It can be defined as any form of energy or matter that causes degradation and pollution the existing natural balance of ecosystems
Examples: Smoke, gases, dust, toxic chemicals etc.
Types of pollutants
Solid pollutants are dividing into several types based on their sources such as lead, tailing mercury.
Huge quantities of mining wastes are dumped on land surface like metallic ores, earthen materials, rocks and other wastes.
Sugar mills produce a large amount of biogases. Copper smatters and aluminum industries produce pollutants, which are very injurious to vegetation and soil.
Throughout the country the se of artificial or chemical fertilizers and land has increased considerably. Though fertilizers are generally used to fertility soil, but they contaminate the soil, to a certain extent sometimes, excessive use of those fertilizers may have an adverse effect.
Though aerosol is a particulate matter it is often considered a gaseous pollutant. Liquid Pollutants
On the basis of the source of pollutants, liquid pollutants may be of the following types: Industrial Pollutants
Chemical pollutants such as chloride, sulphide, ammonical lead, arsenic, boron etc., organic chemical compounds and other waste material of chemicals.
Pesticides, insecticides, herbicides and several other synthetic compounds used to increase crop yield are considered agricultural pollutants. DDT manufacturing units produce acids, which have a corrosive effect.
Various types of ions such as sulphate, nitrate etc. coming from the washout of automobile and fossil fuel combustion; calcium and bio carbonate ions from lime and chemical fertilizer factory etc., are considered as urban pollutions.
Sediments due to weathering and erosion, debris caused by landslides, decomposed organic matter etc., and are natural pollutants.
These can be classified as primary and secondary. Primary pollutants include ashes from a volcanic eruption. Carbon monoxides from motor vehicle exhaust etc. secondary pollutants include some particles formed from gaseous primary pollutants and photochemical smog such as N02, Ozone and peroxyacety nitrate (PAN).
National processes, which release sulphur compounds, include decomposition and combustion of organic matter and volcanic eruptions. The main human activities producing sulphur dioxide are the smelting of mineral ores containing sulphur and combustion of fossil fuels.
Not only the gaseous pollutants, there are also solid or liquid particles that may be suspended in the air, referred to as “particulate matter.” These particles range in size up to 50 micrometers in diameter (there are 1,00,00,00 in a meter) and may reduce visibility and have an adverse effect on health.
Examples of particles in the air include dust smoke plant, and bacteria. Particulate matter may be a primary pollutant, such as smoke particles or a secondary pollutant formed of: the chemical reaction of gaseous pollutants.
Human activities resulting in particulate matter in the air include mining. Burning of fossils fuels, Transportation, agricultural and hazard reduction burning and the use of soiled fuels cooking and heating
The main oxides of nitrogen present in the atmosphere are nitric oxide (NO), nitrogen dioxide (NOJ, and nitrous oxide (N20). Nitrous oxides occur in much smaller quantities than other two, but are of interest as it is a powerful greenhouse gas. And thus contributes to global warming.
Carbon monoxide is an odourless, colorless gas produced by incomplete oxidation (burning Carbon monoxide is produced naturally by oxidation in the oceans and air. In cities, the mot vehicles are by far, the largest human source.
The major source of lead in the air is leaded fuel used in motor vehicles, metal mining and processing facilities. Lead and other metals like mercury, chromium, nickel etc. are toxic in nature.
Pollution Types and Source
Pollutants can pollute any component of the environment. On the basis of pollution of a particu7 component of the environment on the kind of pollutant, pollution can be classified as: air pollution; water pollution, noise pollution, vehicle pollution and industrial pollution, lead pollution etc.