<P> The largest contributor to coal - derived air pollution is household coal usage (65%), followed by industry (30%) and electricity generation (5%). </P> <P> Some coal mines have been abandoned by their owners, mainly due to companies ceasing to exist . Many of these mines, such as the Transvaal and Delagoa Bay Collieries (T&DB) outside Witbank, have not been rehabilitated prior to being abandoned and are a major source of water and air pollution . It is estimated that clean - up and rehabilitation of the T&DB Collieries will cost around R100 million . Coal seam fires were common, but controlled, at T&DB Collieries during the mine's operation, but the fires have been left to burn out of control since the mine was closed in 1953, to the extent that in 1995 flames could be seen above ground . </P>

Why is coal the main energy source in south africa