以固相微萃取偵測台灣兒童尿液中農藥殘留

Abstract

近年來由於層出不窮的食品安全事件，使得國人對於食品安全議題愈發重視。其中，因農藥被大量應用於農產品、家庭、娛樂場所中，農藥殘留一直是台灣一個相當重要的食品安全議題。農藥不但遍及於生活中，研究報告也指出台灣的農藥使用量高於美國、日本；且農藥也有潛藏的健康危害，故如何針對易感族群如兒童進行暴露、風險評估，以維護國人健康是一項重要的議題。先前在台灣已有許多這方面的研究，然而這些研究大多著重於農藥代謝物的偵測。由於許多不同種類的農藥可能會產生同樣的代謝產物，可能會導致農藥暴露量與農藥暴露種類估計上的困難；故本研究使用固相微萃取技術，搭配氣相層析質譜儀，針對兒童尿液中的農藥原型物進行偵測。本研究成功建立了一套同時測量34種農藥原型物的方法，並於180個兒童晨尿樣本中測得了4-Chloroaniline、Pentachlorobenzene、1-Naphthylamine、2-Naphthylamine、Thionazin和Chlorpyrifos等六種農藥殘留。殘留濃度在個體間差異甚大，濃度範圍從2.90 ng/mL到56.94 ng/mL之間。平均濃度最高之農藥為Thionazin（5.49 ng/mL），1-Naphthylamine次之（3.81 ng/mL）。Thionazin也是最常被偵測到的農藥，與2-Naphthylamine皆有20%左右的樣本中含有此兩種農藥。在與問卷調查結果比對後，發現農藥殘留量和飲食攝取量及環境息息相關。例如尿液中1-Naphthylamine的含量與蔬菜的食用量為正相關，且達統計上的顯著（P-value為0.04）。本研究也發現兒童尿液中的農藥平均濃度高於別國，例如墨西哥農民尿液中Thionazin濃度0.33 ng/mL，檢出率18%；但本研究發現兒童尿液中Thionazin濃度是5.49 ng/mL，檢出率則為22%。這顯示了農藥殘留管理在台灣仍是一個重要議題。

Pesticide residues in foods have become a food safety issue in Taiwan due to the extensive use in agriculture and household have raised health concerns. For example, the noncompliance rate for certain kinds of vegetables and fruits was above 30 percent. Besides, most commonly used pesticides, such as organophosphates and pyrethroids, are neurotoxic. The associated exposures might affect children’s neurodevelopment. In order to prevent the unwanted consequences, it is critical to characterize the amount of exposure and the type of pesticides. In Taiwan, many studies focused on measuring the urinary metabolites of pesticide instead of parental compounds. However, organophosphate pesticides generate the same metabolites such as dialkylphosphate (DAP), which can lead to underestimate of the total amount of pesticides and makes it more difficult to execute an exposure assessment. Hence, this study developed an approach by using direct immersion solid­phase microextraction (DI-SPME) coupled with gas chromatography-tandem mass spectrometers (GC-MS/MS) to measure 34 parent compounds at the same time to solve the problem. An ideal parameter were established for detecting pesticide parent compounds in urine and the detection limit was 0.5 ng/mL. Six pesticide residues were found in 180 first-morning-void urine samples, including 4-Chloroaniline, Pentachlorobenzene, 1-Naphthylamine, 2-Naphthylamine, Thionazin, and Chlorpyrifos. The concentration varied from 2.90 ng/mL to 56.94 ng/mL among different samples. Thionazin and 1-Naphthylamine had higher detection rate and mean concentration. Based on the analysis of questionnaire, we discovered that urinary concentration of 1-Naphthylamine was associated with vegetables consumption (P-value = 0.04); 4-Chloroaniline was associated with open burning waste (P-value = 4.9×10-11) and steel mill (P-value = 0.0003); Chlorpyrifos was associated with odor around the house (P-value = 0.001). This study also discovered that the amount of exposure of children in Taiwan was higher than the amount of adults in France and Mexico. This result demonstrates the fact that pesticide residues are still an issue in Taiwan.