Publication: Pre-Submission Gloucester City Plan

Pre-Submission City Plan

Policy C5: Air quality


Proposals for major development mustdemonstrate compliance with EU limit values and achieving national objectives for air pollutants. Proposalsmust:

  1. Not create a new "street canyon", or a building configuration that inhibits effective pollution dispersion; and
  2. Minimise public exposure to pollution sources, e.g. by locating habitable rooms away from busy roads, or directing combustion generated pollutants through well sited vents or chimney stacks; and
  3. Use green infrastructure, trees and hedgerows, to absorb dust and other pollutants; and
  4. Provide infrastructure that promotes modes of transport with low impact on air quality; and
  5. Control dust and emissions from construction, operation and demolition.

Within the city's Air Quality Management Areas (AQMAs) and in areas near schools and hospitals, development which reduces tree cover, hedges and other forms of vegetation will be expected to make provision for a net gain in vegetation onsite and/or within the relevant buffer zone. The use of green roofs and walls in these areas will be strongly supported along with other suitable measures to increase vegetative cover.

3.3.25 Air pollution is a major threat to the health and wellbeing of people living in urban settings. In the UK it has been estimated that the mortality burden of long-term exposure to particulate matter (PM2.5) in 2008 was equivalent to nearly 29,000 premature deaths in those aged 30 or older. The Public Health Outcomes Framework data tool shows the fraction of mortality attributable to air pollution by local authority (range 2.7 - 8.3%, average for England 5.4%). It is likely that removing exposure to all PM2.5 would have a bigger impact on life expectancy in England and Wales than eliminating passive smoking or road traffic accidents. The economic cost from the impacts of air pollution in the UK is estimated at £9-19 billion every year which is comparable to the economic cost of obesity (over £10 billion). In 2013, the International Agency for Research on Cancer has identified outdoor air pollution as causing lung cancer, without identifying the specific pollutants that are the carcinogenic component.

3.3.26 Local authorities have a wide remit and their responsibilities touch on many aspects of our lives. To achieve their objectives, they need to draw on many different resources, some statutory, and some that rely on cooperation with others. Good air quality is one such objective, where many players can affect the outcome through actions taken in different places and sometimes over long periods of time as one development succeeds another.

3.3.27 Determining one application in isolation may not achieve good air quality on its own. This is often achieved through many decisions made in different circumstances guided by a mosaic of policies that implemented together will create better air quality. Gloucester City Council currently has three Air Quality Management Areas (AQMA's) as identified by breaches of the average annual mean action levels. The M5 motorway also runs along the eastern edge of the city and creates impacts in terms of air and noise pollution.

Mitigating impacts through planting

3.3.28 There is evidence that increased urban vegetation can help to reduce the impacts of air pollution, but a distinction should be made between reductions in concentrations of particulate matter and gaseous pollutants. In terms of gases, certain types of vegetation can remove small amounts of pollutants from urban air by deposition, but in terms of particulate matter, the planting of trees can redistribute particulates but not remove them. However reduced air temperature as a result of tree planting is believed to improve air quality because emissions of many pollutants and/or ozone-forming chemicals are temperature dependent -

3.3.29 In terms of trees, it is important to note that the level of effectiveness of any planting will depend on the season, the number of trees, the species, the siting, the canopy density and the prevailing wind direction in the particular street. NPPF Paragraph 81 states that in tackling air pollution green infrastructure provision and enhancement should be considered along with other initiatives.

3.3.30 AQMAs have been targeted for action for obvious reasons but the policy also targets areas around the city's schools and hospitals. This is due to the fact that these areas generally have high levels of vehicular traffic combined with the congregation of large numbers of people who are particularly vulnerable to air pollution. Close proximity in the context of this policy means within 50 m of the site boundary identified in the buffer zones on the Policies Map.