Air pollution biomonitoring in Argentina, application of neutron activation analysis to the study of biomonitors

Due to low population density, total air pollutant emissions in Argentina are still low if compared with highly industrialised countries. Although a significant deterioration of air quality has been observed for a long time, air monitoring did not begin until the 90's and only in a few cities. The use of air pollution biomonitors represents an important contribution to Argentina, as measurements of air pollutants in large areas would require especial technical equipment not easily available and operated. In this project, two lichen species (Ramalina ecklonii (Spreng) Mey and Flot and Usnea amblyoclada (Muell. Rg.) Zahlbr.) and a Bromeliaceae (Tillandsia capillaris) are used as biomonitors of air pollution at a 50, 000 km2 area in Cordoba province (central Argentina). AAS and INAA have been applied for the analysis of samples, determining As, Ba, Br, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hf, Gd, K, La, Lu, Mn, Na, Ni, Pb, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn. The following physiological parameters were also determined: chlorophyll a, chloropyll b, phaeophytin a, phaeophytin b, hydroperoxy conjugated dienes, malonaldehide and sulphur. Some of these parameters were used for calculating a pollution index. These determinations were carried out on pools collected at the sampling sites. AAS and physiological parameters were also applied to the analysis of five-replicate samples in order to study variability sources. For data evaluation, different statistical and other evaluating tools were used: descriptive statistics and Spearman's correlation analysis were used on data from the three biomonitor species while factor analysis and mapping, only for R. ecklonii results. (author)