Environmental Impact of Small-scale and Artisanal Gold Mining in Southern Ecuador

Tarras-Wahlberg, Håkan; Flachier, Adriana; Fredriksson, Göran; Lane, Stuart; Lundberg, Bo; Sangfors, Olof

doi:10.1639/0044-7447(2000)029[0484:eiossa]2.0.co;2

Cited by 19 publications

(20 citation statements)

References 10 publications

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“…The mercury exposure in our dolphins indicates mercury contamination in their habitat. While mercury isotopes' analyses were not conducted in this study to discriminate natural from human-made sources, possible anthropogenic sources of mercury in the Gulf of Guayaquil can include small scale and artisanal gold mining in southern Ecuador (Tarras-Wahlberg et al, 2000;Betancourt et al, 2012;Carling et al, 2013), and emissions from urbanization and industrialization in the Gulf of Guayaquil (Calle et al, 2018). Evidence of chronological emissions of anthropogenic mercury (i.e., amalgamation and cinnabar mining) during Inca, colonial and pre-industrial times (i.e., augmented preindustrial pollution by mercury from 1400 to 1600 AD) in the Andean region of South American can also corroborate the regional atmospheric transport of mercury emissions to this region since preindustrial times (Cooke et al, 2013;Alava and Ross, 2018).…”

Section: Sources and Transport Of Pops And Mercury In Dolphins' Habitatmentioning

confidence: 99%

Persistent Organic Pollutants and Mercury in Genetically Identified Inner Estuary Bottlenose Dolphin (Tursiops truncatus) Residents of the Guayaquil Gulf, Ecuador: Ecotoxicological Science in Support of Pollutant Management and Cetacean Conservation

et al. 2020

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The bottlenose dolphin is one of the most common cetaceans found in the coastal waters, estuaries, and mangroves of Ecuador. However, its population size is gradually declining in the Gulf of Guayaquil, and anthropogenic factors including habitat degradation, uncontrolled dolphin watching, dredging activities, increasing maritime traffic, underwater noise, bycatch, and marine pollution have been implicated in their decline. Very little is known about contamination by persistent organic pollutants (POPs) and mercury in bottlenose dolphins from the Pacific coast of South America. To address this research gap, the first assessment of total mercury (THg) and POPs, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs), in free-ranging bottlenose dolphins in mangroves (El Morro Mangrove Wildlife Refuge) of the Gulf of Guayaquil, was conducted in Ecuador in 2018. Dolphin samples (i.e., skin and blubber; n = 9), were obtained using dart biopsy field methods for contaminant analysis. POP concentrations ranged from 0.56 to 13.0 mg/kg in lipid weight, while THg ranged from 1.92 to 3.63 mg/kg in dry weight. The predominant POPs were OCPs (50% of POP), followed by PCBs (46%) and PBDEs (6.0%); particularly, p,p-DDE, the main DDT metabolite and a potent antiandrogenic, accounting for 42% of POP, ranging from 0.12 to ∼7.0 mg/kg lw, followed by PCB 153 (8.0%) and PCB 180 (5.0%). PBDE 47 accounted for 2.0% of POP. While the POP concentrations are lower than those found in dolphins from many other regions

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Section: Sources and Transport Of Pops And Mercury In Dolphins' Habitatmentioning

confidence: 99%

Persistent Organic Pollutants and Mercury in Genetically Identified Inner Estuary Bottlenose Dolphin (Tursiops truncatus) Residents of the Guayaquil Gulf, Ecuador: Ecotoxicological Science in Support of Pollutant Management and Cetacean Conservation

et al. 2020

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“…Most natural aquatic ecosystems are severely threatened by humanmediated contamination because several industrial establishments are concentrated near river basins for obvious reasons (Uthe et al 1986;Ntekim et al 1992;Yahya 1994;Tarras-Wahlberg et al 2000;Oketola et al 2006). Studies have shown that apart from anthropogenic sources of heavy metals in sediment and biota, concentrations of metals in aquatic ecosystems could arise from atmospheric deposition, drainage basin and land-use histories (Yang and Rose 2005).…”

Section: Introductionmentioning

confidence: 99%

Metal contamination of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River and environmental impact due to Utapete gas flare station, Nigeria

Benson

Etesin

2007

Environmentalist

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Inter-seasonal studies on the trace metal load of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River were conducted between 2003 and 2004. The impact of anthropogenic activities especially industrial effluent, petroleum related wastes, gas flare and episodic oil spills on the ecosystem are remarkable. Trace metals analyzed included cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni), vanadium (V) and zinc (Zn). Sediment particle size analysis revealed that they were characteristically psammitic and were predominantly of medium to fine grained sand ([73%), less of silt (\15%) and clay (\10%). These results correlated with low levels of trace elements such as Pb (0.03 AE 0.02 mg kg À1 ), Cr (0.22 AE 0.12 mg kg À1 ), Cd (0.05 AE 0.03 mg kg À1 ), Cu (0.04 AE 0.02 mg kg À1 ) and Mn (0.23 AE 0.22 mg kg À1 ) in the sediment samples. This observation is consistent with the scarcity of clayey materials known to be good scavengers for metallic and organic contaminants. Sediments indicated enhanced concentration of Fe, Ni and V, while other metal levels were relatively low. The concentrations of all the metals except Pb in surface water were within the permissible levels, suggesting that the petroleum contaminants had minimal effect on the state of pollution by trace metals in Iko River. Notably, the pollutant concentrations in the sediments were markedly higher than the corresponding concentrations in surface water and T. fuscatus tissues, and decreased with distance from point sources of pollution.

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“…This would mean that mercury contamination is much higher in the food web in these communities. Similar mercury poisoning was found among Maroon miners in Suriname (De Kom, Van der Voet, and De Wolff 1998 sites in Brazil and Ecuador also show that miners had mercury levels that were over the WHO tolerable limits (see Tarras-Wahlberg et al 2000;Bezzerra, Verissimo, and Uhl 1996;Ak:agi et al 1995).…”

Section: Mercury Effects and Case Studiesmentioning

confidence: 65%

Small-Scale Gold Mining and Environmental Policy Challenges in Guyana: Protection or Pollution

Roopnarine

2006

Canadian Journal of Latin American and Caribbean Studies

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Small-scale gold mining has caused sorne serious ecological problems in Guyana's interior regions due to irresponsible use of mercury and poor production techniques. The Guyanese government is aware ofthese environmental problems, but controlling them has proved beyond its capabilities. Small-scale mining sites are numerous, mobile, and difficult to reach. Moreover, small-scale miners are far less concerned with good environmental performance than with economie gains. This article suggests that more stringent and serious policy regulations should be developed.Résumé. L'exploitation minière à petite échèle a provoqué de sérieux problè-mes écologiques dans les régions intérieures de la Guyane, cela en raison de 1 'utilisation irresponsable du mercure et de techniques de production déficientes. Le gouvernement guyanais est conscient de ces problèmes environnementaux, mais il s'est montré incapable de les contrôler. Les sites d'exploitation minière à petite échèle sont nombreux, mobiles et difficiles à atteindre. En plus, les miniers à petite échèle sont bien moins portés à développer une bonne gestion environnementale qu'à chercher des gains économiques. Cet article suggère qu'il faudrait mettre en place des politiques de régulation plus strictes.Over the past two decades orso, small-scale gold mining has become a major concem in many developing countries. On the one band,

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Environmental Impact of Small-scale and Artisanal Gold Mining in Southern Ecuador

Cited by 19 publications

References 10 publications

Persistent Organic Pollutants and Mercury in Genetically Identified Inner Estuary Bottlenose Dolphin (Tursiops truncatus) Residents of the Guayaquil Gulf, Ecuador: Ecotoxicological Science in Support of Pollutant Management and Cetacean Conservation

Persistent Organic Pollutants and Mercury in Genetically Identified Inner Estuary Bottlenose Dolphin (Tursiops truncatus) Residents of the Guayaquil Gulf, Ecuador: Ecotoxicological Science in Support of Pollutant Management and Cetacean Conservation

Metal contamination of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River and environmental impact due to Utapete gas flare station, Nigeria

Small-Scale Gold Mining and Environmental Policy Challenges in Guyana: Protection or Pollution

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