The upper Silesia, the region in Poland with the highest density of the heavy industry, with its detrimental technology and improper pollution control systems which should prevent excessive amounts of toxic substance discharged to soil, water and atmosphere, represents an exceptionally degraded area. Such a disturbance of the natural conditions results in exposing living organisms beyond their tolerance ranges. The author presents the extent and range of animal tolerance toward environmental changes. He also suggests taking up urgent integrated research.