Metal smelting is especially harmful to the natural environment. The amounts of smelting waste are at least the same as the cast, and often even higher. Harmful waste is usually stored near smelters. The devastation of the natural environment in Silesia began with industrial development in this area. There are many dump sites dating from this period, which not been inventoried yet. The recultivation which is being carried out is not neutralizing harmful impact of old dumps but it is masking and spreading the toxic substances. An inventory of such old dumps is necessary to prevent further environmental contamination.