Atmospheric pollutants monitoring by analysis of epiphytic lichens

Air Quality Assessment by the Determination of Trace Elements in Lichens (Xanthoria calcicola) in an Industrial Area (Sicily, Italy)

This study provides data on variation in the content of metals and metalloids measured in the lichens (Xanthoria calcicola Oxner) collected in the Syracusan petrochemical complex (Sicily, Italy) which is considered one of the largest in Europe. Concentrations of eighteen trace elements measured in the lichens that were collected from 49 different points were analyzed using an inductively coupled plasma (ICP-MS) device. The concentrations of the typical elements of industrial emissions (As, Cr, Ni, and V) highlight the environmental criticality that exists in the study area. The interpretation of the data in terms of multi-element statistical analysis (FA) and enrichment factor (EFs) proved to be particularly useful in identifying several sources that contribute to the presence of trace elements in the atmospheric particulate between anthropogenic emissions and geogenic emissions. The results of this study reveal the versatility of the lichen species Xanthoria calcicola Oxner in the search for trace elements in highly anthropized environments, so the approach followed in this study can also be applied to other industrial contexts.

Physiological and Molecular Alterations of Phycobionts of Genus Trebouxia and Coccomyxa Exposed to Cadmium

Several studies on aeroterrestrial microalgae are unravelling their resistance mechanisms to different abiotic stressors, including hazardous metals, pointing to their future role as bioremediation microorganisms. In the present study, physiological and molecular alterations of four phycobionts of genus Trebouxia (T. TR1 and T. TR9) and Coccomyxa (C. subellipsoidea and C. simplex) exposed to Cd were studied. Cd accumulation and subcellular distribution, cell wall structure, production of biothiols (GSH and phytochelatins), reactive oxygen species (ROS) formation, expression of key antioxidant genes and ROS-related enzymes were evaluated to determine the physiological differences among the four microalgae, with the aim to identify the most suitable microorganism for further biotechnological applications. After 7 days of Cd exposure, Coccomyxa algae showed higher capacity of Cd intake than Trebouxia species, with C. subellipsoidea being the highest Cd accumulator at both intracellular and, especially, cell wall level. Cd induced ROS formation in the four microalgae, but to a greater extent in both Coccomyxa algae. Trebouxia TR9 showed the lowest Cd-dependent oxidative stress probably due to glutathione reductase induction. All microalgae synthetized phytochelatins in response to Cd but in a species-specific and a dose-dependent manner. Results from this study agree with the notion that each microalga has evolved a distinct strategy to detoxify hazardous metals like Cd and to cope with oxidative stress associated with them. Coccomyxa subellipsoidea and Trebouxia TR9 appear as the most interesting candidates for further applications.

Host tree species mediate corticolous lichen responses to elevated CO2 and O3 after 10 years exposure in the Aspen-FACE system

Lichens contribute significantly to the biodiversity and functioning of many ecosystems. Although lichens are useful air pollution bioindicators and may respond in significant ways to global change, they are studied infrequently under field conditions in chamberless exposure systems. We surveyed corticolous lichens on paper birch (Betula papyrifera) and trembling aspen (Populus tremuloides) after 10 years exposure (1998-2007) to elevated CO₂ (eCO₂) and O₃ (eO₃) in the Aspen-FACE experiment in Rhinelander, WI, USA. This experiment utilized chamberless exposure rings, 30 m in diameter, with both host trees planted together in one quadrant. Four treatments were allocated among 12 rings: ambient, eCO₂, eO₃, and the combination of eCO₂ + eO₃, each replicated once in each of three blocks. Over the course of the experiment, ambient CO₂ increased from 343 to 386 ppm while eCO₂ averaged ~530 ppm CO₂. Ambient ozone concentrations averaged ~37 ppb and ~49 ppb for eO₃ although exposures decreased with time. Tree growth and leaf area index were negatively affected by eO₃ and stimulated by eCO₂, resulting in higher photosynthetically active radiation (PAR) in eO₃ and lower in eCO₂. We assessed lichen richness and cover on five host trees per ring on the north-facing side of the trunks, which were higher on birch than on aspen. Neither of the lichen measures on birch responded to the exposure treatments, while on aspen lichen cover was highest in eO₃ and lowest in eCO₂. On aspen, lichen cover was positively related to PAR and dominated by Caloplaca. No relationship was found for birch, although Lecanora exhibited a negative relationship with PAR. These lichens were insensitive to direct effects of eCO₂ and eO₃ at the levels applied. Instead, they responded to indirect effects, such as host tree species, and changes in understory PAR, resulting from direct effects of eO₃ and eCO₂ on the host trees.

Recognition of Trace Element Contamination Using Ficus macrophylla Leaves in Urban Environment

Urban areas are characterized by numerous pollutants emitted by anthropic sources both in the form of solid and gaseous particulates. Biomonitoring is an easy, economical, and accessible approach for the determination of atmospheric pollutants. In this study, we used the leaves of Ficus macrophylla Desf. ex Pers., collected in the city of Palermo (Italy), to determine major and trace elements. Geogenic elements exhibited the highest concentrations, making up 99% of the weight of the analyzed elements (Ca, K, Mg, P, S, Na, Fe, and Al); they range 21,400 (Ca) to 122 µg g⁻¹ (Al). The remaining elements showed median concentrations in the range 47.5–0.05 µg g⁻¹ in the following order of abundance: Sr > Cu > Mn > Zn > Br > Rb > Ba > Pb > Cr > Sb > As > Mo = Sc. Cluster analysis, with Spearman’s coefficient to measure sample similarity, identified five main groups, namely, three clusters related to the geogenic background and marine spray; one cluster linked to elements essential to plants, and a final group attributed to the influence of traffic emissions. Calculated enrichment factors (EF) showed that the enrichments found for P and K were linked to plant metabolism; Na and Mg confirmed the role of sea spray; Cu and Zn underlined the contribution linked to anthropic processes and the role of micronutrients in plants.. As, Cr, and Mo had EF values ranging from 10 and 20, and Sb had EF > 90. From geochemical distribution maps of As, Cr, Mo, and Sb it was observed that metal and metalloid concentrations were higher in urban areas and immediately decreased as one moved away from these areas. Local pollution sources play a great role in trace element concentrations in airborne particulate matter. The present study confirms that Ficus macrophylla leaves are suitable for screening an urban environment to identify concentrations of inorganic chemicals, since they have high tolerance to pollution.

Multielemental analysis in Nerium Oleander L. leaves as a way of assessing the levels of urban air pollution by heavy metals

In this study, Nerium oleander L. leaves were used as biomonitors to evaluate environmental pollutants levels in a sub-region in the Metropolitan Area of Rio de Janeiro City (Brazil) through X-ray Fluorescence (XRF). Control samples were collected in a rural zone next to the Parque Estadual da Pedra Branca/RJ. The samples were collected during all seasons of 2015 (summer, fall, winter and spring). The concentration of 13 elements (S, Cl, K, Ca, Mn, Fe, Cu, Zn, Br, Rb, Sr, Ba and Pb) was determined. Most of the elements showed, during all seasons, median concentrations of sampling sites higher than the results obtained from the control sites. The principal component analysis (PCA) showed the grouping of the elements in two main factors that can be associated to emission sources of these elements. The elements Cl, K, Ca, Cu, Rb and Sr can be associated as a possible influence from the soil (root uptake and/or resuspension). On the other hand, the elements Fe, Cu, Zn, and Pb can be associated to vehicle and industry emission sources. The study showed that the XRF technique applied to Nerium oleander L. leaves is efficient to environmental pollution analysis in Metropolitan Regions since it is precise, fast and low-cost, besides allowing the monitoring of pollution levels over time.

Lichens and Bromeliads as Bioindicators of Heavy Metal Deposition in Ecuador

We evaluated heavy metal deposition in Parmotrema arnoldii and Tillandsia usneoides in response to air pollution in Loja city, Ecuador. We assessed heavy metal (cadmium, copper, manganese, lead and zinc) content in these organisms at nine study sites inside Loja city and three control sites in nearby forests. Concentrations of all studied heavy metals (i.e., cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn) and zinc (Zn)) were highest in downtown Loja. Our study confirms that passive monitoring using lichens and/or bromeliads can be an efficient tool to evaluate heavy metal deposition related to urbanization (e.g., vehicle emissions). We recommend these organisms to be used in cost-effective monitoring of air pollution in tropical countries.

Morphophysiological variation and metal concentration in the thallus of Parmotrema tinctorum (Despr. ex Nyl.) Hale between urban and forest areas in the subtropical region of Brazil

Anthropic activities such as the emission of pollutants resulting from industrial and agropastoral activities promote several changes in urban and forest areas. Lichens are organisms that are used in air quality evaluations due to their sensitivity to these changes. The aim of this study is to analyze the presence of morphophysiological damages and the metal concentration in samples of the lichen Parmotrema tinctorum, in urban and forest areas, checking for possible parameter variations between these areas, in the different matrices and seasons in the Southern region of Brazil. Six areas were selected (urban and forest), assigned to the rural/urban and urban/industrial matrices belonging to the watershed of the Rio dos Sinos, Brazil. The following parameters were analyzed: Index of photobiont vitality (IPV), photosynthetic pigments (chlorophyll, carotene, and pheophytin) and metals (Cu, Cr, Zn, Pb, and Ni) in the thallus of the lichen. The data were analyzed by an ANOVA one way, Pearson correlation test, and principal component analysis (PCA). Variations in the morphophysiological parameters were recorded in all the areas revealing significant differences. The lowest IPV values and highest concentration of metals were recorded in the urban environment, while low chlorophyll levels were found in the forest areas. The PCA showed a distinction between the areas and the season. The level of urbanization, vehicle traffic, and the weather conditions might have influenced the results. The use of P. tinctorum, the index of photobiont vitality and chlorophyll and pheophytin content, has proved to be an efficient tool to diagnose the air quality in the areas analyzed, allowing its use as a model in air monitoring studies, both in urban and forest areas, as well as in distinct matrices in the subtropical region.

Trace element biomonitoring in the Peruvian andes metropolitan region using Flavoparmelia caperata lichen

In the present study, in situ lichens (Flavoparmelia caperata) were used to assess the deposition of atmospheric trace elements in the metropolitan area of Huancayo (Junín, Peru). In total, ten sampling sites were chosen and categorized as urban, peri-urban (rural-urban) and rural areas according to land use. In addition, samples were also collected from a non-contaminated area categorized as a control site. The concentrations of 16 trace elements were measured using an inductively coupled plasma mass spectrometer (ICP-MS) and examined by enrichment factor (EF), hierarchical cluster analysis (HCA), and principal component analysis (PCA). Twelve of the 16 trace elements in urban and peri-urban sites present concentration higher than those at the rural and control sites (p < 0.05). The EF results revealed significant enrichment (at least twice that of the control site) of Ba, Cr, Cd, Pb, Sb, V, and Zn at most sites. PCA and HCA showed that more elements were derived from vehicular sources and fewer from agricultural and natural sources.

Comunidade de liquens corticícolas em um gradiente de urbanização na Bacia Hidrográfica do Rio dos Sinos, no sul do Brasil

Resumo Liquens são mundialmente conhecidos como indicadores de qualidade ambiental porque são sensíveis às modificações do ambiente, especialmente as de origem antrópica. Neste estudo foram avaliadas a riqueza, a composição e a cobertura de comunidades de liquens corticícolas em nove municípios com diferentes graus de urbanização e verificadas as principais semelhanças na composição das espécies entre as comunidades. Os locais amostrados estavam distribuídos em uma matriz rural, rural/urbana ou urbana/ industrial. Dez forófitos foram amostrados em cada área, utilizando o método do elástico. Ao total, foram identificadas 215 espécies de liquens, das quais nove são novas ocorrências, sendo quatro para o Brasil e cinco para o Rio Grande do Sul. Com o aumento da urbanização, observou-se uma simplificação da estrutura da comunidade de liquens, com diminuição da riqueza e mudanças na composição das espécies. Além disso, na matriz urbana/industrial poucas espécies apresentaram alta porcentagem de cobertura e, em conjunto, somaram grande importância na comunidade. Maior homogeneidade da composição de espécies foi encontrada em áreas mais próximas e inseridas na matriz urbano/industrial. Este estudo demonstrou que a arborização urbana é um fator importante para o estabelecimento das espécies de liquens, ao longo de um gradiente de urbanização.

A novel screening method to identify air pollution by genotoxic compounds

Genotoxic compounds, as common contaminants of the air environment, are of interest in air pollution monitoring. There are several methods to determine the level of these contaminants in different localities, many of which may be difficult to access with the use of conventional active and passive samplers. In the present study, the needles Pinus mugo Turra and Picea abies were used to monitor sampling localities in Austria, Slovakia, and the Czech Republic. Needles were extracted and chemical analysis and the genotoxicity bioassay SOS chromotest were used to obtain complex information about the chemical mixture of pollutants present and their genotoxic effects. The SOS chromotest method was optimized by using a CPRG chromogenic substrate to reduce the false positive genotoxic effect of needle extracts. Pinus mugo Turra and Picea abies were identified as suitable passive sampling matrices for long-term air monitoring using the same plants sampled at the same time. The presented study brings an innovative method for the fast screening and identification of localities loaded by genotoxic active air contaminants.

Land use and air quality in urban environments: Human health risk assessment due to inhalation of airborne particles

Particle matter (PM) and its associated compounds are a serious problem for urban air quality and a threat to human health. In the present study, we assessed the intraurban variation of PM, and characterized the human health risk associated to the inhalation of particles measured on PM filters, considering different land use areas in the urban area of Cordoba city (Argentina) and different age groups. To assess the intraurban variation of PM, a biomonitoring network of T. capillaris was established in 15 sampling sites with different land use and the bioaccumulation of Co, Cu, Fe, Mn, Ni, Pb and Zn was quantified. After that, particles were collected by instrumental monitors placed at the most representative sampling sites of each land use category and an inhalation risk was calculated. A remarkable intraurban difference in the heavy metals content measured in the biomonitors was observed, in relation with the sampling site land use. The higher content was detected at industrial areas as well as in sites with intense vehicular traffic. Mean PM₁₀ levels exceeded the standard suggested by the U.S. EPA in all land use areas, except for the downtown. Hazard Index values were below EPA's safe limit in all land use areas and in the different age groups. In contrast, the carcinogenic risk analysis showed that all urban areas exceeded the acceptable limit (1 × 10^-6), while the industrial sampling sites and the elder group presented a carcinogenic risk higher that the unacceptable limit. These findings validate the use of T. capillaris to assess intraurban air quality and also show there is an important intraurban variation in human health risk associated to different land use.

Towards improved comparability of studies addressing atmospheric concentrations of semivolatile organic compounds based on their sequestration in pine needles

Coniferous needles can be used as a passive air sampler of semivolatile organic compounds (SVOC) and an indicator of atmospheric pollution patterns and trends. There is limited information on whether different parts of the plant (e.g., foliage leaves, dwarf shoots, twig, etc.) contain different levels of SVOC. Only few studies have compared levels of SVOC surface layer of wax and to their total content in all needle tissues and what affects an uptake and distribution of SVOC. It is important to have better understanding of the extent to which sampling and sample preparation procedures affect measured levels of SVOC in pine needles and reduce comparability of data from samples processed in different ways. In the present study, we assessed an impact of various sampling and sample preparation techniques on the levels of SVOC in Pinus sylvestris needles. While the impact of various storing, washing and drying methods was not significant, presence of dwarf shoots in the sample or structural damage of needles affected the results significantly. Results show that levels of SVOC in dwarf shoots are 2-8 times higher than those in foliage leaves. Therefore, dwarf shoots must be carefully removed before foliage leaves extraction to improve comparability of results. There were different patterns in SVOC on the surface of the foliage leaves compared to the whole leaves. An uptake of these substances by the surface wax as well as their occurrence in the internal structure was of function of the physico-chemical properties of the substances (log K_ow, molar weight).

Elemental content of mosses and lichens from Livingston Island (Antarctica) as determined by instrumental neutron activation analysis (INAA)

The total content of 8 major and 32 trace elements in four species of mosses and two of lichens as well as neighboring soil and rocks collected from different places of the Livingston Island Antarctica was determined by instrumental neutron activation analysis. The main goals of the project consisted of evidencing the possible trace of anthropogenic contamination as well as the influence of altitude on the distribution of considered elements. In the absence of a unanimously accepted descriptor, enrichment factor, geo-accumulation, and pollution load indices with respect to soil and rocks were used. The data, interpreted within the model of a reference plant, were compared with previous studies regarding the same organisms in similar geographic and climatological areas. The experimental results evidenced different capacity of mosses and lichens to retain the considered elements, but within experimental uncertainties, no traces of anthropogenic pollution were found. At the same time, it was found that the content of most of the elements decreased with the altitude.

The application of lichens as ecological surrogates of air pollution in the subtropics: a case study in South Brazil

The use of lichens as ecological surrogates has been an important tool to evaluate the impact of air pollution in both ecosystem and human health but remains underused in the subtropics due to lack of knowledge. Aiming to support the application of lichen as ecological surrogates of the effects of air pollution in the subtropics, we hypothesized that urbanization was an important driver of changes on lichen diversity, composition, and vitality. For that, we quantified several lichen diversity metrics (richness, cover, and community composition) and photobiont vitality in relation to atmospheric pollution or its surrogates (modeled pollutant gases, pollutants in lichen thallus, and land cover). We confirmed that air pollution was a key driver for lichen diversity. Changes in lichen community composition and vitality were very significantly related to air pollution and integrated the effect of multiple stressors (particulate matter, NOx, and Cu), thus being powerful ecological indicators of air pollution in the subtropics.

Physiological changes of the lichen Parmotrema tinctorum as result of carbon nanotubes exposition

Carbon nanotubes (CNT) is one of the more abundant nanomaterial produced in the world. Therefore, it is desirable to access its effects in all environment compartments, in order to mitigate environmental distress. This study aims to verify the potential use of lichens - classical atmospheric pollution indicators - as biomonitors of carbon nanotubes aerosols. To examine cause-effect relationships, preserving environmental microclimatic parameters, the lichen Parmotrema tinctorum (Nyl.) Hale was transplanted to open top chambers where aerosols of CNT were daily added. Physiological parameters such as cell viability, photosynthetic efficiency, cell permeability as well as nanoparticle internalization were assessed. Carbon nanotubes exposure led to reduction on the cell viability of P. tinctorum. The treatment with 100µg/mL of MWCNT-COOH resulted in intracellular ion leakage, probably due to changes in membrane permeability. No alterations on photosynthetic efficiency were detected. Carbon nanotubes entrapment and internalization into the lichen thallus were observed. Short term exposition of CNT produced measurable physiological changes in P. tinctorum lichen. This suggests the possibility of use of lichens as models to assess the environmental impact (air related) of engineered nanomaterials.

Assessment of airborne heavy metal pollution in soil and lichen in the Meric-Ergene Basin, Turkey

In the present study, accumulations of airborne heavy metals in lichen and soil samples were determined on the basis of pollutant source groups by conducting Zinc (Zn), Lead (Pb), Iron (Fe), Copper (Cu), Chromium (Cr), Cadmium (Cd), Arsenic (As), Cobalt (Co) and Manganese (Mn) analyses on a total of 48 samples collected in the periods of May 2014 and August 2014 from 12 sampling points in a heavily industrialized area, a mixed industrial and residential area, an agricultural area and a background area in the Meric-Ergene Basin, and pH and total organic carbon determination was carried out on soil samples. With the obtained data, heavy metal levels were statistically assessed in detail by being associated with each other and with their probable sources; the accumulations found in soil and lichen samples were compared and spatial variances were set forth. Based on the results, it was observed that heavy metal pollution is at high levels particularly in industrialized areas, and that the differences between the cleanest and most polluted levels determined from soil samples for As, Cr, Cd and Pb reach 10 folds. The highest levels of all heavy metals were determined in both the soil and lichen samples collected from the areas in the south-east part of the region, where industrial activities and particularly leather and chemical industries are concentrated. With the comparison of the indication properties of soil and lichen, it was determined that significant and comparable results can be observed in both matrices.

[Air pollution biomonitoring with plants and fungi: concepts and uses]

Air pollution remains a major environmental concern of the French. Since about 30 years, due to evolution and diversification of sources, pollution became more and more complex, constituting a true "cocktail". Today, it is very important to know environmental and health effects of this cocktail. In this context air biomonitoring using plants and fungi can bring a lot of information. Biomonitoring includes four concepts: the use of biomarkers, bioindication biointegration and bioaccumulation. These four concepts are articulated according to the levels of biological organization, what links up biosurveillance on fundamental plan with ecotoxicology. It is a complementary approach of the physicochemical techniques of air pollution measurements. The main objectives of biomonitoring studies are the monitoring of the space and temporal distribution of pollutants effect; the monitoring of local sources; participation in the health risks assessment; the information of people and the help to decision in public policies. Biomonitoring of air quality is a method, which made its proof in numerous domains of application and brings fundamental information on the impacts of the quality of air. Recent evolution of low concerning biggest industries allows us to envisage the increase of air quality biomonitoring with plants and fungi applications in the field of the valuation of environmental and health risks. The recent normalization (French and European) of different methods will also allow the development of uses.

Use of bioindicators to evaluate air quality and genotoxic compounds in an urban environment in Southern Brazil

Biological indicators are widely used to monitor genotic compounds and air quality in urban environments. Parmotrema tinctorum and Teloschistes exilis have been used to verify the presence of pollutants and analyze morphophysiological alterations in the thallus of species caused by their action. Species were exposed for seven months, in an urban area, in southern Brazil. Mutagenicity and cytotoxicity of PM10 organic extracts were assessed in the Salmonella/microsome assay at two stations. High concentrations of S, Pb, Cr, Zn and Hg were registered in the last period of exposure and more significant morphophysiological damages were verified in the lichens. Generally a higher mutagenic activity is observed in organic extracts of airborne particulate matter during the first months and in the third period of exposure of lichens. In addition, nitro compounds was detected through nitro-sensitive strains. Lichens and mutagenic biomarkers enabled the evaluation of air quality and the presence of environmentally-aggressive compounds.

Decrease in air pollution load in urban environment of Bratislava (Slovakia) inferred from accumulation of metal elements in lichens

The study illustrates the response of epiphytic lichens to changing atmospheric conditions in Central Europe, where the emission of air pollutants has significantly decreased from 1990, in the area in and around Bratislava City. Variation in concentrations of seven metal elements (Cu, Cd, Cr, Mn, Ni, Pb and Zn) in the thalli of Evernia prunastri, Hypogymnia physodes and Parmelia sulcata is assessed. Samples of these species were exposed in lichen bags in 39 sites throughout the territory of the city (more than 300 km(2)) during the period December 2006-February 2007. The samples were analyzed by AAS for metal element contents prior to and after exposure. The decrease in air pollution (for all studied elements by more than 90%) corresponded to a decrease in the accumulation of elements in lichen thalli, e.g. the contents of Pb decreased by 69% and of Cd by 34% on average. The results show also variations in accumulation between with different lichen species. The background values of metal element contents in thalli of H. physodes growing in situ were measured in semi-natural sites in Slovakia. It is suggested that these can be used as a reference in large-scale monitoring studies in Central Europe. Analysis of compatible data from the current study, and the study performed at the end of 1990s shows a significant decrease of metal elements in the air pollution load.

Use of Lichen and Moss in Assessment of Forest Contamination with Heavy Metals in Praded and Glacensis Euroregions (Poland and Czech Republic)

The concentrations of selected metals-Cr, Ni, Cu, Zn, Cd, and Pb-were determined in the samples of Hypogymnia physodes lichen and Pleurozium schreberi moss collected in Polish and Czech Euroregions Praded and Glacensis. More specifically, the samples were collected in Bory Stobrawskie, Bory Niemodlińskie, and Kotlina Kłodzka (Poland) and in Jeseniki (Czech Republic). The concentration of metals in the samples was measured using the atomic absorption spectrometry (flame AAS technique and electrothermal atomization AAS technique). The results were used to calculate the comparison factor (CF) that quantifies the difference in concentration of a given bioavailable analyte × accumulated in lichens and mosses: CF = 2 (c(x,lichen) - c(x,moss)) (c(x,lichen) + c(x,moss))(-1). The values of CF greater than 0.62 indicate the most probable location of heavy metals deposited in the considered area. In this work, the method was used to show a significant contribution of urban emissions to the deposition of heavy metals in the area of Bory Stobrawskie and in the vicinity of Kłodzko City.

Assessment of atmospheric pollution in the vicinity of a tin and lead industry using lichen species Canoparmelia texana

This paper examines the viability of using Canoparmelia texana lichen species as a bioindicator of air pollution by radionuclides and rare earth elements (REEs) in the vicinity of a tin and lead industry. The lichen and soil samples were analyzed for uranium, thorium and REEs by instrumental neutron activation analysis. The radionuclides (226)Ra, (228)Ra and (210)Pb were determined either by Gamma-ray spectrometry (GRS) (soils) or by radiochemical separation followed by gross alpha and beta counting using a gas flow proportional counter (lichens). The lichens samples concentrate radionuclides (on the average 25-fold higher than the background for this species) and REEs (on the average 10-fold higher), therefore they can be used as a fingerprint of contamination by the operation of the tin industry.

Linking chemical elements in forest floor humus (Oh-horizon) in the Czech Republic to contamination sources

While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the "environmental memory" of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km2 in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources.

The performance of moss, grass, and 1- and 2-year old spruce needles as bioindicators of contamination: a comparative study at the scale of the Czech Republic

Moss (Pleurozium schreberi), grass (Avenella flexuosa), and 1- and 2-year old spruce (Picea abies) needles were collected over the territory of the Czech Republic at an average sample density of 1 site per 290km(2). The samples were analysed for 39 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Rb, S, Sb, Se, Sn, Sr, Th, Tl, U, V, Y and Zn) using ICP-MS and ICP-AES techniques (the major nutrients Ca, K, Mg and Na were not analysed in moss). Moss showed by far the highest element concentrations for most elements. Exceptions were Ba (spruce), Mn (spruce), Mo (grass), Ni (spruce), Rb (grass) and S (grass). Regional distribution maps and spatial trend analysis were used to study the suitability of the four materials as bioindicators of anthropogenic contamination. The highly industrialised areas in the north-west and the far east of the country and several more local contamination sources were indicated in the distribution maps of one or several sample materials. At the scale of the whole country moss was the best indicator of known contamination sources. However, on a more local scale, it appeared that spruce needles were especially well suited for detection of urban contamination.

Can pine needles indicate trends in the air pollution levels at remote sites?

Data from ten years of integrated monitoring were used here to evaluate whether pine needles are a feasible tool for an assessment of long-term trends of the atmospheric contamination. Pine needles collected once a year were compared to high volume air samples collected for 24 h, every 7 days, and passive air samples integrated over 28-day periods. Results showed the same concentration patterns of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) captured in needles and high volume samples. Passive air samplers were less efficient in sampling the particle-bound compounds. Theoretical air volume equivalent to each needle sample (V(EQ)) was calculated as a ratio of the needle concentration over the mean air concentration. Results indicated different equivalent volumes for PAHs and organochlorines, possibly due to the faster degradation rates of PAHs in needles. The most important finding is that in the long term a needle monitoring gives very similar information on temporal trends of the atmospheric pollution as does a high volume air monitoring.

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.