Okwute Enyojo S, Mohammed Zakari, Arthur David E, Wayar Haruna B, Akan Joseph C
Department of Pure and Applied Chemistry, University of Maiduguri, Nigeria.
Toxicol Rep. 2025 Jan 13;14:101905. doi: 10.1016/j.toxrep.2025.101905. eCollection 2025 Jun.
This study evaluates the concentrations of seventeen polycyclic aromatic hydrocarbons (PAHs) in soil and selected vegetable samples (onions, tomatoes, hot peppers, sweet peppers, and garden eggs) from Tiga agricultural locations in Kano State, Nigeria. Soil samples were collected from ten plots (depth profiles of 0-10 cm, 10-20 cm, and 20-30 cm) and combined at each depth to create composite samples. Additionally, 20 g of each vegetable were collected and divided into fruit, stem, and root components. Standard procedures were used for the extraction and clean-up of PAHs from both soil and vegetable samples, and instrumental analysis was conducted using SHIMADZU GC-MS (GC-17A). PAH levels in soil ranged from 1.20E-02 mg/kg to 3.80E-02 mg/kg, while vegetables showed concentrations from 1.00E-03 mg/kg to 8.90E-02 mg/kg. The 0-10 cm soil samples displayed higher PAH concentrations among all the depths studied, while the vegetables with the highest PAH concentration followed the trend: Onions > Sweet Pepper > Tomatoes > Hot Pepper > Garden Egg. Overall, total PAH concentrations in vegetables exceeded those in soil. Estimated daily PAH doses were below the Tolerable Daily Dose Limit set by FAO, indicating low health risks. Incremental lifetime cancer risk values also fell below US EPA acceptable levels (10E-06), suggesting negligible cancer risk while the hazard index was less than 1, implying no appreciable non-cancer health risks. PAH pollution was attributed to both petrogenic and pyrogenic sources. The findings of this study indicate that under the assessed conditions, the five vegetables evaluated from Tiga pose no significant risk and are considered safe for consumption.
本研究评估了尼日利亚卡诺州蒂加农业区土壤以及选定蔬菜样本（洋葱、西红柿、辣椒、甜椒和茄子）中17种多环芳烃（PAHs）的浓度。从10个地块采集土壤样本（0 - 10厘米、10 - 20厘米和20 - 30厘米深度剖面），并在每个深度将样本合并以创建混合样本。此外，每种蔬菜采集20克，并分为果实、茎和根部分。采用标准程序从土壤和蔬菜样本中提取和净化多环芳烃，并使用岛津GC - MS（GC - 17A）进行仪器分析。土壤中多环芳烃水平在1.20E - 02毫克/千克至3.80E - 02毫克/千克之间，而蔬菜中的浓度为1.00E - 03毫克/千克至8.90E - 02毫克/千克。在所研究的所有深度中，0 - 10厘米土壤样本的多环芳烃浓度更高，而多环芳烃浓度最高的蔬菜遵循以下趋势：洋葱＞甜椒＞西红柿＞辣椒＞茄子。总体而言，蔬菜中的总多环芳烃浓度超过了土壤中的浓度。估计的每日多环芳烃摄入量低于粮农组织设定的每日可耐受剂量限值，表明健康风险较低。终生癌症风险增量值也低于美国环保署的可接受水平（10E - 06），表明癌症风险可忽略不计，而危害指数小于1，意味着不存在明显的非癌症健康风险。多环芳烃污染归因于成岩源和热解源。本研究结果表明，在所评估的条件下，从蒂加评估的这五种蔬菜不存在重大风险，被认为食用安全。
