As temperatures soared to new record levels on Tuesday 19th July the London Fire Brigade had it’s busiest day since World War II , attending 1,146 incidents The London Air Quality Network(LAQN), and it’s partner sensor network Breathe London, detected the results of several of these fires.

In the east of London large wild fires burned both north and south of the Thames. To the north the fire at Wellington was detected around 8pm at the LAQN sites just west of there at Rainham in Havering and Scrattons Farm in Barking & Dagenham, with peaks of 96ug/m3 (hourly) and 160ug/m3 respectively. The Breathe London Node at Rainham also detected this plume.

To the south of the river a fire was burning on marsh and grassland just near the river Cray between Dartford and Slade Green. The plume from this was clearly detected around 7pm at the LAQN monitoring site at Slade Green with a peak of 170 ug/m3, and by the Breathe London Nodes at Slade Green and further north at Peareswood Primary School

It was not just wild fires causing problems but also building fires. In Eltham a shop just near the Fiveways junction on the A20 Sidcup road, caught fire. The monitoring site was just across the road and recorded PM10 levels over 400 ug/m3 as an hourly average indicating the density of the plume. In Brent peaks were seen at the monitoring sites at John Keeble and Ark Franklin schools in Brent and Western Avenue in Ealing, all around 9pm. These may have been linked to a building fire in Wembley. Peaks of around 200 ug/m3 were detected.

Peaks were also seen in Wandsworth at the Putney and Lavender Hill monitoring sites. Both showed a signature that would match a fire plume with Nox increases as well as PM. These are still being investigated since no immediate match to a fire has been made.

One characteristic of large fires that we detect across the network is that the highest levels detected are often as the fire is brought under control. The heat is reduced by this point so the plume is not carried as high and hence more likely to be detected at our ground level monitoring.