PHILIP M. FEARNSIDE
Mercury contamination can be one of the social and environmental costs of hydroelectric development in the Amazon. The use of mercury in gold mining has released hundreds of tons of this metal into the environment in the Amazon [1-4]. The source of the mercury may be from gold mining carried out directly in the reservoir area, such as in the area recently flooded by the Madeira River dams and in areas planned for dams on the Tapajós River and its tributaries. [5-7].
Gold mining in the reservoir’s watershed can also be a potential source of mercury, as is the case in the Serra Pelada mining area, upstream of Tucuruí; transport to the reservoir is primarily by water rather than through the atmosphere, and mercury is estimated to be accumulating in the Tucuruí reservoir at a rate of 235 kg per year-1 [8].
However, mercury inputs from gold mining activity are not required to have contamination, and reservoirs in areas with no gold mining history also have high levels of mercury, such as at Balbina. [9-11]. Because soils in the Amazon are ancient, they accumulated mercury over millions of years when dust from volcanic eruptions around the world fell onto the landscape. [12, 13].
Soil erosion in deforested areas carries organic matter and associated mercury into Amazonian rivers, increasing mercury levels in sediments [14]. Atmospheric deposition includes contributions from industrial sources around the world, including the burning of coal. [15]as well as the burning of biomass in the Amazon [16]; [17].
GRADES
[1] Pfeiffer, WC, de Lacerda, LD 1988. Mercury inputs into the Amazon region, Brazil. Environmental Technology Letters 9: 325-330.
[2] de Lacerda, LD, Pfeiffer, WC, Ott, AT, da Silveira, EG 1989. Mercury contamination in the Madeira River, Amazon – Hg inputs to the environment. Biotropica 21: 91-91.
[3] Bastos, WR, Gomes, JPO, Oliveira, RC, Almeida, R., Nascimento, EL, Bernardi, JVE, de Lacerda, LD, da Silveira, EG, Pfeiffer, WC 2006. Mercury in the environment and riverside population in the Madeira River Basin, Amazon, Brazil. Science of the Total Environment 368: 344-351. doi: 10.1016/j.scitotenv.2005.09.048
[4] Bastos, WR, Dórea, JG, Bernardi, JVE, Lauthartte, LC, Mussy, MH, Lacerda, LD, Malm, O. 2015. Mercury in fish of the Madeira River (temporal and spatial assessment), Brazilian Amazon. Environmental Research 140: 191-197. doi: 10.1016/j.envres.2015.03.029
[5] Pfeiffer WC, Malm O. Souza CMM de Lacerda LD Silveira EG Bastos WR 1991. Mercury in the Madeira River ecosystem, Rondônia. Forest Ecology and Management 38: 239-245.
[6] Boischio, AAP, Henshel, D., Barbosa, AC 1995. Mercury exposure through fish consumption by the Upper Madeira River population. Ecosystem Health 1: 177-192.
[7] Forsberg, BR, Kemenes, A. 2006. Technical Opinion on Hydrobiogeochemical Studies, with specific attention to the dynamics of Mercury (Hg). in: Technical Opinions of Sector Specialists—Physical/Biotic Aspects. Content Analysis Report of the Environmental Impact Studies (EIA) and the Environmental Impact Report (RIMA) of the Santo Antônio and Jirau Hydroelectric Power Plants on the Madeira River, State of Rondônia. Public Ministry of the State of Rondônia, Porto Velho, RO. 2 Vol. Part B, Vol. I, Opinion 2, p. 1-32.
[8] Aula, I., Braunschweiler, H., Malin, I. 1995. The watershed flux of Mercury examined with indicators in the Tucurui reservoir in Para, Brazil. Science of the Total Environment 175: 97-107.
[9] Kehring, HA, Malm, O., Akagi, H., Guimarães, JRD, Torres, JPM 1998. Methylmercury in fish and hair samples from the Balbina Reservoir, Brazilian Amazon. Environmental Research 77: 84-90.
[10] Kashima, Y., Akagi, H., Kinjo, Y., Malm, O., Guimarães, JRD, Branches, F., Doi, R. 2001. Selenium and mercury concentrations in fish from the lower Tapajos River and the Balbina Reservoir , Brazilian Amazon. In: 6th International Conference on Mercury as a Global Pollutant (ICMGP). Oct. 15-19, 2001, Minamata, Japan. ICMGP, Minamata, Japan. P. 280.
[11] Weisser, SC 2001. Investigation of the History of Mercury Contamination in the Balbina Reservoir, Amazon. Master’s dissertation in environmental toxicology. Universität Konstanz, Konstanz, Germany. 66 p.
[12] Roulet, M., Lucotte, M. 1995. Geochemistry of mercury in pristine and flooded ferralitic soils of a tropical rain forest in French Guiana, South America. Water, Air and Soil Pollution 80: 1079-1088.
[13] Roulet M, Lucotte M, Rheault I, Tran S, Farella N, Canuel R, Mergler D, Amorim M. 1996. Mercury in Amazonian soils: Accumulation and release. In: Bottrell, SH (ed.). Proceedings of the Fourth International Symposium on the Geochemistry of the Earth’s Surface, Ilkely. University of Leeds, Leeds, UK. P. 453-457.
[14] Roulet, M., Lucotte, M., Canuel, R., Farella, N., Courcelles, M., Guimarães, J.-RD, Mergler, D., Amorim, M. 2000. Increase in mercury contamination recorded in lacustrine sediments following deforestation in central Amazon. Chemical Geology 165: 243-266.
[15] Zhang, MQ, Zhu, YC, Deng, RW 2002. Evaluation of mercury emissions to the atmosphere from coal combustion, China. Ambio 31: 482-484. It hurts:
[16] Veiga MM, Meech JA, Onate N. 1994. Mercury pollution from deforestation. Nature 368: 816-817.
[17] This is a partial translation of Fearnside, PM 2016. Environmental and social impacts of hydroelectric dams in Brazilian Amazonia: Implications for the aluminum industry. World Development 77: 48-65. doi: 10.1016/j.worlddev.2015.08.015. The author’s research is funded by the National Council for Scientific and Technological Development (CNPq) (proc. 304020/2010-9; 573810/2008-7), by the Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM) (proc. 708565). ) and the National Institute for Research in the Amazon (INPA) (PRJ1).
Read too:
Aluminum and Dams: 1 – Series summary
Aluminum and Dams: 2 – Decisions on dams in the Amazon
Aluminum and Dams: 3 – The first step to review energy policy
Aluminum and Dams: 4 – The “curse of natural resources”
Aluminum and Dams: 5 – Aluminum and the construction of hydroelectric plants
Aluminum and Dams: 6 – Exporting energy and importing impacts
Aluminum and Dams: 7 – The “invisible hand” of the economy
Aluminum and Dams: 8 – Economic returns
Aluminum and Dams: 9 – Aluminum and employment
Aluminum and Dams: 10 – Indirect jobs
Aluminum and Dams: 11 – What is “consumed” aluminum?
Aluminum and Dams: 12 – Energy incorporated in commerce
Aluminum and Dams: 13 – Aluminum in international markets
Aluminum and Dams: 14 – The search for cheap energy
Aluminum and Dams: 15 – The context of energy policy
Aluminum and Dams: 16 – Energy Policy Reform
Aluminum and Dams: 17 – The role of corruption
Aluminum and Dams: 18 – Flood losses
Aluminum and Dams: 19 – Downstream impacts
Aluminum and Dams: 20 – Upstream impacts
Philip M. Fearnside holds a PhD from the Department of Ecology and Evolutionary Biology at the University of Michigan (USA) and is a researcher at the National Institute for Research in the Amazon (Inpa), in Manaus (AM), where he has lived since 1978. He is a member of the Brazilian Academy of Sciences and also coordinates the INCT (National Institute of Science and Technology) of the Environmental Services of the Amazon. He received the Nobel Peace Prize by the Intergovernmental Panel on Climate Change (IPCC) in 2007. He has more than 500 scientific publications and more than 200 dissemination texts of his authorship that are available at this link.
