Birmingham’s wood burning emissions increased sevenfold over 12 years

A team from the University of Birmingham has looked into domestic woodburning in the West Midlands and found that it is the source of 20% of the total PM2.5 in the area.

Notably, they also found that woodburning-related PM2.5 emissions were seven times higher than those measured in 2008-2010.

Aside from biomass burning, other dominant sources of PM2.5 were found to be secondary aerosols and resuspended dust and traffic emissions.

The research was conducted as part of the Natural Environment Research Council (NERC)-funded West Midlands Air Quality Improvement Programme (WM-Air), led by Professor Bill Bloss.

The team used advanced receptor modelling techniques to identify and quantify pollution sources in PM2.5 samples collected in 2021 and 2022 at two urban background sites in Birmingham, one of which was the Birmingham Air Quality Supersite (BAQS)

The amount of PM2.5 made up of ammonium sulfate fell from 25% t0 15% while, the proportion of ammonium nitrate has risen slightly, possibly caused by the the large reduction in SO2 levels.

The team also found higher evidence of biomass burning at the BAQS site which, they noted, is situated in an area of relatively higher affluence and typically larger, older housing stock.

We also estimated the approximate number of annual deaths attributed to the identified source factors of the ambient PM2.5 sampled in the West Midlands using

A new Air quality Lifecourse Assessment Toll was used to approximate the number of annual deaths in the West Midlands which could be attributed to the PM2.5 sampled and found that to be 2,070. They added: ‘Assuming equal toxicities per unit mass for different PM2.5 sources (an assumption which may not be correct), the highest mortality was associated with PM2.5 exposure resulting from secondary components and wood burning emissions.’

However, they also believe that significant policy interventions could see a fall in PM2.5 levels by upwards of 50%, reducing PM2.5 exposure by 35% by 2040.

Professor Zongbo Shi from the University of Birmingham, said: ‘We need to see immediate and coordinated actions at local and national levels to reduce wood burning, improve air quality – including enhancement and enforcement of smoke control areas to curb emissions from woodburning stoves and open fires. This has great potential to reduce PM2.5-related health risks and decrease mortality in the region.’

The full research can be read here.