The Centre for Trade Policy and Development (CTPD) says healthy miners and a safe environment are critical aspects of promoting responsible and sustainable supply chains in the artisanal and small-scale gold mining sector.
Although the sector is increasingly becoming a source of hope for many people who cannot get jobs in the formal sector, the income from this sector comes at a cost.
Miners are susceptible to inhaling, absorbing and ingesting chemicals throughout the mining process.
The most common chemical exposures in ASGM are to: mercury used to amalgamate the gold; cyanide used to extract gold, for example from tailings; and other chemicals contained in dust and gases.
People can be exposed to two forms of mercury in an ASGM context: elemental mercury and organic mercury.
Elemental mercury is used in the ASGM process to form gold amalgam. The most important direct route of exposure is by inhalation. Highest concentrations of elemental mercury vapours are released when the gold amalgam is heated, for example during the open burning step.
This heating process may occur onsite, or at gold shops, or at processing centres, many of which are located in populated areas. Individuals working in or living nearby these facilities and can thus be heavily exposed to elemental mercury vapour, often to degrees that exceed World Health Organisation recommended limits. Due to its high volatility, elemental mercury can transform from its liquid state into vapour at typical room temperatures.
Individuals can be exposed to elemental mercury vapour if liquid mercury is not properly stored or if surrounding surfaces have been contaminated. Mercury can also volatilize from contaminated waste materials at mining sites. Only small amounts of ingested elemental mercury, for example coming from contaminated hands, get absorbed in the gastrointestinal tract. Elemental mercury intoxication manifests in neurological, kidney and autoimmune impairment. Symptoms may intensify and/or become irreversible as exposure duration and concentration increase. Acute inhalation can directly affect the lung, causing airway irritation, chemical pneumonitis, and pulmonary oedema, with consequent chest tightness and respiratory distress.
High inhalational exposures can also lead to respiratory failure and death. Systemic absorption of elemental mercury via the lungs causes nausea, vomiting, headache, fever, chills, abdominal cramps, and diarrhoea. When ingested, elemental mercury causes direct irritation of the gastrointestinal tract.
Chronic, lower level exposure to elemental mercury causes gingivostomatitis, photophobia, tremors and neuropsychiatric symptoms such as fatigue, insomnia, anorexia, shyness, withdrawal, depression, nervousness, irritability and memory problems. It can also cause damage to the peripheral nerves and kidneys. Elemental and inorganic mercury toxicity in children can also manifest in oedematous, painful, red, desquamating fingers and toes (acrodynia), as well as hypertension.
There’s need for the government to move in to control things.