The Great Smog: What has it taught us?

The Great Smog of London in December 1952 was a case of severe pollution that led to the deaths of 12,000 people. It was caused by smoke from solid-fuel burning and a period of exceptional cold weather, which formed a thick layer of smog over the city. The smog was so thick that people couldn’t see their own feet.

This event led to the introduction of the Clean Air Act 1956. This new legislation allowed local authorities to declare ‘Smoke Control Areas’ (SCAs). The purpose of SCAs is to reduce air pollution and protect public health.

How does air pollution impact health?

There is now a vast body of research that links air pollution to an increased risk of many diseases including cancers, heart disease, asthma, dementia, low birth weight and mental health conditions. (1)

Air pollution in many parts of Hampshire exceeds the World Health Organization’s guideline levels, as it does in most parts of the UK.

How does solid fuel burning contribute to air pollution?

Burning wood, coal and other solid fuels at home emits dangerous pollution known as fine particulate matter (often referred to as PM2.5), which has been classified by the World Health Organization as a carcinogen and can cause asthma, heart disease and other serious illnesses affecting our lungs, hearts, and brains. Exposure to particulate air pollution can also trigger the symptoms of existing health conditions like asthma and heart disease.

The rise in popularity of open fires and wood burning stoves over recent years has increased the amount of air pollution from domestic solid-fuel burning. In fact, wood burning is now a leading cause of PM2.5 pollution in the UK.(2)

Current evidence suggests there is no safe level of exposure to this pollutant.

What impact does wood burning have on air quality in Hampshire?

Air quality sensors placed in 17 Hampshire locations (2023 – 24) revealed that levels of PM2.5 are much higher during winter evenings. Air pollution, such as wood smoke, gets trapped in cold, still weather conditions and causes unhealthy levels of particulate matter to build up in neighbourhoods and across the region. Researchers at the University of Southampton who analysed the data, concluded that reducing wood burning in our homes could improve air quality for everyone.

Above: An air quality sensor in Hampshire.

What is a Smoke Control Area (SCA)?

SCAs are declared by local authorities to control the types of fuel that can be burnt in heating appliances in buildings. This can help to reduce the amount of air pollution – which benefits everyone.

How do I know if I live in an SCA?

To find out which areas of England are designated smoke control areas, please visit the smoke control area map.

You can also contact your local council to find out if you live in a smoke control area. The environmental services department will be able to help you.

What do Smoke Control Area rules mean?

If you live in a SCA it is an offence to emit smoke from a chimney (commercial or residential) unless:

  • You are using a Defra authorised (also called Defra-exempt) wood burner, or
  • Defra authorised or “smokeless” fuel.

It is only legal to burn certain “smokeless” or authorised fuels, or to use an appliance that has been granted an exemption by the Department for Environment, Food and Rural Affairs (Defra). A Defra exempt appliance must only be used with the type of fuel permitted by Defra for that appliance.

An example of a Defra-exempt appliance might be a modern EcoDesign or ClearSkies certified wood burning stove. Open fireplaces and older stoves are not exempt, and it is illegal to burn anything other than a “smokeless” or authorised fuel in them.

Fuels allowed in an open fireplace are:

  • Anthracite
  • Semi-anthracite
  • Gas
  • Low volatile steam coal
  • Authorised fuels (see below).

Unauthorised fuels include:

  • Wood – except in exempt appliances that list wood as their permitted fuel
  • House coal

You can check the list of authorised fuels here.

You can check the exempt appliances and permitted fuels here.

Wood can only be burned on a Defra-exempted appliance and must be dry and ready to burn. Ready to Burn information can be found here.

What happens if SCA rules are not followed?

A householder may have to pay a penalty of up to £300 if their chimney releases smoke in a smoke control area in England.

In addition, a householder can be fined up to £1,000 if they buy unauthorised fuel to use in an appliance that is not approved by Defra.

More information is available here.

I use a DEFRA-exempt log burning stove – does that mean I don’t have to worry about air pollution?

Burning wood and other solid fuels always produces health-damaging air pollution, even if no visible smoke is present. The best way to help improve local air quality and protect everyone’s health is to avoid burning solid fuels at home, wherever an alternative form of electric or gas heating is available.

What can I do if I rely on solid-fuel heating as the only way of heating my home?

Having a warm home is vital for physical and mental wellbeing.

If you’d like support and advice about keeping warm at home without burning solid fuels – and for advice on financial support for making your home more energy efficient, please contact us. Our team of experienced energy advisers would love to help!

Call our advice line on 0800 804 8601 or email cleanair@environmentcentre.com.

For more information please see our wood burning hub.

What should I do if I’m worried about smoke from a chimney or bonfire?

If you’re suffering from a smoke nuisance, it’s a good idea to speak with the person or business creating the problem.

If this does not resolve the issue and the problem is persistent, you can contact your local authority for advice. You can report a smoke nuisance on your local authority’s website (generally in the Air Quality section), or give them a call.

Where can I get more information about how to breathe cleaner air?

There are simple steps we can all take to reduce our exposure to air pollution both indoors and outdoors. Read about indoor air pollution and outdoor air pollution.

References
1: Chief Medical Officer’s Annual Report 2022 (Section 1:1)
2: Department for Environment, Food and Rural Affairs: Major emission sources of PM10 and PM2.5 in the UK.