mercury pollution in the aquatic environment of suriname vervuiling in het aquatisch... · mercury...
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Mercury pollution in the aquatic
environment of Suriname
Paul Ouboter
National Zoological Collection(NZCS)/
Environmental Research Center (CMO)
Anton de Kom University of Suriname
Small-scale gold mining
in Suriname
• First gold rush 1880-1910
• Present gold rush 1980-present
• 25,000 to 35,000 gold miners (est. GMD
2000)
• Production 10,000-20,000 kg gold/year (est.
Veiga, 1997)
• Many gold miners are mining illegally
• Most miners are Maroons and Brazilians
• Mining concentrated in Greenstone Belt
Small-scale gold mining
in Suriname
• Small-scale operations have recently
changed into medium-scale operations
• Mercury used for amalgamation, usually in
combination with sluice boxes or dredges
• Usually no tailing ponds used
• Mercury lost to environment 10,000-
20,000 kg (est Veiga, 1997)
• 55% of mercury lost to atmosphere, 45%
to streams
Environmental impacts
• Deforestation
• Destruction of hydrology
• Increase of insolation due to deforestation
• Increase of turbidity, metals and nutrients in stream
• Change in aquatic vegetation
• Change in fish community
• Mercury pollution
• Mercury accumulation in food chain
Mercury is
neurotoxic
Mercury remains in ecosystems for ages
Regular consumption of fish with elevated levels poses health
risk
Piscivorous wildlife impacted
Mercury bio-accumulates
Mercury is volatile
Mercury levels globally rising
Fish and wildlife in remote areas have
elevated levels
Mercury is
neurotoxic
Mercury bound to
fine sediments
What is the problem with mercury?
Mercury research other organizations/authors
• OAS project on introduction of retorts (incl. some
measurements) (Pollack, de Kom, Quik & Zuilen, 1998)
• Mercury levels in gold-miners (de Kom, van der Voet &
de Wolff, 1998)
• Mercury in communities at the Lawa River (Cordier,
Grasmick, Paquier-Passelaigue, Mandereau, Weber &
Jouan, 1998)
• Mercury in fish (Mol, Ramlal, Lietar & Verloo, 2001)
• Mercury in gold-mining sites (Arets, v.d. Meer, v.d. Brink,
Tjon, Atmopawiro & Ouboter, 2006)
Mercury research other organizations/authors
(cont.)
• Mercury in pregnant women and new-borns (Mohan,
Tiller, van der Voet & Kanhai, 2005)
• Mercury in communities in the interior (Peplow &
Augustine, 2007)
• Mercury in the coastal and urban atmosphere (Müller,
Wip, Warneke, Holmes, Dastoor & Notholt, 2012)
• Mercury in communities (Min. public health; to start?)
Projects NZCS/CMO • Mercury pollution in the Commewijne River
(Quik & Ouboter, 2000; WWF-Guianas)
• Mercury pollution in the gold mining areas
(Ouboter, Landburg, White, Mol, v.d. Lugt &
Quik, 2007; WWF-Guianas)
• Atmospheric transportation of mercury (Ouboter,
Mol & Quik, 2003; Schure-Beijerinck-Popping
Fund)
• Mercury source in the Fallawatra Formation
(Landburg, 2005; NZCS/CMO)
Projects NZCS/CMO (cont.)
• Mercury poisoning of Brownsweg villagers (Ouboter &
Landburg, 2010; WWF-Guianas)
• Mercury levels in Western Suriname (NZCS/CMO)
• Environmental and community levels of mercury in
Kwakoegron and Pikin Saron (e.g. Hawkins, Lichtveld &
Ouboter, 2011; Tulane University)
• Mercury levels in sediment cores of floodplain rivers
(NZCS/CMO)
• Mercury levels in mud flats before the coast of Suriname
(NZCS/CMO & Tulane University)
Publication incl. most of these projects: Ouboter, Landburg,
Quik, Mol & v.d. Lugt, 2012
Methods • Data based on 9 different projects carried out between 1998-
2013, including 60 localities: – 14 localities in Greenstone Belt
– 18 localities downstream Greenstone Belt
– 7 control localities upstream of gold mining
– 17 localities in central and western Suriname
– 4 localities at the coast of Suriname
• 5 communities, 3 in Greenstone Belt, 1 downstream of Greenstone Belt and 1 upstream of Greenstone Belt for fish consumption study and mercury in hair
• Measurement of water quality in the field (pH, conductivity, dissolved oxygen, temperature, turbidity)
• Sampling of water, sediment and fish tissue according to sampling protocol
• Fish caught using gill nets or bought from local fishermen
• Samples transported to laboratory on ice
• Mercury analyzed with mercury analyzer using cold-vapor atomic absorption
• Quality check for all analytic sessions
Why investigate mercury in aquatic
ecosystems ?
• Air and water are transportation
mechanisms; provide one-moment in time
data
• Terrestrial soil data spatially very variable
• Mercury bound to sediment in aquatic
environment
• Mercury bio-accumulated in fish
Serrasalmus rhombeus
0
0.5
1
1.5
2
2.5
3
3.5
0 5 10 15 20 25 30 35 40 45
Standard length (cm)
Hg
(m
g/k
g)
Gold mining areas
Brokopondo Reservoir
Piki Pada
Upstream gold mining
Western Suriname
Hoplias aimara
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 10 20 30 40 50 60 70 80 90
Standard length (cm)
Hg
(m
g/k
g)
Gold mining areas
Upstream gold mining
Western Suriname
Natural mercury emission sources
• Geologic weathering
• Volcanism
• Evaporation from waters
• Plant transpiration and decomposition
Anthropogenic mercury emission
sources
• Producers of mercury and its compounds
• Consumers of mercury and its compounds
• Burning of fossil fuels
• Pyrometallurgical processes
• Forest fires
Estimated annual anthropogenic Hg
emissions ( in 103 kg Hg yr-1)
Gold
mining
Biomass
burning
Industry
Brazil 1. Lacerda & Marins,
1997
2. Meech et al., 1995
77.91
70 - 1702
8.71
88 - 1042
28.91
Suriname 1. Mol et al., 2001
2. UNEP, 2008
201 0.31 0.15-0.62
Where does the mercury come
from in Suriname??
• Gold mining ?
• Naturally in base rock, sediment and soil ?
Roulet et al.(1998): “… the natural burden of the soils is much
more important than potential new inputs of anthropic Hg from
goldmining or biomass burning, representing more than 97%
of the Hg accumulated in soils. Consequently, the deposition
and incorporation of anthropic Hg is negligible and soils could
be considered as a major reservoir of natural Hg”.
Mercury in core samples from floodplains
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Saramacca1
Saramacca2
Saramacca3
Saramacca4
Coppename1
Coppename2
Coppename3
Coppename4
Nickerie1
Nickerie2
Nickerie3 0-5
5-10
10-15
15-20
20-25
25-30
30-35
35-40
40-45
45-50
Results show:
• Relatively high mercury levels in
undisturbed Western Suriname
• No correlation between mercury levels and
distance from Greenstone Belt
• No mercury source in Fallawatra formation
• Mercury in core samples indicate an
anthropogenic origin
• Mercury in floodplain of Coppename River
(undisturbed) on average higher than in
Saramacca River (gold mining)
Mercury evaporated
and transpirated
in gold mining areas
Mercury vapor
transported to SW by NE
tradewind
Wet and dry depositing of mercury in central and
SW Suriname
Mechanism 1:
• Most depositing occurs in areas with high
precipitation (windward side of mountain
ranges)
In polluted rivers much
of the mercury is
bound to the high load of suspended sediments
Mercury-sediment
complex will not easily
pass biological
membranes
Mercury is less
biological available
In pristine rivers the load of
suspended sediments is
less
Mercury is more
biological available
Higher mercury
levels in biota
Mechanism 2:
Conclusions on mercury levels in
aquatic ecosystems in Suriname
• Levels in predatory fish often above norm for human consumption in most of Suriname
• Levels in bottom sediments often high
• Highest levels in Brokopondo Reservoir
• Increased levels in human population
• Also high levels in shallow sea and “pristine” areas in Central and Western Suriname
• Small-scale gold mining is the main cause of increased mercury levels, also in pristine areas
• Pristine areas are polluted by atmospheric transportation of mercury, precipitation and biological availability.
Impacts of mercury on local
communities
• Drinking water usually below norm
(suspended sediments biggest problem)
• Predatory fish often above norm for
human consumption
• Mercury may remain in system for long
time
• Mercury may interfere with public health
and, in worst case scenario also with
development of communities in interior
Phase 1:
• Additional research
• Increase awareness of population, esp.
local communities
• Advocate restricted consumption of large
predatory fish
Phase 2:
• Regulate and control gold mining
operations
• Train gold miners in methods without
mercury (and other environmental
measures)
• Prohibit the import and use of mercury
Present and future research on
mercury levels:
• Extension of human related projects to other
communities in the interior
• Investigate correlation between mercury in fish
and humans and water chemistry (turbidity, pH
and DOC)
• Investigate mercury levels in mud flats at the
coast