Metal Concentrations In Mosses Research Articles

Traffic exposure increases natural 15N and heavy metal concentrations in mosses

Mosses have been used as biomonitors of atmospheric pollution for some years, but few studies have been carried out on the effect of NOx emissions from traffic on moss tissue N. Eight species of moss (102 samples) growing on walls or roofs next to roads exposed to different traffic densities were collected from urban and rural sites in the UK. The shoots were sampled for total N, their stable isotope 15N/14N content (δ15N) and heavy metal content (Pb, Zn). There was a lack of correlation between tissue total N and traffic exposure, but a very good correlation between traffic exposure and tissue δ15N. Plants collected near motorways or busy urban roads had δ15N values ranging between +6 and −1‰, while in rural areas with hardly any traffic these ranged from −2 to −12‰. In a separate survey of mosses, the average δ15N of shoots from busy roadsides in London was +3.66‰, whereas from samples collected from farm buildings near poultry or cattle pens it was −7.8‰. This indicates that the two main atmospheric N sources, NOx and NHx, have different δ15N signatures, the former tending to be positive and the latter negative. Tissue concentrations of both Pb and Zn show a strong positive correlation with traffic exposure, with Zn in particular being greater than Pb. The results are discussed with regard to the use of moss tissue Zn as a means for monitoring or mapping pollution from vehicles, and of δ15N as an aid to distinguish between urban (NOx) and rural (NHx) forms of N pollution.

Monitoring of heavy metal deposition in Northern Italy by moss analysis

A survey of heavy metal deposition in the mountainous territories of Northern Italy was carried out in 1995–96. Moss samples (mainly Hylocomium splendens) were collected in a dense network of sites (about 3.2 sites/1000 km 2) and the data of metal concentrations in moss tissues were statistically correlated with environmental and climatic factors, as well as with bulk deposition of elements and elemental concentrations in the soil. Three main geographic patterns of metal concentration in mosses could be defined: (1) Fe, Ni, and Cr, all derived both by soil particulates and anthropogenic emissions connected with ferrous metal manufacturing, were mostly concentrated in Northwestern Italy; (2) Cu and Zn, as typical multi-source elements, showed rather high concentrations with little ranges of variation over the whole area and small peaks reflecting local source points; (3) Cd and Pb reflected long-distance transport and showed highest concentrations in the regions with highest precipitation, especially in the Eastern Alps.

Estimation of metal uptake efficiencies from precipitation in mosses in Lithuania

The main sources contributing to heavy metal content in mosses in Lithuania were examined by a comparison of heavy metal concentrations in moss and corresponding deposition levels calculated from bulk deposition analysis. Bulk deposition was collected in open areas as well as under the canopy of trees. Uptake efficiencies in moss were calculated for Cd, Cr, Cu, Fe, Mn, Ni, V and Zn. All elements in moss except Pb and Cd appeared to be more or less influenced by sources other than air pollution. The general order of this influence on the heavy metal content in moss was observed as follows: Ni < V < Cr < Zn < Fe < Mn. The contents of Mn and Zn in moss were greatly influenced by leaching from the canopy while Pb was the only element which showed a net metal retention by the canopy. Concentrations of Fe and Cr in moss were dominating due to contribution from soil dust.

Geographic classification of heavy metal concentrations in mosses and stream sediments in the Federal Republic of Germany

The results of the first German moss monitoring programme to estimate heavy metal pollution in the Federal Republic of Germany were combined with other large-scale investigations carried out in Germany and then classified geographically in a new form. Using Monte Carlo assisted factor analysis, six factors indicating sources of pollution were identified from the sets of element data from the moss monitoring project (As, Cd, Cr, Cu, Fe, Ni, Pb, Ti, V, Zn) and the data sets for SO2 and particulate. The geographic distribution patterns of the factor values showed the regions in which the various sources are to be found. By combining the data the primarily anthropogenic chromium concentrations of the mosses were compared with the mainly geogenic chromium concentrations of the stream sediments in the form of examples. After normalization, the transformed chromium concentrations were transferred to a map of the entire area using inverse distance weighting. Anthropogenic and geogenic influences are being discussed on the basis of the results.

Stress responses and metal exchange kinetics following transplant of the aquatic moss Fontinalis antipyretica

SUMMARY1. We studied stress responses and metal exchange (uptake and loss) kinetics in the aquatic moss Fontinalis antipyretica Hedw. following transplant (in plastic mesh bags) to clean and metal‐contaminated river sites and under laboratory conditions.2. The stress response (estimated on the basis of chlorophyll:phaeophytin ratio) was more pronounced, and the moss took longer to recover, following transplant to heavily contaminated sites.3. Metal uptake over the 28 day exposure period was predicted well by a two‐compartment kinetic model: uptake velocity was initially high and gradually declined, with metal concentration in the moss showing a tendency to reach an equilibrium with metal concentration in the water. Mean uptake rate, time to reach equilibrium and metal concentration in moss at equilibrium all increased with increasing metal concentration in the water.4. Bioconcentration constants calculated on the basis of our data rank the metals studied in the order Zn &lt; Ni &lt; Co &lt; Cu &lt; Pb &lt; Cd.5. Following retransplant of mosses to a clean site, metal loss was not predicted well by a passive exchange mode of the above type; instead, two phases (rapid and slow) were apparent. Loss rates during both phases, and proportion of metal load lost during the rapid phase, were proportional to the concentration of metal in the moss at the start of the recuperation trial.6. We present nomograms to allow estimation of severity of contamination on the basis of metal concentration in moss and duration of transplant.

Influence of Environmental Factors on Heavy Metal Concentration in Lake Sediments in Southern Norway Indicated by Path Analysis

We studied relationships between environmental factors and accumulation of Hg, Cd, Pb, and Ni in sediments in 132 lakes in southern Norway. Generally, the concentrations of Hg, Cd, and Pb in surface sediments were considerably elevated as compared with sediments deposited in preindustrial times whereas Ni concentrations showed only minor increases. By path analysis, we modelled how different environmental factors may influence the metal concentrations in surface sediments. The models indicated that both Hg and Pb were associated with sedimenting organic matter, and sediment concentrations were strongly influenced by atmospheric deposition (indirectly measured as metal concentration in mosses) and the amount of organic carrier particles in lake water. Cd behaved similarly, except for a weaker association with organic matter and a positive effect from pH, indicating that Cd is mobilized during acidification. Ni was associated with the inorganic fractions in lake sediments and seemed also to be mobilized during acidification. Geochemical contributions of Ni were larger in sediments than atmospheric deposition whereas atmospheric deposition was the major source of Pb. For the other two elements, estimates of geochemical contributions were lacking.

Ecosystem monitoring at global baseline sites

Integrated ecosystem and pollutant monitoring is being conducted at prototype global baseline sites in remote areas of the Noatak National Preserve, Alaska, the Wind River Mountains, Wyoming, and Torres del Paine National Park, Chile. A systems approach has been used in the design of these projects. This approach includes: (1) evaluation of source-receptor relationships, (2) multimedia (i.e., air, water, soil, biota) monitoring of key contaminant pathways within the environment, (3) the use of selected ecosystem parameters to detect anthropogenic influence, and (4) the application of a systems conceptual framework as a heuristic tool.Initial short-term studies of air quality (e.g. SO2, NO2) plus trace metal concentrations in mosses generally indicate pristine conditions at all three of the above sites as expected although trace metals in mosses were higher at the Wyoming site. Selected ecosystem parameters for both terrestrial (e.g. litter decomposition) and aquatic (e.g. shredders, a macroinvertebrate functional feeding group) habitats at the Wyoming site reflected baseline conditions when compared to other studies.Plans also are being made to use U.S. Department of Energy Research Parks for global change monitoring. This will involve cross-site analyses of existing ecological databases and the design of a future monitoring network based on a systems approach as outlined in this paper.