One of the lasting effects of the COVID-19 pandemic is that many of us are much more aware of the air we breathe, especially in indoor environments. But compared to outdoor air pollution, indoor air quality is less well understood. Polling and focus groups consistently find that people are more familiar with common sources of outdoor air pollution and its related health harms, but less so when it comes to indoor air quality.
Indoor air quality is determined by two things: pollution generated in the home and pollution generated outside that seeps in.
Air pollution generated in the home is a product of the occupant’s activities. This varies significantly from home to home, and is determined by almost everything inside the home including soft furnishings, paint, dust levels, pets, candles, cigarette smoke, cleaning products, cosmetics, building materials… The list goes on.
There are, however, two major sources of indoor air pollution – gas cooking and domestic burning (solid fuel/wood burners and open fires) – which trump all others.
Gas hobs emit carbon monoxide (CO), carbon dioxide (CO2), and nitrogen dioxide (NO2), all of which are harmful to human health. A recent report by CLASP estimates that indoor air pollution from gas cooking costs the UK around £1.4billion annually in healthcare costs, including lower life expectancy, illnesses, greater healthcare expenditure and lower productivity.
Wood burners are the biggest source of small particle air pollution (PM2.5) in the UK, despite being used by only a tiny minority of the population. Even homes with “eco” wood burners are three times more polluted than those without. PM2.5 has been identified by the World Health Organization (WHO) as the most harmful pollutant to our health because it can reach every organ in the body causing cardiovascular and respiratory disease and cancers. The more PM2.5 pollution you are exposed to, the more likely you are to die from cardiopulmonary disease or lung cancer.
But the issue of indoor air pollution is not just about how we cook and heat our homes – it is intrinsically linked to how and where we live.
Pollution in the home is also determined by pollution from outside. Building design and construction materials are important in terms of air tightness and ventilation and how much pollution gets in and out.
Everyone can be affected by indoor air pollution, but the impact is more significant for people with lung conditions and for children, whose lungs are still developing. Exposure to indoor pollution may also disproportionately impact low-income households for a variety of reasons including housing characteristics and location to outdoor sources of air pollution
The most immediate action you can take to improve indoor air quality is to ventilate your home by regularly opening windows and using extractor fans. This does get complicated if you live near a busy road (in which case, it is best to open windows when traffic levels are lower) and during winter – although the German method of Stoßlüften (shock ventilation: opening windows for a few minutes) can be effective to exchange air.
Ultimately, removing gas cookers and all other forms of combustion from our homes will create the healthiest indoor environments, as well helping to decarbonise our homes and tackle climate change. If you cannot replace your gas hob, make sure that it is serviced annually along with your boiler (and any other gas appliances you might have). You should also consider installing a low-concentration carbon monoxide detector.
Individuals cannot be expected to decarbonise heating and cooking without government and industry support. The UK Government should adopt laws protecting consumers by setting limits on pollution emissions from gas cooking appliances, and provide incentives and grants for households to help them make the transition to electric cooking – in the same way that support is provided for the transition away from gas heating.
There will be a time when we look back at having naked flames and highly combustible material in our homes as the absolutely madness that it is. In the meantime, open the window and get some fresh air.
More information about gas cooking, domestic burning and the health effects of air pollution can be found on the Clean Air Hub.
Sign up to our webinar (8 June 11.00-12.00) to learn more about the health and environmental impacts of gas cooking, with contributions from CLASP, Professor Prashant Kumar, and Global Action Plan.
