Atmospheric quality and distribution of heavy metals in Argentina employing Tillandsia capillaris as a biomonitor.

The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.

Relationship between foliar chemical parameters measured in Melia azedarach L. and environmental conditions in urban areas.

A diagnostic study was done on Melia azedarach L. in relation to atmospheric pollutants in Córdoba city, Argentina. The study area receives regional pollutants, and it was categorized taking into account traffic level, industrial level, location of the sample point in relation to the corner, treeless condition, building type, topographic level and distance to the river. Water content and Specific Leaf Area (SLA) were calculated; and concentrations of soluble proteins, sulphur, hydroperoxy conjugated dienes (HPCD), chlorophylls (Total Chl) and pheophytins (Total Paeoph) were determined in leaf samples. HPCD correlated positively with industry, topographic level and distance to the river, and with a combination of the environmental variables (ECI); pigments correlated negatively with traffic level and with ECI; Total Phaeoph/Total Chl ratio correlated positively with traffic, building and ECI. On the basis of our results, traffic level, industrial level, building type, topographic level and distance to the river are the environmental variables to bear in mind when selecting analogous sampling points in a passive monitoring program. An approximation to predict tree injury may be obtained by measuring water content, soluble proteins, sulphur, HPCD and pigments as they are responsible for the major variability of data. This study revealed that M. azedarach was sensitive to air pollutants from traffic and industry. Thus, in those sampling sites with the maximum score for traffic level, industrial level and ECI, the highest values of the parameters that indicate foliar damage together with the least pigment concentration were observed.