General concepts of biotic and abiotic Environment - The concept of Pollution - Definitions. Historical overview of pollution – Units of measurement of pollution. SOIL POLLUTION AND DEGRADATION – Heavy metal pollution - Nitrogen pollution – Radioactive pollution - Soil erosion – Desertification, causes and consequences with emphasis on the consequences on agriculture. WATERS POLLUTION (LAKES, RIVERS AND SEAS)  - Nutrient pollution - The phenomenon of eutrophication - Dissolved Oxygen - Biochemical Oxygen Demand (BOD) - Fertilizers, Pesticides (insecticides, herbicides, etc.), Contamination by waste microorganisms - Pollution by toxic metals - Bioaccumulation - Biomagnification. The case of mercury. Thermal pollution. Pollution from Organic substances (Chlorinated compounds - Oil). Pollution from ship accidents or subsea oil extraction systems - Remediation methods - Effects on aquatic organisms. Accidents related to agriculture (Bhopal Accident- Seveso Accident, Rhine River Accident). ATMOSPHERIC POLLUTION. Sources of air pollution - Primary and secondary pollutants - Types of air pollution - Photochemical Pollution (Los Angeles type) - Smog Pollution (Smog or London type). Historic fatal air pollution episodes - The case of London. Transport of atmospheric pollution - Transboundary pollution - The grasshopper effect. Urban pollution - The phenomenon of temperature inversion. The "cloud" of Athens. IMPORTANT ATMOSPHERIC POLLUTANTS. Carbon monoxide (CO) - Sources of CO, distribution of CO in the atmosphere - effects of CO on plants and humans - toxicity limits. Nitrogen oxides (NOx) - Sources of NOx - distribution of NOx in the atmosphere - effects of NOx on plants and humans - toxicity limits. Sulfur oxides (SOx) - Sources of SOx - distribution of SOx in the atmosphere - effects of SOx on plants and humans toxicity limits. Acidification. Effect of acid rain on aquatic ecosystems - Effects of acid rain on plants, birds, cultural heritage. Ozone (O3). The ozone hole effect - implications - protection of the stratospheric O3 layer. Tropospheric O3 as a photochemical pollutant - formation - spatiotemporal variation. Effects of O₃ on human health. O₃ as a phytotoxic pollutant - the AOT40 phytotoxicity estimator. Chlorofluorocarbons (CFCs) - Methyl bromide (MeBr) - Peroxyacetyl nitrate (PAN) - Volatile hydrocarbons (VOCs). Particulate Pollution (PMS) - Effects of Particulate Pollution on Agriculture. Hydrocarbons. The oxidation of the atmosphere - The role of hydroxyls (OH). CLIMATE CRISIS - THE "GREENHOUSE" EFFECT. Climate forcing. Greenhouse gasses. Carbon dioxide (CO₂). Water vapor as a greenhouse gas. Methane (CH₄) - Methane hydrates. Nitrous Oxide (N₂O). Biomonitoring - bioindicators-biometers monitoring the quality of the environment. Bioremediation - phytoremediation. The utilization of metal hyperaccumulator plants. Elements of Environmental toxicology - Ecotoxicology. Ecological risk assessment. The rush phenomenon in toxicology. Ecological networks, Fragmentation of ecosystems. PROTECTED NATURAL AREAS - National and International Legal Framework. Fragmentation of ecosystems - The role of ecological corridors.