Smoke and Sulphur Dioxide Monitoring Network, 1961 - 2005

This network has the longest history of all the UK Networks, as it was in operation for over 30 years. The individual sites were operated by local authorities, with the network mananged and quality controlled by NETCEN, on behalf of Defra and formerly the Department of the Environment.
The network recorded the decline in smoke and SO₂ concentrations that followed from the implemetation of the Clean Air Acts. Details of this are discussed in the Long Term Trends answer in the FAQ section.

Each site in this network, monitored black smoke and SO₂ on a daily basis. The methods used to determinepollutant concentrations were:

SO₂ : Acid titration
Black Smoke : Reflectance from a filter

The aims of this monitoring programme were as follows:

To provide information on long term trends and to calculate a national average concentration on a consistent basis
To monitor for compliance with EC Directive 80/779 on SO₂ and Suspended Particulate Matter

Site Information

This page gives access to a series of files which give information about the sites that monitored smoke and sulphur dioxide in the UK. Site information is divided up by regions of the UK, so accessing a file will give you information about all the sites in that region.

Accessing Regional Site Information

The UK has been divided up into Goverment Office Regions. Data can be accessed by selecting one of the names in the list below.

Government Office Regions
Scotland Northern Ireland North East North West & Merseyside Yorkshire & Humberside East Midlands	West Midlands Wales Eastern London South East South West

Contents of the site information files

The following information is given for each site:

Sitename :Name of site - usually the town or village of its location

Code No:Site ID number

Starting Date that monitoring started

Ending: Date that monitoring ended (blank indicates site is still monitoring)

East: Four fig. OS grid reference, East coordinate (*)

North: Four fig. OS grid reference, North coordinate (*)

Type:Code describing the type of location of the site. Full details in table below

Local authority: Name of local authority (local government in UK) that operate the site

Gov region: Name of the Goverment office region of the UK that the site is situated in.

County: Name of the UK county that the site is situated in.

(*) NB. Sites in Northern Ireland have co-ordinates given on Irish grid. Both the easting and the northing are prefixed by a 9 to indicate that they are not on the OS grid.

Site Code Details

As indicated in the table above, monitoring sites are located in a variety of locations. The following codes were used in the files to describe the sites.

Code	Area Description
A1	Residential area with high-density housing (probably terraced), or with medium-density housing in multiple occupation, in either case surrounded by other built-up areas.
A2	Predominantly A1, but interspersed with some industrial undertakings.
A3	Residential area with high-density housing or medium-density housing in multiple occupation surrounded by, or interspersed with, other areas with low potential air pollution output (parks, fields, coast).
B1	Residential area with medium-density housing, typically an inner suburb or housing estate, surrounded by other built-up areas.
B2	Predominantly B1, but interspersed with some industrial undertakings.
B3	Residential area with medium-density housing surrounded by or interspersed with areas with low potential air pollution output (parks, fields, coast), or any residential area with low-density housing.
C1	Industrial area without domestic premises.
C2	Industrial area interspersed with domestic premises of high density or in multiple occupation.
D1	Commercial area or one with predominantly central heating.
D2	Town centre with limited commercial area, possibly mixed with old residential housing and/or minor industry.
E	Smoke control area or smokeless zone (the letter to be added to the primary classification).
R	Rural community.
O1	Open country but not entirely without source(s) of pollution, eg airfields.
O2	Completely open country; no sources within at least 400 metres.
X	Unclassified site, or mixed area.