Soil plays an important role in the global and regional mercury fluxes, which includes (i) the mercury which is biologically available or potentially available in the ecosystem (e.g. sorbed to soils or sediments), (ii) the mercury which is released from geogenic sources (e.g. ore deposits and geothermal sources) and, (iii) the mercury which is released by anthropogenic activity. A major issue is the importance of anthropogenic mercury relative to the mercury content in pristine environments.
The pilot report compiles and synthesizes available information on mercury in soil in the context of global mercury cycles as it acts as a source and a sink of mercury. The complexity of mercury behaviour in soil is addressed and the new evidence in relation to the role of soil under changing climate and land-use is also addressed. Comparability of data for soil characterisation points to the need of further harmonisation and standardisation of monitoring strategies, including sampling design, sampling, sample processing and detection of mercury and its compounds in soil. Elements to be considered for mercury in the effectiveness evaluation are also addressed.