RT Journal Article T1 Industrial and natural sources of gaseous elemental mercury in the Almadén district (Spain): An updated report on this issue after the ceasing of mining and metallurgical activities in 2003 and major land reclamation works A1 Higueras, Pablo A1 Esbrí Víctor, José María A1 Oyarzun Muñoz, Roberto A1 Llanos Lazcano, Willans R A1 Martínez Coronado, Alba A1 Lillo Ramos, F. Javier A1 López Berdonces, M.A. A1 García Noguero, Eva María AB wo events during the last decade had major environmental repercussions in Almadén town (Spain). First it was the ceasing of activities in the mercury mine and metallurgical facilities in 2003, and then the finalization of the restoration works on the main waste dump in 2008. The combination of both events brought about a dramatic drop in the emissions of gaseous elemental mercury (GEM) to the atmosphere. Although no one would now call the Almadén area as ‘mercury-free’, the GEM levels have fallen beneath international reference safety levels for the first time in centuries. This has been a major breakthrough because in less than one decade the site went from GEM levels in the order of “tens of thousands” to mere “tens” nanogram per cubic meter. Although these figures are per se a remarkable achievement, they do not mark the end of the environmental concerns in the Almadén district. Two other sites remain as potential environmental hazards. (1) The Las Cuevas mercury storage complex, a partially restored ex-mining site where liquid mercury is being stored. The MERSADE Project (LIFE—European Union) has tested the Las Cuevas complex as a potential site for the installation of a future European prototype safe deposit of surplus mercury from industrial activities. Despite restoration works carried out in 2004, the Las Cuevas complex can still be regarded as hotspot of mercury contamination, with high concentrations above 800 μg g−1 Hgsoil and 300 ng m−3 Hggas. However, as predicted by air contamination modeling using the ISC-AERMOD software, GEM concentrations fade away in a short distance following the formation of a NW–SE oriented narrow plume extending for a few hundred meters from the complex perimeter. (2) Far more dangerous from the human health perspective is the Almadenejos area, hosting the small Almadenejos village, the so-called Cerco de Almadenejos (CDA; an old metallurgical precinct), and the mines of La Nueva Concepción, La Vieja Concepción and El Entredicho. The CDA is an old metallurgical site that operated between 1794 and 1861, leaving behind a legacy of extremely contaminated soils (mean concentration=4220 μg g−1 Hg) and GEM emissions that in summer can reach levels up to 4,000–5,000 ng m−3. Thus the CDA remains the sole ‘urban’ site in the district surpassing GEM international reference safety levels. In order to prevent these emissions, the CDA requires immediate action regarding restoration works. These could involve the full removal of soils or their permanent capping to create an impermeable barrier. PB Academic Press Inc. Elsevier Science SN 0013-9351, ESSN: 1096-0953 YR 2013 FD 2013 LK https://hdl.handle.net/20.500.14352/34609 UL https://hdl.handle.net/20.500.14352/34609 LA eng NO project MERSADE NO Spanish Ministry of ‘‘Economıía y Competitividad’’ NO Castilla-LaMancha Regional Government ‘‘Consejería de Educación’’ DS Docta Complutense RD 9 abr 2025