Metrological stations in the study area.

Sesame (Sesamum indicum L.) is a major oilseed crop globally, and white sesame is a key contributor to the foreign exchange earnings of Ethiopia. The main production districts of white sesame in Ethiopia are Humera, Metema, Tegedie, Mirab-Armachiho and Tachi-Armaciho. This study assessed the levels of trace metals (Fe, Cu, Zn, Mn and Ni) in white sesame seeds from these regions and evaluated the associated health risks to consumers. A total of 53 samples were collected from 19 farmer villages across the five districts. Homogenized samples from each village were analyzed using the acid digestion method followed by flame atomic absorption spectroscopy (FAAS). The limit of detection of the method ranged from 0.75 to 865 mg/kg, and the limit of quantitation ranged from 2.55 to 28.8 mg/kg for the different elements analyzed. The recovery of the method was in the range of 90.9‒99.6%. The results showed trace metal levels ranging from 164 ± 6 to 381 ± 4 mg/kg for Fe, 94.0 ± 1.9 to 126 ± 0.8 mg/kg for Zn, 11.8 ± 0.4 to 14.2 ± 0.4 mg/kg for Cu, 11.9 ± 0.9 to 15.0 ± 0.7 mg/kg for Mn and 16.2 ± 1.1 to 21.0 ± 1.2 mg/kg for Ni across the production districts. One-way ANOVA revealed significant differences (p <  0.05) in trace metal concentrations among the districts, indicating a geographical effect on the trace metal content of sesame. Importantly, the study found no non-carcinogenic health risks from the analyzed metals for either adult or child consumers. These findings suggest that the trace metal levels in the sesame seeds are within safe limits for human consumption.

芝麻（Sesamum indicum L.）是全球重要的油料作物，白芝麻亦是埃塞俄比亚外汇创收的关键品类。埃塞俄比亚白芝麻主产区涵盖胡梅拉（Humera）、梅特马（Metema）、特格迪耶（Tegedie）、米拉布-阿玛奇霍（Mirab-Armachiho）与塔奇-阿玛奇霍（Tachi-Armaciho）。本研究针对上述五大产区白芝麻种子中的痕量金属（trace metals）水平展开测定，并评估了其对消费者的相关健康风险。研究团队从这五个产区的19个农户村落中共采集53份样本，将各村落的样本混匀后，采用酸消解方法结合火焰原子吸收光谱法（flame atomic absorption spectroscopy, FAAS）开展分析。该方法对各待测元素的检出限范围为0.75~865 mg/kg，定量限范围为2.55~28.8 mg/kg，方法回收率介于90.9%~99.6%之间。检测结果显示，各产区白芝麻种子的痕量金属含量分别为：铁（Fe）164±6 至 381±4 mg/kg、锌（Zn）94.0±1.9 至 126±0.8 mg/kg、铜（Cu）11.8±0.4 至14.2±0.4 mg/kg、锰（Mn）11.9±0.9至15.0±0.7 mg/kg以及镍（Ni）16.2±1.1至21.0±1.2 mg/kg。单因素方差分析（one-way ANOVA）结果表明，各产区间的痕量金属浓度存在显著差异（p<0.05），证实地理因素对芝麻的痕量金属含量存在影响。尤为关键的是，本研究未发现上述待测金属会对成人或儿童消费者带来非致癌健康风险。上述研究结果表明，供试白芝麻种子中的痕量金属含量处于人类食用的安全限值范围内。