Wood burning stoves: pollution and health impacts

Wood burning stoves remain a popular way to heat your home on cold winter nights. 

But there is also increasing concern about the potential health and environmental impacts of wood burning stoves, for you and the air inside your home, for your neighbours and the air in your local area and for the environment overall. The exact extent of these impacts remains unclear.

If you're thinking of installing a stove, or you have a stove and want to know more, we've rounded up the facts below.

Be inspired to make home improvements. Sign up for our Home newsletter, it's free monthly

Types of pollutant  

Wood burning stoves release two types of pollutant: gases and particulate matter.

Any appliance that burns solid fuel, such as wood burning or multifuel stoves, releases dangerous gases. These include organic gaseous compounds (OGC), carbon monoxide (CO), nitrogen oxides (NOx), carbon dioxide (CO2).

Stoves also release particulate matter (PM) – tiny solids or liquids that are suspended in the air. These include dirt, dust, and soot.

Some of these particles are visible to the naked eye. For example, smoke is made of visible PM, including particulates of carbon and tar. However, many types of PM are invisible.

It is clear that both of these pollutants (gases and PM) are linked to negative environmental and health outcomes. 

Are wood burning stoves bad for the environment? 

Wood burning stoves release greenhouse gases, including CO2 and NO. These gases trap heat in the earth’s atmosphere, which contribute to global warming.

Global warming detrimentally affects the environment both directly and indirectly and has been linked to extreme weather events, rising sea levels and drought.

Wood burning stoves also release particulate matter (PM). These include particulates of carbon and tar, which are small enough to be suspended in the air.

PM can be carried by the wind and settle on the ground or the water. The impacts include:

• Making bodies of water (including lakes and streams) more acidic
• Contributing to the development of acid rain
• Depleting or changing the balance of different nutrients in soil
• Affecting environmental biodiversity

Are wood burning stoves bad for your health? 

Long-term exposure to greenhouse gases affects multiple different organs within your body, particularly those which make up the respiratory and cardiovascular systems (i.e., your lungs and heart).

However, most research into the impact of wood burning stoves has focused on the health impacts of two types of PM released during stove usage – PM2.5 and PM0.1.

‘2.5’ and ‘0.1’ refer to the diameter, in micrometres, of the particles making up the particulate matter. For context, the average human hair is about 70 micrometres in diameter. 

Due to the size of PM2.5 and PM0.1, these particles enter your lungs when they are inhaled, and then cross from your lungs into your bloodstream. 

This means they can be carried around the body and cause damage to other organs. A review of current research has linked to PM to conditions including:

• Heart and lung disease
• Diabetes
• Dementia
• Bladder cancer
• Brittle bones

It also found that PM affects fertility and foetuses.

Find out more about stove fines and regulations

What is the amount of pollutants released by wood burning stoves?

It is clear that the pollutants released by wood burning stoves are linked to negative health and environmental outcomes. 

However, to gain a complete picture of the impact of stove usage, you need to consider the amount of pollutants they release when you use them. 

Pollutants in the environment 

According to a report released in 2021 by the European Environmental Bureau, one Ecodesign-compliant wood burning stove releases the same amount of particulate matter per hour as 18 newer diesel cars or six modern heavy goods vehicles. 

In 2021, DEFRA (the Department for Environment, Food & Rural Affairs) released a report which found that domestic wood burning has become one of the biggest sources of PM pollution in the UK, exceeding that of road traffic.

The same report found that emissions of PM2.5 from domestic wood burning increased by 124% between 2011 and 2021, to represent 21% of total PM2.5. emissions in 2021.

Finally, a study from Imperial College London found "hotspots" of pollution in North London where there are a high concentration of wood burning stoves. This suggests that PM pollution from a stove can settle over a neighbourhood. 

However, these studies have been criticised by the Heating Equipment Testing and Approval Scheme (HETAS) and Stove Industry Alliance (SIA). 

HETAS is a not-for-profit organisation that provides certification to stove retailers, installers and manufacturers. The SIA is the trade industry association for the UK stove sector. 

The SIA highlighted that these figures include all domestic wood burning (e.g., including open fires) and therefore do not reflect pollution from wood burning stoves alone. 

Pollutants in the home

A 2020 study (funded by The Grantham Centre for Sustainable Futures, The University of Sheffield and The University of Nottingham) found that the concentration of PM2.5 in the home was almost 200% higher than normal when a wood burning stove was in use.

The concentration was between 250% and 400% higher after the stove door was opened to add more fuel. The researchers named these ‘flooding events’.

The level of PM2.5 in the home while the wood burning stove was burning was between 27 and 195 micrograms per cubic metre of air. 

The World Health Organisation (WHO) suggests that exposure should be limited to below an average of 15 micrograms per cubic metre in a 24 hour period. 

The SIA (the trade industry association for the UK stove sector) also responded to this and similar studies.

They suggested that factors including fuel quality and refuelling process all impact the volume of pollutants released by a stove. As these are not reported in the above paper, they concluded that is difficult to interpret the findings. 

If you are considering buying a stove, see our ratings of wood burning stove brands

Deciding whether to use or install a wood-burning stove

It is clear that the pollutants (gases and PM) released by wood burning stoves have negative environmental impacts. They also impact the health of the stove owner, their neighbours, and wider society. 

However, the volume of pollutants released by stoves during normal use is debated. Variation in the conclusions formed by different researchers can be attributed to differences in measurement, metrics and interpretation. 

It is ultimately up to individuals to decide whether or not you want to burn fuel at home and how, within the confines of tightening wood burning rules and regulations.

Those living in spaced-out rural communities, for example, might have different needs and consider the direct impact of burning fuel at home to be less than those in built-up urban areas. 

We wouldn't recommend installing a new wood-burning stove without seriously considering how and when you will use it, and what the health and environmental impacts will be on those in your own home and your neighbours. 

If you've already got one, it's still worth thinking about these issues when weighing up how frequently to use it. 

Alternatives to wood burners include gas stoves, electric stoves, or underfloor heating