Correlation between atmospheric deposition of Cd, Hg and Pb and their concentrations in mosses specified for ecological land classes covering Europe

Roland Pesch,Ilia Ilyin,Harry Harmens,Simon Schonrock,Gina Mills,Anne Hertel,Winfried Schröder

doi:10.5094/apr.2013.029

Abstract

Referring to Europe as a whole and to single European countries, previous studies have shown that heavy metal concentrations in mosses (1) are primarily determined by atmospheric deposition of heavy metals; (2) are country and element–specific; and (3) agree well with respect to element–specific spatial patterns and temporal trends of atmospheric deposition of heavy metals. This paper investigates correlations between the concentrations of cadmium, lead and mercury in atmospheric deposition and mosses within the units of an ecological land classification of Europe. To this end, measurements from the 2005/2006 European moss survey and modeled atmospheric deposition in the previous three years were intersected with a map on ecologically defined land classes of Europe. Then, the minimum numbers of sampling sites required within the ecological land classes were computed. Considering spatial auto–correlations, subsequently the correlations between the concentrations of heavy metals in mosses and corresponding deposition were calculated and mapped for each of those ecological land classes containing moss sampling sites. It was concluded that the numbers of sampling sites within Europe and most participating countries as well as within most of the ecological land classes are sufficient for estimating the mean of measurements for the above mentioned three spatial levels within 20% of its true value with 95% confidence. Spatial patterns of correlations between the atmospheric deposition and bioaccumulation were shown to vary by element and ecologically defined land classes.

Highlights

The Convention on Long–range Transboundary Air Pollution (LRTAP) from 1979 has been extended with eight protocols aiming at reducing emissions of air pollutants
Compared to the European Monitoring and Evaluation Programme (EMEP) monitoring network, the spatial resolution of the moss survey in terms of extent, i.e. area covered by sampling sites, and grain, i.e. number of sampling sites, is much higher and spatial and temporal trends are determined for more metals
Non–significant or significant low negative correlations were found in ecological land classes where mosses were sampled in a relative small number of EMEP grid squares

Summary

Introduction

The Convention on Long–range Transboundary Air Pollution (LRTAP) from 1979 has been extended with eight protocols aiming at reducing emissions of air pollutants. In addition to EMEP, under the LRTAP–Convention, the Working Group on Effects, established in 1980, provides information on the impacts of air pollutants on the environment and human health, and reports on the deposition of atmospheric pollutants to ecosystems and the exceedances of critical loads or levels This information is supplemented by the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation, 2005) which has been coordinating the European moss survey since 2000. The heavy metal concentrations in mosses provide no direct quantita‐ tive measurement of atmospheric deposition, the moss survey data yield a time–integrated measure of the spatial patterns and temporal trends of heavy metal deposition from the atmosphere to terrestrial ecosystems This was corroborated at the national level by, amongst others, Berg and Steinnes (1997), Berg et al (2003) and by Harmens et al (2012), and at the European level by Holy et al (2009), Schröder et al (2008) and Schröder et al (2010)

Methods

Results

Conclusion