The process transforms elemental mercury into methyl mercury. Methyl mercury is one of the most toxic organic compounds and a powerful neurotoxin that works its way up the food chain through bioaccumulation
Artisanal small-scale gold mining is recognised as a considerable source of revenue for millions of people in about 80 countries.
Artisanal small-scale mining takes place mostly in the global South—sub-Saharan Africa, Asia, Oceania, Central and South America. However, in Kenya despite being a source of revenue, it has been argued that environmental degradation caused by ASM is growing with the intensification and growth of artisanal mining.
This is further aggravated by the fact that institutions responsible for managing the environment are unable to effectively regulate and monitor for lack of resources.
The practice results in physical environmental damage to rivers, with consequent siltation of rivers, weirs and dams downstream. Some artisanal miners use mercury to recover gold, resulting in contamination of river systems thereby posing the danger of poisoning plant and animal life dependent on these river systems for survival.
Environment and health and safety are some of the effects of artisanal gold mining as it relies on a mostly unskilled workforce using rudimentary tools and techniques. Its environmental, health and safety practices tend to be very poor. For instance, dust and fine particles resulting from blasting and drilling cause respiratory illnesses. It also degrades crops and farmlands, resulting in lost food production.
Streams and rivers often become polluted near ASM sites, which make water unsafe for drinking and can also affect fish stocks relied on for food. Artisanal and small-scale mining is also the source of the largest releases of mercury, estimated at 1,400 tonnes per year in 2011 according to the Minamata Convention.
Exposure to mercury can have serious health impacts, including irreversible brain damage. Mercury is also difficult to contain and can be toxic at even very small doses. It can be transported long distances by air or water, poisoning the soil and waterways, and eventually.
Also, cyanide is used in the extraction of gold from low-grade ore by converting it to a water-soluble complex, but it is also one of the most poisonous and toxic chemicals known to mankind.
When introduced to the human body in large quantities, it prevents cells from using oxygen and eventually they die. It also affects the heart, the respiratory system and the central nervous system, leading to seizures, breathlessness and cardiac arrest.
Impacts of artisanal small-scale gold mining include deforestation, land degradation, deterioration of water and air quality, depletion of water resources, loss of grazing land and the overall reduction in biodiversity. The nature of the mining activity promotes the destruction of large tracts of land through deforestation and land degradation.
The practice has also become the worst enemy of water, air and the general biodiversity posing a threat to the ecosystem survival. Environmental degradation has reduced the capacity of the ecosystem to meet the future needs of people for food and other products, and to protect them from flood and drought hazards.
Degradation and loss of the ecosystem are capable of worsening already negative impacts on human well-being such as reduced availability of goods and services to local communities, diseases and reduced economic activity.
The gold panning process on the river banks, beds and the surrounding areas discharges huge amounts of loose silt and heavy metals into the river system. A better understanding of the processes that lead to environmental problems can help promote environmentally friendly gold mining practices.
Soil and water quality are sensitive variables as they are the main drivers of ecosystems. Gold panners use mercury to accomplish the concentration and amalgamation process. Mercury is a harmful substance to humans, animals and aquatic life, either indirectly or directly through bioaccumulation in the food chains.
The use of mercury in the extraction and processing of gold, therefore, is posing a threat to humans and aquatic life. According to a UNDP report in 2005, mercury is a poisonous substance when either inhaled or washed away. It causes lung cancer and skin disease if inhaled and if washed away during the amalgamation process, it settles into the surrounding environment, where it is absorbed and processed by a variety of living organisms.
Mercury used by panners is discharged in an abusive manner into ecosystems. UNDP in its report further noted that the amalgamation process transforms mercury into a highly toxic substance.
“The process transforms elemental mercury into methyl mercury. Methyl mercury is one of the most toxic organic compounds and a powerful neurotoxin that works its way up the food chain through bioaccumulation,” it noted.
Technological alternatives and environmentally friendly practices are critical to tackling chemical usage in ASM.
However, while technical alternatives exist, they are not always applicable due to geological, socioeconomic, cultural and other site-specific factors.
One barrier to adopting cleaner technologies for mining communities is cost-effectiveness; the technology must increase the amount of minerals recovered and reduce efforts. Also, ASM operators are usually risk-averse and will not change their practices until the benefits have been clearly demonstrated to them.
Therefore, there is need for mobilisation of human capital and resources that will help in coping with mining impacts.
Secretary, National Environmental Complaints Committee [email protected]
