LOW-MOLECULAR-MASS PHENOLICS IN FOLIAGE OF BETULA-PUBESCENS EHRH IN RELATION TO AERIAL POLLUTION

Correlation between air pollution and concentrations of low molecular mass phenolics (LMMP) was studied in young and mature birch leaves (Be tula pubescens Ehrh.) in trees growing at different distances from Har javalta copper-nickel smelter, SW Finland. Concentrations of low molec ular mass phenolics were determined by analytical HPLC. Contents of in dividual phenolics correlated negatively with the distance from the sm elter: for the young leaves, Pearson correlation coefficients ranged f rom -0.04 to -0.96. However, these coefficients and differences in con centrations of individual compounds in young leaves between the most p olluted (0 km from the factory) site and the control(10 km from the fa ctory) site were significant only for l-O-galloyl-beta-D-(2-O-acetyl)- grucopyrano, neochlorogenic acid (trans-5-caffeoylquinic acid), trans- 5-p-coumaroylquinie acid and quercetin-3-O-beta-D-galactopyranoside. I n mature leaves, differences between the control and most polluted are a were significant only for two compounds: -O-acetyl)-glucopyranose(2- O-acetyl)-glucopyranose and neochlorogenic acid. Accordingly, the air pollution of Harjavalta smelter is a stress factor for birch trees ass ociated with accumulation of low molecular mass phenolics in leaves. W e discuss use of phenolics as stress and pollution indicators. (C) 199 7 Elsevier Science Ltd.