Venezuela
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COUNTRY FOCAL POINT: N/A
ASSISTANT TO COUNTRY FOCAL POINT: N/APROJECT SITE:
El Callao, Bolivar State
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DOCUMENTS
Uniidades de Demonsttraciión y Campaña de Educaciión
para Miineros Arttesanalles de Oro.
II FORO INTERNACIONAL SOBRE LA MINERIA EN PEQUEÑA ESCALA,
ESTADO BOLIVAR, VENEZUELA Author: Marcellllo Veiiga
(12-13 de mayo, 2006)
Introducción de
Tecnologías Limpias en la Minería Artesanal de Oro.
II FORO INTERNACIONAL SOBRE LA MINERIA DEL ORO EN
PEQUEÑA ESCALA. Ciudad Guayana, Venezuela. Author:
Pablo Huidobro, ONUDI (12-13 de mayo 2006)
Mercurio y Enfermedades Inmunológicas en Comunidades de
Minería Artesanal de Oro: Una Interacción Peligrosa?
II FORO INTERNACIONAL SOBRE LA MINERIA EN PEQUEÑA ESCALA.
Author: Janis Shandro, Dept Mining Engineering
University of British Columbia (12-13 de mayo 2006)
Contaminación
por mercurio en la minería artesanal en el Bloque B de
El Callao: Evaluación de la salud. II FORO
INTERNACIONAL SOBRE LA MINERIA EN PEQUEÑA ESCALA.
Author: R. Darío Bermúdez Tirado, UNIDO (12-13 de
mayo, 2006)
Mercurio y Cianuro en Minería Artesanal de la Provincia
de El Oro, Ecuador Ing. Author: Patricio C.
Velásquez, UNIDO and University of British Columbia.
(12-13 de mayo, 2006)
Mercury Pollution from Artisanal Gold Mining in Block B,
El Callao, Bolivar State, Venezuela: Health and
Technological Assessment. Authors: Marcello M.
Veiga, Vienna Dario Bermudez, Heloisa Pacheco-Ferreira,
Luiz Roberto Martins Pedroso, Aaron J. Gunson, Gilberto
Berrios. (May, 2004).
Mercury Pollution from Artisanal Gold Mining in Block B,
El Callao, Bolívar State, Venezuela in: Dynamics of
Mercury Pollution on Regional and Global Scales:
Atmospheric Processes, Human
Exposure Around the World, p. 421-450. N. Pirrone &;K.
Mahaffey (Eds), July 2005, Springer Publisher, Norwell,
MA, USA. Contributors: Marcello M. Veiga, Dario
Bermudez, Heloisa Pacheco-Ferreira, Luiz Roberto Martins
Pedroso, Aaron J. Gunson, Gilberto Berrios, Ligia Vos,
Pablo Huidobro, Monika Roeser. (July, 2005)
Mercury Bioaccumulation by Aquatic Biota in
Hydroelectric Reservoirs: Review and Consideration of
the Mechanisms:The Guri Case, Bolivar State, Venezuela.
Paper presented at the 1st International Forum on
Mercury Problems in Hydroelectric Reservoirs, 2001.
Authors: Marcello M. Veiga and Jennifer Hinton, Dept.
Mining & Mineral Process Engineering, University of
British Columbia. (2001)
Advisory
Assistance on Avoidance of Mercury Pollution from
Artisanal Gold Mining perations in Bolivar State,
Venezuela. Author: Marcello M Veiga. March,
1996.
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VENEZUELAThe southern part of Venezuela,
below the Orinoco River, involving State of Bolivar,
State of Amazonas and the Federal Territory of Delta
Amacuro is called Guayana Region. The main mining
activities are conducted in the State of Bolivar which
has an area of 240,528 km², comprising 75% of the
hydroelectric potential of the country. The number of
inhabitants in Venezuela reaches some 24.2 million with
a population density of 26.4 persons per km². In 2000,
87% of the population lived in cities and towns with
more than 2,500 inhabitants. Less than 5% of the
population lived in the Guyana Region. In 1999, the
labor force experienced 1.1% decrease in number
resulting in an unemployment rate of 13.2% (1,365,752
people). In 2000, 63% of the individuals making up the
workforce were men. Unemployment among men reached
12.5%, 1.1% higher than 1999. In 2000, 14.4% of women
did not have a job. This was 1.7% higher than in 1999.
In the Bolivar State, with a population of 1,214,486,
there are about 15,000 people4 directly involved in
artisanal and small-scale gold mining. The number of
artisanal miners and its gold production has been
declined since most artisanal miners working in dredges
in the Caroni River have been removed since 2000 and
many parts of the river are now flooded by four large
hydroelectric reservoirs. Many artisanal miners are now
concetrate in km 88 and El Callao, which is a
traditional artisanal mining site. El Callao is located
in the Northeastern part of the State of Bolivar, 150 km
distant from Ciudad Guayana. Gold was discovered in El
Callao in 1865 and in 1870 a company was established to
produce gold. In 1970, CVG (Government owned company)
incorporated a company, Minerven, which nowadays has two
cyanidation plants producing together approximately 200
to 300 kg of gold/month: Peru Plant processing 5,200
tonnes of material/month and Caratal plant processing
14,000 tonnes/month. About 15% of the Peru Plant
material is Hg-contaminated tailings purchased by the
company from the artisanal gold miners.
The area with high concetration of artisanal gold miners
in El Callao is known as "Block B" which belongs to
CVG-Minerven that rents concessions to small-scale
mining individuals/companies. Miners extract the ore
from 30-80 m deep shafts using explosives and transport
it in small trucks to the Processing Centers (locally
known as "molinos") to be crushed, ground, concentrated
and amalgamated. Based on the average gold production,
the Block B production might be around 1 to 2 tonnes
Au/a considering that there are 28 active Processing
Centers in the area. In all El Callao, the gold
production can reach as much as 5 to 6 tonnes Au/a
considering that there are 80 to 90 Processing Centers
in all region. By using copper-amalgamating plates to
amalgamate the whole ground ore, large amount of mercury
is lost with the tailings. The amalgam recovered from
the plate is burned on a tray or a shovel. Some millers
have good retorts available for miners but the miners
insist that the retorting time is too long (15 minutes)
and they simply use a propane blowtorch to decompose
amalgam, emitting large amount of mercury to the
atmosphere and exposing themselves to mercury vapor.
This is clearly contaminating everyone directly involved
in the ore processing as well as their neighbors, since
the Processing Centers are very near the houses. The
ratio Hglost: Auproduced is around 1.5 to 2. The mercury
emission in Block B is estimated to be between 2 and 4
tonnes/a. In all El Callao, the mercury emission can
reach as much as 12 tonnes/a.
The levels of mercury intoxication of the gold miners
and millers working in the Block B, El Callao,
Venezuela, is one of the most serious in the world. More
than 90% of the sampled individuals working in the
Processing Centers (millers) have Hg levels in urine
above the alert level (5 ?g Hg/g creatinine). . Symptoms
typically associated with chronic exposure at very high
levels of mercury, acute intoxication, long term
exposure at low levels of mercury vapors and long term
exposure at high levels of mercury vapors (e.g. muscular
tremor) were identified in Block B workers and
residents. As a result of indirect exposure of mercury
vapors, it was observed that about 27% of the women have
Hg concentration in urine above the alert level and 21%
above the action level. About 53% of the 62 children
sampled have Hg concentration in urine above the alert
level and 14.5% above the action level (20 ?g Hg/g
creatinine). Almost 10% of the sampled children have
levels of mercury in urine above 100 ?g/g creatinine.
It is urgent the introduction of methods to reduce the
use of mercury in the gold processing phase, such as
gravity concetration, to eliminate the large loss of Hg
to the environment due to the use of copper-amalgamating
plates. Protection for individuals is also urgent.
Different types of retorts must be brought to the
miners' attention to reduce occupational exposure and
emission of Hg vapor.
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