3. Individual site analyses

Projections of CO concentrations at monitoring sites have been calculated as a first step in the mapping process. These projections do not have the additional uncertainties associated with the mapping methods. Maximum running 8-hour CO concentrations show considerable year to year variability due to meteorology. Data from 1990 to 1998 were therefore examined and the maximum running 8-hour concentration from each site recorded for years with more than 50% data capture. The emissions projections listed in Table 1 were then applied to the maximum concentration at each site to calculate an equivalent concentration for 1998 and the years up to and including 2004 (the projection for Stevenage in 1998, for example, was calculated by dividing the maximum measured concentration, which was recorded in 1991, by the emissions total for 1991 and multiplying by the emissions total for 1998: 2.9 = ( 4.9 / 2838 ) x 1678 . The results of this analysis are presented in Table 2. Projections will be more reliable for the sites with the most years of data. Only 1 or 2 years data are available for about half of the sites so the projections from these sites will be subject to greater uncertainty and are more likely to be underestimates than overestimates.

The recently published emission inventory for Greater Belfast (Buckingham et al, 1999) concluded that road traffic contributes 75% of CO emissions in this urban area, with emissions from domestic combustion making up the bulk of the remainder. The projections of CO concentrations for the Belfast Centre and Derry background monitoring sites listed in Table 2 have therefore been calculated on this basis, with the assumption that domestic emissions will remain unchanged.

The first year that all sites are predicted to achieve the proposed limit value of 8.59 ppm is 2001. The highest projected concentrations are generally at roadside and kerbside monitoring sites. The development of a model of roadside concentrations is described in the next section.

Table 2. Individual monitoring site projections of maximum running 8-hour CO concentrations (ppm)

# of years

year of max

site

type

max

1998 equiv.

1999 equiv.

2000 equiv.

2001 equiv.

2002 equiv.

2003 equiv.

2004 equiv.

maximum running 8-hour CO concentrations (ppm)

4

1991

Stevenage

SUBURBAN

4.9

2.9

2.6

2.3

2.1

1.9

1.8

1.6

7

1990

London Cromwell Road

KERBSIDE

15.5

9.0

8.2

7.2

6.6

6.0

5.5

5.1

9

1991

West London

URBAN BACKGROUND

15.8

9.3

8.5

7.5

6.8

6.2

5.7

5.3

9

1991

Glasgow City Chambers

URBAN BACKGROUND

12.5

7.4

6.7

5.9

5.4

4.9

4.5

4.2

6

1992

Manchester Town Hall

URBAN BACKGROUND

12.5

7.9

7.2

6.3

5.7

5.2

4.8

4.4

7

1992

Sheffield Tinsley

URBAN INDUSTRIAL

7.4

4.6

4.2

3.7

3.4

3.1

2.8

2.6

8

1991

London Bridge Place

URBAN BACKGROUND

11.2

6.6

6.0

5.3

4.8

4.4

4.0

3.7

7

1997

London Bloomsbury

URBAN CENTRE

6.7

6.1

5.6

4.9

4.4

4.1

3.7

3.4

6

1993

Edinburgh Centre

URBAN CENTRE

4.8

3.2

2.9

2.6

2.3

2.1

2.0

1.8

7

1993

Cardiff Centre

URBAN CENTRE

5.9

3.9

3.6

3.2

2.9

2.6

2.4

2.2

7

1994

Belfast Centre

URBAN CENTRE

13.4

10.3

9.7

8.8

8.3

7.8

7.4

7.0

7

1992

Birmingham Centre

URBAN CENTRE

10.8

6.8

6.2

5.4

4.9

4.5

4.1

3.8

7

1993

Newcastle Centre

URBAN CENTRE

6.1

4.1

3.7

3.3

3.0

2.7

2.5

2.3

6

1994

Leeds Centre

URBAN CENTRE

9.5

6.8

6.2

5.4

4.9

4.5

4.1

3.8

6

1994

Bristol Centre

URBAN CENTRE

5.6

4.0

3.6

3.2

2.9

2.6

2.4

2.2

6

1993

Liverpool Centre

URBAN CENTRE

3.4

2.3

2.1

1.8

1.7

1.5

1.4

1.3

5

1994

Birmingham East

URBAN BACKGROUND

11.9

8.5

7.7

6.8

6.2

5.6

5.1

4.8

5

1994

Hull Centre

URBAN CENTRE

5.2

3.7

3.4

3.0

2.7

2.5

2.2

2.1

5

1995

Leicester Centre

URBAN CENTRE

7.9

6.1

5.6

4.9

4.4

4.1

3.7

3.4

5

1997

Southampton Centre

URBAN CENTRE

9.2

8.4

7.6

6.7

6.1

5.6

5.1

4.7

5

1996

London Bexley

SUBURBAN

8.5

7.1

6.5

5.7

5.2

4.7

4.3

4.0

4

1998

Swansea

URBAN CENTRE

4.2

4.2

3.8

3.4

3.1

2.8

2.6

2.4

4

1996

Middlesbrough

URBAN INDUSTRIAL

3

2.5

2.3

2.0

1.8

1.7

1.5

1.4

3

1996

Manchester Piccadilly

URBAN CENTRE

4.7

3.9

3.6

3.2

2.9

2.6

2.4

2.2

3

1996

Sheffield Centre

URBAN CENTRE

4.2

3.5

3.2

2.8

2.6

2.3

2.1

2.0

3

1996

Wolverhampton Centre

URBAN CENTRE

4.8

4.0

3.7

3.2

2.9

2.7

2.4

2.3

3

1997

London Brent

URBAN BACKGROUND

9.9

9.0

8.2

7.2

6.6

6.0

5.5

5.1

3

1997

Sutton Roadside

ROADSIDE

10.4

9.5

8.6

7.6

6.9

6.3

5.8

5.3

3

1996

London N. Kensington

URBAN BACKGROUND

8

6.7

6.1

5.4

4.9

4.5

4.1

3.8

3

1997

Tower Hamlets Roadside

ROADSIDE

9.9

9.0

8.2

7.2

6.6

6.0

5.5

5.1

1

1998

Oxford Centre

ROADSIDE

3.7

3.7

3.4

3.0

2.7

2.5

2.2

2.1

2

1997

Exeter Roadside

ROADSIDE

12

10.9

10.0

8.8

8.0

7.3

6.6

6.1

2

1997

London Hillingdon

SUBURBAN

7

6.4

5.8

5.1

4.6

4.2

3.9

3.6

2

1997

Glasgow Centre

URBAN CENTRE

5.8

5.3

4.8

4.2

3.8

3.5

3.2

3.0

2

1997

Bristol Old Market

ROADSIDE

7.9

7.2

6.6

5.8

5.2

4.8

4.4

4.0

1

1998

Leamington Spa

URBAN BACKGROUND

2.7

2.7

2.5

2.2

2.0

1.8

1.6

1.5

2

1998

Nottingham Centre

URBAN CENTRE

6.8

6.8

6.2

5.5

5.0

4.5

4.1

3.8

2

1997

Thurrock

URBAN BACKGROUND

6.6

6.0

5.5

4.8

4.4

4.0

3.7

3.4

2

1997

Bath Roadside

ROADSIDE

4.1

3.7

3.4

3.0

2.7

2.5

2.3

2.1

1

1998

Stockport

URBAN BACKGROUND

4.7

4.7

4.3

3.8

3.4

3.1

2.9

2.6

2

1998

London Hackney

URBAN CENTRE

6.6

6.6

6.0

5.3

4.8

4.4

4.0

3.7

2

1997

Bury Roadside

ROADSIDE

4.7

4.3

3.9

3.4

3.1

2.8

2.6

2.4

2

1998

Bolton

URBAN BACKGROUND

4.5

4.5

4.1

3.6

3.3

3.0

2.7

2.5

2

1997

Coventry Centre

URBAN CENTRE

4.1

3.7

3.4

3.0

2.7

2.5

2.3

2.1

2

1997

London Southwark

URBAN CENTRE

8

7.3

6.7

5.8

5.3

4.8

4.4

4.1

2

1997

Glasgow Kerbside

KERBSIDE

8.3

7.6

6.9

6.1

5.5

5.0

4.6

4.3

1

1998

Salford Eccles

URBAN INDUSTRIAL

4.5

4.5

4.1

3.6

3.3

3.0

2.7

2.5

2

1998

Stoke-on-Trent Centre

URBAN CENTRE

7.8

7.8

7.1

6.3

5.7

5.2

4.7

4.4

2

1998

London A3 Roadside

ROADSIDE

7.6

7.6

6.9

6.1

5.5

5.0

4.6

4.3

2

1997

Southwark Roadside

ROADSIDE

12.1

11.0

10.1

8.8

8.0

7.3

6.7

6.2

2

1998

Derry

URBAN BACKGROUND

4.2

4.2

3.9

3.6

3.4

3.2

3.0

2.9

2

1998

Bromley Roadside

ROADSIDE

11

11.0

10.0

8.8

8.0

7.3

6.7

6.2

1

1998

Redcar

SUBURBAN

3.9

3.9

3.6

3.1

2.8

2.6

2.4

2.2

1

1998

Sandwell Oldbury

URBAN BACKGROUND

3.2

3.2

2.9

2.6

2.3

2.1

1.9

1.8

1

1998

London Marylebone Road

KERBSIDE

6.5

6.5

5.9

5.2

4.7

4.3

4.0

3.7

1

1998

Norwich Centre

URBAN CENTRE

5.2

5.2

4.7

4.2

3.8

3.5

3.2

2.9

1

1998

Reading

URBAN BACKGROUND

4.7

4.7

4.3

3.8

3.4

3.1

2.9

2.6

1

1998

Hove Roadside

ROADSIDE

4.4

4.4

4.0

3.5

3.2

2.9

2.7

2.5

1

1998

Hounslow Roadside

ROADSIDE

6.6

6.6

6.0

5.3

4.8

4.4

4.0

3.7

1

1998

Bradford Centre

URBAN CENTRE

5.2

5.2

4.7

4.2

3.8

3.5

3.2

2.9

1

1998

Plymouth Centre

URBAN CENTRE

2.9

2.9

2.6

2.3

2.1

1.9

1.8

1.6

1

1998

Brighton Roadside

ROADSIDE

4.8

4.8

4.4

3.9

3.5

3.2

2.9

2.7

1

1998

London Cromwell Road 2

ROADSIDE

4.1

4.1

3.7

3.3

3.0

2.7

2.5

2.3

 

Chapter 2         Chapter 4
Report and site prepared by the National Environmental Technology Centre, part of AEA Technology, on behalf of the UK Department of the Environment, Transport and the Regions