How our heating choice affects air pollution in and around our home
- Published: 31 Mar 2016
It might be nearly spring, but clear March skies mean cool nights so it’s not time to turn the heating off just yet. However, prolonged settled weather means air pollution often builds up at this time of year – and days with high pollution levels are common. Last month a report from the Royal College of Physicians (RCP) was published alerting us to the health impacts of air pollution. The report links the deaths of an astounding 40,000 people to outdoor air pollution in the UK. It also raises concerns about air pollutants in our indoor spaces – after all most of us spend around 90% of our time indoors. This indoor air pollution arises from the heating and cooking we do indoors and some of the products and materials we use.
Outdoor air pollution
Until the 1960s air pollution was obvious as thick smogs were frequent in towns and cities – caused by industry and burning coal for heating. This filthy air was tackled by the UK clean air acts, which changed the way we heat our homes – banning smoky open fires from homes in many towns and cities. Now fuels and the appliances we use are much cleaner, but they still cause pollution problems. Present day pollutants are either colourless gases or particles so tiny that we can’t see them which is why modern air pollution has been called ‘the invisible killer’. When air pollution outdoors reaches unhealthy levels, the advice from experts is to avoid polluted areas and strenuous exercise, and if possible stay indoors. Young children, older people and anyone with existing lung or heart conditions are more at risk from harmful health impacts.
Where does outdoor air pollution come from?
Outdoor air pollution can be caused by a range of nasties that come mostly from us burning fuel. There are also natural irritants which cause allergies and air pollutants can interact with these:
Pollutant |
Source |
Effects |
Nitrogen oxides – NO and NO2 |
Vehicles, power plant, industry |
Irritates the lungs |
Ozone – summer smog |
Formed when nitrogen oxides react in sunlight |
Can inflame the airways and trigger asthma |
Particles (PM10 and PM2.5) |
Diesel fuel |
Larger particles irritate eyes, nose and throat. Tiny particles can penetrate deep into the lungs and harm those with heart or lung conditions |
Smoke |
Dirty coal fires, burning damp wood, bonfires, industry |
Irritates airways, lung problems |
Sulphur dioxide |
Coal burning |
Irritates airways, lung problems |
Allergens |
Trees, grass, flowers |
Some people have an allergic reaction to pollens, air pollution can interact with these |
Most of air pollution around our homes and workplaces comes from cars, vans and lorries. However, the fuels we use at home also affect the quality of the air we breathe. While about 85% of us rely on gas central heating, many people also enjoy an open fire or wood burner. If you live in a smoke control area, you must use an authorised appliance and the correct fuel to minimise pollution. Burning unseasoned wood, non-smokeless coal or using the wrong appliance can cause smoke and particles in the air which will contribute to air pollution indoors and out. If you use electric heating, you won’t be contributing any pollution to the air around (or inside) your home. (Although if your electricity comes from a coal fired power station your heating won’t be completely pollution free!)
Indoor air pollution
Air pollution outside gets a lot of attention, but how many of us think about the air indoors? Very few people smoke inside now – but there are still plenty of pollution sources in the homes where we spend most of our time. While better insulation cuts our energy use and reduces bills, we also need to make sure our homes are ventilated with ‘fresh’ outdoor air. During the dark, damp days of our recent winter, it’s been easy to forget about opening windows and not notice unhealthy mould in corners and on window frames. Just as pollution builds up outside when the air is still, without regular exchange of air, pollution builds up inside our homes.
Where does indoor air pollution come from?
Indoor air pollution comes from our activities – heating, cooking appliances and products we use. Also moisture from cooking, heating and even us breathing leads to condensation that can cause harmful mould.
Pollutant |
Source |
Effects |
Carbon monoxide |
Faulty gas boilers, tobacco smoke |
At low concentrations drowsiness, impaired sight at high concentrations headaches, dizziness, death |
Nitrogen oxides |
Unvented gas cookers, faulty gas cookers, tobacco smoke |
Eye, nose and throat irritation, lung problems and infections |
Volatile organic compounds (vocs) |
Gases that come from many household products including cleaning fluid, paints, varnishes, fabric and building materials |
Eye, nose and throat irritation, headaches, nausea – some are linked to cancer |
Particles |
Open fires, wood stoves, tobacco smoke |
Eye, noise throat irritation, trigger infections, linked to cancer |
Mould |
Moisture on surfaces, spores in the air |
Can trigger allergies and respiratory conditions |
Allergens |
Pet hair and dander, mould, chemicals in cosmetic or household products |
Can trigger eye, nose and throat irritation |
Outdoor contaminants |
Fumes from traffic and industry through windows or ventilation systems |
Eye nose and throat irritation, respiratory conditions |
While this might look like a list of toxic horrors – there’s no need to panic.
How can I prevent indoor air pollution?
Many of our normal activities at home produce air pollution – but this isn’t a problem as long as we look after our indoor environment. Here’s how we can keep the air in our homes healthy to breathe:
• Avoid products that contribute to indoor air pollution or ensure good ventilation when using them
• Don’t allow anyone to smoke indoors
• Use an extractor hood when cooking with gas
• Use an extractor hood or open a window when cooking produces steam to avoid condensation
• Ensure gas boilers and cookers are well maintained
• If using solid fuel, only burn clean coal and an authorised fireplace or dry wood in a wood burner
• Gas fires and heaters produce condensation so ensure good ventilation to avoid mould
For more information, consult the Committee on the Medical Effects of Air Pollutants.
So, while gas is convenient and solid fuel fires are cosy, both of these heating options produce pollution indoors and contribute to condensation. If you use electric heating in your home no fuel is being burnt indoors so, there won’t be any indoor pollutants to worry about! Also, you’ll be generating dry heat and reducing the risk of condensation and mould.
There are many factors to consider when choosing the right heating for your home, but if it's clean air indoors you care about, electric radiators could be your best choice.