Evolution of mercury contamination in Brazil

This paper reviews the history off Ig contamination m Brazil by characterizing and quantifying two major sources of Hg emissions to the environment: industrial sources and gold mining industry was responsible for nearly 100% of total Hg emissions from the late 1940's to the early 1970's when efficient control policies were enforced, leading to a decrease in emissions. Gold mining on the other hand was nearly insignificant as a Hg source up to the late 1970's, but is presently responsible for over 80% of total emissions. Presently, over 210 t of Hg are released into the environment in Brazil annually. Nearly 170 t come from gold mining operations, 17 t come from chlor-alkali industry and 10 t come from all other industrial uses. Emissions to the atmosphere are the major pathway of Hg releases to the environment and reach over 160 tyr−1 with approximately 136 tyr−1 from gold mining.