Exposure to air pollutants has been linked to suppressed lung growth, asthma, heart disease, foetal brain growth damage and the onset of diabetes
Air pollution from traffic and industry is leading to the premature death of more than three million people a year. Globally, that’s more than malaria and HIV/Aids combined.
Pollutants including nitrogen dioxide and particulate matter from road traffic and sulphur dioxide, from the burning of fossil fuels, have been linked to suppressed lung growth in children, asthma, heart disease and the onset of type 2 diabetes. The exposure of pregnant women to air pollution has also been found to affect to foetal brain growth.
It is an avoidable and unequal health burden. In London, for example, more than 400 schools are located in areas that exceed limits for nitrogen dioxide pollution, but four-fifths of those are in deprived areas.
Even in countries with a long history of tackling air pollution, the problem has not gone away. The UK, which passed its first anti-air pollution legislation 60 years ago today, is currently involved in a long-running legal battle over its failure to cut pollution to legal levels.
The main pollutants and their health impacts
• Sulphur dioxide
From the burning of fossil fuels, mostly power stations.
• Nitrogen dioxide
Highest levels found close to road traffic or indoor gas cookers.
• Ozone (ground-level)
Caused by chemical reactions between natural, traffic and industrial pollution in strong sunlight.
• Particulate matter (PM)
Solid particles or liquid droplets in the air, primarily from road traffic. When smaller than 2.5 micrometers (that’s 60 times thinner than a human hair), they are known as PM2.5. Larger particles, which could be dirt or dust stirred up from vehicles are known as PM10.
• Metals, including lead, mercury, arsenic
Less of a problem in some countries due to controls on emissions. Iron and steel sectors dominate lead emissions, while disposal of treated wood by burning is source of arsenic.
These health impacts have all been linked to the main pollutants
• Lungs
Suppresses normal lung growth in children. Accelerates lung function decline or an ageing lung in adults and a known cause of lung cancer. Also linked to onset of asthma.
• Pancreas
Linked to onset of type 2 diabetes in adults.
• Heart
Linked to the development of cardiovascular diseases, such as a stroke and heart disease, including atherosclerosis (furring of the arteries). Can also exacerbate existing conditions.
• Brain
Exposure of pregnant women found to affect to fetal brain growth. Also impacts mental and physical development in children and cognition in adults.
