Using mercury in small-scale mining stays a major threat

A woman mixing the sand-filled gold with mercury, a part of the refining process for many small-scale miners in Tanzania. Despite the health risks mercury poses, many still do this with bare hands and no masks.  PHOTO | HALILI LETEA

What you need to know:

  • Despite repeated warnings on the negative effects of mercury, small-scale miners still can’t afford to make the change

Mara/Geita. After a roughly hour-long journey on the back of a motorbike from Mugumu centre in Serengeti district, weaving through a rough, dusty road, we finally see Naigoti-Bukole village in Kyambahi ward. The village is just 15 kilometres away from the renowned Serengeti National Park.

Leaving the main road to the left as we begin approaching the village, you hear the sound of machines, a drilling-like sound that increases the closer we get.

The road is even rougher here, and we are sometimes forced to get off our bike and push it, especially in the dry valleys.

Viewing the village from some 200 metres away, we see some mining pits for small-scale miners. More pits cut across the village centre at another 100 meters, covering an area the size of two football fields.

The drilling sound was coming from here, and it was there that I met Raphael Mwera, one of the mine pit owners with an active license. There are three active licences in that area.

Raphael Mwera, one of the mine pit owners standing next to sand that awaits refinery. PHOTO | HALILI LETEA

He calls for the operator to shut down the machines, and I see a busy field of at least 100 workers, most of them women with no uniforms and some with boots but no gloves. Mwera explained that up to 300 people are employed and up to 5,000 district-wise.

As the dust settles at the drilling site, I see even more people; they had no protective glasses or safety hats, and other people were mixing the soil and water with their bare hands.

We could easily see the silvery-white mercury in the mixtures as we were walking through the fields. Waste water used in soil mixing seeps and accumulates in some holes.

“In evenings like these, most of the workers rest, which is why you don’t find them in uniform,” said Mwera, who is also Chairperson for the Mara Region Miners Association (MAREMA) in Serengeti district.

Mwera said some licences were revoked for those owners who don’t uphold the law. “Even now, one of the licences is on the verge of being revoked due to safety issues,” he adds.

According to the World Health Organization (WHO), mercury is a naturally occurring element that is found in air, water, and soil. Exposure to mercury, even in small amounts, may cause serious health problems and is a threat to the development of the child in-utero and early in life.

Mercury has toxic effects on the nervous, digestive, and immune systems, as well as on the lungs, kidneys, skin, and eyes. Mercury is considered by the WHO to be one of the top ten chemicals or groups of chemicals of major public health concern.

In the gold refining process carried out in this region, mercury is used. “Mercury absorbs the gold in the soil, and that’s why we mix it in the soil; the process helps to get about 25 to 30 percent of the gold, and so we keep the soil for further refining,” Mwera explains.

However, he does believe that mercury is harmful and explains that after the mixing process, they burn the mixture to get gold. This is even more hazardous on account of the fumes it produces for both people and the environment.

According to the production manager of the area, Iddi Kurwa, they buy mercury, which costs between Sh50,000 and Sh70,000 for 20 cubic centimetres, which can get you up to 30 grammes of gold at best or nothing at all, at worst.

This is also echoed by Mr Christhopher Kadeo, a miner in Nyarugusu Geita, who said they buy the same amount, on average, at Sh40,000 from authorised buyers.

On stopping the use of mercury, Kadeo, who is also the Chairperson for the Mwanza Region Miners Association (MWAREMA), says that they use mercury due to the expenses associated with other methods, but they will stop as the government has requested they do.

Back to the workers

Ms Neema Samuel was among the labourers in the mine who were mixing the soil and mercury with their bare hands. She is aware of the dangers of doing so but shares: “They do give us uniforms and gloves, which unfortunately wear out and tear faster than they can give us new pairs.”

“We can’t afford to buy these gloves by ourselves because the pay we get is very little, and we can’t wait for them to get us other pairs either because we have families that depend on us,” she noted. A pair of gloves and a mask cost Sh40,000, and they can only be used for a week or less and are provided once a month.

Another worker, Mr Awilo Abel, who was wearing worn-out shoes and a reflector, also pointed a finger at the working environment and shared that at times they dive into holes with poor equipment.

According to Kurwa, they pay an average of Sh40,000 to Sh60,000 per week, depending on the nature of the work that one does. He agreed with the issue of the need for tool disbursement, noting that the high cost of production is the major cause.

“We don’t have stable electricity or water. “We pump it from our pits, and a gramme of gold is, on average, Sh80,000 before taxes, which can take up to 30 percent of the value,” he said.

Mr Golden Hainga, a miner in Nyarugusu, Geita, said although they have electricity, it has been very unstable recently, which has forced them to use petroleum generators, hence the high costs of production.

Water shortage is a threat

As we were conducting the interview, a group of animals came by and started drinking the stagnant water. I was shocked; they weren’t. It was then that Mr Limbu Maguburu, a village leader, explained that their village has 500 to 600 people, most of whom are labourers in the mine, farmers who depend on rain, and animal keepers.

“We all depend on a single well, and during the dry seasons, the well usually has water from 4 p.m. to 10 p.m. before it dries up again. “We are forced to provide only three 20-litre buckets per household, and some remains for the next day,” he said.

He continued to say that: “We know the effects, and there were cases of animal deaths some years ago due to the contaminated water, so we always advise the villagers to share the little water they do get with their animals. Some do and others opt not to.”

Kyambahi ward counsellor Herman Kinyariri said they are aware of the problems facing the village and, as such, conduct seminars on safety periodically. “For the issue of water, we have a 152-metre well, and we are still lobbying for money from the council to supply better infrastructure.”

According to Mr. Hainga, who is also the Secretary of MWAREMA, they rely on drilling water as well, and he adds that there is a project underway to bring in water from Lake Victoria. This also reflects on the high costs of production.

NEMC on environmental protection

The (NEMC) Director General, Dr Samuel Gwamaka, said they supervise both small and large-scale mining activities by means of staff in all regions and main offices to ensure the environment is protected and people are not harmed.

“We do not favour anyone who spills waste or contributes to noise pollution in the environment. Be it a small or big miner, they are all given the appropriate punishment, including making changes or being banned from carrying out mining activities,” he said.

In the case of noise pollution, Makuburu explained that they have laws requiring that all machinery operate only during the day up to 7 p.m., although some still defy them, claiming that the higher-ups ignore them.

Mercury health effects and alternative methods for gold refining

Health issues

According to Mwera, there are five mining areas with small-scale miners in the Serengeti, which are in the Nyigoti, Melenge, Boringe, Kemorambo, and Majimito districts.

Most of the patients in that area are diagnosed at Majimoto Dispensary. Ms Sophia Nyamwino, a nurse at that hospital, admits that the area has many skin disease issues, coughs, worm-related diseases, and malaria.

A medical doctor based in Dar es Salaam, Mr Daniel Magomere, said that because mercury is a metal, it remains as it is even if it evaporates or is consumed. “One of the effects, if consumed, makes someone lose the ability to sense and feel. It can also have effects on the digestive system because it does not melt, and it also affects the respiratory system,” he explains.

According to him, due to its nature, it can be transferred from animals or from plants that dissolve it in the soil to humans.

Another expert is Mr Emmanuel Mbise, an Environmental Management Specialist who conducted three research projects on mercury use in the Geita and Mara regions, among others. He said the more serious consequences of mercury are found when burning to get the gold, more so than when it comes into contact with the skin.

“People tend to lose their senses and suffer memory loss, and in worst-case scenarios, some can become paralysed,” he said, noting that other immediate symptoms include being quick to anger and giving birth to disabled children.

Mbise, who is also a programme officer with the HakiMadini organisation for the rights of marginalised Tanzanians through research, education, and development projects; said the symptom can easily be observed in places with an old mining history such as Nyarugusu and Mgasa in the Geita region.

In their research, the Foundation to Promote Formal and Legal Artisanal and Small-Scale Mining (ASM) Development (FADev) found that an estimated 25 percent to 33 percent of small-scale gold miners in Tanzania  are affected by mercury. The study also discovered that small-scale gold miners use 13.2 tonnes to 24.4 tonnes of mercury per year.

To reduce human exposure to mercury, the WHO recommended stopping the use of mercury in gold mining, eliminating the mining of mercury, and phasing out non-essential mercury-containing products. In efforts to mitigate the effects of mercury, Mara Reginal Mineral Officer (RMO) Mr Joseph Kumburu told The Citizen that they ensure that the miners uphold the laws, like wearing protective gear, by educating them.

Alternatives to mercury: mitigating the effects

Geita is estimated to have at least 250,000 to 300,000 small-scale miners, the highest in Tanzania, while the Mara region has at least 100,000, according to Mineral Officers in their respective regions.

This also means that these are among the regions with the highest mercury consumption.

According to Deputy Minister for Minerals, Dr Stephen Kiruswa, there is a protocol from WHO for the use of mercury that wants us to stop using it by 2029.

“As a country, we still haven’t strictly enforced that, although we have started to provide seminars and education on user-friendly ways and push for the shift to other methods,” he said, adding that they have a sustainable plan for that, and one possible solution is the use of cyanide.

“If this method is effective, it has much fewer effects than mercury, and even the last redial can be used as fertilizer,” he added.

Mwera said he knows about the protocol, but for now they will proceed with their method as other methods are still very expensive. “I have one mine pit with modern technology that requires no use of chemicals, but I put it on standby as it is very costly to operate,” he explains.

Kurwa also said they failed to shift to other methods because their current method allows them to refine a small amount of soil, while other methods need tonnes of soil. “We need money to pay workers daily or weekly; how long can we wait just to reach 10 tons?”

With regards to other methods, Mbise said there are at least four others apart from mercury that are also effective, even though they too have their share of limitations. “Carbon in Pulp (CIP) is one such method and is effective enough to produce 80 to 90 percent of gold in a load of at least 5,000 tonnes of soil at once,” he mentions.

Although State Mining Corporation (STAMICO) has three small CIPs that can take 10 tons, the demand from miners is high, according to Mr Tiberio Kaduma, the organization’s senior engineer.

“We have three CIPs in Chunya: Mbeya, Rwamgasa, and Kitete. Although we built them for demonstrations, people liked them, and the demand rose,” he said.

According to Kaduma, another method is shaking the table, which is more effective than mercury but not CIP. “The method is effective only if there is gold grain and not gold dust,” he said.

Mbise then mentions cyanide (vat leaching), which needs 20 to 50 tonnes of soil. “This method also has effects on the environment if not managed well, and we know it is very difficult to manage small-scale miners.”

He also mentions Clean Gold, which at the moment is the only method that needs water and machines and is 99 percent effective.

“Although it was very effective in the DRC, Rwanda, and Burundi; the trial in Geita and Shinyanga has failed due to soil texture.” According to Mbise, all these methods are effective and less harmful than mercury, but they require high capital, which is also an issue for small-scale miners.

Government chemist on the use of chemicals

Dr Fidelice Mafumiko, the Government Chief Chemist, stated that World Health Organization (WHO) statistics show that deaths from chemical effects have increased by more than half to 2 million per year.

Knowing that, Mafumiko urged chemical users and importers to follow laws and regulations to avoid harm and death.

“Now if they all understand that when we bring chemicals into the country, there is a system of common recognition for follow-up, people will carry out their activities in accordance with laws and regulations to avoid harm,” he said, noting that the chemicals to which he refers are those that are particularly harmful to their health and the environment.