Mercury Pollution a Threat to Agusan Marsh

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.


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.


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


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


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


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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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.


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)


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


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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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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Bioaccumulation

Biomagnification

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Bioaccumulation & Biomagnification

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http://www.on.ec.gc.ca/coa/2001/images/mercury-4b.jpg

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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Documents

Mercury Pollution a Threat to Agusan Marsh