Human activities release heavy metals into the atmosphere where they are also transported across national boundaries. This has resulted in an enrichment of heavy metals in environments that are far from emission sources. Atmospheric deposition of mercury and lead in particular are calculated to be too high, affecting 77 % and 42 % of European ecosystems respectively in 2000.
Heavy metals emissions, depositions, critical loads and exceedances in Europe
Scope of the report
This report summarizes knowledge of - and comparison between:
- heavy metal emission reduction scenario’s
- resulting depositions
- a comparison of depositions to critical load to calculate exceedances.
The focus of the report is on the relative assessment of the effects of the three “priority” heavy metals cadmium, mercury and lead, and - more tentatively - of 6 additional heavy metals (chromium, nickel, copper, zinc, arsenic and selenium) on endpoints for human health and the environment. Scenario analysis has been applied and described in this report to enable a tentative comparison of emission reduction alternatives in terms of these endpoints. For 2020 the scenarios are Current Legislation (CLE), Full implementation of the LRTAP Convention Protocol on heavy metals done at Aarhus in1998 (FI) and full implementation of this protocol plus additional measures (FIAM).
The risk of cadmium, mercury and lead, are confirmed in the scenario analysis presented here. The European ecosystem area at risk in 2000 of adjusted national emissions of cadmium, mercury and lead is about 0.34 %, 77 % and 42 % respectively. In 2020 - after full implementation of the protocol plus additional measures - these areas are reduced to 0.02 %, 74 % and 19 % respectively. The distribution and magnitude of the deposition of mercury and lead in particular puts large areas of European ecosystems at risk of adverse effects both in 2000 and 2020
The effect based scenario analysis of emissions of chromium, nickel, copper, zinc, arsenic and selenium indicates that a relatively small ecosystem area in Europe is subject to risk of adverse effects of these metals in 2000 and in the future.
While it is noted that data on emission used for this study are likely to be underestimated, this report provides further substantiation that the policy focus on priority metals is justified.
- Reports on heavy metal critical loads can be downloaded from the CCE website.
- The Task Force on heavy metals under the LRTAP-Convention produced scientific and technical documents that can be downloaded.