ANTHROPOGENIC MERCURY EMISSIONS TO THE ATMOSPHERE IN BRAZIL - THE IMPACT OF GOLD MINING

Emissions of Hg to the atmosphere in Brazil were estimated using consu me and production parameters for each sector and technologies actually operating in the country. However, whenever no data were available, i nternational parameters were used. Total estimated emissions reach app roximately 116 t yr(-1). Chlor-alkali production presently emits only 12 t yr(-1) of Hg (10.1% of the total), although it had been the major source of Hg to the environment in Brazil up to the 1970's. Paint and dye industry, electro-electronics manufacturers, and energy productio n from fossil fuel and biomass burning, respond to less than 0.5% of t he total input. Pyrometallurgy of Pb, Zn and Cd mainly, responds with 3.9% of the total with 4.6 t yr(-1) whereas steel and iron production may emit 12 t yr(-1) (10.4%). Burning of natural vegetation to produce agriculture lands or pastures may represent an important diffuse sour ce of Hg to the atmosphere in Brazil and may reach 8.7 t yr(-1), (7.5% ). Gold mining is presently the major source of Hg to the atmosphere i n the country with an average input of 77.9 t yr(-1) (67.3%). Mercury emissions from gold mining are practically restricted to the Amazon re gion which results in a very high emisson per area of approximately 16 g km(-2), and atmospheric deposition rates larger than in industrial areas.