Human Mercury Exposure in Yanomami Indigenous Villages from the Brazilian Amazon

Abstract

In the Brazilian Amazon, where the majority of Yanomami villages are settled, mercury (Hg) exposure due to artisanal small-scale gold mining (ASGM) has been reported since the 1980s. This study assessed mercury exposure in the Yanomami reserve and whether the level of contamination was related to the ASGM geographical location. It was conducted using a cross-sectional study of 19 villages. Direct interviews were performed and hair samples were used as a bioindicator of Hg exposure. The Prevalence-Ratio (PR) was estimated as an indicator of association between ASGM geographical locations and human exposure to mercury. Mercury levels (239 hair samples) ranged between 0.4 and 22.1 μg·g−1 and presented substantial differences amongst the villages. In the Waikas-Aracaça region, where current ASGM was reported, we observed the highest Hg concentrations (median = 15.5 μg·g−1). Almost all participants presented with hair-Hg levels >6 μg·g−1 (prevalence = 92.3%). In the Paapiu region, we observed the lowest concentrations (median = 3.2 μg·g−1; prevalence = 6.7%). Our findings showed that the Waikas Ye’kuana and Waikas Aracaca villages presented with 4.4 (PR = 4.4; Confidence Interval (CI) 95% = 2.2–9.0) and 14.0 (PR = 14.0; CI 95% = 7.9–24.9) times higher prevalence of hair-Hg concentration, respectively, compared with Paapiu. Considering seasonal variation of Hg-exposure, the lowest concentrations were observed during the wet season (June–September) and the highest in the dry season (December–April). Our study suggests that there is an association between mercury exposure and ASGM geographical locations.

A State‐of‐the‐Art Review of Indigenous Peoples and Environmental Pollution

“…These alliances extend to scientists because access to scientific information on pollution impacts has been important in spurring indigenous protests in many regions (Stetson 2012). For example, knowledge of high levels of Cd in their blood triggered a change in the resistance methods employed by the Achuar in the Corrientes River (Orta‐Martínez and Finer 2010) and the Yanomami in Brazilian Amazonia (Vega et al 2018). Based on their own experiences, some indigenous representatives have also travelled to warn others against accepting polluting industries on their lands (Kirsch 2007).…”

Mercury Exposure through Fish Consumption in Traditional Communities in the Brazilian Northern Amazon

“…This activity is generally coordinated by illegal networks and conducted by wildcat gold miners, and dealers [ 7 ]. ASGM has adversely affected the health of riverside communities—particularly indigenous people [ 8 , 9 ]—that rely on fish as their main protein source [ 10 , 11 ]. Fisheries in the Amazon provide food security and reduce malnutrition rates, as fish are the dominant dietary source of essential amino acids, lipids with fatty acids, minerals, and vitamins [ 12 , 13 ].…”

Mercury-Based Mining in Yanomami Indigenous Lands and Accountabilities

“…Recent studies (FIOCRUZ, 2016;VEGA et al, 2018) have confirmed that indigenous communities living near facer mining activities carried out in Uraricoera River have shown worrisome levels of contamination with mercury -which is a toxic metal with bioaccumulation properties -mainly in the form of methylmercury, which leads to severe and permanent damages to human health (LARINI, 1997;GIBB;O´LEARY, 2014).…”

“…Despite state accountabilities and the acknowledged vulnerability of indigenous populations, the Yanomami people have been continuously exposed to the effects of mercury for at least three decades (VEGA, 2018). Studies have reported high contamination levels in communities living in Roraima State (CASTRO; ALBERT; PFEIFFER, 1991;SING et al, 2003;VEGA, 2018), but little is known about the direct clinical effects of this contamination on the health and well-being of these populations.…”

“…Despite state accountabilities and the acknowledged vulnerability of indigenous populations, the Yanomami people have been continuously exposed to the effects of mercury for at least three decades (VEGA, 2018). Studies have reported high contamination levels in communities living in Roraima State (CASTRO; ALBERT; PFEIFFER, 1991;SING et al, 2003;VEGA, 2018), but little is known about the direct clinical effects of this contamination on the health and well-being of these populations. Given the uninterrupted artisanal gold mining activity in the aforementioned region, the aims of the present study were to carry out an interdisciplinary analysis of mercury use in mining sites at the Yanomami Indigenous Land, Roraima State, Brazilian Amazon region, as well as to assess State agencies' responses to this phenomenon.…”