Wood-burning stoves serious problem for your health, environment

Asit Kumar Mishra and John Wenger For The Conversation

Cork (Ireland): There is something cosy and appealing about settling down next to a roaring fire in winter but, every year, nearly 61,000 premature deaths in Europe are caused by air pollution as a result of people burning wood or coal to heat their homes.

Wood-burning stoves are often considered safer, cleaner and more attractive than open fires. This may, in part, explain why from 2021 to 2022, sales of wood-burning stoves increased by 40 per cent in the UK.

However, burning wood is not necessarily a healthier or greener alternative to coal or gas for home heating.

Wood burning produces a complex chemical mixture of fine particulate matter (PM2.5) and gases, which can be breathed deep into the lungs. The specific contents vary based on the type of stove and the type of fuel, but chemicals can include carbon monoxide, oxides of nitrogen and a range of volatile organic compounds, such as cancer-causing formaldehyde and benzene.

Exposure to wood smoke affects the heart, blood vessels and the respiratory system – and PM2.5 is considered to be the biggest threat. Wood smoke increases the risk of heart attacks and strokes and can exacerbate chronic obstructive pulmonary disease (COPD) and asthma. Exposure to PM2.5 from wood burning can also cause premature death.

Exposure to this pollution also leads to loss of work days, reduced productivity, higher expenses on healthcare and increased hospital admissions.

The risks are higher for people over 65, children, pregnant women and people with existing heart or lung conditions. Chronic wood smoke inhalation has been associated with systemic inflammation, which can make the lungs more vulnerable to infections, such as flu and COVID.

In the UK and Ireland, solid fuel heating is the main source of outdoor PM2.5 during wintertime. While wood is the dominant solid fuel in the UK, peat burning is regularly found to make the largest contribution to PM2.5 in Ireland.

Under cold, stagnant weather conditions, air pollution, even in small rural towns, can be as high as that found in very polluted parts of north India.

Exposure to outdoor air pollution caused by wood burning is an obvious health risk. But the pollution also finds its way into homes, worsening indoor air quality. Also, when lighting or refuelling a wood stove, large quantities of PM2.5 escape into the indoor air. Depending on how effective the home ventilation is, the PM2.5 levels can take hours to reduce.

Looks aren’t everything

In surveys carried out in Ireland and the UK, it was found that most people using solid fuel stoves did it for the aesthetics and the “homely feel”. The desire to save money or necessity came next.

Most people who use indoor wood burning in London are in wealthier neighbourhoods, while those most affected by the consequent air pollution are in poorer areas.

Educational campaigns regarding the effect of wood-burning stoves on health and the environment can be an important tool to reduce their usage. New initiatives, such as the Clean Air Night held in the UK and Ireland, are valuable in raising awareness and possibly changing long-term heating habits.

Encouraging users to move to more efficient and renewable heating technologies like heat pumps can reduce emissions and harm to health. This move even works out to be cheaper, except for people who source their own wood.

Communities can also be provided with information on their local air quality, allowing them to visualise real-time effects of their actions. For example, the PM2.5 sensor network map for Cork is freely accessible to the community and identifies locations and times when PM2.5 pollution is unhealthy.

If you have a wood burner, you could check that the pollution levels aren’t too high before you fire it up.

How to reduce emissions

People who rely on solid fuel stoves as their only source of home heating can adopt the following measures to reduce emissions. Use low-emission labelled stoves that reduce pollution. When burning, have small hot fires, with enough air supply and do not let the fire smoulder.

Choose carefully what is burnt, in compliance with relevant regulations. Do not burn garbage, plastics, cardboard, treated or painted wood in your stoves. These items increase exposure to toxic pollutants.

Ensure that stoves are installed and maintained annually by professionals. And, when lighting up or refuelling, make sure that the room the stove is in is well ventilated. This means open windows, no blocked vents, and exhaust fans or kitchen hoods can be used for additional ventilation.

People who use solid fuel stoves as a secondary source of heating could consider using the stove less or even stopping using it altogether. That really would be a breath of fresh air.

The authors are Research Fellow in School of Public of Health, University College Cork; Professor in Physical and Environmental Chemistry, University College Cork