1. Zambia Copper belt lead contamination

2. Background
Kabwe is the second largest city in Zambia with a population of 300,000.
In 1902 lead was discovered in the mine
Ore veins with lead concentrations up to 20% have been mined deep into the earth.
The mine closed in 1994
The government failed to address the potential danger of lead
The city has been left with hazardous concentrations of lead in the soil and water.

3. Problem Wide spread soil contamination
Highly contaminated mine waste dumps simply left once the mine closed

4. Smelters emitted dust particles that settled over a 20 km circumference and became buried in the soil.
The local canal became contaminated with lead which lead further ground contamination during flood events

6. Ground Effects High concentrations of lead found in soils
levels of lead right next to the smelter measured 245,000 parts per million (ppm)
Levels in a local township ranged from 7,000 ppm to 38,000 ppm
Lead content of soil in residential areas should not be more than 400 parts per million
Industrial and agricultural sites

8. Human Effects Lead is one of the potent neurotoxins in the world
In total 200,000 people were affected by the contamination
Some children were found to have more than 200µg/dl
Symptoms of acute poisoning occur at levels above 20µg/dl
Levels above 70µg/dl are considered a medical emergency

9. Solution Implemented Removal of 39,000 m3 of mine waste
Removal of m3 of dredged sediments
Contaminated soil removed to a depth of 30cm.
Liming of soil
Planting a vegetation cover
Demolition of defunct plant infrastructure

10. Alternative Solutions
Vitrification
Capping
Soil washing
Relocate neighbourhoods
Improve public awareness and education programme