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Air quality monitoring

Why we monitor air quality

Local authorities have a duty to monitor the air quality in their district under the Environment Act 1995, because poor air quality has the potential to adversely affect public health.

The council is required under this law to carry out regular reviews and assessments of air quality in North Hertfordshire against standards and objectives set out by the National Air Quality Strategy.

If we find any place where the objectives are not likely to be achieved, we are required to declare an Air Quality Management Area (AQMA) there. In North Hertfordshire there are two Air Quality Management Areas.

How we monitor air quality

We monitor nitrogen dioxide at 42 sites across the district.

We also maintain two Air Quality Monitoring Stations, both currently located at Stevenage Road in Hitchin. One continuously measure levels of nitrogen dioxide, the other measures particles, PM2.5 and PM10, in the air.

Objectives set out in the Air Quality Regulations 2000 identify a level of pollutants for which there would be no, or extremely low risk to health. The council monitors against these objectives. If this level is exceeded, more detailed monitoring action would be required, which may highlight actions to be taken to improve the air quality.

The main source of air pollution in North Hertfordshire is from traffic.

Air quality reports

The most recent annual reports can be found below.

We also participate in the Herts & Beds Air Pollution Monitoring Network. Their website has historical and current data from Air Quality Monitoring Stations in the region. Older air quality reports that are specific to North Hertfordshire can also be found there.

Air pollution alerts

You can sign up to receive air pollution alerts on your phone.

Industrial activity

Although North Hertfordshire does not have a large industrial base which affects air quality, the council has a duty to regulate a number of industrial activities.

To protect against high concentrations of air pollutants at ground level, the Clean Air Act 1993 allows Local Authorities to control the height of chimneys serving industrial processes.

We must consider an application for approval for chimney height for a furnace. Certain industrial processes are regulated by the Pollution Prevention and Control Regulations 2000 within which are provisions for calculating chimney heights.