Using a bioindicator plant, Eleagnus ebbingei, to predict the concentrations of polycyclic Aromatic Hydrocarbons in the atmosphere of temperate areas in Europe
(1) Institut de Chimie de Nice, UMR 7272, Université Nice Côte d’Azur, France (2) ABTE (Aliments Bioprocédés Toxicologie Environnements), UR 4651 , Université Caen Normandie, France
Many studies use evergreen trees for Polycyclic Aromatic Hydrocarbons (PAHs) biomonitoring. The most studied trees belong to the genus Quercus and Pinus. However, these corresponding specimens are not implanted in all European temperate areas, limiting the comparison between regions. The aim of this study is to investigate the potential of the hedge plant Elaeagnus Ebbingei as a bioindicator. This plant is very common in Europe, regardless of the geographical area. A one-year field campaign targets two French cities with different climates: Caen (oceanic climate) and Nice (Mediterranean climate). In each city, concentrations in plants are determined and compared to atmospheric concentrations for 4 sites. Results highlight correlations between the atmospheric concentrations and concentrations found in leaves with significative Pearson correlation coefficients for acenaphthene, phenanthrene, anthracene, fluoranthene and pyrene. In addition, the strong negative correlation with temperature and relative humidity highlights the seasonality of PAHs, whether in the atmosphere or in the leaves. These strong correlations allow to set up two models to estimate atmospheric concentrations from the concentrations found in plants. A first model using the plant-air phenanthrene concentration distribution constant and temperature (KPA-PHE) was developed. It estimates atmospheric concentrations of fluorene and phenanthrene from concentrations in plants. In view of the strong correlations between PAHs in plants, a second model using the Partial least squares regression has been implemented. Model validation was performed by studying relative biases as well as Nash Sutcliffe criteria. Field trials using the two models developed seem to give an advantage to the KPA-PHE model, where the estimated concentrations of fluorene and phenanthrene in air are very close to the actual concentrations. Elaeagnus Ebbingei seems to be a good bioindicator for predicting PAHs atmospheric concentrations.
Keywords: PAHs, atmospheric concentrations, bioindicator, evergreen hedge plant, Elaeagnus Ebbingei, Plant-air partitioning constant, model prediction
