# Environmental and Health Issues of Sulphur Dioxide

Sulphur dioxide, SO2 is one of the by-products of the Contact Process. It is one of the source of environmental pollution.

### Acid Rain

1. Sulphur dioxide (SO2) is the pollutant primarily associated with acid rain.
2. Acid rain occurs when pH of the rain is between 2.4 and 5.0. This is due to the reaction of sulphur dioxide, SO2 with rainwater.
$S O 2 + H 2 O→ H 2 S O 3$
3. The negative effect of acid rains include
1. corrosion of concrete building and metal structure.
2. corrosion of monuments and statues made from marble
3. causes erosion of top soil.
4. killing aquatic life.

### Health Effects

1. SO2 is an irritant when it is inhaled and at high concentrations may cause severe problems in asthmatics such as narrowing of the airways, known as bronchoconstriction.
2. Asthmatics are considerably more sensitive to the effects of SO2 than other individuals.

### Sources of SO2

1. The principal source of SO2 is from the combustion of fossil fuels in domestic premises and , more importantly, non-nuclear power stations.
2. Other industrial processes such as manufacturing of sulphuric acid also contribute to the presence of SO2 in the air.