Health risks posed by the use of mercury

Monday October 11 2021
Mercury PIC

Artisanal and Small-Gold Miners (ASGM) in Tanzania.

By Hellen Nachilongo

Dar es Salaam.  Artisanal and Small-Gold Miners (ASGM) in Tanzania continue to use mercury without using protective gear, despite the health hazards posed by the toxic substance. Over 30 percent of small gold miners have been badly affected by mercury.
Between 13.2 and 214.4 tonnes of mercury are used in the country every year, with artisanal miners - around 1.2 million in all - being the largest number of users. Between 10 and 20 percent of all the gold produced in Tanzania is produced by small scale miners, about 30 percent of whom are women.
Inhaled mercury causes neurological problems and other health issues, and the communities around the mines are likely to get affected due to mercury contamination of water and soil. Mercury emissions from mining activities are also said to lead to both physical and mental disabilities in children.
The majority of female miners in Chikoa/Noli in Dodoma Region who spoke to The Citizen claimed they were not aware of the health risks associated with mercury. Many thought it was safe since they have been using it for years without getting affected.
A small scale miner, Celina Joseph, 46, who is a resident of Chikoa, has been working in the small mining industry for over 27 years. Celina - who lost her husband ten years ago - believes that mercury does not have any ill-effects because she has been using it for over two decades and has never experienced any related health problems.
“Before my husband died, we used to work together in several mines. The Chikoa Mine is the fourth I am working in - and have never been ill because of using mercury,” said Celina.
Despite having been sensitised on the importance of wearing protective gear when mining, Celina goes about her activities without any physical protection.
According to her, mining helps her put the food on table, as well as keep her five children at school. One of her children is now a teacher working in Mbeya and is in the process of building her (Celina) a house.
Another small scale miner at the Chikoa/Noli mine, Mariam Omary, 34, said the miners don’t use protective equipment like gloves, gumboots and mining face masks because they cannot afford to buy them. She says they have been sensitised to use alternative mining technology. ... “We use mercury to extract gold with our bare hands because we cannot afford to buy protective equipment,” said Mariam.
Mariam has been working as a labourer at the mine for four months now, where she is paid between Sh4,000 and Sh5,000 per day. She said the majority of women at the mine are specifically employed to crush the gold-bearing gravel and wash the gold concentrate powder.
The Environment director at the Vice President’s Office, Mr Andrew Komba, said mercury is one of the top ten chemicals of global public health concern owing to its persistence in the environment, long distance transport, bio accumulation and high toxicity.
A few years ago, Mr Komba toured Minamata City in Japan and visited one of the industries that produced mercury from some 1300 years ago. The side effects of producing mercury started showing over 600 years later, in the 1930s. Therefore people who were born in 1930 and later became victims of mercury effects.
In Tanzania, mercury is still largely used in different sectors. But, the biggest challenge is in the way it is disposed of. The government is currently working hard to ensure miners adopt alternative technology when searching for gold.
An Environmental engineer in the Vice President’s Office, Mr Kamkuru Maganya, said joint efforts are needed to prohibit the illegal and easy accessibility of mercury to prevent health hazards and loss of jobs to more than a million artisanal and small-scale gold miners who are exposed to toxic levels of mercury in their search for gold.
He said although the government has not banned the use of mercury, its importation is informal as there are no official records based on the information provided by the Government Chemist Laboratory Authority.
“Mercury is illegally imported into the country through Sirari, Namanga, Dar es Salaam and Tunduma,” said Kamkuru, adding that measures are being taken to ensure construction of sluice boxes at the mines. He said the move is likely to control water contamination as the amount used to wash gold concentrates is directed to designated streams.
Mr Kamkuru made the remarks during a seminar on the Minamata Convention on mercury held in Dodoma Region recently. The meeting brought together environment stakeholders and journalists under the umbrella of the Journalists’ Environmental Association of Tanzania (JET).
He stressed that mercury was mostly used in production of medical equipment, researches, industries and laboratories.
The government developed a five-year National Action Plan (NAP) for Artisanal and Small Scale Gold Mining (2020—2025) as part of its efforts to reduce the use of mercury among small scale miners by 30 percent, increase public awareness on the impact of mercury, promote adaptation of mercury control and capture technologies as well as introduce mining technologies that do not require mercury use.
The control and elimination measures that are being undertaken by the government are in line with the Minamata Convention whereas as one of the signatories, Tanzania ratified the international treaty on October 5, 2020 with the intention of protecting human health and the environment. It first signed the convention in October, 2013. Some 134 countries have so far signed the protocol.
In regard to the Minamata Convention, Kamkuru said the government has established a number of policies including the Minerals Policy of Tanzania (2009), the National Environment Policy (1997) and the National Health Policy (2007). The government also came up with a number of laws on environment, minerals and chemicals.
According to Mr Kamkuru, the government has been conducting research to come up with an alternative gold processing technology for artisanal miners instead of mercury as well as ensuring that small scale miners applying mercury in gold processing use personal protective equipment.
National Environment Management Council representative, Mr Benjamin Mchwampaka, said it was high time the country came up with alternative gold processing technologies for artisanal miners as mercury use is expected to end in 2032.
“Mercury will not be produced anywhere in the world after 2032. We need an alternative to it to ensure continued gold production by artisanal miners because large companies are already using other technologies such a cyanide, shaking tables and concentrators,” he said.
The Tanzania Mining Commission’s senior environment officer, Mr Abel Madaha, said some of the symptoms that people affected by mercury are likely to exhibit include headaches, weak body, shaking, memory loss and reduced thinking capacity. He said 25 to 33 percent of small gold miners in Tanzania have been affected by mercury.
Inhaling mercury vapour is most dangerous, and those that manipulate the mercury directly in the process of gold extraction, especially by burning mercury, are therefore most at risk.
Through the use of contaminated soil and water for livestock and crops, mercury can also enter the food chain. Communities near artisanal mining locations can therefore gradually accumulate mercury in their bodies, which is especially dangerous for pregnant women, children and the elderly.
Extended exposure to mercury can cause mercury poisoning, and can damage kidneys, impair hearing, vision, and balance. In extreme situations, it can claim lives.
Madaha said the government through the State Mining Corporation has established three centres of excellence (processing plants) at Itumbi area in Chunya District, Lwamgasa in Geita Region and Katente in Bukombe District in Shinyanga Region. The districts were chosen considering the high number of miners involved in the sub-sector.
“Small scale miners are allowed to process their gold at these established plants,” he said.
The Chikoa Gold Mine manager, Mr Zebedayo Machande, said the mine has been in operation for five months since its establishment and that most of the miners, especially those involved in gold searching, are aware of the health and environment risks posed by mercury, and that they always wear protective gear during the process.
“We have four sluice boxes here, water used to wash gold concentrates is properly managed and directed to designated streams. We do this to avoid contaminating water with mercury. Having the sluice boxes has really helped to protect us and the environment,” he said - adding that they have already drilled a well which is the main source of water for miners.