Artisanal gold mining in Antioquia, Colombia: a successful case of mercury reduction

• Monitoring of mercury in atmosphere, together with health assessment in 5 municipalities in Antioquia, Colombia.
• Implementation of a successful project to reduce mercury pollution in artisanal gold mining.
• It describes the initiatives of a project that reduced up to 70% of mercury emissions/releases to the environment.
• Participation of different stakeholders was key to the success of the project.

Five municipalities in Antioquia, Colombia, with population of 162,000 inhabitants, were the world's largest mercury polluter from artisanal gold mining in 2010, releasing and emitting an average of 92 (73–110) tonnes/a of mercury. UNIDO – United Nations Industrial Development Organization joined forces with the Government of Antioquia, National University of Colombia and University of British Columbia to start The Colombia Mercury Project to reduce mercury use and losses.1 The actions consisted of assessment of mercury losses, health monitoring and awareness campaign. This was supported by technical demonstrations of methods to reduce the amount of mercury used in the processing centres (“entables”). Enhanced enforcement of existing local and federal regulations accompanied these activities. Demonstrations of cleaner methods to miners and owners of “entables” generated 39 new mercury-free processing plants. The presence of the company Gran Colombia Gold buying ore from the miners at a fair price also contributed considerably to observed reductions in mercury use. Mercury entering in the whole ore amalgamation in the 323 “entables” was reduced on average 43% from 2010 levels. In 2013, mercury losses were reduced by 63%, resulting in 46 to 70 tonnes/a, less mercury entering the environment than in 2010.