Manual for calculating critical loads of heavy metals for soils and surface waters; preliminary guidelines for environmental quality criteria, calculation methods and input data

Methodologies are described for calculating critical loads of lead, cadmium, copper, zinc, nickel, chromium and mercury for soils and surface waters. The aspects which are discussed are: selection of a computation model, determination of environmental-quality criteria for the metals, collection of input data, and assessment of the sources of uncertainty. The computation models described are based on the concept of equilibrium partitioning between dissolved and adsorbed phases in soil, surface water and sediment compartments in a steady-state situation. Application examples show that present loads of heavy metals in Europe may exceed critical loads, especially for lead, cadmium, copper and zinc