Air quality

Air pollution does it matter?

The quality of air we breathe in Plymouth is good in most areas. The Council has completed a Review and Assessment of Air Quality and determined that the levels of common pollutants comply with National Air Quality Objectives, in all but three areas detailed below.

Air quality in an urban area is continuously changing especially with increasing traffic on our roads. Plymouth City Council is committed to monitoring and reviewing air quality within the city.

Why monitor?

Plymouth City Council has been monitoring air quality in the city for sometime through a mobile unit and a static site in the city centre.

The mobile monitoring unit is located in different areas of the city, to establish what levels of pollution are experienced around the city.

The static monitoring site in the city centre now forms part of the Automated Urban Network (AUN) which is a country wide network providing details to the Government and the public on air pollution information. At the AUN we monitor for:

• Sulphur Dioxide (SO2)
• Carbon Monoxide
• Ozone
• Nitrogen Dioxide (NO2)
• Benzene

Plymouth Automated Urban Network Site

The Council also operates a diffusion tube monitoring programme for Nitrogen Dioxide (NO2), a pollutant that is associated with vehicular traffic and some types of industrial process. Surveys of NO2 levels around most towns and major roads in Plymouth have been undertaken. This information has been used in the 2003 screening assessment.

Monitoring is extremely important in determining if the air quality in the city is complying with the following objectives.

Objectives included in the Air Quality Regulations 2000 and (Amendment) Regulations 2002 for the purpose of Local Air Quality Management

Pollutant	Concentration	Measured as	Date to be achieved
Benzene
All authorities	16.25 µg/m3	Running annual mean	31 December 2003
Authorities in England and Wales only	5.00 µg/m3	Annual mean	31 December 2010
1,3 Butadiene	2.25 µg/m3	Running annual mean	31 December 2003
Carbon monoxide	10.0 mg/m3	Maximum daily 8 hour mean	31 December 2003
Lead	0.5 µg/m3	Annual mean	31 December 2004
	0.25 µg/m3	Annual mean	31 December 2008
Nitrogen dioxide	200 µg/m3 not to be exceeded more than 18 times a year	1 hour mean	31 December 2005
	40 µg/m3	Annual mean	31 December 2005
Particles (PM10) (gravimetric) All Authorities	50 µg/m3 not to be exceeded more than 35 times a year	24 hour mean	31 December 2004
	40 µg/m3	Annual mean	31 December 2004
Sulphur dioxide	350 µg/m3 not to be exceeded more than 24 times a year	1 hour mean	31 December 2004
	125 µg/m3 not to be exceeded more than 3 times a year	24 hour mean	31 December 2004
	266 µg/m3 not to be exceeded more than 35 times a year	15 minute mean	31 December 2005

The results of the monitoring in the city centre are available on Ceefax (BBC 1) page 416 and DEFRA provide historical data on all the sites associated with the AUN across the country, including Plymouth. This can be found on the Air Quality website.

A variety of air pollutants have known or suspected harmful effects on human health and the environment. In most areas of Europe, these pollutants are principally the products of combustion from space heating, power generation or from motor vehicle traffic. Pollutants from these sources may not only prove a problem in the immediate vicinity of these sources but can travel long distances, chemically reacting in the atmosphere to produce secondary pollutants such as acid rain or ozone. If you wish to find out more information on specific air pollutants and their potential health effects please visit the Air Quality website.

Air Pollution Bandings and Index and the Impact on the Health of People who are sensitive to Air Pollution

Banding	Index	Health Descriptor
Low	1	Effects are unlikely to be noticed even by individuals who know they are sensitive to air pollutants
	2
	3
Moderate	4	Mild effects, unlikely to require action, may be noticed amongst sensitive individuals.
	5
	6
High	7	Significant effects may be noticed by sensitive individuals and action to avoid or reduce these effects may be needed (eg reducing exposure by spending less time in polluted areas outdoors). Asthmatics will find that their 'reliever' inhaler is likely to reverse the effects on the lung.
	8
	9
Very High	10	The effects on sensitive individuals described for 'High' levels of pollution may worsen.

For more detailed information on Plymouths air quality please visit the Air Quality website.

One of the main statutory duties that the Pollution Control section has regarding air pollution control is to regulate certain specified industrial processes under the Environmental Protection Act 1990 and the Pollution Prevention Control Act, 1999. There is a public register of all of the processes, which are regulated by Pollution Control in this way. The register can be inspected at the Civic Centre by prior arrangement.

The review and assessment of Air Quality

Air quality and its effects on health has been recognised as an important issue for sometime. The Environment Act 1995 was introduced to establish the statutory provisions for local air quality management in the UK.

In 1999, all local authorities in the UK were required to complete a review and assessment of air quality in their area. This involved a detailed investigation in to potential sources of certain key pollutants included in the Air Quality Strategy.

The 7 key pollutants are:

• Sulphur Dioxide (SO2)
• Nitrogen Dioxide (NO2)
• Benzene
• 1,3 Butadiene
• Lead
• Particles
• Carbon Monoxide

If a local authority decided that the air quality objectives would not be met by the date specified in guidance then Air Quality Management Areas (AQMAs) would have to be declared. These could range in size to cover an individual property or whole areas. Local authorities would need to issue Action Plans detailing measures to reduce the concentration of the pollutants, which were expected to breach the objectives. These measures could include traffic management, speed control, and promotion of the use of public transport.

After the exercise was completed, a review of the whole process of Review and Assessments was completed on behalf of the Government and it was decided that the way in which the reviews of air quality are completed should be changed. The new guidance documents have changed some of the Air Quality Objectives, by imposing more stringent air quality standards in some circumstances, and have changed some of the dates by which the objectives are supposed to be met.

The new process of Air Quality Management involves completing an updating and screening exercise, which was completed in May 2003. The idea is for local authorities to only undertake a level of assessment that is commensurate with the risk of an air quality objective being exceeded. As a result not every local authority will need to proceed beyond the updating and screening exercise.

Recommended timescales for submission of reviews and assessments and progress reports

Local air quality management activity	Completion date	Which authorities
Updating and Screening Assessment	End of May 2003	All authorities
Detailed Assessment	End of April 2004	Those authorities which have identified the need for Detailed Assessment in their May 2003 Updating and Screening Assessment
Progress Report	End of April 2004	Those authorities which have identified no need for Detailed Assessment in their May 2003 Updating and Screening Assessment
Progress Report	End of April 2005	All authorities

Updating and screening assessment

This is based on a checklist and is the starting point to identify what has changed since the first review and assessment. It covers new monitoring data and new objectives. If there is a risk that an objective will not be met, the local authority must complete a detailed assessment. The updating and screening assessment highlighted that there were several areas of potential concern in Plymouth for traffic related pollution, namely Mutley Plain, Exeter Street, Embankment Road and Plymouth Road and two areas of concern for particles of less than 10 microns in size, called PM10. These two areas relate to Victoria Wharves and Cattedown Wharf for loading and unloading of dusty cargoes. Finally, the updating and screening assessment required a further examination of Exeter Street Petrol Station, which is situated on a busy road, with a school within 10 metres of a petrol pump.

Detailed assessment

The aim of the detailed assessment is to identify with reasonable certainty whether or not an exceedance of the air quality objectives is likely to occur. If the exceedance is expected, an AQMA should be declared. The detailed assessment was completed in April 2004 and the summary and complete document are available in the column on the right.

Monitoring has been undertaken to investigate the levels of benzene around Exeter Street Petrol Station where a residential property and a Primary School are located within ten metres of a petrol pump. Monitoring is carried out using diffusion tubes and although the diffusion tubes have an accuracy of +/-25%, the monitoring indicated that the objective may be at risk of being exceeded in 2010. As the exposed population are a sensitive group, it has been decided to declare an AQMA as a precautionary approach. Further accurate and detailed monitoring will be carried out over the next 12 months.

For nitrogen dioxide, a detailed assessment was carried out at four sites across Plymouth, which has included diffusion tube monitoring and some chemiluminescent analysis at one site. The air quality objective level for 2005 is likely to be exceeded at two of the four locations based on monitoring data, but modelling of the four locations indicated that the 2005 objective will be met. It has been decided to take a precautionary approach and declare two AQMA’s at Mutley Plain, and Exeter Street. Monitoring will continue at all four locations.

For PM10, two areas required further assessment, which involved the loading and unloading of dusty cargos. One site had changed the type of product stored from animal feed to ball clay, and consequently complaints have been resolved. It has been decided that this does not require a detailed assessment although the situation will be kept under review.

The second site requiring a detailed assessment for PM10 is Victoria Wharves, which is a commercial dock primarily loading and unloading china clay from storage areas to ships. Monitoring using a gravimetric analyser was carried out at the site, which has shown a number of exceedences of the 24-hour mean, but these are below 35 exceedences per year. However, monitoring has only been carried out for 6 months, over the winter months and it is recommended to continue monitoring for a further 12 months to obtain a more accurate picture of the number of exceedences which occur. The annual mean figure monitored to date is below the air quality objective of 40µg/m3.

Further assessment

The council is currently carrying out further work within the proposed AQMA’s, which includes detailed monitoring and diffusion tube data. This is providing a more complete picture of the state of the air quality both within and just outside of the proposed AQMA’s.

The proposed AQMA’s

The council is required to declare AQMA’s where it has reasonable certainty that the air quality objectives will be exceeded at areas where members of the public may be exposed.

Monitoring has continued at areas across the city where members of the public are regularly exposed, mostly at residential properties that are situated close to busy roads. This has resulted in the council proposing three AQMA’s.

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