Determination of Potentially Toxic Heavy Metals (Pb, Hg, Cd) in Popular Medicinal Herbs in the Coal Power Plant Area

摘要

Medicinal and aromatic plants are of particular interest for human health. The purpose of this research is to determine the concentration and dispersion of heavy metals Pb, Cd, Hg, in medicinal herbs Chelidonium majus L, Crataegus monogyna, Artemisia absinthium L, Hypericum perforatum, from spontaneous flora bordering coal power plants. The method used (AAS) is recommended by high performance parameters in the determination of trace metals in plant samples. Detection Limit (mg.L-1): Pb (0.10), Hg (0.0002), Cd (0.005); sensitivity (mg.L-1): Pb (0.5), Cd (0.025). The metals detected in the coal used as fuel are found in all samples analyzed: ash, slag, soil, vegetation, medicinal plants of spontaneous flora. The concentration in the soil exceeds national normal value for Pb: 55.10 mg.Kg(-1). The metal bioaccumulation in medicinal plants is reflected in the values of transfer coefficient (TF): Cd (0.47) > Hg (0.15) > Pb (0.13). The concentration level related to the maximum extent permitted under the force rules for herbs: FAO / WHO (2011), Ph Eur (2008), RC / EC (2006) have been exceeded for lead in Hypericum perforatum (7.21 mg.Kg-1), Artemisia absinthium (5.37 mg.Kg-1). The trophic transfer of toxic heavy metals in plants used as medicines may represent a potential health hazard to consumers, fact which imposes the need for a systematic control.