Mercury Pollution in La Libertad, a Gold Mining Town in Central Nicaragua. Uncontrolled Mining, Economic Crisis, and Climate Effects—A Dangerous Mixture

Abstract

PP-31-159 Background/Aims: Mercury is a global pollutant with serious implications at the local and regional level, and is widely used through gold mining communities, especially in developing countries, as Nicaragua where the gold mining activity represents one of the major income sources. Methods: Mercury pollution emitted by small scale mining activities was evaluated in the mining town “La Libertad” in Chontales, central Nicaragua. The crushing/amalgamation centers “Rastras” where most mercury is released were georeferenced and monitored during 2008 and 2009. Furthermore, the concentration of mercury was analyzed using atomic absorption spectrophotometry in the environment (water and soil) and in blood samples from 124 miners and non-miners grouped in miners and non-miners families from the same town. Results: The crushing/amalgamation centers as an indicator of the mining activity were located all around the town and their numbers were almost doubled in 2009. High concentrations of total mercury were found in water samples (range concentration: 1.56–235.9 μg/L) where water level in creeks and rivers were reduced by drought and season. Concentrations of mercury in the total sample exceeded 15.36 μg/L of total mercury, which might represents a risk for health. Comparing total mercury in blood samples from miners and non-miners families, there was no significant difference between median groups (5.31 vs. 5.145 μg/L; R > 0.005) detonating environmental exposure more important than working exposure in agreement with the short distance between crushing/amalgamation centers and houses. Conclusion: Mercury used in gold mining represents a risk for general population in the mining town La Libertad.