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Air quality monitoring

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.

In North Hertfordshire there are two Air Quality Management Areas.

The main source of air pollution in North Hertfordshire is from traffic. 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. North Hertfordshire District Council monitors against these objectives and if exceeded, more detailed monitoring action would be required, which may highlight actions to be taken to improve the air quality.

How do we monitor air quality?

The Council monitors Nitrogen Dioxide at 42 sites across the district. We also maintain two Air Quality Monitoring Stations, both currently located at Stevenage Road, Hitchin. One continuously measure levels of Nitrogen Dioxide. The other measures particles, PM2.5 and PM10, in the air.

Historical and current data from these Air Quality Monitoring Stations can be found at

Air Pollution Alert System

To help people to manage their exposure to local air pollution, we have part funded a FREE to use Air Pollution Alert System. The system sends a message to your mobile phone when local air pollution is forecast to be high. The alert will be received in advance of the forecast air pollution episode so that people are informed and able to take the necessary precautions. Sign up here to receive alerts

Effects of air pollution

Generally if you are in a good state of health, moderate air pollution levels are unlikely to have any serious short term effects.

However, elevated levels and/or long term exposure to air pollution can lead to more serious symptoms and conditions affecting human health. This mainly affects the respiratory and inflammatory systems, but can also lead to more serious conditions such as heart disease and cancer. People with lung or heart conditions may be more susceptible to the effects of air pollution.

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.

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