Air quality monitoring – winter 2022/23

Do you ever think about the air that you’re breathing in your neighbourhood?

The majority of local authority air quality monitoring stations are situated in city centre locations to gather data about air pollution peaks, which are largely due to vehicle emissions. Until recently, the quality of the air that we breathe in our neighbourhoods has gone under the radar.

An air quality monitor in a residential area in Winchester.

In partnership with Southampton City Council, Winchester City Council, Eastleigh Borough Council, and New Forest District Council, we’ve been monitoring air quality in several neighbourhoods this winter, to give an indication of what residents are breathing where they live and go to school.

Between December 2022 and February 2023, Zephyr air quality sensors were placed in the gardens of volunteer residents living in low traffic residential areas who were interested in seeing how air quality changes over the course of a 24 hour period. 

We found that on cold evenings in neighbourhoods where domestic wood burning is common, the levels of particulate matter – tiny particles of chemicals, dust, soot and carbon – were around four times higher than they were at midday. These levels were also far higher than they were in non-residential areas where wood burning is much less common.

The sensors recorded the levels of PM2.5 [1] – the name given to the most health-damaging type of particulate matter. These miniscule particles are invisible to the naked eye and small enough to pass through the lungs, into the bloodstream and lodge in the heart, brain and other organs. 

Pollution caused by a log burner.

Breathing in particulate matter can have serious impacts on health and can cause and worsen diseases such as asthma, heart disease, stroke, cancers and dementia. Specifically, wood smoke contains a lot of PM2.5 in the form of soot and dust which can remain suspended in the air for long periods of time. The majority of smoke from a log burner is invisible – you may be able to smell it much more easily than you can see it.

A Winchester resident who is participating in the project said:

“I’ve had a sensor in my front garden for several months this winter. I’m surprised and concerned to see the rise in PM2.5 air pollution during the evening. I often notice a smell of wood smoke in my street and assumed that it would just get blown away – but I can see from the data that this isn’t the case and that the pollution is hanging around for quite some time. The pollution levels can stay quite high until the following morning.

I worry that it is affecting our indoor air quality too. To have clean and healthy indoor air you need to have clean air outside. This data shows that the air in our street is quite dirty in the evenings and at weekends.”

It’s vital that everyone is warm and well at home. With the fuel crisis causing hardship this winter, some people have considered switching to a log burner as a way of saving money on their gas and electricity bills. The financial pros and cons of wood-burning versus gas central heating is a cause of great debate and new research on this will soon be published.

If householders do choose to burn wood, the amount of air pollution emitted from a log burner can be reduced by taking steps to burn less, burn better and burn cleaner.  Burning better also makes your heating system more efficient, therefore saving money on wood supplies.

Financial help might be available to residents looking to find cleaner and more environmentally-friendly options to heat their homes.

If you’d like to know more about how we might be able to help you manage your home energy, please contact us on 0800 804 8601 or email We serve the areas of Southampton, Hampshire and Portsmouth.


[1] Particulate matter is classified according to its size. The smaller the particles are, the more harmful they are to health. PM2.5 is the matter most commonly measured and refers to particles that are less than 2.5 micrometres in size – so tiny that they are invisible.

Further reading

According to DEFRA, wood burning remains the greatest source of Particulate Matter air pollution in the UK – more so than traffic and industry.