Use of mercury in local mining at Lorgorien area in Kenya

Located in western Kenya, Lorgorien is part of the extensive gold-rich areas and has attracted prospecting and mining companies that want a share of these mineral deposits. Besides the licensed companies operating in this area, small scale miners influx the region and are actively involved in artisanal gold mining (AGM), a subset of great environmental health concern. It’s during this process of mining that mercury is used to hold to hold together the gold particles while washing the crushed stones, a process done using bare hands.

The fact that the workers are in direct contact with the mercury element means that they are exposed to the many health risks associated with mercury. You’ll find women and underage children deeply rooted in these activities, perhaps ignorant of the eminent hazards of health risks. In fact, a study conducted by Aduwo, D.O (2012) found out that mercury is widely used in the processing of gold with majority of the miners (64%) indicating low awareness to mercury toxicity.

Despite its positive contribution to social and economic development, small scale gold mining is often characterized by improper handling, unintentional spillage and dumping into rivers and waterways of the mercury used to purify the gold. The health effects of mercury remain poorly studied in Kenya, and especially in Lorgorien area and thus the need for both scaling up awareness campaigns on what mercury does to human health and on-site training of miners on safe and healthy mining practices. Local miners dump waste with high concentration of mercury on open lands which then vaporized while others absorbed into the soil. This is dangerous as it finds its way into water bodies where human beings drink it or inhale the contaminated air. “Mercury is a heavy metal and its heavy consumption can lead to cancer and Deoxyribo Nucleic Acid (DNA) mutilation resulting to birth deformities”, explains Nyakinye, the regional geologist.

This mercury eventually finds itself either on land or in water, the latter being the most probable outcome as rain water washes the mercury elements on land into rivers and streams. Some of the mercury is ‘pumped’ into the air through the process of burning and thus being availed to humans and other organisms for inhalation. On land, the mercury element is transformed into organic mercury by bacteria and this improves the fertility of the soil. Farmers are therefore ‘lured’ into planting crops on this land not knowing the dangers of this. The crops are able to absorb the mercury which then bioaccumulates naturally in the plant tissue and is eventually biomagnified across the food chain. What this means is that, humans, being at the top of the food chain, have a higher percentage of mercury concentration thus being at a greater risk. The process does not end here! In water certain microorganisms can change it into methyl mercury, a highly toxic form that builds up in fish and in other organisms that eat fish. The methyl mercury is again biomagnified across the food chain, with humans getting the largest concentrations. If used for human consumption, the water in rivers and streams poses a risk to human health as it contains high concentrations of mercury depositions from surface runoff.

The dangers and risks associated with mercury on humans is a major concern as rampant cases of disorders and diseases emerge with every passing day. Since mercury is odorless, invisible and accumulates in the meat of the fish, it is not easy to detect and can't be avoided by trimming off the skin or other parts. Once in the human body, mercury acts as a neurotoxin, interfering with the brain and nervous system.

Exposure to mercury can be particularly hazardous for pregnant women and small children. During the first several years of life, a child's brain is still developing and rapidly absorbing nutrients. Even in low doses, mercury may affect a child's development, delaying walking and talking, shortening attention span and causing learning disabilities. Less frequent, high dose prenatal and infant exposures to mercury can cause mental retardation, cerebral palsy, deafness and blindness.

In adults, mercury poisoning can adversely affect fertility and blood pressure regulation and can cause memory loss, tremors, vision loss and numbness of the fingers and toes. A growing body of evidence suggests that exposure to mercury may also lead to heart disease.

The solution to these problems is not in inciting the locals against the practice of mining that has for long been an important socio-economic pillar. No! The government in collaboration with the county leadership should find a better solution to this problem. This can be achieved through sensitization among the locals on the effects of small-scale mining on the environment and health of the miners. There should be better cooperation between the mining companies and the local miners such that the companies employ the local residents in their mining activities. The government, through agencies such as NEMA should see to it that the miners working in the caves are provided with full protective gear to avert any possibility of direct contact with elemental mercury. Helmets should be a priority and the use of modern technology in mining should be encouraged. The locals can also start up community based organizations (CBOs) so as to pool resources and purchase required equipment for the mining processes. This will improve the effectiveness of the mining process and thus the revenue collected.