Mercury is highly toxic, especially to the developing nervous system. Some populations are especially susceptible, most notably the fetus and young children. Yet mercury continues to be used in many products and processes all over the world, including in small-scale gold mining; manometers and thermometers; electrical switches; fluorescent lamps; dental amalgams, batteries and VCM (vinyl-chloride-monomer) production and some pharmaceuticals. The most significant mercury releases to the environment are emissions to air, but mercury is also released from sources directly to water and land. Important emissions sources include: coal-fired power generation, waste incineration, cement, steel and chlor-alkali production, gold and other metals mining, cremation, landfills and other sources such as secondary smelting operations and industrial inorganic chemical production.
Once released, mercury persists in the environment where it circulates between air, water, soils and biota in various forms. Once deposited, the form can change (by microbes) to methyl mercury, a particularly hazardous form that concentrates up food chains, especially the aquatic food chain. Most people are primarily exposed to methyl mercury through the diet, especially fish, and to elemental mercury due to dental amalgams and occupations (such as small-scale mining). Other sources of exposure include skin-lightening creams, mercury used for ritualistic purposes and in traditional medicines, and mercury spills in the home.
For more detailed information on chemistry, toxicology, exposures and risk evaluations for humans, impacts on the environment, cycling in the global environment and possible prevention and control technologies for controlling releases and limiting use and exposure to mercury, see the Global Mercury Assessment report (UNEP, 2000).
Context of this Toolkit
This Toolkit was published for the first time as a pilot draft in November 2005. This revised Version 1.2 (January 2013) is the result of pilot testing and comments undertaken since the previous release. It will be further developed and revised versions published as appropriate. The most current version of the Toolkit will at any time be available on the UNEP Chemicals mercury web page at http://www.unep.org/hazardoussubstances/Mercury/tabid/434/Default.aspx.
The revised Toolkit includes a revised Inventory Level 1, a simplified and more standardized inventory methodology. The total Toolkit now consists of a Guideline to Inventory Level 1, accompanying MS Excel spreadsheets for calculation of estimates of mercury inputs and releases on Inventory Level 1 and Inventory Level 2, an inventory reporting template for each level, templates for data collection for Inventory Level 1, and this Reference Report which gives more detailed description of mercury source categories and additional guidance on inventory development, and describes the Inventory Level 2 methodology.
The Inventory Level 1 Guideline describes a simplified step by step procedure. It also describes limitations of the Inventory Level 1 methodology and gives advice for situations where you may want to refine your inventory on Inventory Level 2. Finally the guideline provides advice for the reporting of your inventory on Inventory Level 1.
This revision of the Toolkit includes revisions of default factors for a number of potentially important mercury release sources. The revisions made here have been coordinated to the extent possible with UNEP’s work of updating the Global Mercury Assessment.
The original 2005 pilot draft Toolkit, and Inventory Level 2 of the revised version follows closely the approach and methodology developed and applied in the second edition (February 2005) of the document “Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases”, published by UNEP Chemicals. Where relevant, text passages from the dioxins and furans toolkit have been applied in this mercury Toolkit. The dioxins and furans toolkit, whose approach and methodology has been pilot-tested in a number of countries, has already been subject to several rounds of comment and review by those experienced in inventory development.
Further development of this Toolkit
As with any methodology, the Toolkit needs live testing, validation and updating. The Toolkit is considered an evolving set of tools, which will be updated and revised, as appropriate and feasible, to take account of emerging information and experience. Also, as the Toolkit is predominantly based on experience and information available from industrialized countries, it might not, for some release sources, fully reflect conditions in the developing countries. Input and data from other regions of the world is therefore very important, in order to provide a broader knowledge base for the different sources of mercury releases and improve the Toolkit’s applicability.
UNEP Chemicals invites all users of the Toolkit to provide feedback on all aspects of this product. Users of the pilot draft Toolkit may consult with UNEP Chemicals where problems with application, interpretation and implementation occur or where the system does not seem to apply to the situation found in the country.
Countries are encouraged to use the Toolkit to submit their inventories to UNEP Chemicals, who will make them publicly available on the mercury programme webpage at http://www.unep.org/hazardoussubstances/Mercury/tabid/434/Default.aspx. Over time, it is hoped to be able to provide, in addition to national inventories from various regions, a forum for exchange of information on countries’ experience with inventory development, case studies, relevant new publications, etc.
