Environmental Pollution are defined as the “presence of impurities or pollutant substances (gases, particulate matter, radioactive substances etc) in environment that causing the harmful effect on the human, plant and animal”.
Primary Pollutants: These are emitted directly from the point source (identifiable sources) e.g. carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur (SOx), Hydrocarbons, Radioactive substances etc.
Secondary Pollutants: These are formed by interaction of primary pollutants with other primary pollutants or with some constituents e.g. ozone, peroxyacetyl nitrate (PAN), photochemical smog etc.