Chinese supplier outed selling banned mercury to artisanal miners

Brenna Matendere

Harare–A Chinese-owned supplier, STC Chemicals, is feeding artisanal gold miners with mercury, which the government banned in December 2020, a new study has revealed.

The study by Information for Development Trust (IDT), a non-governmental organisation promoting access to information on private-public sector accountability, has revealed that STC Chemicals is supplying the miners with mercury in different parts of Zimbabwe.

The 60-page study report is titled Purses and Curses: Impact of Chinese Mining on Local Communities in Zimbabwe.

STC Chemicals, which supplies a broad range of other chemicals and substances that include cyanide, carbon, caustic and lime, has been openly advertising its mercury on social media.

The IDT study revealed that STC was selling the dangerous chemical indiscriminately, meaning that artisanal and small-scale gold miners from different parts of the country that include the Midlands and Mashonaland West provinces had easy access to the mercury.

“Despite the ban (on industrial use of mercury), STC Chemicals is still selling mercury to artisanal and small-scale miners who do not have adequate knowledge on how to use it with care.

“In this sense, STC is driving the illegal use of mercury and, in turn, acute harm to the environment as well as human and animal health,” notes the report.

There is no blanket ban on mercury, though, as it is still permissible to buy it for other purposes.

“This is apparently the loophole that STC Chemicals is thriving on. It emerged that the company did not vet clients who buy mercury from it and it is likely that it knows some of them are artisanal gold miners,” reads the report.

The Minamata Convention defines artisanal and small-scale mining (ASM as “mining conducted by individual miners or small enterprises with limited capital investment and production”.

A 2023 report by the Intergovernmental Forum on Mining, Minerals, Metals and Sustainable Development warned that artisanal and small-scale mining can “contribute to environmental pollution”.

Zimbabwe is estimated to have at least half a million artisanal and small-scale gold miners, most of who use mercury to extract the mineral from ore or alluvial deposits.

Mercury is banned under the Minamata Convention on mercury and Zimbabwe followed suit in late 2020, introducing, in addition, regulatory mechanisms to avoid its release through industrial processes.

Mercury vapour from the burning of amalgam during gold processing impacts negatively on miners, their families and nearby communities.

Most gold mining activities are carried out near or in rivers and streams, which drain into dams and lakes.

“Mercury contaminates water, accumulates in sediments and bio-accumulates in fish and tissues of other aquatic species,” says the report, adding that the chemical “may settle in water bodies and affect water quality… and accumulates in fish at levels that may harm the fish and other animals that eat them”.

It adds: “Methyl mercury exposure on wildlife can cause mortality, reduced fertility, slow growth and development and abnormal behaviour that affects survival. Once present in aquatic ecosystems, elemental and inorganic mercury can undergo chemical transformations to methylated mercury and enter the food web and high-level predators such as birds as humans could be in danger of contamination.”

An STC marketing executive based in Harare, Takudzwa Pedzi, told NewsHub in a telephone interview that the company had stopped supplying mercury.

He initially claimed STC never sold the chemical, but later said they had discontinued.

Artisanal miners who talked to this publication after the interview with Pedzi, however, insisted that they were still buying mercury from STC.