Industries & Urban Air Pollution :

Industries contribute significantly to the air pollution problem in the Urban Areas also as we identified before that during the Industrial Revolution industries were often located in urban areas. Following the Clean Air Acts and with the decline of heavy industry, few large industries are located in towns and cities today. Many large industries and power stations are now located in remote areas far from urban areas. However, most urban areas have some smaller industries and possibly a power station. The larger industrial sources, even though located out of town, also have an impact on urban air quality.

Industrial Smoke Pollution

Smoke pollution can be defined as particulate material smaller than 15µm in diameter which arises from the incomplete combustion of fuel.

The significant sources of smoke pollution are therefore not completely industries but rather vehicles. In the past, urban air pollution was dominated by thick black smoke which was emitted from industries and power plants burning coal.

Levels of smoke in cities and towns during the winter time in particular were at much higher concentrations then now days. The reason for this has been due to technical air pollution control, the decline in the use of coal for domestic purposes, industries and power plants and also the removal of heavy industries far from towns & cities (in rural areas).

Industrial Sulphur Dioxide Pollution

Industries are the major source of Sulfur dioxide pollution, Power stations and all other types of industry account for big amount  of all  SO2 pollution.

Most industries and power stations are now located in rural areas but urban areas often lie in the prevailing wind path of these industries. Sulphur dioxide, along with smoke, are both pollutants which have long been associated with urban air pollution. Furnace oil and other heavy oil burning industries and power stations emit large quantities of SO2 into the atmosphere via their tall chimney stacks.

Small industries located within urban areas may greatly affect local SO2 levels as their emissions may become trapped by temperature inversions in the urban environment. Sulphur dioxide pollution is one of the main pollutants that causes acid rain when it combines with water in the atmosphere to form sulphuric acid.

Because the main source of SO2 is industry, industries are therefore major contributors to rainfall acidity. Acid rain affects urban areas by causing faster erosion of certain building materials, and it can cause damage to urban vegetation.

Industrial Oxides of Nitrogen Pollution

Power stations contribute significantly to the total emission of nitrogen oxides . Majority of the NOx came from this source and a further  arose from other industries, iron and steel and refineries.

Whilst the majority of NOx emissions arise from road transport, the contribution of industrial NOx pollution is still important. Nitrogen oxides are also converted into nitric acid when combined with water in the atmosphere, hence, like SO2, contributing to acid rain.