Working Group on Effects

According to the recommendation of the EMEP Steering Body MSC-E continued collaboration with the Working Group on Effects (WGE) in the field of assessment of heavy metal pollution levels across Europe and Central Asia and evaluation of modelling results against observations, including the heavy metals in mosses. Moreover, this year MSC-E together with the ICP-Vegetation of WGE worked on comparison of calculated heavy metal deposition and concentrations in mosses. The results of the common activity could be useful for complex analysis of temporal and spatial variability of heavy metals pollution over the EMEP domain. The ICP-Vegetation provided MSC-E with data on concentrations of lead, cadmium and mercury in mosses sampled during four moss surveys: 1990, 1995, 2000 and 2005/2006. These surveys involved more than 30 European countries.

The joint analysis of calculated heavy metal deposition and measured concentrations in mosses was focused on comparison of spatial distribution of modelled and measured levels and their long-term trends. For a number of countries significant spatial correlation between deposition and concentrations in mosses was found (Fig. 4.1). The highest correlation was found for Scandinavian countries (Finland, Sweden, Norway). For example, for lead the correlation coefficient in these countries was 0.7 - 0.9 (Fig. 1a). Satisfactory agreement between spatial distributions of modelled deposition and concentrations in mosses was also noted for some countries in central and western Europe (Fig. 1b.c).

a        b       c

Fig. 4.l. Comparison of calculated total deposition fluxes of lead and concentrations in mosses in Finland (a), Czech Republic (b) and France (c). Rc is correlation coefficient

Long-term trends of deposition and moss concentrations are favourably comparable in different parts of Europe. For example, long-term decrease of cadmium deposition following the decrease of emission agrees well with the decrease of country-averaged cadmium concentrations in mosses in the northern and central parts of Europe (Fig 2a, b). In Bulgaria (south-eastern Europe) calculated trend of deposition follows that of national emissions (Fig. 2c), but not consistent with the trend of cadmium concentrations in mosses. In order to explain this inconsistency, further joint efforts of emission, modelling and measurement communities together with national experts are needed. Analysis of modelled deposition and concentrations in mosses can give additional information not only on pollution levels, but also on model performance and on the quality of emission data.

ab c
Fig. 2. Long-term trends of deposition and concentrations in mosses of cadmium in Finland (a), Germany (b) and Bulgaria (c)

Results of the joint work of MSC-E and the ICP-vegetation were presented and discussed at the 22nd Task Force Meeting of the ICP Vegetation (Braunschweig, Germany, February 2009) and at the 10th TFMM annual meeting (Paris, France, June 2009). It was agreed to continue this joint activity in future. Detailed description of modelled EMEP heavy metal deposition against moss measurements is available in section 1.4 of EÌÅÐ/MSC-E Technical report [Gusev et al., 2009].