A fire in a metal recycling yard in Scrubs Lane, Willesden, Hammersmith & Fulham started yesterday afternoon and has been attended by 8 fire engines from London Fire Brigade overnight. They advised residents living nearby to keeps doors and windows closed.

The smoke from the fire appears to have been detected at several LAQN monitoring sites overnight. Around midnight the plume was detected at the Brent Neasden between 23:30 and 01:00, with an 15 minute maximum of 232ug/m3. Shorter, lower concentration peaks were then detected in other locations as the smoke travelled north west. The plume was detected locally at the Brent - Ikea monitoring site between 00:30 and 01:15 (15min peak 63ug/m3) and then for the same duration half an hour later at Harrow Stanmore ( 15min peak 90ug/m3).

Closer to the source Brent - John Keeble Primary School detected the smoke as two distinct peaks between 00:30 to 01:30, the higher of the two being the first at 00:45 (15min peak 95ug/m3).

All above mentioned monitoring sites use TEOMs to measure their particulate matter. All measurements listed have been adjusted using the Volatile Correction Model to make them EU reference equivalent.

It is possible that elevated readings seen at Enfield Bowes Primary School, beside the north circular, 3 hours earlier may have been from this fire but wind direction information currently available is inconclusive. This monitoring site (using an FDMS) recorded elevated readings between 20:00 and 23:00. Only hourly readings are available from this instrument which peaked at 116ug/m3 between 21:00 and 22:00.

A picture of the smoke plume taken by Jeff Hervel from 12th floor of hotel in Wembley.

Note below All measurements given are provisional.

Note: The FDMS (Filter Dynamics Measurement System) is a more advanced version of the TEOM (Tapered Element Oscillating Microbalance) and is better at measuring the part of the particles which is volatile and may evaporate or react. The VCM (Volatile Correction Model) uses the amount of volatile measured by FDMSs to correct the initial measurements made by the TEOMs in the surrounding area.

Item date 25/04/2012