Air pollutants can be generated from local, national and international sources and travel long distances resulting in 'transboundary' pollution, for example ozone.
The major pollutants and their main sources are:
- nitrogen dioxide - produced by petrol or diesel burning engines and coal/oil burning furnaces
- sulphur dioxide - produced by burning fossil fuels (eg fuel oil and coal)
- carbon monoxide - produced by the incomplete burning of carbon-containing fuels, such as petrol, coal and wood
- particles (PM10) - produced by diesel vehicles, power stations, industrial processes, mining and quarrying, and domestic sources
- benzene - produced by petrol burning engines, diesel burning engines and petrol evaporation from vehicles
- 1, 3-butadiene - produced by the combustion of petrol and diesel fuel, house fires and the burning of other fossil fuels
- lead - produced by petrol burning engines and industrial combustion plants and processes
The biggest cause of poor air quality in the UK is caused by car fumes. Opting to drive less will help improve local air quality.
Local air quality management (LAQM)
After seeing improvements in air quality in recent years, in 2025 we were able to revoke four of our five declared AQMAs as the annual objective for nitrogen dioxide had been met for at least five consecutive years. These four were the AQMAs in Tonbridge High Street, The A20 at Larkfield, The A20 at Aylesford and the A25 at Borough Green.
We now have just one declared AQMA in the borough which is at
- A26 - Red Hill/Tonbridge Road junction Wateringbury
To monitor air quality we use:
- 57 diffusion tubes located at 37 sites across the borough
- Two continuous NOx (Nitrogen oxides) analysers, one in Tonbridge High Street and another in Borough Green
- One PM10 (particulate matter) monitor for PM10 levels at Borough Green 24hrs a day.
See our latest Air quality report and Air quality action plan
Kent County Council’s Air Quality Network monitors air quality in the borough and details of current levels of pollution are available on its website.