The source and fate of sediment and mercury in the Tapajós River, Pará, Brazilian Amazon: Ground- and space-based evidence

Telmer, Kevin; Costa, Maycira; Angélica, Rômulo Simões; Araújo, Eric Santos; Maurice, Y T

doi:10.1016/j.jenvman.2005.09.027

Cited by 71 publications

(72 citation statements)

References 14 publications

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“…Por exemplo, na Amazônia, há uma crônica exposição ao mercúrio em comunidades ribeirinhas que se alimentam principalmente do pescado. Isso ocorre devido à emissão de toneladas de mercúrio no ambiente e que são acumulados por meio da cadeia trófica 6,7 . A exposição humana ao mercúrio pela ingestão de alimentos contaminados é, sem dúvida, a mais importante forma de exposição não ocupacional.…”

Section: Introductionunclassified

Manifestações neurológicas em ribeirinhos de áreas expostas ao mercúrio na Amazônia brasileira

et al. 2013

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No presente estudo, foram avaliados comparativamente os níveis atuais de exposição ao mercúrio e as manifestações neurológicas em ribeirinhos residentes em comunidades situadas no Estado do Pará, Brasil. Participaram do estudo 78 ribeirinhos de Barreiras (bacia do rio Tapajós), 30 de São Luiz do Tapajós (bacia do rio Tapajós) e 49 do Furo do Maracujá (bacia do rio Tocantins). As concentrações de mercúrio total foram quantificadas, em cabelo, pela espectrofotometria de absorção atômica, e a avaliação neurológica foi realizada por meio de testes de rotina. As concentrações de mercúrio nas comunidades do Tapajós foram maiores que as do Tocantins (p < 0,01). A avaliação das alterações neurológicas não mostrou diferença significativa entre as comunidades das áreas expostas e controle para os resultados observados pelo exame neurológico convencional, exceto para desvio da marcha (p < 0,05). Concluiu-se que, apesar dos níveis de exposição ao mercúrio, houve uma baixa frequência de alterações somatossensoriais encontradas por meio de exames neurológicos convencionais.

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Section: Introductionunclassified

Manifestações neurológicas em ribeirinhos de áreas expostas ao mercúrio na Amazônia brasileira

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“…Information about biogeochemistry [21,33] and hydrological optics of the upstream section of the river is rare. As opposed to the semi-lentic conditions of the Tapajós Lake section, the upstream section starting from Aveiro City (Figure 1) is narrower (2-4 km), with a strong advection current [30].…”

Section: Methodsmentioning

confidence: 99%

“…The characteristics and concentration of the suspended sediments change abruptly as the Tapajós River receives clay-rich tributaries, such as the heavily-mined Crepori River (TSS~111.3 mg·L −1 , particulate organic matter <3%, and euphotic depth~2.0 m; defined as Class 5). The sediment plume from the Crepori River only fully mixes with the Tapajós River waters at about 200 km downstream after passing through rapids [21,51]. After these rapids, as the water velocity decreases, the fine suspended solids sink, and concentrations decrease to values similar to those of the upstream Tapajós River (see Telmer et al [21]).…”

Section: Mining-derived Tss As the Main Factor Changing The Water Optmentioning

confidence: 99%

“…The Tapajós River Basin includes the largest small-scale gold mining area in the world (28,186 km 2 ), which has been intensively mined, either using water-jets to remove top soil layers, or using small boats called 'balsas' that take the sediment from the bottom of the rivers using suction and gravity processes [20,21]. Currently, more than 300 small-scale mines (most without mining licenses) with the participation of more than 50,000 miners produce gold within the Artisanal Gold Mining District.…”

Section: Study Areamentioning

confidence: 99%

“…Amongst the sampled rivers, the upstream section of the Tapajós River is naturally classified as "clearwater" [21,24,25]. This class presented relatively low TSS (~5.0 mg·L −1 ), low dissolved organic matter (a cdom < 2.5 m −1 ), and low chl-a (<1.0 µg·L −1 ), thus resulting in a relatively deep euphotic zone (Z 1%~6 .0 m).…”

Section: Mining-derived Tss As the Main Factor Changing The Water Optmentioning

confidence: 99%

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Effects of Small-Scale Gold Mining Tailings on the Underwater Light Field in the Tapajós River Basin, Brazilian Amazon

et al. 2017

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Artisanal and Small-scale Gold Mining (ASGM) within the Amazon region has created several environmental impacts, such as mercury contamination and changes in water quality due to increased siltation. This paper describes the effects of water siltation on the underwater light environment of rivers under different levels of gold mining activities in the Tapajós River Basin. Furthermore, it investigates possible impacts on the phytoplankton community. Two field campaigns were conducted in the Tapajós River Basin, during high water level and during low water level seasons, to measure Inherent and Apparent Optical Properties (IOPs, AOPs), including scattering (b) and absorption (a) coefficients and biogeochemical data (sediment content, pigments, and phytoplankton quantification). The biogeochemical data was separated into five classes according to the concentration of total suspended solids (TSS) ranging from 1.8 mg·L −1 to 113.6 mg·L −1 . The in-water light environment varied among those classes due to a wide range of concentrations of inorganic TSS originated from different levels of mining activities. For tributaries with low or no influence of mining tailings (TSS up to 6.8 mg·L −1 ), waters are relatively more absorbent with b:a ratio of 0.8 at 440 nm and b 660 magnitude of 2.1 m −1 . With increased TSS loadings from mining operations (TSS over 100 mg·L −1 ), the scattering process prevails over absorption (b:a ratio of 10.0 at 440 nm), and b 660 increases to 20.8 m −1 . Non-impacted tributaries presented a critical depth for phytoplankton productivity of up to 6.0 m with available light evenly distributed throughout the spectra. Whereas for greatly impacted waters, attenuation of light was faster, reducing the critical depth to about 1.7 m, with most of the available light comprising of red wavelengths. Overall, a dominance of diatoms was observed for the upstream rivers, whereas cyanobacteria prevailed in the low section of the Tapajós River. The results suggest that the spatial and temporal distribution of phytoplankton in the Tapajós River Basin is not only a function of light availability, but rather depends on the interplay of factors, including flood pulse, water velocity, nutrient availability, and seasonal variation of incoming irradiance. Ongoing research indicates that the effects of mining tailings on the aquatic environment, described here, are occurring in several rivers within the Amazon River Basin.

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World emissions of mercury from artisanal and small scale gold mining

Telmer¹,

Veiga²

2009

Mercury Fate and Transport in the Global Atmosphere

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SummaryWe estimate mercury releases from artisanal and small scale gold mining (ASGM) based on available data about mercury and gold exports and imports by country and from field reports from the countries known to have active ASGM communities. The quality of the estimates ranges from reasonable to poor across the countries. This paper aims to give a first order estimate of the amount and location of mercury being released into the environment globally by ASGM, to motivate stakeholders to improve the quality of these estimates, to illustrate the linkages between global mercury trade and its use in ASGM, and the fourth objective is to provide a practical outline of the options available for reducing mercury use in ASGM. We estimate that artisanal and small scale gold mining releases between 640 to 1350 Mg of mercury per annum into the environment, averaging 1000 Mg yr -1 , from at least 70 countries. 350 Mg yr -1 of this are directly emitted to the atmosphere while the remainder (650 Mg yr -1

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The source and fate of sediment and mercury in the Tapajós River, Pará, Brazilian Amazon: Ground- and space-based evidence

Cited by 71 publications

References 14 publications

Manifestações neurológicas em ribeirinhos de áreas expostas ao mercúrio na Amazônia brasileira

Manifestações neurológicas em ribeirinhos de áreas expostas ao mercúrio na Amazônia brasileira

Effects of Small-Scale Gold Mining Tailings on the Underwater Light Field in the Tapajós River Basin, Brazilian Amazon

World emissions of mercury from artisanal and small scale gold mining

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