Unit - II Pollution and Its Types
1. Definition of Pollution and Pollutant Pollution Pollution is the undesirable change in the physical, chemical or biological characteristics of air, water or land that harms living organisms, property and the environment . 👉 Example: Smoke from vehicles mixing with air and causing breathing problems. Pollutant A pollutant is any solid, liquid or gaseous substance present in the environment at a concentration that causes harm or discomfort . 👉 Examples: Carbon monoxide, plastic waste, sewage, industrial chemicals, noise. 2. Air Pollution Definition Air pollution occurs when harmful gases, dust or smoke enter the atmosphere and reduce air quality . Classification of Air Pollutants 1. Primary Pollutants Emitted directly from sources. Carbon monoxide (CO) Sulphur dioxide (SO₂) Nitrogen oxides (NOx) 👉 Example: Exhaust gases from vehicles. 2. Secondary Pollutants Formed by chemical reactions in the atmosphere. Ozone (O₃) Photochemical smog ...