| 摘要: | 人體攝取硝酸鹽主要途徑為水及蔬菜，而藉由食用蔬菜攝入硝酸鹽，一般被認為是最主要的暴露途徑。在攝入硝酸鹽之前或之後，硝酸鹽可能轉化為具高鐵血紅蛋白亞硝酸鹽，並產生潛在的風險，進而對人類健康產生不利的影響。本研究探討於夏季及冬季收穫蔬菜，對總硝酸鹽濃度之影響，並進行因食用蔬菜而暴露於硝酸鹽的成年男性和女性之人體健康風險評估。研究對象鎖定在臺灣的成年(19-44歲)男性與女性，計算其對因蔬菜攝食對硝酸鹽的每日攝入量 (DI) 。考量因子包括蔬菜中硝酸鹽濃度(Cveg)、成年男性和女性的蔬菜攝食率 (IR) 和平均體重 (BW)。透過計算危害商數 (HQ)及標的終生風險(TR)值，以評估因攝食蔬菜攝入硝酸鹽所造成的致癌性和非致癌性潛在風險。 本研究中，夏季和冬季的Cveg平均值分別為 1,908.84 和 1, 490.24 mg/(kg*day)。夏季蔬菜部分，男性和女性DI 值之 95% 信賴區間上限分別為 1.37 和 1.73 mg/(kg*day)；冬季蔬菜部分，男性和女性DI 值之 95% 信賴區間上限則分別為 1.08和1.45 mg/(kg*day)。危害商數HQ部分，男性和女性攝食夏季蔬菜之模擬結果分別為 0.82 和 1.08；若考量攝食冬季生產之蔬菜，男性和女性之HQ 值則分別為 0.67 和 0.91。研究結果顯示，除針對女性攝取夏季生產之蔬菜外，其餘所有HQ值之95%信賴區間上限都低於1，代表臺灣居民因攝食蔬菜而暴露於硝酸鹽之潛在非癌症風險落於可接受之範圍。另一方面，男性和女性之癌症風險值TR的 95%信賴區間上限值，於攝食夏季產蔬菜分別為1.33 x10-5 和1.73 x10-5，於攝食冬季產蔬菜則為 1.09 x10-5和 1.45 x10-5。研究結果顯示，所有癌症風險 (TR) 值介於可忽略及可接受之間，而攝食夏季產之蔬菜風險高於攝食冬季生產之蔬菜。另，本研究中不論考量攝食夏季或冬季生產之蔬菜，成年女性之 DI、HQ 和 TR 值皆高於男性。 由於蔬菜攝食為硝酸鹽攝取之主要來源，且其對人體健康危害有影響，因此該議題普遍受到公共衛生及政府相關管理機構之重視，此亦為進行本研究之主要原因及動機。
Majority of nitrates are consumed through water and vegetables. In addition, the intake of nitrate through vegetable consumption is regarded as an extensive exposure route in humans. Before and/or after ingestion, the conversion of methaemoglobin-producing nitrite from nitrate develops a potential risk and is frequently associated with adverse effects on human health. An investigation was conducted to study the total nitrate concentration under the influence of harvesting time during summer and winter. The subsequent human health risk of nitrate exposure was then assessed for both adult male and female exposed to nitrate through vegetable consumption. Total exposure of nitrate from vegetable consumption was assessed using the data gathered from adult (19-44) male and female Taiwanese residents. The total daily intake (DI) values were determined by using the data of vegetable nitrate concentration (Cveg), ingestion rate of vegetable (IR), and the body weight (BW) of both adult male and female residents. The potential non-carcinogenic and carcinogenic risks of nitrate exposure from vegetables consumption were evaluated by the characterization of hazard quotient (HQ) values and the target lifetime risk (TR) values. In the present result, mean values of Cveg for both summer and winter are 1,908.84 and 1,490.24 mg/(kg*day), respectively. The upper 95% confidence limit of DI values during summer time for male and female were 1.37 and 1.73 mg/(kg*day), respectively. On the other hand, DI values during winter time for male and female were respectively 1.08 and 1.45 mg/(kg*day). Simulation results showed that for the upper 95% confidence limit of HQ values during summer time for male and female were 0.82 and 1.08, respectively. In addition, HQ values for winter time for male and female residents were 0.67 and 0.91. In the present result, all predicted upper 95% confidence limit of HQs were lower than 1, indicating the potential non-cancer risk of nitrate associated with vegetable consumption for Taiwan residents was acceptable except for female during summer time. For cancer risk, result demonstrate that the upper 95% confidence limit of TR for male and female was respectively 1.33 x10-5 and 1.73 x10-5 during summer, and was 1.09 x10-5 and 1.45 x10-5 for winter time, respectively. This results showed that all cancer risk (TR) value ranged between the negligible level (10-6) and acceptable level (10-4). Therefore, the cancer risk of nitrate associated with vegetables consumption should be noticed. The cancer risk for vegetables in summer season was higher than that in winter season. In addition, the DI, HQ, and TR values for adult female were higher than those for male, both for summer and winter season vegetable consumption. Since that vegetable consumption became a major source for dietary nitrate intake and often associated with harmful effects on human health, long-term adverse health effects gathered interest to public health providers and even government regulators, hence, this study was conducted. |
