Element concentrations in the lichen Pseudevernia furfuracea (L.) Zopf transplanted around a cement factory (S Italy)

Samples of the lichen Pseudevernia furfuracea (L.) Zopf collected from an unpolluted area were transplanted for 3 months at 60 sites around a cement factory in S Italy and then analysed by ICP-MS for their Al, Ca, Fe, K, Mg, Mn, Na and V contents. These elements have the highest emission factors during cement production. Data were processed using both univariate and multivariate statistics, i.e. ANOVA, Bray-Curtis analysis and multi-response permutation procedure (MRPP). All these elements accumulated in the transplanted lichens, with Ca being the most abundant element. The Bray-Curtis analysis identified 10 groups of sites along axis 1, which accounted for 88.5% of the total variance. The MRPP results supported the results of the Bray-Curtis analysis. The groups at the two ends of axis 1 were those least affected (group 10) and most affected (group 1) by air pollutants from the cement factory. In view of the element concentrations measured in group 10, it was considered an “internal control” and then compared to the other groups to detect statistically significant differences (ANOVA). This data analysis revealed spatial trends suggesting that the cement factory contributed to the Fe, Al and V enrichment in the exposed lichens. Moreover, the sites in group 10 showed values comparable to or even lower than those of unexposed samples for all elements except vanadium, further supporting this element's role in air pollution monitoring.