Native mercury, hydrargyrism and the birth of occupational toxicology in Colombia

The “La Esperanza” native mercury mine in Aranzazu, (Caldas, Colombia) was active from 1948 until 1975. Before the final closure of the mine, the company began using dimercaprol (BAL, British Anti-Lewisite) and penicillamine for the treatment of hydrargyrism among workers. Mercury poisoning among miners was frequent due to precarious working conditions, inadequate technology, difficult terrain, and the high toxicity of native mercury within the mine. The costs associated with the treatment was one of the causes of the closure of the mine. The early use of these chelators corresponds to the first systematic use of an antidote in occupational health in Colombia. This paper describes the context in which dimercaprol and penicillamine were used, a milestone in the history of toxicology, medical geology and occupational health in Colombia and Latin America.