Gold Mining as a Source of Mercury Exposure in the Brazilian Amazon

Malm, Olaf

doi:10.1006/enrs.1998.3828

Cited by 479 publications

(236 citation statements)

References 21 publications

Supporting

Mentioning

204

Contrasting

Unclassified

Order By: Relevance

“…Gold mining of alluvial sediments using amalgamation is one of the greatest contributions for the Amazon mercury (Hg) contamination (Pfeiffer and Lacerda 1988;Pfeiffer et al 1991;Malm 1998). This is followed by deforestation and forest burning (Lacerda 1995), degassing from soils (Almeida et al 2005) together with loss by soil erosion (Roulet et al1999;Roulet et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Flood pulse and spatial dynamics of mercury in sediments in Puruzinho lake, Brazilian Amazon

et al. 2014

View full text Add to dashboard Cite

The study was conducted in Puruzinho lake (Humaitá, AM) considering seasonal periods of rainy and dry in way to elucidate the flood pulse importance in the deposition, remobilization and distributions of mercury and organic matter in bottom sediments in the Madeira River Basin (Brazilian Amazon). Bottom sediments and soils samples were analyzed for total mercury and organic matter. Mercury concentrations obtained in bottom sediment were 32.20-146.40 ng g -1 and organic matter values were 3.5 -18.0%. The main region for accumulation of mercury and organic matter was in the central and deepest lake area In the rainy season there was a greater distribution of Hg and organic matter, mainly controlled by means of income of the Madeira river water during flooding, while the predominant process in the dry season was the remobilization of total Hg due to the resuspension of bottom sediments.

show abstract

Section: Introductionmentioning

confidence: 99%

Flood pulse and spatial dynamics of mercury in sediments in Puruzinho lake, Brazilian Amazon

et al. 2014

View full text Add to dashboard Cite

show abstract

“…It has been estimated that between 2000 to 3000 tons of Hg's have been released in the middle of the Amazon environment and nowadays small gold extraction activities using Hg can still be found (Malm, 1998;Lacerda & Salomons, 1998;Lacerda, 2003). About 60% of this mercury is believed to be were lost to the atmosphere and 40% went directly to the watercourses (Pfeiffer & Lacerda, 1988).…”

Section: Introductionmentioning

confidence: 99%

“…Although gold mining in the Brazilian portion of the Madeira River basin has decreased significantly from 1995 onwards to about 0.3 to 0.5 t.yr -1 nowadays, the activities continued and even increased in the Bolivian side of the basin, and the Hg released there eventually drains into the Madeira River from its major Bolivian tributaries (Maurice-Bourgoin et al, 2000). It is also suggested that burning and deforestation would allow long term atmospheric mercury deposited on soils, to run-off into rivers, justifying the high Hg concentrations in areas without a gold mining history (Veiga et al, 1994;Lacerda, 1995;Malm, 1998). Studies performed in distant areas and without gold mining activities registrations in the high Negro River reveal elevated Hg concentrations, what it carries to consider its natural source (Fadini & Jardim, 2001).…”

Section: Introductionmentioning

confidence: 99%

A description of mercury in fishes from the Madeira River Basin, Amazon, Brazil

et al. 2008

Self Cite

View full text Add to dashboard Cite

Over the last 20 years several projects carried on the Madeira River basin in the Amazon produced a great amount data on total Hg concentration in different fish species. In this paper we discuss temporal trends in Hg contamination and its relation to body weight in some of those fishes, showing that even within similar groups, such as carnivorous and non-migratory fish, the interspecies variability in Hg accumulation is considerable.

show abstract

“…Although gold mining activities were considered the unique source of mercury pollution into the Amazon for many years (Malm, 1998), pioneering studies in the Tapajo´s River Basin in Brazil have shown that the mercury content in the water column is influenced by the amount of particulate matter, independently from upstream gold mining activities (Roulet et al, 1998a), and regional variations of mercury concentrations and burdens in soil compartments cannot be explained by the presence of gold mining centers in the region (Roulet et al, 1998b). In fact, removal of forest cover and destruction of root systems subsequent to deforestation and ''slash and burn'' agricultural practices deplete the soil, releasing naturally occurring mercury into the water systems (Roulet et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Daily mercury intake in fish-eating populations in the Brazilian Amazon

Passos

Silva

Lemire

et al. 2007

J Expo Sci Environ Epidemiol

105

View full text Add to dashboard Cite

Although high levels of fish consumption and bioindicators of mercury exposure have been reported for traditional populations in the Amazon, little is known about their actual daily intake of Hg. Using an ecosystem approach, calculate daily mercury intake in adult fish-eaters, examine the relations between mercury intake and bioindicators of exposure and the factors that influence these relations. A cross-sectional dietary survey on fish and fruit consumption frequency was carried out with 256 persons from six villages of the Tapajo´s River. Fish portion per meal was determined. Mercury concentration was determined for 1123 local fish specimens. Daily mercury intake (mg/kg/day) was determined for men and women from each village using the average fish-mercury concentration for the fish caught in their fishing zone, the average quantity of fish per meal, fish-species frequency consumption and participants' body weight. Fish-mercury averaged 0.33 mg/g70.33. Daily mercury intake varied between 0 and 11.8 mg/kg/day (mean 0.92 mg/kg/day70.89) and varied by gender and village. Mean blood-and hair-mercury were 58.7736.1 mg/l and 17.9711.5 mg/g, respectively. There was a strong and positive relation between blood-mercury and daily mercury intake, with an inverse relation for fruit intake and schooling; significant variations were observed with immigrant status, and among villages. Hair-mercury was directly associated with daily mercury intake and inversely related to schooling and fruit consumption. Fruit consumption modified the relation between daily mercury intake and blood-mercury levels: for the same daily mercury intake, persons eating more fruit had lower blood-mercury concentrations (ANCOVA Interaction term: F ¼ 10.9, Po0.0001). The median difference of the ratio of blood-mercury to daily mercury intake between low and high fruit consumers was 26, representing a 26.3% reduction. These findings reveal high levels of daily mercury intake. Rigorous studies for developing risk-based reference doses in the Amazon should be undertaken to orient viable risk-management strategies to reduce exposure, while maintaining fish diet.

show abstract

Gold Mining as a Source of Mercury Exposure in the Brazilian Amazon

Cited by 479 publications

References 21 publications

Flood pulse and spatial dynamics of mercury in sediments in Puruzinho lake, Brazilian Amazon

Flood pulse and spatial dynamics of mercury in sediments in Puruzinho lake, Brazilian Amazon

A description of mercury in fishes from the Madeira River Basin, Amazon, Brazil

Daily mercury intake in fish-eating populations in the Brazilian Amazon

Contact Info

Product

Resources

About