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

Abstract

Artisanal small-scale gold mining (ASGM) is the main source of anthropogenic mercury emissions and contamination in Latin America. In the Brazilian northern Amazon, ASGM has contaminated the environment and people over the past century. The main contamination route is through fish consumption, which endangers the food security and livelihoods of traditional communities. Our study aims to assess the potential toxicological health risks caused by the consumption of Hg-contaminated fish across five regions in Amapá State. We sampled 428 fish from 18 sites across inland and coastal aquatic systems. We measured the total mercury content in fish samples, and the results were applied to a mercury exposure risk assessment targeting three distinct groups (adults, women of childbearing age, and children). Mercury contamination was found to exceed the World Health Organization’s safe limit in 28.7% of all fish samples, with higher prevalence in inland zones. Moreover, the local preference for carnivorous fish species presents a serious health risk, particularly for communities near inland rivers in the region. This is the first study to provide clear recommendations for reducing the mercury exposure through fish consumption in Amapá State. It builds scientific evidence that helps decision-makers to implement effective policies for protecting the health of riverine communities.

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

“…There is a well-established relationship between human mercury exposure and fish consumption, not only in our study area but also in other parts of the Amazon region [37]. Amazon fish are the most important protein source for the local riverine populations, and fishing is a significant and traditional economic activity throughout the region [118,119].…”

“…The principal human exposure route to MeHg is the consumption of contaminated aquatic organisms, such as fish, shrimp, and crabs. To support this statement, numerous studies [31][32][33][34][35][36][37][38][39][40][41][42][43][44] carried out in the Amazon basin have revealed mercury concentrations in different fish species above the limits to commercialization established by FAO/WHO [45] (i.e., 0.5 µg MeHg/g for non-piscivorous fish and 1.0 µg MeHg/g for piscivorous fish). As a direct consequence of this fact, many scientific studies have been shown hair mercury concentrations from traditional Amazonian people that correspond to methylmercury intake in amounts several times greater than the safe limits recommended by FAO/WHO [25] and U.S.EPA [26], as we can see in some review papers [5,46,47].…”

Rural Wage-Earners’ Attitudes Towards Diverse Wildlife Groups Differ Between Tropical Ecoregions: Implications for Forest and Savanna Conservation in the Brazilian Amazon

“…This new deforestation frontier in the Brazilian Amazon is facing several threats including mercury contamination from mining activities (Akagi et al., 1995; Fostier et al., 2000; Guimaraes et al., 1999; Hacon et al., 2020), construction of new hydroelectric dams (Fearnside, 1995; Norris et al., 2018), and increased agriculture production with consequent land cover change (IBGE, 2019a). The Brazilian savanna ecoregion in the south and east of the Amazon rainforest is in rapid decline due to agriculture expansion (Brannstrom et al., 2008), coupled with an increased demand for crop (cereal, beans and oil seeds) in eastern Amazonia, with Amapá state producing 56,542 tons per year by December 2017 (IBGE, 2019b).…”

Non-Lethal Concentration of MeHg Causes Marked Responses in the DNA Repair, Integrity, and Replication Pathways in the Exposed Human Salivary Gland Cell Line

“…Methylmercury (MeHg) is an organic form of mercury considered a potent environmental pollutant (Clarkson, 2002). In Brazilian northern Amazon, the artisanal small-scale gold mining (ASGM) is the main source of anthropogenic mercury emissions and contamination (Hacon et al, 2020). Communities whose diet involves vast ingestion of fish are potentially exposed and vulnerable to MeHg toxicity, which endangers the food security and livelihoods of traditional communities (Crespo-López et al, 2009;Crespo-Lopez et al, 2016;Hacon et al, 2020).…”

“…In Brazilian northern Amazon, the artisanal small-scale gold mining (ASGM) is the main source of anthropogenic mercury emissions and contamination (Hacon et al, 2020). Communities whose diet involves vast ingestion of fish are potentially exposed and vulnerable to MeHg toxicity, which endangers the food security and livelihoods of traditional communities (Crespo-López et al, 2009;Crespo-Lopez et al, 2016;Hacon et al, 2020). Contaminated seafood is widely absorbed in the gastrointestinal tract and ubiquitously distributed to the body with an extensive effect in several organ systems (Kershaw et al, 1980).…”