Lichens as biomonitors for the determination of polycyclic aromatic hydrocarbons (PAHs) in Caracas Valley, Venezuela

Abstract

Biomonitoring of PAH air pollution using lichens was carried out. Sixteen PAHs were studied in 11 locations along the valley of Caracas (Venezuela). The results of this work indicate that 14 of the 16 analysed PAHs were highly accumulated into the lichen thalli of Pyxine coralligera Malme. PAH levels in the samples revealed that the several volatile PAHs (naphthalene, acenaphtylene, acenaphtene, and fluoranthene) have the highest levels in the majority of the studied locations. The fluoranthene/pyrene and phenantrene/antracene ratios suggested that the major sources of PAHs are anthropogenic, mainly associated with gasoline and diesel combustion (pyrolytic) and unburnt oil derivates (petrogenic). The total PAH concentrations obtained in the present study were in the range of 0.24 to 9.08 µg/g, similar to those reported by other works in European and Asian cities.

Keywords:

• PAHs
• atmospheric pollution
• Pyxine coralligera Malme
• fossil fuels
• Caracas

Acknowlegements

This work was financially supported by CDCH-UCV (Project No. PG 03-00-6054-2005) and FONACIT (Project No. Lab-19998003690). The authors also thank Dr. Andrés Escalona, MSc. Janet Salas and Matilde Gómez for the HPLC analysis, as well as Professor Roschman Gonzales, Kizzy De Freitas and Jenny Bracho for technical assistance.