Pollution - air

The Environmental Protection Unit operates an automated air pollution monitoring station and a number of individual diffusion tube sites throughout the borough.

The quality of the air we breathe is important for our health and wellbeing. During large scale events such as the fire at the fuel depot site at Buncefield, the pollution of the air is a very obvious and visible occurrence. However, pollution from traffic and industry is quite often not visible but is still present.

Hertfordshire and Bedfordshire local authorities have been monitoring air quality for a number of years and in 1999 formed the Hertfordshire and Bedfordshire Air Pollution Monitoring Network (HBAPMN). All local authorities have been assessing air quality across their areas and comparing it against national objectives for a number of pollutants including carbon monoxide, benzene, 1,3 butadiene, lead, nitrogen dioxide, particulate matter and sulphur dioxide. Where air quality is poor an Air Quality Management Area is declared and, where possible, local action taken to improve the air in that area.

Anyone with asthma or any other respiratory complaint can register for free online  or you can fill out a free-post response form which is attached to the airAlert leaflets available from Hertsmere Borough Council at: Civic Offices, Elstree Way, Borehamwood; The Bushey Centre, Bushey High Street; and Wyllyotts Centre, Darkes Lane, Potters Bar.

For more information on the airAlert service, please contact Sarah Hoggett, Senior Environmental Health Officer, on 020 8207 2277 ext. 5740 or at sarah.hoggett@hertsmere.gov.uk

Currently Hertsmere's Environmental Protection Team monitors for nitrogen dioxide, Ozone, Carbon Monoxide and particulate matter.

As well as recording meteorological data, the stations are equipped to monitor for;

• Fine Particles (PM10)
• Oxides of Nitrogen (NOx)
• Ozone (O3)

In May 1997 the Government produced the National Air Quality Strategy (NAQS). The strategy represents a comprehensive approach to maintaining and improving the quality of ambient air in the United Kingdom.

Outlined in the strategy are the air quality objectives for a number of pollutants the Government feels are of most concern at present and the dates it feels these targets should be met. These objectives are shown in the table below.

PM10 Particulates

PM10 describes the fraction of airborne particulate matter that is less than 10 microns in size.These fine particles are of the greatest concern since they are capable of being easily transported over long distances on currents of air. Also, fine particles may be drawn into the lungs where they may adversely affect health. Recently, the attention of scientists has been drawn towards studying the PM2.5 fraction and even smaller particles, which can penetrate the very deepest parts of the lung.

PM10 and other particulate matter may vary considerably in chemical and physical composition. The principal sources of these particles are combustion processes, including traffic and industry.

Nitrogen Dioxide (NO2)

Nitrogen dioxide is one of a number of nitrogen oxides, which are formed during high temperature combustion processes. Road traffic is the main source, accounting for approximately 50% of all European emissions. Therefore, concentrations tend to be highest in urban environments with high traffic levels. Large industrial sources can also have a significant impact. In Hertsmere, almost all N02 comes from transport based emmisions.

Nitrogen dioxide is a respiratory irritant and also plays a part in the production of another atmospheric pollutant, Ozone. Nitrogen oxides remain in the atmosphere for approximately one day before they are oxidised to nitric acid. Nitrogen oxides are therefore a contributory factor in the production of acid rain.

Ozone (O3)

Ozone is a very reactive chemical, which is potentially toxic to both plants and animals. Up in the Stratosphere, ozone helps to protect the earth from the harmful effects of ultra-violet rays from the sun. However at ground level it is a pollutant. Unlike the other pollutants mentioned above, ozone is not emitted directly. Rather, it is formed as a result of a complex series of reactions involving hydrocarbons, sunlight and nitrogen dioxide (NO2). The involvement of sunlight in this process means that ozone levels tend to be highest in summer.

The reactions take time to generate ozone and the highest concentrations are frequently experienced many miles away from the source of the pollution, perhaps in rural areas. In fact, a significant proportion of ozone incidents experienced in the UK are due to pollution imported from abroad. The problem of ozone pollution can therefore only be adequately dealt with as a result of international agreements.

There are no substantial sources of Sulphur Dioxide (S02) pollution within Hertsmere and it is not of concern.

Where can I get more information?

The HBAPMN aims to provide consistency in monitoring across the region and collates air quality monitoring results from across Hertfordshire and Bedfordshire. This data is available to the public on the network website. The home page of this site includes a map showing the location of air quality analysers and by clicking on these you can look at the daily, weekly or annual levels of pollution at this site.

The website also has lots of information on all aspects of air quality including annual reports for the network area, Review and Assessment reports for individual authorities and information/links to the health effects of air pollution, how to reduce your own impacts and lots more.

The website also allows you to link directly to your local authority if you have any concerns or questions about air quality near you or any other aspect of air pollution. The review and assessment documents for the local authorities are also available on this site.

So visit the Herts and Beds Air Pollution Monitoring Website  today and find out about the air you breathe.

.hmi