Effect of metallic pollutants on the physiology of lichen, Pyxine subcinerea Stirton in Garhwal Himalayas

Chl. a, Chl. b, total Chl., Carotenoid, Protein and OD 435/OD 415 ratio were measured to estimate the possible damage caused by the metallic pollutants in the lichen, Pyxine subcinerea Stirton collected from four different sites of Srinagar Garhwal, Uttaranchal, India. Multiple correlation analysis revealed significant correlation (P < 0.001) among the Fe, Ni, Cu, Cr, Zn and Pb metals analysed. Cd did not correlate with any other metals except Fe (P < 0.05). Cu, Pb and Zn, are the main constituents of the vehicular emissions had significant positive correlation (P < 0.001) with protein content while, the OD 435/OD 415 ratio values decreased statistically (P < 0.001) with increase in amount of Cu, Pb and Zn.     

Lichen recolonisation in an urban-industrial area of southern Poland as a result of air quality improvement

Dynamics of epiphytic lichen distribution and diversity in the town of Skawina, one of the major industrial centres of southern Poland, over the last 30 years, was documented in relation to air quality changes. Fieldwork was conducted in 2006-2007. A total of 34 species were recorded at 202 sites, which is similar to the historical data, however, significant qualitative changes occurred. Nitrogen- and dust-tolerant species have expanded and dominate, while some acidophytes, such as Lecanora conizaeoides, are in decline. Lichens have recolonised the former 'lichen desert' in the town centre. Species richness at study sites has increased; and an improvement in the health of lichen thalli was noted. These trends reflect air quality improvement, mainly SO(2) decline in the last few decades and transport-related compounds, mainly NO(x) and dust that have became the main pollutants. Host tree species and diameter diversity also contribute significantly to lichen species diversity in the study area. The recolonisation process seems far from complete and further changes in the lichen distribution and diversity in the study area are expected.     

Air quality monitoring system using lichens as bioindicators in Central Argentina

Air quality studies with bioindicators have not been well developed in South America. In the city of Córdoba, there are not permanent air pollutant measurements by equipment. In order to develop an air quality biomonitoring system using lichens, we applied a systematic sampling in the city of Córdoba, Argentina. A total of 341 plots were sampled in the area of the city which is a square of 24 × 24 km. In each sample plot we selected three phorophytes and estimated the frequency and cover of lichen species growing at 1.5 m on trunks. We also calculated the Index of Atmospheric Purity (IAP) using lichen frequencies. Maps with number of lichen species, cover values, and IAP were performed. The lichen community was described with nine species where Physcia undulata and Physcia endochryscea were the most frequent. Moreover, these two species were dominant in the community with the highest cover index. The central area of the city is considered a lichen desert with poor air quality. The southeast and northwest areas of the city showed the highest IAP values and number of species. In general, the city shows fair air quality and few areas with good and very good air quality.     

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.     

Diversity of epiphytic lichens and metal contents of Parmelia caperata thalli as monitors of air pollution in the town of Pistoia (c Italy)

The results of a biomonitoring survey carried out in the town of Pistoia (central Italy) using the biodiversity of epiphytic lichens and the accumulation of heavy metals in thalli of Parmelia caperata as indicators of air pollution are reported. Compared to previous surveys, the overall situation generally improved, with higher lichen diversity at most stations and lower metal concentrations in P. caperata thalli. However, the general picture according to a calibrated scale of environmental naturality/alteration was substantially negative, with about 87% of the study area classified as `altered' (including the lichen desert) or `semi-altered'. To explain this apparent contradiction, it has been suggested that lichen colonization is determined by declining SO₂ concentrations, while major injuries to lichen communities are caused by the constantly high levels of NO_X. In spite of the low levels of Pb measured in P. caperata thalli, vehicular traffic was excluded as the main source of atmospheric pollution. Domestic heating seems to be the main cause of changes in the diversity of epiphytic lichens in the study area.     

Lichen Diversity and Lichen Transplants as Monitors of Air Pollution in a Rural Area of Central Italy

The results of a biomonitoring study carried out in the Municipality of Colle di Val d'Elsa (central Italy), using the diversity of epiphytic lichens and the accumulation of selected elements in thalli of the lichen Evernia prunastri transplanted in two urban sites are reported. The results indicate that the survey area suffers from different types of pollution. The main air pollutants are NO _X and Pb. Vehicular traffic and domestic heating are the main sources of the former, and traffic and a crystal factory of the latter. Furthermore, most study area is eutrophicated due to diffuse agricultural activities and the presence of pig and sheep stockfarms.     

Spatial scales of variation in lichens: implications for sampling design in biomonitoring surveys

The variability of biological data is a main constraint affecting the quality and reliability of lichen biomonitoring surveys for estimation of the effects of atmospheric pollution. Although most epiphytic lichen bioindication surveys focus on between-site differences at the landscape level, associated with the large scale effects of atmospheric pollution, current protocols are based on multilevel sampling, thus adding further sources of variation and affecting the error budget. We test the hypothesis that assemblages of lichen communities vary at each spatial scale examined, in order to determine what scales should be included in future monitoring studies. We compared four sites in Italy, along gradients of atmospheric pollution and climate, to test the partitioning of the variance components of lichen diversity across spatial scales (from trunks to landscapes). Despite environmental heterogeneity, we observed comparable spatial variance. However, residuals often overcame between-plot variability, leading to biased estimation of atmospheric pollution effects.     

Long-Term Biomonitoring with Lichens: Comparing Data from Different Sampling Procedures

The results of 2 biomonitoring surveys carried out over a span of 7 years (1996–2003) in the Province of Ancona (central Italy) using the diversity of epiphytic lichens are reported. According to a recent standardisation process, in 2003 a different protocol was adopted, raising the problem of data comparability with the previous study. For this reason, a ‘pilot study' was carried out in which the two sampling tactics were both used. The high correlation between biodiversity values proved by the results of this study, let to compare the two lichen diversity data set and to identify the impacts on lichen communities of temporal variations of atmospheric quality in the study area, showing a reduction of stations classified as ‘altered' and an increase in stations classified as ‘semi-altered'. Furthermore, possible reduction of the sampling effort was detected performing a study on the sampling density of the survey area, indicating in a 6 × 6 km grid the best density to adopt in order to save financial resources for the future.     

Identifying the origin of atmospheric inputs of trace elements in the Prades Mountains (Catalonia) with bryophytes, lichens, and soil monitoring

The biomonitors Hypnum cupressiforme and Xanthoria parietina were used to assess the deposition of trace elements and their possible origin in the Prades Mountains, a protected Mediterranean forest area of NE Spain with several pollution sources nearby. Al, As, Cd, Co, Cu, Cr, Ni, Pb, Sb, Ti, V, and Zn were determined in 16 locations within this protected area. Soil trace element concentrations were also ascertained to calculate enrichment factors (EF) and use them to distinguish airborne from soilborne trace element inputs. In addition, lichen richness was measured to further assess atmospheric pollution. EF demonstrated to be useful not only for the moss but also for the lichen. Cd, Cr, Cu, Ni, and Zn presented values higher than three in both biomonitors. These trace elements were also the main ones emitted by the potential sources of pollutants. The distance between sampling locations and potential pollution sources was correlated with the concentrations of Cu, Sb, and Zn in the moss and with Cr, Ni, and Sb in the lichen. Lichen richness was negatively correlated with lichen Cu, Pb, and V concentrations on dry weight basis. The study reflected the remarkable influence that the pollution sources have on the presence of trace elements and on lichen species community composition in this natural area. The study highlights the value of combining the use of biomonitors, enrichment factors, and lichen diversity for pollution assessment to reach a better overview of both trace elements’ impact and the localization of their sources.     

Rinodina sophodes (Ach.) Massal.: a bioaccumulator of polycyclic aromatic hydrocarbons (PAHs) in Kanpur City, India

The aim of this study is to determine the possibility of using Rinodina sophodes (Ach.) Massal., a crustose lichen as polycyclic aromatic hydrocarbons (PAHs) bioaccumulator for evaluation of atmospheric pollution in tropical areas of India, where few species of lichens are able to grow. PAHs were identified, quantified and compared to evaluate the potential utility of R. sophodes. The limit of detection for different PAHs was found to be 0.008–0.050 μg g^− 1. The total PAHs in different sites were ranged between 0.189 ± 0.029 and 0.494 ± 0.105 μg g^− 1. The major sources of PAHs were combustion of organic materials, traffic and vehicular exhaust (diesel and gasoline engine). Significantly higher concentration of acenaphthylene and phenanthrene indicates road traffic as major source of PAH pollution in the city. Two-way ANOVA also confirms that all PAHs content showed significant differences between all sampling sites (P 1%). This study establishes the utility of R. sophodes in monitoring the PAHs accumulation potentiality for development of effective tool and explores the most potential traits resistant to the hazardous environmental conditions in the tropical regions of north India, where no such other effective way of biomonitoring is known so far.     

Passive monitoring of atmospheric heavy metals in a historical city of central India by Lepraria lobificans Nyl.

Using an organism living in situ for monitoring is referred as passive monitoring. Lepraria lobificans Nyl., a leprose lichen growing naturally on monuments and buildings in the city Mandav in central India is used for passive monitoring of atmospheric metals. Seven metals (Cd, Cr, Ni, Al, Fe, Cu, and Zn) were analyzed. Samples collected from road site exhibit the maximum concentration of Fe, Cd, Cr, Ni, and Zn. Iron exhibit maximum accumulation both in lichen thallus and the substratum with mean values of 2,195.63 μg g^???1 dry weight. As compared with other growth form of lichens, L. lobificans exhibits the higher accumulation of Fe than foliose and fruticose lichens. On the basis of these results, it can be hypothesized that L. lobificans is an excellent accumulator of different metals. The statistical analysis applied to the element concentration between the metals as well as between the sites by analysis of variance found the difference to be significant at 1% and 5%, respectively. Student–Newman–Keuls test also shows significant difference for iron between the different metals.     

The lichen transplant methodology in the source apportionment of metal deposition around a copper smelter in the former mining town of Karabash, Russia

The lichen transplant monitoring methodology has been tested for source apportionment of metal deposition around the Cu smelter and former mining town of Karabash. Transplants of the lichen Hypogymnia physodes (L.) Nyl., collected from a ‘control’ site in July 2001, were set up at 10 stations along a 60 km NE–SW transect centred on Karabash. Samples were collected after 2 and 3 month monitoring periods and analysed using established wet-chemical techniques. The sources of particulate investigated were the smelter blast furnace and converter, floatation tailings, metallurgical slags, local road dusts, top soils and ambient airborne total suspended particulate. From multi-element least-squares modelling the blast furnace was the main source of particulate in transplants close to the smelter (<10 km). Particulate from the converter, with relatively high Pb and Zn, was found to be more widely dispersed, being finer-grained and so having a longer atmospheric residence time. Ambient airborne particulate, sampled in Karabash town using air-pump apparatus, was almost entirely derived from the converter, very different to the lichen transplants from the same area which mainly contained blast furnace particulate. It is proposed that lichens close to the smelter mainly trapped larger blast furnace-derived particulate as they have a low capture efficiency for smaller (converter) particles. The study demonstrates the utility of lichen transplants for monitoring atmospheric deposition and highlights the caution required in their use to assess ambient air quality in human health studies.     

Lichen transplants as a suitable tool to identify mercury pollution from waste incinerators: a case study from NE Italy

A lichen transplant study aimed at investigating a strong increase in mercury concentrations in lichens was run in a territory of NE Italy where background values were very low only 8 years before. Thalli of the lichen Pseudevernia furfuracea collected in a pristine area were exposed for 1.5, 3 and 6 months at 31 sites selected according to the observed pattern of Hg concentrations, location of the suspected source (a new waste incinerator) and prevailing wind direction. Hg strongly increased at eight sites after 1.5 months, at 12 after 3 months and at 20 after 6 months. The highest values were always located SW and S of the incinerator, in good agreement with the prevailing night wind direction. It was concluded that, although the immediate risk for the population living close to the incinerator is low, long-term hazard due to Hg accumulation in the surrounding environment should be seriously taken into account.     

Lichens as Bioindicators of Atmospheric Heavy Metal Pollution in Singapore

Lichens have been used as bioindicators in various atmospheric pollution assessments in several countries. This study presents the first data on levels of heavy metals (As, Cd, Cu, Ni, Pb, and Zn) in lichens at different locations in Singapore, Southeast Asia. Singapore is a fully industrialised island nation, with a prevailing tropical climate and a population of 4 million people within a confined land area of less than 700 km². The ubiquitous lichen species, Dirinaria picta was collected from six sample sites across Singapore and analysed for heavy metals using inductively coupled plasma mass spectrometry (ICPMS). No significant relationship existed between metal levels in lichen and soil, indicating that accumulated metals in lichen are primarily derived from the atmosphere. Peak concentrations of zinc (83.55 μg g⁻¹), copper (45.13 μg g⁻¹) and lead (16.59 μg g⁻¹) in lichens were found at Sembawang, Jurong and the National University of Singapore campus which are locations associated with heavy petroleum and shipping industries, and road traffic respectively. The mean heavy metal levels of lichen samples in Singapore were found to be at the upper range of values reported in the literature for temperate countries.     

Uranium series radionuclides in surface waters from the Shu river (Kazakhstan)

The concentrations of (238)U, (234)U, (226)Ra, (210)Po and (210)Pb have been determined in surface waters collected along the course of the Shu River, lying on the border between Kazakhstan and Kyrgyzstan. In the study area, the river runs through some of the largest uranium deposits worldwide, which were actively exploited during the nuclear weapons and nuclear energy programmes of the former Soviet Union. The data show an increasing trend in uranium concentrations downstream the river from the city of Tokmak to the city of Shu, with good correlation between total uranium concentrations and total dissolved solids. Data on uranium isotopes disequilibrium show the presence of technogenic uranium inputs into the Shu River downstream from the city of Karasu, evidenced by a decrease in the measured (234)U/(238)U isotopic ratio from 1.63 in uncontaminated sites to 1.29 in sites affected by past mining activities.     

Plutonium uptake and behavior in vegetation of the desert southwest: a preliminary assessment

Eight species of desert vegetation and associated soils were collected from the Nevada National Security Site (N2S2) and analyzed for 238Pu and 239 + 240Pu concentrations. Amongst the plant species sampled were: atmospheric elemental accumulators (moss and lichen), the very slow growing, long-lived creosote bush and the rapidly growing, short-lived cheatgrass brome. The diversity of growth strategies provided insight into the geochemical behavior and bio-availability of Pu at the N2S2. The highest concentrations of Pu were measured in the onion moss (24.27 Bq kg-1 238Pu and 52.78 Bq kg-1 239 + 240Pu) followed by the rimmed navel lichen (8.18 Bq kg-1 and 18.4 Bq kg-1 respectively), pointing to the importance of eolian transport of Pu. Brome and desert globemallow accumulated between 3 and 9 times higher concentrations of Pu than creosote and sage brush species. These results support the importance of species specific elemental accumulation strategies rather than exposure duration as the dominant variable influencing Pu concentrations in these plants. Total vegetation elemental concentrations of Ce, Fe, Al, Sm and others were also analyzed. Strong correlations were observed between Fe and Pu. This supports the conclusion that Pu was accumulated as a consequence of the active accumulation of Fe and other plant required nutrients. Cerium and Pu are considered to be chemical analogs. Strong correlations observed in plants support the conclusion that these elements displayed similar geochemical behavior in the environment as it related to the biochemical uptake process of vegetation. Soils were also sampled in association with vegetation samples. This allowed for the calculation of a concentration ratio (CR). The CR values for Pu in plants were highly influenced by the heterogeneity of Pu distribution among sites. Results from the naturally occurring elements of concern were more evenly distributed between sample sites. This allowed for the development of a pattern of plant species that accumulated Ce, Sm, Fe and Al. The highest accumulators of these elements were onion moss, lichen flowed by brome. The lowest accumulators were creosote bush and fourwing saltbush. This ranked order corresponds to plant accumulations of Pu.     

Soil Contribution to the Elemental Composition of Epiphytic Lichens (Tuscany, Central Italy)

Total concentrations of Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Sr, Ti, V and Zn in the epiphytic lichen Parmelia sulcata and superficial soils from 60 remote sampling sites in Tuscany (central Italy) were determined to evaluate the contribution of soil to the elemental composition of the lichen. The results showed that in the Mediterranean environment, the trace element content of unwashed lichen samples is greatly affected by soil contamination. However, despite the strong correlations between the concentrations of lithogene elements such as Al, Fe and Ti in P. sulcata, lichen levels of these elements were not at all linearly correlated with their concentrations in the soil, suggesting that dust contamination is highly variable and probably dependent on local site characteristics. All methods evaluated to minimize soil contamination indicated Cu, Pb and Zn as elements of atmospheric origin. However, while levels of Pb were similar to those reported for background areas, moderate pollution by Cu and Zn, probably from fertilizers used in agriculture, was revealed. For elements such as Cd and Mo, identified as atmophile, some uncertainty exists due to the fact that they are essential for lichen metabolism and accumulate intracellularly in lichens; they may therefore occur in soluble form in the lichen thallus.     

Empirical assessment of incorporating sediment quality triad data into a single index to distinguish dominant stressors between sites

Benthic infaunal community structure, sediment contamination, and sediment toxicity data (Sediment Quality Triad) were condensed into a single index based on the area of tri-axial plots, which were examined in relation to various habitat parameters. The purpose was to assess its utility for evaluating the relative impact of contaminants versus other stressors on benthic communities. The regression relationship between the areal index and the Effects Range?CMedian quotient (ERMq) was used to separate contaminant-impacted sites from sites impacted by hypoxia in Chesapeake Bay. Regression using the areal index and bottom oxygen confirm the utility of the approach. Data from Delaware, Galveston, and Biscayne Bays were also examined to determine if the approach may be effective in other estuaries.     

Assessment of trace metals using lichen transplant from automobile mechanic workshop in Ile-Ife metropolis,Nigeria

The level of air pollution around the automobile mechanic workshops has been generally overlooked. This study, examined the level of trace metals in automobile mechanic workshops and the suitability of using transplanted lichen thalli of Lepraria incana for measuring air pollution in such areas. Samples of the lichen thalli were transplanted into seven different sites and were attached to the bark of trees at each site. The samples were harvested from the sites after 3-month exposure. Concentrations of Pb, Cu, Cd, Fe, Zn, and S content were determined using an atomic absorption spectrophotometer. Results showed that there was a significant difference in the trace metals concentrations across the sites (p?<?0.05). The analyzed lichen samples showed a range of 91.26–119.35 ppm for Fe, 30.23–61.32 ppm for Zn, 1.25–2.45 ppm for Cu, 0.017–0.043 ppm for Cd, 0.018–0.051 ppm, and 0.37–0.42 ppm for S. From the study, sites 6 and 7 presented higher concentrations of Cd, Pb, and Zn than other sites. The enrichment factor calculated showed that Zn, Cd, and Pb were greatly enriched from the workshops. The trend in the concentration of these heavy metals suggests that activities in these workshops might become a major source of certain heavy metals in the environment and if the pollution activities persist, it might become worrisome over time.