Anthropogenic mercury emissions to the atmosphere in Brazil: the impact of gold mining

Abstract

Emissions of Hg to the atmosphere in Brazil were estimated using consume and production parameters for each sector and technologies actually operating in the country. However, whenever no data were available, international parameters were used. Total estimated emissions reach approximately 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 production from fossil fuel and biomass burning, respond to less than 0.5% of the total input. Pyrometallurgy of Ph, Zn and Cd mainly, responds with 3.9% of the total with 4.6 t · yr−1, where as 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 source 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 in 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 region which results in a very high emisson per area of approximately 16 g · km−2, and atmospheric deposition rates larger than in industrial areas.