Pollutants that affect air quality

• The combustion of fuels is a major source of atmospheric pollutants that can be harmful to health and the environment.
• Carbon monoxide is formed by the incomplete combustion of hydrocarbon fuels when there is not enough air. Carbon monoxide is a toxic gas that combines very strongly with haemoglobin in the blood.
• At low doses it puts a strain on the heart by reducing the capacity of the blood to carry oxygen. At high doses it kills.
• Sulfur dioxide is produced by burning fuels that contain some sulfur. These include coal in power stations and some diesel fuel burnt in ships and heavy vehicles. Sulfur dioxide turns to sulfuric acid in moist air.
• Oxides of nitrogen are produced by the reaction of nitrogen and oxygen from the air at the high temperatures involved when fuels are burned.
• Sulfur dioxide and oxides of nitrogen cause respiratory problems in humans and cause acid rain. Acid rain damages plants and buildings. It also harms living organisms in ponds, rivers and lakes.
• Particulates in the air include soot (carbon) from diesel engines and dust from roads and industry. The smaller particulates can go deep into people’s lungs and cause damage that can lead to heart disease and lung cancer.