The Clean Air Act.

The Great Smog of 1952 and the Development of Clean Air Law

Air pollution remains one of the most significant environmental risks to public health, but the pollution affecting modern towns and cities is very different from the thick coal smog that once regularly covered London.

The most notorious incident was the Great Smog of December 1952. A combination of coal smoke, industrial emissions, fog and unusually still weather created a toxic blanket over the capital.

Thousands of people died during the smog and in the weeks and months that followed. The disaster eventually led to the Clean Air Act of 1956 and a major change in the way air pollution was regulated.

What Happened in December 1952?

The Great Smog began on Friday, 5 December 1952, and remained over London until Tuesday, 9 December.

Visibility fell to only a few metres in some places. Road transport was severely disrupted, ambulances struggled to operate, and the pollution entered homes, hospitals, theatres and public buildings.

People with respiratory and cardiovascular conditions were particularly vulnerable, although the effects were not limited to those already known to be unwell.

Initial estimates suggested that approximately 4,000 additional deaths occurred during the incident and its immediate aftermath. Later research placed the total number of premature deaths associated with the smog as high as approximately 12,000.

What Caused the Great Smog?

The disaster resulted from a combination of pollution and weather conditions.

Major sources included:

• coal burned in domestic fireplaces;


• coal-fired power stations;


• industrial furnaces and boilers;


• steam locomotives;


• diesel vehicles; and


• pollution carried towards London from other areas.

December 1952 was cold, which increased the amount of coal burned for heating.

Much of the coal used in homes was of relatively poor quality and produced large quantities of smoke and sulphur dioxide.

Temperature Inversion

An area of high pressure settled over London and created a temperature inversion.

Normally, warmer air near the ground rises and allows pollutants to disperse. During an inversion, a layer of warmer air sits above colder air near the surface.

The warmer layer acts like a lid, trapping smoke, gases and particles close to the ground.

Water droplets in the fog mixed with pollution produced by coal burning. Chemical reactions contributed to the formation of sulphuric acid and other harmful substances within the smog.

Why Was the Smog So Deadly?

The pollution contained extremely high concentrations of smoke particles and sulphur dioxide.

Exposure could cause or worsen:

• bronchitis;


• pneumonia;


• asthma;


• breathing difficulties;


• heart disease;


• chest infections; and


• other cardiovascular and respiratory conditions.

Older people, babies and people with existing heart or lung conditions were at particular risk.

The absence of modern pollution warnings, emergency planning and widespread understanding of the health risks made the situation more dangerous.

Pollution Before 1952

The Great Smog was not the first serious air-pollution incident in Britain.

Dense urban fogs associated with coal smoke had been recorded since the Industrial Revolution and were sometimes described as "pea-soupers".

Earlier legislation attempted to control industrial smoke, but enforcement was limited and domestic coal burning remained largely unregulated.

Smoke was also widely accepted as an unavoidable consequence of industrial prosperity and city life.

The scale of the deaths in 1952 made that position increasingly impossible to defend.

The Clean Air Act 1956

The Clean Air Act of 1956 was introduced following the recommendations of the Committee on Air Pollution.

The Act gave local authorities powers to establish smoke control areas, sometimes referred to as smokeless zones.

Within these areas, restrictions could be placed on smoke emitted from domestic and commercial chimneys.

The legislation also:

• restricted emissions of dark smoke;


• required new furnaces to operate without producing smoke as far as practicable;


• introduced controls over grit and dust from industrial furnaces;


• required approval for the height of certain chimneys; and


• provided financial assistance towards converting fireplaces and heating systems.

Resistance to Smoke Control Areas

The reforms were not universally popular.

Many households relied on open coal fires for heating and cooking. Conversion to gas, electricity or approved smokeless fuel could involve considerable expense.

Grants were therefore made available to assist with the cost of altering fireplaces and heating equipment.

The changes were introduced gradually rather than through an immediate nationwide ban on domestic coal burning.

The Clean Air Act 1968

Further legislation followed through the Clean Air Act of 1968.

The 1968 Act strengthened controls over industrial emissions and chimney heights.

Taller chimneys were intended to help disperse emissions from furnaces and industrial processes over a wider area.

This reduced severe local concentrations, although it did not eliminate the pollution itself.

The 1956 and 1968 Acts contributed to major reductions in visible coal smoke and the sulphurous fogs historically associated with British cities.

The Clean Air Act 1993

The Clean Air Act 1993 consolidated much of the earlier clean-air legislation into one Act.

It remains an important part of the legal framework governing:

• dark smoke;


• smoke control areas;


• emissions from furnaces;


• chimney heights;


• grit and dust;


• approved fuels; and


• authorised fireplaces.

Local authorities can declare all or part of their district to be a smoke control area.

In England, a person may face a financial penalty if smoke is emitted from a chimney in a smoke control area without a valid exemption.

Can You Use a Wood-Burning Stove in a Smoke Control Area?

A person living in a smoke control area must generally use either:

• an authorised fuel; or


• an exempt appliance operated in accordance with its conditions.

An ordinary open fire or non-exempt stove may not be lawful when used with unauthorised fuel.

Householders should check the current rules applying in their local authority area before buying or installing a stove.

Planning permission, building regulations and rules applying to listed buildings or conservation areas may also need to be considered.

The Shift From Coal Smoke to Modern Pollution

The dramatic coal smogs of the twentieth century have largely disappeared, but air pollution has not.

Modern pollution is often less visible and comes from a wider range of sources, including:

• road traffic;


• diesel and petrol engines;


• domestic wood burning;


• industrial processes;


• construction;


• agriculture;


• shipping and aviation;


• energy production; and


• pollution transported from other countries.

Important pollutants include nitrogen dioxide, fine particulate matter, ozone, sulphur dioxide, ammonia and carbon monoxide.

What Is Particulate Matter?

Particulate matter consists of very small solid particles and liquid droplets suspended in the air.

PM10 refers to particles with a diameter of 10 micrometres or less. PM2.5 refers to finer particles with a diameter of 2.5 micrometres or less.

PM2.5 is of particular concern because the particles can travel deep into the lungs, and some can enter the bloodstream.

Long-term exposure is associated with increased risks involving:

• heart disease;


• stroke;


• lung cancer;


• chronic respiratory disease;


• asthma;


• reduced lung development in children; and


• premature death.

Domestic Wood Burning

Wood-burning stoves and open fires can be important sources of fine particulate pollution.

Even where wood is described as renewable or carbon neutral, burning it can release smoke and particles harmful to local air quality.

Rules in England restrict the sale of traditional house coal and small quantities of wet wood for domestic burning.

Wood sold for immediate use should generally meet the required moisture standards.

Householders should use the correct fuel, maintain appliances and chimneys, and avoid burning treated wood, waste or other unsuitable materials.

Road Traffic Pollution

Road vehicles remain a major source of nitrogen oxides and particulate pollution, particularly in busy urban areas.

Pollution can arise from:

• exhaust emissions;


• brake wear;


• tyre wear;


• road-surface wear; and


• dust being disturbed by passing traffic.

Electric vehicles remove exhaust emissions at the point of use but still produce particles through brakes, tyres and road wear.

The Environment Act 1995

The Environment Act 1995 established the system of Local Air Quality Management.

Local authorities must review and assess air quality within their areas.

Where national air-quality objectives are unlikely to be met, the authority may need to declare an Air Quality Management Area and prepare an action plan.

Measures may include:

• traffic management;


• changes to road layouts;


• clean-air zones;


• planning controls;


• restrictions on idling vehicles;


• improvements to public transport;


• controls over industrial sources; and


• public information campaigns.

The Environment Act 2021

The Environment Act 2021 introduced a new framework for legally binding environmental targets in England.

It required the Government to set targets addressing fine particulate matter.

The statutory targets include:

• an annual mean PM2.5 concentration of no more than 10 micrograms per cubic metre by the end of 2040; and


• a reduction of at least 35% in average population exposure to PM2.5 by the end of 2040, compared with 2018.

The first target is intended to limit concentrations in the most polluted locations. The second is intended to reduce the pollution experienced across the population as a whole.

Air Quality Strategy for England

The Air Quality Strategy for England provides a framework for local-authority action.

It encourages councils to consider emissions from:

• transport;


• domestic combustion;


• industry;


• agriculture;


• construction; and


• local planning and development.

Different national strategies and legal arrangements apply in Scotland, Wales and Northern Ireland.

Planning and Air Quality

Air quality can be a material consideration when planning applications are determined.

A proposed development may require an air-quality assessment, which could:

• increase traffic;


• introduce residents into a polluted location;


• create industrial emissions;


• involve substantial construction dust;


• affect an Air Quality Management Area; or


• undermine an air-quality action plan.

Planning conditions or legal obligations may require mitigation such as electric vehicle charging, dust controls, altered access arrangements or improved public transport.

Clean Air Zones

Some cities have introduced Clean Air Zones or similar charging schemes to reduce emissions from older and more polluting vehicles.

The precise rules differ by area and may apply to:

• buses and coaches;


• heavy goods vehicles;


• vans;


• taxis and private-hire vehicles; and


• private cars in some schemes.

Clean Air Zones are not created directly by the Clean Air Act 1956. They form part of the broader modern response to transport pollution and local air quality duties.

Can Air Pollution Give Rise to Legal Action?

Air pollution may give rise to several different legal issues.

Depending on the circumstances, legal action may involve:

• statutory nuisance;


• private nuisance;


• negligence;


• environmental permitting;


• planning law;


• judicial review;


• human rights;


• workplace health and safety;


• breach of smoke-control rules; or


• regulatory enforcement.

Proving that a particular source caused an individual's illness can be difficult because pollution often comes from multiple sources and health conditions may develop over many years.

Air Pollution as a Statutory Nuisance

Smoke, fumes, gases, dust, steam or smells emitted from premises may constitute a statutory nuisance where they unreasonably interfere with the use of property or are prejudicial to health.

A local authority can investigate complaints and may serve an abatement notice where the legal test is met.

Failure to comply with an abatement notice can result in prosecution or other enforcement.

Not every unpleasant smell, occasional bonfire or visible emission will amount to a statutory nuisance. The frequency, duration, intensity, location and effect will be relevant.

Bonfires and Domestic Burning

There is no general national law prohibiting every garden bonfire.

However, smoke may result in action where it:

• causes a statutory nuisance;


• creates a danger to road traffic;


• involves burning commercial waste unlawfully;


• breaches waste-management rules;


• produces dark smoke from prohibited materials; or


• breaches local restrictions.

Burning plastics, painted timber, tyres, household rubbish or treated materials can release toxic pollutants and may constitute an offence.

Reporting Air Pollution

Concerns about local smoke, fumes, dust or odours can normally be reported to the local authority's environmental health department.

Reports about regulated industrial sites may need to be made to the Environment Agency or the relevant devolved regulator.

Useful evidence may include:

• dates and times;


• photographs or video;


• the duration of the pollution;


• wind and weather conditions;


• the source where known;


• how often it occurs;


• the effect on health or use of property; and


• details of previous complaints.

What the Great Smog Teaches Us

The Great Smog demonstrated that polluted air can cause death on a very large scale.

The Clean Air Act of 1956 helped remove the dense coal smogs that had become associated with British industrial cities.

However, modern pollution is often invisible, and its effects can develop gradually through long-term exposure.

The sources have also changed. Road traffic, domestic wood burning, agriculture and fine particles now feature prominently alongside industrial emissions.

The legal challenge is no longer simply to prevent black smoke from chimneys. It is to reduce exposure across entire communities while addressing transport, heating, housing, industry and land use.

Getting Legal Advice

A solicitor may advise on:

• smoke-control offences;


• statutory nuisance;


• industrial emissions;


• environmental permits;


• planning applications;


• air-quality assessments;


• judicial review;


• property disputes involving smoke or fumes;


• workplace exposure; and


• regulatory investigations.

Use the search facility at the top of this page to find a solicitor experienced in environmental, planning, regulatory or property law.

Disclaimer

Solicitors.com is not a firm of solicitors. This article provides general information about air-pollution law and history and does not constitute legal, environmental or medical advice. Different legislation and procedures may apply in Scotland, Wales and Northern Ireland.

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