EnvironLab, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria.
Environ Monit Assess. 2023 Jan 14;195(2):299. doi: 10.1007/s10661-023-10922-6.
Use of medicinal herbs is now gaining popularity especially among the low-income people because it is cheap, readily available and its "seeming" lack of side effects. However, environmental pollution is a potential threat to its continued use. This study examines the effect of air pollution on the soil and consequently on the medicinal herbs grown on such soils. Soil and four medicinal herbs, Chromolaena odorata, Vernonia amygdalina, Carica papaya and Ocimum gratissimum, commonly used in the south western part of Nigeria either as purely medicinal herbs, soup vegetables or both were carefully harvested from Fasina, a polluted area, and Moro, a relatively unpolluted area, all in Ile-Ife, Nigeria. Samples were prepared following standard practice and analysed for nickel, chromium, cadmium and lead using atomic absorption spectroscopy (AAS). The results showed that elemental concentrations at the two locations were within the permissible limit for both soil and herbs, the statistical test also established no significant difference between the two locations. However, toxic metals concentrations (chromium, cadmium and lead) were found higher at the polluted site while that of the essential metal, nickel, was higher at the unpolluted site. Of the four metals, cadmium has the highest transfer ratio (0.39 and 0.34) while lead has the least (0.21 and 0.25) for Moro and Fasina sites respectively. Similarly, Chromolaena odorata has the highest transfer ratio (0.34) while Carica papaya has the least (0.28). In conclusion, gradual build-up of the toxic metals at the polluted site is evident and may eventually contaminate the herbs.
草药的使用现在越来越受欢迎，尤其是在低收入人群中，因为它价格便宜、易于获得，而且似乎没有副作用。然而，环境污染是对其持续使用的潜在威胁。本研究考察了空气污染对土壤的影响，以及由此对在这种土壤中生长的草药的影响。土壤和四种草药，即臭天竺葵、苦艾、木瓜和罗勒，在尼日利亚西南部地区通常被用作纯草药、汤菜或兼而有之，它们是从尼日利亚伊费的法西纳（一个污染地区）和莫罗（一个相对未受污染的地区）精心采集的。样品按照标准程序制备，并使用原子吸收光谱法（AAS）分析镍、铬、镉和铅的元素浓度。结果表明，两个地点的元素浓度均在土壤和草药的允许限值内，统计检验还确定两个地点之间没有显著差异。然而，在污染地点发现有毒金属（铬、镉和铅）浓度较高，而在未污染地点发现必需金属（镍）浓度较高。在这四种金属中，镉的转移率最高（分别为 0.39 和 0.34），而铅的转移率最低（分别为 0.21 和 0.25），分别用于莫罗和法西纳地点。同样，臭天竺葵的转移率最高（0.34），而木瓜的转移率最低（0.28）。总之，在污染地点，有毒金属逐渐积累的情况明显，最终可能会污染草药。
