Concepts of ecotoxicology. Biological effects and consequences of environmental pollution. Xenobiotics. Concepts of hazard and risk.The concept of biomarkers. Biomarkers in toxicology. Biochemical monitoring. Sources and types of pollution in all environmental matrices (atmospheres, soil, water). Persistence and pseudopersistence. Acute exposure. Chronic exposure. Fate and behavior of poisons in the environment. Parameters of ecotoxicological risk assessment, theoretical concept and limit values (Toxicity Exposure Ratio and Hazard Quotient). Sources of pollution of the environmental matrix. Polluting substances from water and soil. Toxicological profile of detergents, pesticides, persistent organic pollutants, heavy metals, air pollutants and aerosols. Toxic effects of burnout pollutants. Toxic substances originating from plants and animals. Risk assessment of the most common environmental pollutants. Circulation, expansion and accumulation of xenobiotics in nature, food chains.