Protocol on Heavy Metals

The Protocol on Heavy Metals, a protocol to the Convention on Long-Range Transboundary Air Pollution, was adopted in Aarhus, Denmark, in 1998. As of 2004, it had 36 signatories.^[1] As of 2016, it had 35 signatories and 33 parties, with no country having become a signatory since 1998.^[2] The protocol addresses the reduction of cadmium, lead and mercury emissions in the interests of environmental protection.^[3] Amendments to the Protocol were agreed in 2012^[4] to introduce more stringent emission limits^[5] but are not yet in force.

The protocol was established with the objective to control the airborne emissions of heavy metals caused by human activity.^[6] These heavy metals were susceptible to long-range atmospheric transport and capable of causing adverse human health effects, including cancer and chronic respiratory diseases.^[7] The protocol specifically targeted the reduction of heavy metals emitted from all kinds of industrial processes, including the emissions from fossil fuel combustion; iron and steel industries; primary and secondary non-ferrous metal industries; the cement and glass industries; the chlor-alkali industry, and the waste management industry, each of which were assigned specific emission limit values and emission control measures.^[8][9] These mitigation actions have contributed to the reduction of heavy metal emissions between 2005 and 2023 with cadmium emissions decreasing by 43%, mercury emissions by 57%, and lead emissions by 46% across the EU member states.^[10]

The Task Force on Heavy Metals was established in Executive Body Decision 2004/2 to review the scientific and technical aspects of heavy metal emissions, as required by the protocol to assess its efficiency.^[11][12] This task force would later by integrated into the Task Force on Techno-economic issues in 2014. Rather than solely focusing on heavy metals, the main objective of this task force focused on updating and assessing information on the reduction of a broad variety of air pollutant emissions, along with evaluating the costs associated with emission-reducing technologies.^[13]

Other protocols and global agreements that intertwined closely with the Protocol on Heavy Metals includes:

• The EMEP Protocol: Responsible for the collection of the emission data for a variety of airborne pollutants, including heavy metals, and the modelling of their atmospheric deposition.^[14]

• The Gothenburg Protocol: Responsible for the abatement of acidification, eutrophication, and ground-level emissions. Intertwined with heavy metals due to their ability to exacerbate acidification.^[15]

• The 1994 Oslo Protocol: Responsible for the reductions of sulphur emissions. Intertwined with heavy metals due to both of their emissions being sourced from the same industries.^[16]

• Minamata Convention on Mercury: A global agreement that focused specifically on the reductions of mercury.^[17]