Based on the data available in the literature and his own findings, the author determines the urgency of study of environment-dependent diseases in a poor ecological area. The analytical survey presents data available about the ecological situation in the town of Omsk, a center of chemical and oil-refining industries of Western Siberia from 1997 to 2003. Particular emphasis is laid on a child's responses to the combined exposure to unfavorable environmental factors. The signs characterizing ecopathology are considered and the main principles of the treatment and prevention of environment-dependent diseases are given.