mercury pollution a threat to agusan marsh
TRANSCRIPT
Mercury Pollution: A threat to Agusan Marsh
Elnor C. RoaMSU-Naawan
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- occurs naturally in the environment and exists in a large number of forms.
- a constituent element of the earth ( like lead or cadmium)
Mercury
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Mercury
-“heavy metal” because it is
very dense. A cup of
mercury, for example,
weighs more than three
kilograms; that’s nearly
fourteen-times heavier
than a cup of water
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Mercury Pollution
The Minamata tragedy
The hazards of methylmercury poisoning received international attention in 1956 when many of the residents of Minamata, Japan, became seriously ill, or died, after eating the fish and shellfish in Minamata Bay.
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The Iraq Hg poisoning incident
-1971
-6,500 people were hospitalized and more than 400 died after eating wheat grain treated with a methylmercury fungicide
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Status of Mercury Pollution
One of the biggest mining operations in the Philippines is located in Diwalwal, one of the Barangays in the municipality of Monkayo, in Compostela Valley.
Mercury pollution in the Philippines
-is mainly due to the presence of small-scale mining.
the most controversial small-scale mining area in the Philippines due to mercury pollution.
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highly environmentally sensitive because of its location.
Status of Mercury Pollution
Figure 1 . Map showing the Agusan Marsh area7
The creeks around Diwalwalflow into the Mamunga and Naboc rivers that in turn drain into the Agusan River, which is about 24 kilometers away from the mining site
Hence, the impact of mercury pollution due to mining in Diwalwal extends far beyond the site.
The provinces of Agusan del Sur and Agusan del Norte that are crossed by the Agusan River to Butuan Bay are also affected.
Status of Mercury Pollution
Table 2. Estimated annual mercury consumption in various gold rush areas in Davao Region
Gold Rush Area Estimated Number of Establish- ments
Estimated Monthly Hg Consumption
Estimated Monthly THg ConsumptionIn kilogram
Estimated Total Annual Mercury Consumption in kilogram
Diwalwal 318 1 to 1.5 477* 5,724*
Boringot 60 1 60 720
Biasong 50 1 50 600
Diat 199 1 199 2,388
Panganason 49 1 49 588
Gumayan 30 5.5 165 1,980
Bango 37 2 74 888
Lumanggang, Maco 7 1 7 84
Lumanggang, Pantukan
21 1 21 252
Inopuan-Saravan 25 1 25 300
GRAND TOTAL 796 13,524
Source of Basic Data: Mines and Geoscience Bureau, Region XI, Davao City cited by Ed. B. Prantilla & C. Martinez in Heavy Metals Contamination in Davao RegionNote: Asterisk means the figure uses the 1.5 kilograms average monthly consumption.
Estimated Total Annual Mercury Consumption 13,524 kg
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Table 3. Mercury levels (ppm) in fish samples from seven sampling stations, Davao City, 1982
Status of Mercury Pollution
Station/ Sample
September October November
Fish Hg in ppm Fish Hg in ppm Fish Hg in ppm
Tibungko 123
Tabangko 0.175 Matambaka 0.027 Matambaka 0.018
Matambaka 0.202 Barilis 0.270 Matambaka 0.026Tamban 0.147 Matambaka 0.026 Bilung-bilung 0.015
Ilang 123
Samin-samin 0.186 Manalangsi 0.474 Matambaka 0.201
Moro-moro 0.149 Tulingan 0.504* Biling-bilung 0.142
Dangit 0.371 Barilis 0.941* Bilung-bilung 0.182
COACO 123
Dangit 0.079 Timbungan 0.0.28 Moro-moro 0.032
Dangit 0.038 Matambaka 0.028 Matambaka 0.098Dangit 0.023 Tulingan 0.134 Tulingan 0.055
Bucana 123
Tangigue 0.622* Barilis 0.776* Timbungan 0.449
Maya-maya 0.497 Barilis 0.922* Matambaka 0.224
Barilis 0.560* Barilis 0.936* Bilung-bilung 0.309Times 1
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Moro-moro 0.249 Matambaka 0.048 Timbungan 0.414
Pirit 0.202 Tulingan 0.064 Moro-moro 0.403
Matambaka 0.121 Matambaka 0.080 Tulingan 0.771*
Godo 123
Tangigue 0.230 Barilis 0.342 Barilis 0.177Barilis 0.702* Barilis 0.164 Tulingan 0.154
Barilis 0.819* Barilis 0.294 Barilis 0.228
Guinoo 123
Buga-ong 0.178 Barilis 0.650* Moro-moro 0.416
Diwit 0.144 Diwit 0.628* Barilis 0.500Tangigue 0.132 Diwit 0.549* Barilis 0.502*
Source: Rosita Fundador, “Environmental Quality of Coastal Waters of Davao City with Special Reference to Pollution”, Ph.D. Dissertation, University of the Philippines, August 1984 (Unpublished), Table 17 as cited by Prantilla & Martinez Heavy Metals Contamination in Davao Region10
Status of Mercury Pollution
Table 4. Mercury levels (ppm) in shellfish samples from seven sampling stations, Davao City, 1982
Station/ Sample
September October NovemberShellfish Hg,ppm Shellfish Hg, ppm Shellfish Hg, ppm
Tibungko 1
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Trachycardium egmontianum
0.158 Anadara cepoides 0.554* Lingula anatifera 0.074
Polinices sp. 0.122 - do - 3.378* Venus euglypta 0.095
Oliva sp 0.118 Gafrarium tumidium 1.931* Gafrarium tumidium 0.038
Ilang 1
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Gafrarium tumidtum 0.162 Terebralia sp 0.766* Nerita sp 0.141
- do - 0.351 Turbo sp 0.760* Nerita sp 0.114
- do - 0.413 Nerita sp 0.664* Nerita sp 0.254
COACO 123
Cypreae arabica 0.063 Andara antiquata 0.060 Venus euglypta 0.103
- do - 0.028 - do - 0.107 Gafrarium tumidium 0.058
- do - 0.049 Gafrarium tumidium 0.026 Gafrarium tumidium 0.063
Bucana 123
Lingula anatifera 0.439 Tivela sp 0.084 Hydrobia sp 0.238
Tivela sp. 0.520* Tivela sp 0.085 Tellina sp 0.241
Tivela sp 0.504* Tivela sp 0.069 Tellina sp 0.142
Times 1
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Venus mercenaria 0.066 Venus mercenaria 0.086 Venus mercenaria 0.046
Tivela sp 0.069 - do - 0.101 - do - 0.145Venus mercenaria 0.081 - do - 0.120 - do - 0.150
Godo 123
Haliotis sp. 0.545* Haliotis sp. 0.291 Haliotis sp. 0.097
Haliotis sp. 0.535* Haliotis sp. 0.226 Haliotis sp. 0.175
Haliotis sp. 0.287 Haliotis sp. 0.257 Haliotis sp. 0.096Guinoo 1
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Nerita sp. 0.153 Terebralia sp 0.254 Tellina virgata 0.071Tellina virgata 0.263 Terebralia sp 0.408 Tellina virgata 0.061Anadontia sp. 0.250 Terebralia sp 0.272 Terebralia sp 0.016
Source: Rosita Fundador, “Environmental Quality of Coastal Waters of Davao City with Special Reference to Pollution”, Ph.D. Dissertation, University of the Philippines, August 1984 (Unpublished), Table 17 as cited by Prantilla & Martinez Heavy Metals Contamination in Davao Region11
Status of Mercury Pollution
Table 6. Mercury Levels in Human Population
Source: a Dr. Nelia C. Maramba (Consultant, Occupational Toxicology Program, DOH and Head, UP NPCIS) and Dr. Cristina S. Dablo (MOH, Officer in Charge, NCDCS DOH), “Executive Summary on The Health and Toxicological Assessment Activities Undertaken in Diwalwal and Apokon (Tagum City), Davao del Norte”, 1996
b based on the presentation of Dr. Annabelle Yumang of DOH XI on the findings of the study conducted by DOH XI to the Economic Development Committee (EDC) of the Regional Development Council (RDC), Region XI as recorded by the EDC Secretariat on the levels of mercury contamination in the blood and hair samples of the miners living in Mt. Diwata and the soil sediments in Mt. Diwata and fish samples from Davao Region[1].
Sample/Site Hg conc., ppb Remarks
Blooda
(114 school children)0.48-13.68 24/114 – exhibited Hg
blood levels more than 10 ppb
Blooda
urinea
(70- miners, field personnel & residents in Diwalwal)
2.25-26.23
0.79-99.23
6/70 – registered Hg blood levels more than 20 ppb
3/70 – exhibited elevated Hg urine levels<50 ppb
bloodb
(75 directly involved in gold mining, 25 coming diff.
sectors)
3.51-299.99 60% of those who are directly involved in gold mining & 12% of those w/ no direct exposure - Hg blood levels <
15 ppb
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Status of Mercury Pollution
Table 7 . Mean concentrations and ranges of Hg in rice grains sampled in the vicinity of the communal irrigation area (metal values are μg/g dry weight, unless otherwise stated)
Rice grain Mean Range
Polished + cooked 0.015 0.006-0.037
Polished + no t cooked
0.018 0.008-0.050
Unpolished 0.020 0.001-0.043
Dry weight 0.021 0.009-0.058
Wet weight 0.016 0.008-0.050
Source:Appleton et al. 200614
Much lower Hg concentrations (0.05-0.99 mg/kg) within the range expected for uncontaminated soils, characterize soils on which corn and bananas are cultivated, largely because these are not irrigated with Hg-contaminated water from the Naboc River.
Status of Mercury Pollution
Venezuelan Miner burning amalgam to separate gold from
mercury (Photo: UNIDO)15
-The estimated total weekly MeHg intake for a person living in the Naboc area related to the weekly consumption:
2.1 kg of rice = 15 ug MeHg1 kg of fish = 220 ug MeHg100 g of mussels = 50 mug MeHg
total = 285 ug MeHg
equivalent to 4.75 ug/kg bw for a 60 kg adult(nearly three times the PTWI of 1.6 ug/kg bw)
Status of Mercury Pollution
Sample Suspended sediments
Bottom sediment
Surface sediment
Naboc River
52-166 ppm
13 - 55 ppm
Agusan Riverabove Naboc River
Agusan River near
Butuan Bay
<0.04-2 ppm
0.1 ppm
Mamunga River & Tributaries
5-84ppm
2-51ppm
Appleton et al., 2006Roa, 2001
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0.04-1.15ppm
Comparison of Hg levels in sediments collected from upstream & downstream of Agusan Marsh
Total Hg concentration range in selected plants collected in Agusan River (January 2001).
Cyperus alternifolius(0.33 - 0.77 ppm THg)
Lumnitzera sp. (0.16-0.22 ppm THg)
E. Crassipes(38.32- 236.16 ppm THg)
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Johnius vogleri (dulama) (0.19 ppm THg) Gobius guirus
(0.24 ppm THg)
Total Hg concentration range in selected fish species collected in Agusan River (January 2001) & Butuan Bay.
Tuway = 0.056 ppm THg
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Source: Resource & Ecological Assessment of Butuan BayMSU-NaawanMercury content of selected fish and aquatic plants in Agusan River & EstuaryRoa, EC, MSU-Naawan
Status of Mercury Pollution
An Initial Geochemical Assessment ofThe Agusan Marsh in Mindanao
Uncorrected draft report, not official reference
A project supportred by VSO & Ecocaritas Association
Surface Sediment Samples (4/2006)Lapag Creek – 1.07 ppmDinagat Lake – 0.37 ppm
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Status of Mercury Pollution
Gold Ore
Manual Crushing
Amalgamation/Rod milling
Lime + waterHg
Amalgam separation
Blowtorching
AmalgamBorax
Sponge Gold(14-16 Carats)
Tailings
Hg Vapor
Diagram of the Amalgamation Process In Small-Scale Mining21
Mercury released to the atmosphere — either directly or indirectly — may do one of three things
It may fall out near the point where it is emitted (local deposition)
It may also be transported long distances before it is deposited at some point downwind. If this takes place within several hundred kilometers - regional deposition
Or it could be transported great distances and enters to the global atmospheric mercury pool.
THE TRANSPORT and DEPOSITION OF MERCURY
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Effects of mercury
Mercury and methylmercury - are referred to as nerve toxicants or neurotoxicants
- affect the central nervous system, causing a number of serious disorders.
Neurological and behavioral disorders in humans have been observed following inhalation of elemental mercury vapor. Specific symptoms include:
-tremors, emotional lability, insomnia, memory loss, neuromuscular changes, and headaches.
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In addition, there are effects on the kidney
and thyroid.
High exposures have also resulted in death.
Ecological and wildlife effects: Biological conversion, uptake, and build-up of mercury in food webs
There are three properties of methylmercury that makes it particularly harmful to humans and other organisms
- it persists,
- and it bioaccumulates or builds up in organisms and up along the food chain,
- it is toxic to most life forms
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Ecological and wildlife effects: Biological conversion, uptake, and build-up of mercury in food webs
Bioaccumulation
Biomagnification
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Ecological and wildlife effects: Biological conversion, uptake, and build-up of mercury in food webs
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Bioaccumulation & Biomagnification
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1. Natural sources
2. Currentanthropogenic
releases from the mobilization of Hg
in raw mat’ls
3. Currentanthropogenic
releases resulting from Hg used intentionally in
products & processes
4. Re-mobilizationof historic
AnthropogenicHg
The releases of mercury to the biosphere can be grouped in four
categories :
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Sources and cycling of mercuryWays for Hg Reduction in the Environment
Releases Mostly beyond Human control
Reduce consumption Use alternate raw materials
“pollution prevention”
1. Reducing mercury mining and
consumption of raw materials and
products that generate releases;
2. Substitution of products
and processes containing or
using mercury;
3. Controlling
mercury
releases through end-of-
pipe controls
4. Mercury waste
management.
Ways for Hg Reduction in the Environment
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