Atlas of Contaminated Sites

Notable case, Tsumeb, Oshikoto, Namibia

Tsumeb smelter

A copper smelter in northern Namibia, next to a mine worked from 1905 to 1996, which in recent years has processed high-arsenic concentrates imported from Bulgaria. A stockpile of arsenic trioxide estimated at about 300,000 tonnes has built up on the site.

Phytoremediation

Status
Not addressed
Activity
since 1905
People affected
34,960 (2023)1
Media
soil, air, living organisms
Kind of site
smelter, mining
  1. People affected. Population of the town of Tsumeb in 2023 (Wikipedia); not an estimate of the people exposed.

Contaminants

Metals

Metalloids

Status

Not addressed

The smelter is operating. In August 2024 Dundee Precious Metals sold it to China's Sinomine Resource Group for 20 million dollars; Namibia's competition authority approved the sale with no conditions on the arsenic trioxide stockpile. In 2024 the company put the rehabilitation cost at 23 million dollars (The Namibian, January 2025).

Story

The Tsumeb mine opened in 1905 under German colonial rule and until 1996 yielded about 30 million tons of ore, giving 2.8 million tons of lead, 1.7 of copper and 0.9 of zinc. The smelter outlived the mine by processing other producers' concentrates.

Dundee Precious Metals bought it in 2010 to treat the arsenic-rich copper concentrate from its own Chelopech mine in Bulgaria, shipped by sea to Walvis Bay and then by rail. The arsenic separated in the process comes out as trioxide: former managers put the amount stockpiled on site at about 300,000 tonnes, though the exact figure is not known. According to Wikipedia the smelter's operation has caused widespread soil contamination with arsenic and other metals; analyses by the University of Bern in 2023 found up to 2% arsenic in soil.

The company says it spent 85 million dollars on cutting emissions, reduced average exposure by 72% since 2012, installed six air monitoring stations and 31 groundwater boreholes, and planted 15,000 tamarisk shrubs. A 2014 study recommended banning the growing of leafy and root vegetables within 10 km west of the smelter; the government did not act on it.

Timeline

  1. 1905The Tsumeb mine opens.
  2. 1996Mining ends.
  3. 2010Dundee Precious Metals acquires the smelter.
  4. 2011Study of 148 people: one in six with urinary arsenic above the WHO limit.
  5. 2024August: the smelter is sold to Sinomine Resource Group for 20 million dollars.

Health

A 2011 study by the University of Namibia with Germany's federal geoscience institute tested 148 people: one in six had urinary arsenic above the WHO limit. In 2014 the same group found accumulation of lead, cadmium and arsenic in all 43 samples of Tsumeb produce. In 2023 the University of Bern found more than 1 mg/kg of arsenic in 12 hair samples from residents, with values up to 100 times those of unexposed populations (as reported by The Namibian, 2025).

Remediation

  1. —emission controls and monitoringMeasures stated by the company between 2010 and 2024: 85 million dollars spent on reducing arsenic contamination, six air monitoring stations, 31 groundwater boreholes.

Plants and fungi at this site

From the literature

Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.

Plants

Fungi

The rest are on the contaminant pages.

Sources

  1. Canadian copper company leaves a legacy of toxic waste in Namibia, The Namibian, 2025
  2. Tsumeb, Wikipedia, 2026

Draft compiled from public sources, not yet reviewed.