Synthesizing bioaccumulation data from the German metals in mosses surveys and relating them to ecoregions

Unlikely lead-bearing phases in river and estuary sediments near an ancient mine (Huelgoat, Brittany, France)

Anthropocene mineral diversity is the result of the purification of metals naturally combined with other chemical elements in natural environment. Moreover, the advent of human mining and manufacturing mineral-like compounds has experienced a punctuation event in diversity and distribution owing to the pervasive impact of human activities. In this context, the wastes of an abandoned historical mine, Huelgoat mine (Brittany, France), famous during the eighteenth and the nineteenth century contain significant amounts of chemical elements potentially dangerous to the environment. Lead concentration and Pb-bearing phases were quantified in 7 sediments samples located from mine upstream to the Aulne estuary (100 km downstream to the mine). Results show very high concentrations of lead in the stations located upstream and downstream of the Huelgoat mine, using X-ray fluorescence spectroscopy, ranging from 7000 mg/kg downstream of the mine to a natural concentration of about 80 mg/kg upstream. At the same time, Pb-bearing phases were identified depending on the particle sizes, fine (< 50 μm) and coarse (> 50 μm), using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), total organic carbon (TOC), and pH analyses. For the first time, evidence of anthropogenic mineral "iodoplumbate" formation has been described in a natural environment.

Impact of nickel mining in New Caledonia assessed by compositional data analysis of lichens

The aim of this study is to explore the use of lichens as biomonitors of the impact of nickel mining and ore treatment on the atmosphere in the New Caledonian archipelago (South Pacific Ocean); both activities emitting also Co, Cr and possibly Fe. Metal contents were analysed in thirty-four epiphytic lichens, collected in the vicinity of the potential sources, and in places free from known historical mining. The highest Ni, Co, and Cr concentrations were, as expected, observed in lichens collected near ore deposits or treatment areas. The elemental composition in the lichens was explored by multivariate analysis, after appropriately transforming the variables (i.e. using compositional data analysis). The sample score of the first principal component (PC1) makes the largest (positive) multiplicative contribution to the log-ratios of metals originating from mining activities (Ni, Cr, Co) divided by Ti. The PC1 scores are used here as a surrogate of pollution levels related to mining and metallurgical activity. They can be viewed as synthetic indicators mapped to provide valuable information for the management and protection of ecosystems or, as a first step, to select locations where air filtration units could be installed, in the future, for air quality monitoring. However, as this approach drastically simplifies the problem, supplying a broadly efficient picture but little detail, recognizing the different sources of contamination may be difficult, more particularly when their chemical differences are subtle. It conveys only relative information: about ratios, not levels, and is therefore recommended as a preliminary step, in combination with close examination of raw concentration levels of lichens. Further validation using conventional air-monitoring by filter units should also prove beneficial.

Spatially valid data of atmospheric deposition of heavy metals and nitrogen derived by moss surveys for pollution risk assessments of ecosystems

For analysing element input into ecosystems and associated risks due to atmospheric deposition, element concentrations in moss provide complementary and time-integrated data at high spatial resolution every 5 years since 1990. The paper reviews (1) minimum sample sizes needed for reliable, statistical estimation of mean values at four different spatial scales (European and national level as well as landscape-specific level covering Europe and single countries); (2) trends of heavy metal (HM) and nitrogen (N) concentrations in moss in Europe (1990-2010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (1990-2010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (1990-2013). While the minimum sample sizes on the European and national level were achieved without exception, for some ecological land classes and elements, the coverage with sampling sites should be improved. The decline in emission and subsequent atmospheric deposition of HM across Europe has resulted in decreasing HM concentrations in moss between 1990 and 2010. In contrast, hardly any changes were observed for N in moss between 2005, when N was included into the survey for the first time, and 2010. In Norway, both, the moss and the soil survey data sets, were correlated, indicating a decrease of HM concentrations in moss and soil. At the site level, the average N deposition inside of forests was almost three times higher than the average N deposition outside of forests.

Correlating concentrations of heavy metals in atmospheric deposition with respective accumulation in moss and natural surface soil for ecological land classes in Norway between 1990 and 2010

This study investigated whether statistical correlation of modeled atmospheric heavy metal deposition and respective accumulation in moss and natural surface soil varies across natural landscapes in Norway. Target metals were cadmium, lead, and mercury, and analyses were run between 1990 and 2010 on a 5-year interval. The landscape information was derived from the Ecological Land Classification of Europe. Correlations between concentration and respective deposition data were computed for each land class. The strongest correlations between heavy metal concentrations in atmospheric deposition and corresponding levels in moss and natural surface soil were observed for lead. Correlations for mercury were weaker compared to those calculated for cadmium and lead, indicating that atmospheric transport of mercury occurs at a larger spatial scale, while accumulation additionally seems to be influenced by factors operating on smaller scales. The correlation between concentrations in atmospheric deposition and moss is landscape-specific and metal-specific. The same holds true for the relations between heavy metal concentration in modeled atmospheric deposition and natural surface soil. The results of this investigation are in line with similar calculations from across Europe. They further confirm previous studies indicating that for Norway atmospheric transport is a main source of lead and cadmium accumulation in moss as well as in natural surface soil.

Social-ecological patterns of soil heavy metals based on a self-organizing map (SOM): a case study in Beijing, China

The regional management of trace elements in soils requires understanding the interaction between the natural system and human socio-economic activities. In this study, a social-ecological patterns of heavy metals (SEPHM) approach was proposed to identify the heavy metal concentration patterns and processes in different ecoregions of Beijing (China) based on a self-organizing map (SOM). Potential ecological risk index (RI) values of Cr, Ni, Zn, Hg, Cu, As, Cd and Pb were calculated for 1,018 surface soil samples. These data were averaged in accordance with 253 communities and/or towns, and compared with demographic, agriculture structure, geomorphology, climate, land use/cover, and soil-forming parent material to discover the SEPHM. Multivariate statistical techniques were further applied to interpret the control factors of each SEPHM. SOM application clustered the 253 towns into nine groups on the map size of 12 × 7 plane (quantization error 1.809; topographic error, 0.0079). The distribution characteristics and Spearman rank correlation coefficients of RIs were strongly associated with the population density, vegetation index, industrial and mining land percent and road density. The RIs were relatively high in which towns in a highly urbanized area with large human population density exist, while low RIs occurred in mountainous and high vegetation cover areas. The resulting dataset identifies the SEPHM of Beijing and links the apparent results of RIs to driving factors, thus serving as an excellent data source to inform policy makers for legislative and land management actions.

Substance-related environmental monitoring: Work group 'Environmental Monitoring'-Position paper

BACKGROUND

Due to the requirements of the EU Water Framework Directive and other legal regulations (e.g., national laws like the German Federal Soil Protection Act), but also due to the implementation of the new EU chemicals management system REACH, environmental monitoring will gain increasing importance for the surveillance of environmental quality as well as for the assessment of chemicals. Against this background, the Work Group on 'Environmental Monitoring' of the Division of 'Environmental Chemistry and Ecotoxicology' within the German Chemical Society has compiled a position paper on substance-related environmental monitoring.

SCOPE

Core elements of this position paper are the definitions of important terms like monitoring, exposure monitoring, effect monitoring, and integrated monitoring. Moreover, temporal and spatial aspects (monitoring of spatial distributions, trend monitoring, and retrospective monitoring) and their applications are discussed. The main focus of this position paper is the coverage of aspects which have to be observed for the preparation and implementation of a monitoring program. Essential is the clear specification of the targets of the monitoring which determine the development of the monitoring concept and its realization, e.g., if environmental media (compartments) or organisms are most appropriate as samples for the aim of the study. Of course, also the properties of the target substances are important (e.g., lipophilicity/bioaccumulation as pre-requisite for an exposure monitoring with organisms). Finally, the monitoring phases of sample planning, sampling, storage and transport of samples, selection of analytical methods, quality assurance measures as well as reporting are discussed.

PERSPECTIVES

An important issue for the future is to link the quantification of chemicals in environmental compartments (exposure and pollution monitoring) more closely to the study of biological effects (effect monitoring) than has been the case up to now. Furthermore, by inclusion of a spatial differentiation, a comprehensive evaluation of the state of an ecosystem can be obtained and the relevance of the results improved. Practical examples of monitoring studies which illustrate various aspects covered in this position paper will be presented in a series of publications by members of the Work Group in the following issues of this journal.

Assessing the effect of disturbances on ectomycorrhiza diversity

Ectomycorrhiza (ECM) communities can be described on a species level or on a larger scale at an ecosystem level. Here we show that the species level approach of successional processes in ECM communities is not appropriate for understanding the diversity patterns of ECM communities at contaminated sites. An ecosystem based approach improves predictability since different biotic and abiotic factors are included. However, it still does not take into account the hierarchical structure of the ecosystem. We suggest that diversity patterns of ECMs communities in forests can best be investigated at three levels. This hypothetical approach for investigation can be tested at sites of secondary succession in areas contaminated with metals. Once the diversity patterns are appropriately described by a hierarchical ecosystem approach, to the species level is used to explain these patterns by populational and ecotoxicological mechanisms.

Monitoring nitrogen accumulation in mosses in central European forests

In order to assess whether nitrogen (N) loads in mosses reflect different land uses, 143 sites in North Rhine-Westphalia, the Weser-Ems Region and the Euro Region Nissa were sampled between 2000 and 2005. The data were analysed statistically with available surface information on land use and forest conditions. N bioaccumulation in mosses in the Weser-Ems Region with high densities of agricultural land use and livestock exceeded the concentrations in the more industrialised Euro Region Nissa. In all three study areas agricultural and livestock spatial densities were found to be positively correlated with N bioaccumulation in mosses. In North Rhine-Westphalia, the N concentrations in mosses was also moderately correlated with N concentrations in leaves and needles of forest trees. The moss method proved useful to assess the spatial patterns of N bioaccumulation due to land use.

Translating biomonitoring data into risk management and policy implementation options for a European Network on Human Biomonitoring

BACKGROUND

The "European Environment & Health Action Plan 2004-2010" originates from the concern of the European Commission on the well-being of individuals and the general population. Through this plan, the Commission has set the objectives to improve the information chain for a better understanding of the link between sources of pollution and health effects, to better identify existing knowledge gaps, and improve policy making and communication strategies. Human biomonitoring (HBM) has been included as one of the tools to achieve these objectives. As HBM directly measures the amount of a chemical substance in a person's body, taking into account often poorly understood processes such as bioaccumulation, excretion, metabolism and the integrative uptake variability through different exposure pathways, HBM data are much more relevant for risk assessment than extrapolations from chemical concentrations in soil, air, and water alone. However, HBM primarily is a stepping stone between environmental and health data, and the final aim should be an integrated and holistic systematic risk assessment paradigm where HBM serves as a pivotal point between environment and health, on the one hand leaning on environmental data to provide detailed information on the sources and pathways of pollutants that enter the human body, and on the other hand clarifying new and existing hypotheses on the relationship between environmental pollutants and the prevalence of diseases. With the large amount of data that is being gathered in the different national survey projects, and which is expected to become available in Europe in the near future through the expected European Pilot Project on HBM, a framework to optimize data interpretation from such survey projects may greatly enhance the usefulness of HBM data for risk managers and policy makers.

RESULTS

This paper outlines an hierarchic approach, based on the stepwise formulation of 4 subsequent steps, that will eventually lead to the formulation of a variety of policy relevant risk reduction options.

CONCLUSION

Although the usefulness of this approach still needs to be tested, and potential fine-tuning of the procedure may be necessary, approaching the policy implications of HBM in an objective framework will prove to be essential.