Mercury Speciation in Hair of Children in Three Communities of the Amazon, Brazil

Abstract

Children from riverside communities located downstream of gold mining areas may be chronically exposed to relatively high levels of MeHg through the consumption of fish of this region. The objective of this study was to evaluate and compare levels of THg and MeHg in hair of children less than 12 years in communities near mines in the municipality of Itaituba and in communities far from prospecting areas in the city of Abaetetuba. The communities of Itaituba (Barreiras and São Luiz do Tapajós) had THg mean levels of 5.64 ± 5.55 μg·g−1 (0.43–27.82) and 11.41 ± 7.16 μg.g−1 (1.08–28.17), respectively, and an average count of MeHg relative to THg of 92.20% and 90.27%, respectively. In the Maranhão community, the THg average concentrations results were 2.27 ± 2.11 μg·g−1 (0.13–9.54) and the average values were 93.17% for MeHg. Children of Itaituba had average levels of mercury above the limit established by the World Health Organization (10 μg·g−1) and the strong correlation coefficient between the communities (R = 0.968 and P = 0.0001) suggests the hair as an excellent biomarker of human exposure to organic mercury in riverside populations of the Tapajós, which has the intake of fish daily as main source of protein dietary.

Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China

“…Brazilian children living in a gold-mining region showed the highest hair THg concentrations, with average values of 2.3 to 17 μg/g [61,62,63,64,65,66,67]. The results in this study were comparable with THg concentrations in children’s hair from Ghana and Portugal [68,69].…”

Large‐scale degradation of Amazonian freshwater ecosystems

“…2; Nevado et al, 2010;Swenson et al, 2011;Asner et al, 2013;De Miguel et al, 2014;Marinho et al, 2014). Although gold mining activities have existed in the Amazon for decades, they have recently surged following a 360% increase in gold prices after 2000 ( Fig.…”

“…Mercury, for example, is one of several pollutants that are produced or accumulated in reservoirs, dispersed downstream, and magnified in food webs (Schwarzenbach et al, 2006;Ashe, 2012;Marinho et al, 2014). Mercury, for example, is one of several pollutants that are produced or accumulated in reservoirs, dispersed downstream, and magnified in food webs (Schwarzenbach et al, 2006;Ashe, 2012;Marinho et al, 2014).…”

“…Although gold mining activities have existed in the Amazon for decades, they have recently surged following a 360% increase in gold prices after 2000 (Fig. 2;Nevado et al, 2010;Swenson et al, 2011;Asner et al, 2013;De Miguel et al, 2014;Marinho et al, 2014). Artisanal miners extract gold by dredging sediments from the river bottom and using mercury (Hg) to amalgamate fine gold particles, thereby altering stream and river morphology, increasing suspended sediment loads, and polluting waters via the release of Hg.…”

“…In addition to these physical changes to stream water, mining exploration, agricultural development, and dam construction can introduce new pollutants into freshwater ecosystems. Mercury, for example, is one of several pollutants that are produced or accumulated in reservoirs, dispersed downstream, and magnified in food webs (Schwarzenbach et al, 2006;Ashe, 2012;Marinho et al, 2014). The anoxic conditions commonly found in dam reservoirs increase natural levels of MeHg.…”