1. Environmental and Health Assessments
Global Mercury Project
Environmental and Health Assessments
Summary of Results
AJ Gunson
Marcello M Veiga
Lao PDR, 2003

2. Global Mercury Project
In collaboration with UBC Dept of Mining Engineering
Senegal
Guinea
Sudan
Venezuela
Laos
Indonesia
Suriname
Cambodia
Ghana
Tanzania
Brazil
Ecuador
Mozambique
Zimbabwe
Started on Aug. 2002
it will last until Sept 2007

3. Objectives Global Mercury Project
Environmental, health & socio-economic evaluation
Create policies to insert artisanal mining into the formal society; suggest legislations
Education of miners and communities
Improve gold recovery; building equipment
Reduce mercury exposure and emission
Evaluate mercury mobility in water streams

4. Key Environmental Assessment Findings
Two MAIN SOURCES of Hg pollution from ASM
Miner burning amalgam in an open pan
The whole ore is amalgamated using a Hg-Copper plate

5. Outline of the Environmental Problem Findings
Global Mercury Project
Outline of the Environmental Problem Findings
Hg emissions range from 2 kg/a in the project site in Laos to 23 tonnes/a in the project site in North Sulawesi, Indonesia
Mercury does not stay in water
Mercury is not travelling far in the streams except in Brazil and Indonesia: use of dredges and hydraulic monitors increase water siltaton and Hg transportation

6. Outline of the Environmental Problem Findings
Global Mercury Project
Outline of the Environmental Problem Findings
How far is Hg vapor going?...hard to answer
Amalgamation of the WHOLE ORE is the MAIN cause of Hg pollution of water systems
Mercury methylation is occurring in Brazil, Indonesia and Zimbabwe due to the use of Hg and cyanide together
High levels of CH3Hg in fish in these countries
Cyanidation of Hg-contaminated tailings exaccerbates methylation

7. Global Mercury Project
GMP sites
Mean Hg in fish
(ppm or mg/kg)
Number of samples
Brazil São Chico
2.53 73
Creporizinho
0.36
161
Indonesia Galangan
0.21
264
Talawaan
0.58
156
Laos Luang Prabang
0.066 65
Sudan Blue Nile
0.05
108
Tanzania Rwamagasa
0.13
285
Zimbabwe Kadoma
0.41 52

8. Main Findings Hgo CH3Hg in fish Hgo vapor lungs
Global Mercury Project
Main Findings
Amalgamation of the Whole Ore
Huge Hg losses, large environmental problem
and/or
Cyanidation of Hg-contaminated tailings
Hgo CH3Hg in fish
Hgo vapor lungs
Burning Amalgams in Pans
Health problem for miners, family and neighbors

9. Amalgamation of the Whole Ore = Lots of Hg is lost to the Environment
Global Mercury Project
Amalgamation of the Whole Ore =
Lots of Hg is lost to the Environment
Use of Copper Amalgamation Plates Generates High Hg-Tailings
Zimbabwe, 2005

10. Amalgamation of the Whole Ore = Lots of Hg is lost to the Environment
Global Mercury Project
Amalgamation of the Whole Ore =
Lots of Hg is lost to the Environment
Adding Hg into the Grinding Circuit
About 20 tonnes/a of Hg are lost
Indonesia, Talawaan, 2001

11. Hg-contaminated tailings are submitted to cyanidation in Zimbabwe
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in Zimbabwe
Tailings from the Hg-copper plates are submitted to cyanidation
Hg becomes soluble and bioavailable (easier to be methylated)
Zimbabwe, Kadoma, 2005

12. Hg-contaminated tailings are submitted to cyanidation in Indonesia
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in Indonesia
Tailings with Hg cyanide are poorly stored and reach the streams
North Sulawesi, Indonesia, 2005

13. Hg-contaminated tailings are submitted to cyanidation in Brazil
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in Brazil
Abandoned cyanidation heap in São Chico, Brazil near a water stream
Hg-cyanide in tailings reach the rivers
Brazil, São Chico, 2003

14. Carnivorous fish, Ave = 4.16 ppm Hg Non-carnivorous, Ave = 1.33 ppm Hg
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in São Chico, Brazil
Carnivorous fish, Ave = 4.16 ppm Hg
Non-carnivorous, Ave = 1.33 ppm Hg
60% of fish >0.5 ppm Hg
One fish sample = 22 ppm Hg
WHO max guideline for edible fish = 0.5 ppm Hg

15. Hg-contaminated tailings are submitted to cyanidation in Ecuador
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in Ecuador
92 cyanidation tanks in the town of Portovelo
Portovelo, Ecuador, 2007

16. Hg-contaminated tailings are submitted to cyanidation in Ecuador
Global Mercury Project
Hg-contaminated tailings are submitted to cyanidation in Ecuador
Tailings with Hg cyanide are dumped into the Amarillo River
Portovelo, Ecuador, 2007

17. Cyanidation of Hg-contaminated Tailings
Occurring in
Brazil
China
Colombia
Ecuador
Indonesia
Peru
Philippines
Zimbabwe
China, 2002
Photo AJ Gunson

18. Outline of the Health Problem Findings
Global Mercury Project
Outline of the Health Problem Findings
High levels of Hg in lungs and urine of miners in all pilot countries (exposure to Hg vapor)
URINE:
Highest average in Zimbabwe = 35.7 µg/g creatinine
Highest value in North Sulawesi, Indonesia = 1,697 µg Hg/g creatinine
Normal level = 0.5 to 5 µg/g creatinine
High levels of neurological problems in miners and people living around the mining operations

19. Outline of the Health Problem Findings
Global Mercury Project
Outline of the Health Problem Findings
Relatively low Hg in HAIR (exposure to methylmercury from fish ingestion):
Highest average in Zimbabwe and N. Sulawesi = 4.5 and 4.4 ppm Hg
Normal level = 0.4 – 3.2 ppm Hg
Low fish availability and consumption in mining sites

20. Hg occupational exposure is… obvious
Problems with Hg vapor
Hg occupational exposure is… obvious
Venezuela, 1995

21. Hg in the Expired Air
Normal levels depends on the number of Hg-dental fillings; usually between 10 and 300 ng/m3
Miners have between 1,000 and 60,000 ng/m3
Mozambique, 2005

22. Hg in the Expired Air Indonesia, 2005
LUMEX portable atomic absorption bought by GMP to all project countries
Mozambique, 2005

23. Retorted Au still has 2 to 5% Hg
Brazil, 1990

24. Retorted Au (still with Hg) is sold to gold shops and melted: Hg vapor is released in the villages...
Brazil, 1990

25. …contaminating neighbors
Brazil

26. In Indonesia, miners burn amalgams in
a grocery store
Indonesia, Kalimantan, 2005
Indonesia, Bogor, 2005

27. Cilantro is a candidate being investigated in the lab
Global Mercury Project
Reducing the Negative Health Impacts of Mercury Exposure Using Native Food Plants as Scavengers
GMP/UBC/Smith-Nagal Foundation is investigating antioxidant protection in the prevention of mercury toxicity
Potential for the use of local plant foods to remove mercury from miners’ bodies. Particularly useful are those plants with antioxidant and chelating properties
Cilantro is a candidate being investigated in the lab