What is Air Pollution?
Air pollution is defined as a mixture of gases and particles that have been emitted into the atmosphere. The combustion of fossil fuels such as coal, oil, petrol or diesel is the most significant source of the key pollutants of concern to local authorities.
Emissions of oxides of nitrogen (NOx) and man-made particulate (especially fine particulate, PM2.5) must be reduced to meet the health based national air quality objectives in York and improve public health.
Why should it concern you?
Most healthy adults are unlikely to be affected by the levels of air pollution normally found in the UK – so why should it concern you?
Every year thousands of people in the UK are known to die prematurely due to the effects of air pollution. Thousands more have to be admitted to hospital. Those most at risk are the young, the elderly and those who are already suffering from existing lung and heart conditions. Even if you don’t fall into any of these high risk categories, you may have relatives or friends who do. Some pollutants are known to cause cancer and their effects on people are still not fully understood.
Air pollution also causes damage to plants, animals and buildings. In a historic city like York there is concern about the impact of air pollution on buildings such as the Minster.
The costs associated with treating the effects of air pollution run into billions of pounds every year. If you are a tax payer you are contributing towards these costs.
Main pollutants of concern in York
The main air pollutants of concern in York are nitrogen dioxide (NO2) and particulate matter (PM10 and PM2.5). Based on estimates from the National Atmospheric Emissions Inventory (NAEI), the transport sector continues to be the largest contributor (57%) to total NOx emissions in York. Road transport specifically, comprises approximately 45% of the total NOx emissions across York, compared to 12% and 13% of PM10 and PM2.5 emissions respectively. As a comparison, domestic combustion makes up 17% of NOx emissions compared to 24% of PM10 emissions and 37% of PM2.5 emissions. It should be noted that the exact contribution from road transport will vary by location and in some urbanised areas will be considerably higher than the figure stated above.
Nitrogen Dioxide (NO2)
The main sources of nitrogen dioxide in York are:
- Transport related emissions, arising mainly from road transport but also including a small contribution from rail. This is the major threat to clean air in York.
- Emissions from large industrial chimney stacks.
- Emissions from domestic and commercial space heating and any other local source emissions.
Nitrogen dioxide is a gas which acts as an irritant to the eyes, nose, throat, and respiratory tract. Nitrogen dioxide can have both short term ‘acute’ effects and long term ‘chronic’ effects. The short term ‘acute’ effects of nitrogen dioxide involve irritation of the eyes, nose and throat and an increase the symptoms of existing respiratory conditions such as asthma, bronchitis or emphysema. Based on current medical evidence the short term concentrations of nitrogen dioxide found in York are unlikely to give rise to acute health impacts, even in the most vulnerable members of society.
The long term ‘chronic’ effects of nitrogen dioxide are associated with a gradual deterioration in the health of people who are already suffering from lung diseases, and an increased susceptibility to respiratory infections within the general population. In York the annual average nitrogen dioxide objective has been found to be currently exceeded at a number of locations around the inner ring road. There are also a number of locations along the radial routes into the city where concentrations are approaching the annual average objective level.
Air Pollution and Health Links:
A report from the Royal College of Physicians examines the impact of exposure to air pollution across the course of a lifetime – see ‘Every breath we take: the lifelong impact of air pollution’
- Defra together with PHE have published a toolkit which provides details on how local authorities can use the Public Health Outcomes Indicator to specify appropriate mitigation measures to reduce the impact of both short term and long term exposure of air pollution – see ‘Air Quality: a briefing for directors of public health’