Environmental Engineering Reference
In-Depth Information
50
40
30
20
10
0
450
400
350
300
250
Pre
Pre
Pre
CT
CT
CT
PE
PE
200
150
100
50
0
Rust Rust Rust Rust Rust Rust
Pre
Pre
Pre
CT
CT
CT
PE
PE
Fig. 3
Platinum concentrations in road dust in Rustenburg (Rust), Pretoria (Pre), Cape Town (CT)
and Port Elizabeth (PE)
Pretoria is located approximately 150 km from Rustenburg and elevated Pt concentra-
tions in Pretoria are attributed to atmospheric transport of Pt emitted from the mines.
Conclusions
Elevated Pb and Pt concentrations were found in South African road dust. The
occurrence of Pb is attributed to automobile traffic owing to the use of leaded gaso-
line. Leaded gasoline has recently been banned in South Africa and environmental
Pb concentrations are expected to decrease in the near future. In contrast, automo-
bile emissions are a minor source of Pt due to the limited number of vehicles cur-
rently equipped with an exhaust catalyst. South Africa is the world's leading Pt
producer and elevated Pt concentrations were found in road dust collected near Pt
mines in Rustenburg.
Atmospheric dispersion of emitted Pt also results in contamination further from
the mines and elevated Pt concentrations were also found in Pretoria. Further stud-
ies are needed to characterize emissions from Pt mines and associated risks of
should be assessed. Automobile traffic may become an additional source of Pt in
South Africa owing to the introduction of automobile exhaust catalysts.
