Hebe A. Carreras

Biomonitoring of heavy metals and air quality in Cordoba City, Argentina, using transplanted lichens

The objective of the present study was to test the concentrations of some elements in the transplanted lichen Usnea amblyoclada transplanted in Córdoba, Argentina, and to investigate the relative air quality of the area as indicated by a Pollution Index. Analyses of Cu, Co. Pb, Fe, Ni, Mn, S and Zn in addition to analyses of physiological parameters were performed after the transplantation period. No significant differences were observed among the sampling stations for the physiological parameters, except the dry weight/fresh weight ratio. The concentration of most elements was similar to or lower than those found in non-polluted and even polluted areas. The significant correlation found between Cu, Pb and Zn with the content of hydroperoxy conjugated dienes suggests an important oxidative effect probably caused by these ions. The distribution patterns of the elements were quite similar, with maximum values around a cement plant and the metallurgical industries. The Pollution Index distribution pattern does not coincide with the elements distribution, due to the fact that the index values probably reflected the emissions of gaseous phytotoxic pollutants.

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.

Comparative biomonitoring of atmospheric quality in five zones of Córdoba city (Argentina) employing the transplanted lichen Usnea sp.

Abstract The lichen Usnea sp. was transplanted to five zones plus a control one in the city of Cordoba, with different levels of industrial and traffic pollution. The chlorophyll a+b, hydroperoxy conjugated dienes, malondialdehyde concentration, chlorophyll b/chlorophyll a, phaeophytin a/chlorophyll a, DW/FW ratio and sulfur accumulation were determined. A pollution index (PI) was calculated to compare the air quality of the zones biomonitored. It was observed that the content of chlorophylls a+b increased parallel to the level of pollutants emitted by traffic, but at the same time, there was an increase in the degradation of chlorophyll a. These results indicate that chlorophylls would be affected by air pollutants emitted by traffic and as a compensatory mechanism the lichen would increase their synthesis. Significant differences were observed in hydroperoxy conjugated dienes concentration and sulfur content in samples transplanted to high traffic level sampling points. At the same time, a higher sulfur content was observed in lichens transplanted to sampling points located in downtown, in neighboring areas or with high industrial level, suggesting an additive effect of industrial with traffic pollutants. PI results allow us to differentiate areas with different air quality in the city, the highest pollution levels being observed in the downtown area with high traffic. Two other areas near downtown with high traffic are also in this category. Except for downtown and a far away zone with high industrial density, the other areas showed higher PIs at high traffic sites. The lowest PIs were observed in the control zone and at the low traffic sampling points.

Comparison among air pollutants, meteorological conditions and some chemical parameters in the transplanted lichen Usnea amblyoclada

The response of Usnea amblyoclada (Müll. Arg.) Zahlbr. to real concentrations of atmospheric pollutants measured by two automatic monitoring stations, was studied in Córdoba City, Argentina. The influence of different weather conditions on the biomonitors response was also assessed. The concentration of chlorophyll a, chlorophyll b, hydroperoxy-conjugated dienes, and malondialdehyde were quantified in lichen thalli collected from a clean area and in transplanted thalli after 1 month of exposure in an urban area, from April to October, 1996. The dry weight/fresh weight, chlorophyll b/chlorophyll a and phaeophytin a/chlorophyll a ratios were also calculated. Data sets were evaluated by two-way analysis of variance and correlation analysis. It was observed that hydroperoxy-conjugated dienes, malondialdehyde, chlorophylls, and pigment degradation increase during winter-time, when higher levels of suspended particles, non-methane hydrocarbons, hydrogen sulfide and ozone were also measured. These findings would be connected mainly with meteorological conditions, as most pollutants did not exceed prescribed threshold levels.

Differences in responses to urban air pollutants by Ligustrum lucidum Ait. and Ligustrum lucidum Ait. f. tricolor (Rehd.) Rehd.

This study examined the chemical response of Ligustrum lucidum Ait. and Ligustrum lucidum Ait. f. tricolor (Rehd.) Rehd. when exposed to different sources of atmospheric pollutants. Dry weight/fresh weight ratio, specific leaf area (SLA), sulfur content, chlorophyll concentration, carotenoids, soluble proteins, malondialdehyde (MDA) and hydroperoxy conjugated dienes (HPCD) were determined for leaf samples taken from different sites in the city of Córdoba, Argentina. These sites were categorized in terms of their traffic levels and industrial levels. Both L. lucidum as well as L. lucidum f. tricolor accumulated sulfur in their leaves in sites with high traffic levels, the former being the most sensitive to this type of pollution. Ligustrum lucidum exhibited significantly low concentrations of soluble proteins, in sites with high industrial pollution levels. Ligustrum lucidum f. tricolor did not exhibit a significant response to industrial pollution.

Assessment of human health risk related to metals by the use of biomonitors in the province of Córdoba, Argentina.

The evaluation of metal contents in the environment is of vital importance for the assessment of human exposure. Thus the species Usnea amblyoclada, Ramalina celastri and Tillandsia capillaris were tested as bioaccumulators of transition metals in the urban area of Córdoba city, Argentina. The level of metals on biomonitors was compared to that of total deposition samples. All three species discriminated zones within the urban area of Córdoba city with different pollution levels; they revealed high levels of Zn in the downtown area and confirmed high levels of some transition metals in an industrial area. The correlation analysis revealed that the lichen R. celastri had the highest correlation rates with total deposition samples, suggesting it is a valuable biomonitor of atmospheric pollution. A significant relationship was also observed between respiratory diseases in children and the contents of metal accumulated in R. celastri and T. capillaris, indicating their usefulness when assessing human exposure to metals.

Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina

The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency.

Distribution of atmospheric trace elements and assesment of air quality in Argentina employing the lichen, Ramalina celastri, as a passive biomonitor: detection of air pollution emission sources

Ramalina celastri was used as a passive biomonitor to study the relationship between elemental accumulation, emission sources and physiochemical parameters used as air pollution biomarkers in Argentina. The concentration of 27 elements was determined in the thalli by Neutron Activation Analysis (NAA). The content of photosynthetic pigments, peroxidation products, water and sulphur was determined and a Pollution Index (PI) was calculated. Factor analysis was used to locate the possible emission sources of elements. Overall, the elemental concentrations were similar to other biomonitoring studies. The higher levels of arsenic were related to the soil particulate matter, which is characteristically rich in this element. High uranium concentrations were found near a uranium mine and levated levels of zinc were found in areas congested with heavy traffic. Although there is no direct relationship found between the physiological parameters and the elemental concentrations, the geographical distribution of the PI allowed to detect areas with increased lichen damage.

Integral assessment of pollution in the Suquía River (Córdoba, Argentina) as a contribution to lotic ecosystem restoration programs.

The Suquía River lower-middle basin (Córdoba, Argentina) is subject to a strong anthropic impact because it receives pollutants from different sources (industries, wastewaters, heavy traffic, agricultural land use, etc.) We have assessed the degree of watershed degradation of Suquía River lower-middle sections through the analysis of different ecosystem compartments (air, water, riparian soil, sediments and biota), in order to provide useful data to be considered in future river restoration programs. Four study sites were selected along the river (La Calera city, Córdoba city, Corazón de María village and Río Primero city) which were sampled during the low- and high-water flow periods. We analyzed: a) chemical and physical characteristics of water, sediments, and riparian soil; b) heavy metal content of water and sediments, and c) semi-volatile organic compounds in air. Besides, pollutant bioindicators such as fish assemblages, lichens (Usnea amblyoclada), vascular plants (Tradescantia pallida), and microorganisms (fecal coliform and Escherichia coli) were used to further assess the status of the river. All analyzed ecological compartments were affected by water pollution, particularly, fish assemblages, sediments and riparian soils by heavy metal and coliform bacteria. Moreover, we detected a possible contribution of sulfur and a high pollutant content in air that merit further research about other air-water exchanges. Accordingly, we strongly suggest that an action to restore or remediate the anthropic effect on the Suquía River be extended to all possible compartments along the river.

Exposure to polycyclic aromatic hydrocarbons in urban environments: health risk assessment by age groups.

A detailed investigation was conducted into the concentration of polycyclic aromatic hydrocarbons (PAHs) associated with PM10 particles collected during 2012 in an urban area in Cordoba, Argentina. Their composition was studied and the lifetime lung cancer risk resulting from exposure to total and individual PAHs was estimated. Samples of PM10 were collected daily on fiber glass filters with PAHs being extracted with methylene chloride and analyzed by HPLC. Mean PAH concentrations were higher during autumn and winter. In contrast, during warm months, high ambient temperature and wind speed contributed to a decrease in the PAH ambient concentrations. The PAH levels found in the present study were within the range of those reported in other polluted urban areas. However risk factors calculated for exposure to individual and cumulative PAHs exceeded the carcinogenic benchmark level of 1×10(-6) early in childhood, implying that these PAH concentrations represent a serious risk to public health.