How our heating choice affects air pollution in and around our home

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.