Mercury exposure of children living in Amazonian villages: influence of geographical location where they lived during prenatal and postnatal development

Abstract

Introduction: In some Amazonian river basins, hair mercury concentration is above the recommended levels. We evaluated the influence of birth geographical location in the hair mercury level of Amazonian riverine children. materials and methods: hair mercury concentration was measured in 219 children living in four Amazonian riverine communities: Tapajós River (São luiz do Tapajós and Barreiras villages, n = 110), Tocantins River (limoeiro do Ajurú village, n = 61), and Caeté River (Caratateua village, n = 48). We used Poisson regression analysis to evaluate the association between native and nonnative children from each village and its hair mercury concentration. Results: higher mercury exposure was found in native children from São luiz do Tapajós (range = 0.81-22.38 µg/g) followed by native children from Barreiras (range = 0.48-13.46 µg/g), non-native children from São luiz do Tapajós (range = 0.26-22.18 µg/g), non-native children from Barreiras (range = 0.43-20.76 µg/g), followed by the children from Caeté and Tocantins river basins. We observed that Tapajós villages' native children had higher prevalence of mercury exposure children than other children (p < 0.05). Conclusions: Birth geographical location has association to mercury levels in the hair of children who lived in a same community with history of mercury exposure.

Mercury Exposure in Munduruku Indigenous Communities from Brazilian Amazon: Methodological Background and an Overview of the Principal Results

“…There is a long and ongoing history of gold mining activities in the Tapajos River basin and its impacts are well documented [5,13,14,41,43,63,64,66,67,[108][109][110]. It is widely known that artisanal gold mining activities are responsible for emitting 200 metric tons of mercury annually; approximately 27% of global emissions are discarded annually without any control [111,112], constituting a potential risk to human health and the environment.…”

Health Risk Assessment of Mercury Exposure from Fish Consumption in Munduruku Indigenous Communities in the Brazilian Amazon

“…Given the current federal government's effort to create strategies to facilitate the invasion of protected areas in the Amazon by garimpeiros and mining industries, it is essential to clarify that the contamination of fish by mercury and all related health damages are caused (or intensified) by exploitation of gold. Many studies have already shown mercury contamination in the fauna of the Tapajós River Basin at least two decades ago [55][56][57][58][59][60][61][62][63][64][65]. Dórea et al [59] detected mean mercury levels in piscivorous fish of 0.578 µg/g and 0.052 µg/g Hg in non-piscivorous in the upper Tapajós basin, whilst Brabo et al [56] investigated fish contamination in the Sai Cinza region, also inhabited by indigenous Munduruku.…”

Economic Impacts on Human Health Resulting from the Use of Mercury in the Illegal Gold Mining in the Brazilian Amazon: A Methodological Assessment

“…As an organic form of Hg, MeHg has extremely neurotoxic effects and is readily accumulated in biota due to its lipophilic and protein-binding properties [102,103]. A series of studies have shown the average levels of contamination of aquatic species in the Brazilian Amazon [49,[52][53][54][55][56][57][58][104][105][106][107][108][109]. For example, contamination can reach 0.13 to 2.85 µg Hg/g for certain fish species [104] and Dórea et al [55] detected mean mercury levels of 0.578 g Hg/g piscivorous fish and 0.052 g Hg/g non-piscivorous fish in the upper Tapajós basin.…”

“…A vast body of literature has analyzed the increase in contamination levels in the Amazon population [47][48][49][50][51][52][53][54][55][56][57][58]. Vasconcellos et al [49] found an average methylmercury hair level of 7.0 µg/g in the Munduruku indigenous community in Tapajós and Vega et al [58] observed that the Yanomami indigenous community, also in Brazil, had hair methylmercury levels higher than 6.0 µg/g, which is far above the maximum recommended level of 1.0 µg/g by the United States Environmental Protection Agency (U.S.EPA) [59] and 2.3 µg/g recommended by The Food and Agriculture Organization of the United Nations (FAO/WHO) [60].…”