Geochemistry of mercury in tropical swamps impacted by gold mining

Marrugo‐Negrete, José; Pinedo‐Hernández, José; Dı́ez, Sergi

doi:10.1016/j.chemosphere.2015.03.012

Cited by 53 publications

(38 citation statements)

References 26 publications

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“…For soils, all sites exceed the USEPA THg soil standard of 0.1 µg/g, with some sites exceeding this value by up to two orders of magnitude [USEPA, 1985]. Maximum soil THg concentrations at Senegalese ASGM sites were greater than those observed at all ASGM sites except one site in Venezuela [Santos-Francés et Nyanza et al, 2014;Marrugo-Negrete et al, 2015]. For river water, all four ASGM sites exceed the USEPA THg standard of 12 ng/L for the protection against toxic levels of bioaccumulation in aquatic organisms, including fish consumed by humans [USEPA, 1985].…”

Section: Comparison To Regulatory Standards and To Other Studiesmentioning

confidence: 99%

Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

Gerson

Driscoll

Hsu‐Kim

et al. 2018

Elementa: Science of the Anthropocene

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Gerson, JR, et al. 2018 Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers. Elem Sci Anth, 6: 11. DOI: https://doi.org/10.1525/elementa.274 Introduction Mercury (Hg) -predominantly in the form of methylmercury (MeHg) -is a potent neurotoxin that can significantly impair human health [Driscoll et al., 2013]. Prolonged exposure increases the risk for brain and neurological damage, which is especially harmful for pregnant women and children [Harada, 1995; Grandjean et al., 1997;Selin, 2014]. Although there are many potential sources of Hg, direct inhalation from anthropogenic emissions and consumption of fish constitute the major pathways of human exposure. Even when Hg concentrations are low in water, Hg concentrations can reach dangerously high levels in fish due to bioaccumulation and biomagnification [Morel et al., 1998; Driscoll et al., 2007]. Controlling Hg contamination in the environment has been a primary target of local and national health and environmental agendas for decades and, most recently, an issue of international concern addressed by the 2013 Minamata Convention on Mercury, which came into force in August 2017 [UNEP, 2013;Selin, 2014].The largest source of Hg to the environment is artisanal and small-scale gold mining (ASGM), which releases 1,400 tons of Hg annually into the air, soil, and water [Schmidt, 2012] and accounts for an estimated 37% of global anthropogenic Hg emissions [Telmer and Veiga, 2009; UNEP, 2013]. In the process of ASGM, liquid elemental Hg (Hg 0 ) is utilized to separate gold from sediments. After the formation of a Hg-gold amalgam, the mixture is heated to create pellets of gold, while the Hg is released into the atmosphere or deposited as mining waste directly into soil and water. Despite the health effects, many of which are unknown to ASGM communities, Hg is used in this process because it is inexpensive to obtain, easy to use, does not require time-consuming processing, and results in a high gold recovery rate [Telmer and Veiga, 2009] It is estimated that more than 10 million people, including over 3 million women and children, work in ASGM across more than 70 developing countries in Asia, South America, and sub-Saharan Africa. Families directly involved in the mining are exposed daily to levels of Hg vapor that far exceed the World Health Organization's guidelines [Cordy et al., 2011] The largest source of global mercury (Hg) anthropogenic inputs to the environment is derived from artisanal and small-scale gold mining (ASGM) activities in developing countries. While our understanding of global Hg emissions from ASGM is growing, there is limited empirical documentation about the levels of total mercury (THg) and methylmercury (MeHg) contamination near ASGM sites. We measured THg and MeHg concentrations in soil (n = 119), sediment (n = 22), and water (n = 25) from four active ASGM villages and one non-ASGM reference village in Senegal, West Africa. Nearly all samples had THg and MeHg concent...

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Section: Comparison To Regulatory Standards and To Other Studiesmentioning

confidence: 99%

Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

Gerson

Driscoll

Hsu‐Kim

et al. 2018

Elementa: Science of the Anthropocene

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“…More than 17 departments and 80 municipalities in the country are affected by gold mining (Díaz-Arriaga, 2014). Mercury has been identified in water sources in several regions of the country, such as the Ciénaga de Ayapel and the waters of the Cai River in the department of Chocó, as well as in the Ciénaga de Grande Achi in the department of Bolivar (Díaz-Arriaga, 2014;Marrugo-Negrete, 2015). Likewise, in the region of La Mojana, the presence of mercury in biological samples of mining workers was evidenced, establishing a statistical correlation with water sources as a source of contamination (Díaz et al, 2018).…”

Section: Resultsmentioning

confidence: 99%

Presence of pesticides, mercury and trihalomethanes in the water supply systems of Ibagué, Colombia: threats to human health

et al. 2020

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Chemical contamination of the water supply system caused by anthropic activities can cause adverse health effects. This study determined the presence of toxic metals, organic substances, pesticides and trihalomethanes in the water supply systems of the urban area of Ibague City. The economic and sanitary activities located in the 25 surface streams of the 32 water supply systems of the municipality were characterized. A total of 25 water samples were taken from the surface streams, and 35 samples in the water network of each drinking water service provider for the identification of pesticides (carbamates, organochlorines, organophosphorus), mercury, arsenic, cyanide, lead, cadmium, antimony, cobalt, selenium, silver, nickel and hydrocarbons. The presence of trihalomethanes was sampled after the treatment process given. A total of 775 economic and sanitary activities were detected in the surface streams of the water supply systems, highlighting the human settlements, agricultural and tourist activities impact on the water sources. Organochlorine pesticides (0.009-0.109 mg/L), mercury (0.001-0.004 mg/L) were identified in the water supply system in concentrations higher than those permitted by local regulation. Concentrations of trihalomethanes (0.064-1.260 mg/L) were detected in 68.7% of the water supply systems with treatment. The presence of chemical contaminants occurs mainly in communities with water supply systems of low complexity with high anthropic affectation. It is necessary to strengthen the assessment of hazards and risk by health surveillance, as well as intersectoral intervention for the protection of water sources and the improvement of water treatment technologies.

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“…It is worth highlighting that Hg is part to this cluster, but it can be presumed that it is of a different anthropogenic origin. The presence of Hg in soils is ascribed to gold mining sites (Marrugo‐Negrete et al, ; Pinedo‐Hernández et al, ). PC3 and PC4 are both accounted for 11% of the variance (PC3 + PC4 = 22%) and pointed to OM, CEC, and pH as important drivers of the soil variability.…”

Section: Resultsmentioning

confidence: 99%

“…The socio‐economic and ecological implications of these climatic events in La Mojana floodplain are worrisome, as half of the maize and rice production is lost during drought and maize production is entirely lost during flood events. Moreover, floods caused by the overflowing of the rivers, which collect wastes containing toxic metals from surrounding mining areas, have led to crop losses and severe pollution (Marrugo, Benítez, Olivero, Lans, & Vazquez, ; Marrugo‐Negrete, Olivero Verbel, Lans Ceballos, & Norberto Benitez, ; Marrugo‐Negrete, Pinedo‐Hernández, & Díez, ; OCHA, ; Pinedo‐Hernández, Marrugo‐Negrete, & Díez, ). At present, the dry season lasts longer, and the rains are torrential, causing floods that can occasionally be severe, as in the 2010–2011 La Niña phenomenon, when several areas such as La Mojana were completely flooded for almost 2 years (Vargas, Hernández, & Pabón, ).…”

Section: Introductionmentioning

confidence: 99%

Flood‐induced metal contamination in the topsoil of floodplain agricultural soils: A case‐study in Colombia

et al. 2019

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Anomalously cold conditions in the tropical Pacific, related to a strong La Niña event, affected numerous countries in 2010. Several areas in Colombia were severely impacted, including agricultural fields in La Mojana floodplain that were completely flooded for almost 2 years. This study assesses the effects of flooding on the levels, spatial distribution, and sources of trace metals in 222 agricultural topsoils of this floodplain. Our results show that mean concentrations of Cu 48.4 mg kg −1 (11-103 mg kg −1 ), Zn 79.2 mg kg −1 (6-207 mg kg −1 ), Ni 58.1 mg kg −1 (17-101 mg kg −1 ), Pb 3.2 mg kg −1 (0.13-14 mg kg −1 ), Cd 0.56 mg kg −1 (0.05-1.4 mg kg −1 ), Mn 411 mg kg −1 (55-1,277 mg kg −1 ), and Hg 0.10 mg kg −1 (0.05-0.22 mg kg −1 ) were higher than the world's averages. Topsoils revealed different degrees of pollution depending on the metal, of which Pb was the most problematic element, with 82% of the soil samples classified as heavily contaminated. Principal component analysis suggests that soil contamination was primarily derived from poor agricultural practices and contaminated river overflows from upstream mining areas. Our results show that an extreme flood event might increase the bioavailability of metals (especially Pb) for crops in most (66%) of the agricultural soils, posing a potential threat to human health.

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Geochemistry of mercury in tropical swamps impacted by gold mining

Cited by 53 publications

References 26 publications

Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

Presence of pesticides, mercury and trihalomethanes in the water supply systems of Ibagué, Colombia: threats to human health

Flood‐induced metal contamination in the topsoil of floodplain agricultural soils: A case‐study in Colombia

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