How air pollution is being monitored in Southampton and Reading

As part of its Air Day coverage, BBC South visited Southampton and Reading to understand how pollution builds up and is measured.

The main source of pollution in the UK is local emissions, such as road traffic, industrial processes, heating and agriculture.

On a windy day, any pollution that builds up could be blown away, but on a calm day, particularly in winter, the pollution can be trapped at the earth’s surface.

I met Simon Hartill, scientific officer for Southampton City Council’s environmental health department, at one of its four ground-based air monitoring stations.

At the station in Brintons Road, near St Mary’s Stadium, the council and Environment Agency monitor levels of nitrogen dioxide, sulphur dioxide and other pollutants.