collected from the Taoyuan area, and another 200 rice samples were collected from the Taichung and Changhua areas. The copper, arsenic, cadmium, and lead levels were assessed in the rice samples and used for health risk assessment through Monte Carlo simulation. Results: The results indicated that arsenic exposure resulted in the highest non-carcinogenic risk of 0.518 (5th percentile to 95th percentile: 0.166-1.663). The median carcinogenic risks were 2.33 × 10-4 (7.48 × 10-5, 7.48 × 10-4) for arsenic exposure. If the standards for arsenic content in rice are set at 0.20, 0.15, or 0.10 µg/g, the corresponding median carcinogenic risks for arsenic exposure through rice consumption in Taiwan were reduced by 4.3%, 13.3%, and 31.8%, respectively, and the proportions of the population with a health risk less than 1 × 10-4 were 12.1%, 14.3%, and 22.7%, respectively. Conclusions: The extent of the effects of body weight, rice intake, metal type, metal concentration, cancer slope factor, and non-cancer reference dose on the health risk assessment could scrutinized through the health risk assessment processes. The reduction of health risk through the implementation of various rice arsenic standards could also be evaluated and used accordingly as reliable reference for making policy decisions pertaining to rice food safety.