Polycyclic aromatic hydrocarbons in traditionally used medicinal plants from Varna region, Bulgaria

The content of polycyclic aromatic hydrocarbons (PAHs) was determined in Matricaria chamomilla L., Thymus serpyllum L., Tilia L., Sambucus nigra L. and Achillea millefolium L., collected from urban and rural region near Varna, Bulgaria. The aim of this study was to compare the levels of PAHs in traditionally used medicinal plants from different regions to assess environmental pollution. Benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene are among the 16 priority pollutants pointed out by US EPA. The EU legislation has set a limit of 50 µg/kg dry weight (dw) for the sum of the 4 PAHs. The PAH levels were determined in extracts of medicinal plants by GC-MS after purification. Chrysene was registered as most abundant compound in all plant species investigated. Benzo[a]pyrene, identified by the International agency for research on cancer as carcinogenic to humans, was not detected in the samples analyzed. The levels of investigated PAHs were significantly higher in samples from areas with intensive traffic compared to samples from suburban areas. The sum of 4 PAHs in all plant species were found in the range from 0.68 (Sambucus nigra L.) to 6.82 µg/kg dw (Tilia L.) and was below the permissible limit of the European commission.