Lichens as bioindicators of atmospheric heavy metal deposition in Valencia, Spain

The lichens due to their symbiotic nature have unique characteristics that confer thema key role as bioindicators of the environmental contamination. Many investigationshave been done using epiphytic lichens as bioindicators, but only a few of thesestudies have used epilithic-crustose lichens. Three different epilithic-crustose lichensspecies: Candelariella sp., Lecanora sp. and Caloplaca sp. were studied asbioindicators of V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, Cd, Sb, Ba, Pb, Bi and Utrace elements. Inductively Coupled Plasma Mass Spectrometry routine procedure isused to determining these element concentrations. Two sites were selected for lichenssampling according to environmental contamination. The lichens were collected on thefacade of the Santos Juanes church in an urban area of Valencia; and on the ruralarea of Albarracin. The main aim of this work is showing the efficacy of the epilithiccrustoselichens as bioindicators of the air pollution. This study shows that the city ofValencia, compared with the rural area has high levels of Cu and Pb as detected usinglichens as bioindicators. Therefore on the basis of these results, it can be hypothesizedthat Candelariella sp.Lecanora sp. and Caloplaca sp. are good accumulators of airborne heavy metals.