Air Pollution and Health

Air pollution has a significant effect on public health. Poor air quality is the largest environmental risk to public health in the UK. Long-term exposure to air pollution can cause chronic conditions such as cardiovascular and respiratory diseases as well as lung cancer, leading to reduced life expectancy.

The mortality burden of air pollution in England is estimated to be between 26,000 and 38,000 a year, but in addition many people suffer avoidable chronic ill health as a result of it.

Air pollution that people breathe is a mixture of gases and particulates – all of which may interact and have greater health effects if combined. There are numerous sources of indoor and outdoor air pollution.

How does it affect people?

Air pollution affects us all. It is associated with impacts on lung development in children, heart disease, stroke, cancer, exacerbation of asthma and increased mortality, among other health effects. 

When air pollutants enter the body, they can have effects on various different organs and systems, not just the respiratory system.

This includes:

  • the eyes, nose and throat
  • the lungs and respiratory system
  • the heart – heart and blood vessel diseases, including strokes and hardening of the arteries, are one of the main effects of air pollution

Emerging evidence suggests that air pollution may also affect the brain and is possibly linked to dementia and cognitive decline. There is also emerging evidence associating air pollution with early life effects such as low birth weight.

The three main conditions associated with air pollution are respiratory illnesses (e.g. asthma), cardiovascular disease, and lung cancer. The Committee on the Medical Effects of Air Pollutants (COMEAP) has highlighted that exposure to air pollution contributes to thousands of deaths each year in the UK. There is increasing evidence associating poor air quality to dementia, low birth weight and Type 2 diabetes.

Respiratory Conditions

Asthma is a common, long-term inflammatory respiratory condition of the lung's airways. It leads to coughing, wheezing, chest tightness, and shortness of breath. The Committee of Medical effects of Air Pollution (COMEAP) advises that air pollution can increase the severity of symptoms in Asthma sufferers. There is also increasing evidence that air pollution may have a role in causing asthma, especially in people who live near busy roads, as well as being a trigger exacerbating asthmatic symptoms.

For further information visit Asthma UK

Cardiovascular Disease (CVD)

There is strong evidence for the effects of both short and long-term exposures to air pollution on CVD in adults. Air pollution can both contribute to the development of cardiovascular disease in adults and exacerbate existing heart conditions. This is particularly associated with particulate matter (PM). The risk of heart failure, myocardial infarction (heart attacks), arrhythmias (abnormal rhythms), and stroke is increased by both short and long-term exposure to air pollution in susceptible individuals. This includes older people and anyone with pre-existing cardiovascular and respiratory conditions.

There is less clarity whether exposure to air pollution during childhood influences the development of CVD in later life. There is evidence though, there are changes in key biomarkers of cardiovascular function, such as blood pressure, found in children after exposure to air pollution.

For further information visit the British Heart Foundation.

Lung Cancer

Ambient (outdoor) air pollution and particulate matter pollution have been classified as carcinogenic by the International Agency for Research on Cancer. There is strong evidence that they are linked to lung cancer in adults. The World Health Organisation has concluded there was ‘insufficient evidence for ambient air pollution and childhood cancer’. However, lung cancer can take a long time to develop following exposure, and some research indicates that exposure in childhood could contribute to the development of cancers in later life.

For further information visit Cancer Research UK

Air pollution over lifetime

Air pollution has negative effects on health throughout the life course, from pre-birth to old age, summarised in the figures below.

Pregnancy and early childhood are critical times for the formation and maturation of body systems, during which the most rapid changes take place. Factors adversely affecting human development, including air pollution, can have both immediate and longer lasting effects on a person’s health, and some health impacts may only emerge later in life. In addition to potential effects on foetal growth, air pollution exposure is associated with low birth weight and premature birth.

Exposure to air pollution in early life can have a long-lasting effect on lung function. Evidence indicates that the process of normal lung function growth in children is suppressed by long-term exposure to air pollution. There is a natural development of lung function throughout childhood and maximising this is important, as low lung function leads to less reserve if lung disease develops.

Lung function in adulthood naturally declines with age, but air pollution and living near a busy road can potentially accelerate this decline, for both adults and older people. Minimising exposure is important to maximise reserve, especially if respiratory conditions develop in later life.

Vulnerable groups

The effects if air pollution are seen across the population but some individuals are more vulnerable to the impacts of air pollution than others due to existing health conditions, age, socio-economic gradient and ethnicity.

These disparities are both by air pollution exposure and by vulnerability – for example pregnant women, children and those with health conditions are more vulnerable to harm, even if their exposure is the same as other population groups.

Those more at risk from air pollution include:

  • Children
  • Pregnant people
  • Older people
  • People with lung conditions such as: asthma, chronic obstructive pulmonary disease (COPD) and lung cancer
  • People with heart conditions such as: coronary artery disease, heart failure and high blood pressure.
  • People from socio-economically disadvantage and racialised communities

For people with respiratory conditions, being aware of local air pollution is important and, when required, changing activities or taking additional measures can be undertaken to reduce exposure to poor air quality.

Monitoring and modelling of air quality throughout the UK allows air pollution levels to be forecast. Be prepared by being informed of current air pollution levels in your local area using the available local monitoring interactive maps, signing up to Daily Air Quality Index forecasts and following health advice:

Air Pollution Banding

Value

Accompanying health messages for at-risk individuals*

Accompanying health messages for the general population

Low

1-3

Enjoy your usual outdoor activities.

Enjoy your usual outdoor activities.

Moderate

4-6

Adults and children with lung problems, and adults with heart problems, who experience symptoms, should consider reducing strenuous physical activity, particularly outdoors.

Enjoy your usual outdoor activities.

High

7-9

Adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms. People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion.

Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors.

Very High

10

Adults and children with lung problems, adults with heart problems, and older people, should avoid strenuous physical activity. People with asthma may find they need to use their reliever inhaler more often.

Reduce physical exertion, particularly outdoors, especially if you experience symptoms such as cough or sore throat.

* Adults and children with heart or lung problems are at greater risk of symptoms. Follow your doctor's usual advice about exercising and managing your condition. It is possible that very sensitive individuals may experience health effects even on Low air pollution days. Anyone experiencing symptoms should follow the guidance provided on the Defra UK-AIR website.

Air Pollutants

A variety of air pollutants have known or suspected harmful effects on human health and the environment. Pollutants may not only cause problems in the immediate vicinity of generating sources but can travel long distances and affect more people and places.

The UK government’s Clean Air Strategy covers emissions of 5 of the most damaging air pollutants: fine particulate matter; nitrogen oxides; sulphur dioxide; ammonia and non-methane volatile organic compounds. A summary of the health impacts of these and ozone are provided below. Review the air pollutants page for further information on their sources and impacts and other air pollutants.

Particulate Matter is considered to be the most important air pollutant in terms of health impacts. Particulates are classified according to their size: studies generally consider PM10 and PM2.5 (the subscript refers to the maximum mean aerodynamic diameter, in microns). Particles of PM2.5 are 200 times smaller than a grain of sand.

PM is associated with a number of anthropogenic sources: generally combustion processes such as solid fuel burning, as well as through processes such as tyre and brake wear on road vehicles, quarrying and mining. There are also natural sources of PM such as Saharan Dust and sea salt.

The size of particles and the duration of exposure are key determinants of potential adverse health effects. Particles larger than 10 µm are mainly deposited in the nose or throat, whereas particles smaller than 10 µm pose the greatest risk because they can be drawn deeper into the lung.

PM2.5 is small enough to pass through the lungs into the bloodstream and into other organs. These particles may carry surface-absorbed toxic, or carcinogenic, compounds into the body.  While the effect of the PM size classes PM10 and PM2.5 on human health are known, differences in contribution to human health effects from each of the chemical components remains unknown.

PM can have short-term health impacts over a single day when concentrations are elevated. Long-term exposure to PM increases mortality and morbidity from cardiovascular and respiratory diseases and can cause cancer. Effects are amplified in vulnerable groups including young children, the elderly, and those suffering from breathing problems like asthma. It is also causally linked to dementia and decline in cognitive function. There is growing evidence for associations with adverse birth outcomes and diabetes.

The World Health Organization (WHO) advises there is no safe exposure level to PM.

Sulphur dioxide (SO2) is produced when sulphur-containing fuels or material, such as coal, are burned.

SO2 has an irritant effect on the lining of the nose, throat and airways, and the effects are often felt very quickly. It can exacerbate asthma and cause respiratory effects and is associated with chronic bronchitis. It is also associated with cardiovascular effects.

High concentrations of SO2 in the air generally also lead to the formation of other sulphates which can react with other compounds in the atmosphere to form small particles and contribute to PM pollution.

Concentrations of SO2 greatly declined across the UK over the last 50 years due to the reduction in coal burning as fuel.

O3 is a gas and occurs in the earth’s upper atmosphere and at ground level. O3 at ground-level is an irritant gas with known impacts on health. It can cause inflammation of the respiratory tract, eyes, nose and throat. It can trigger asthma attacks and cause chest discomfort whilst breathing.

Likely causal metabolic effects from short-term exposure have also been identified. For long-term exposure, there is a likely causal association with respiratory effects such as asthma development, but the evidence is less clear for other health outcomes.

Ozone is formed by a complex series of reactions involving volatile organic compounds (VOC), sunlight and nitrogen dioxide (NO2). The involvement of sunlight in this process means that ozone levels in the UK tend to be highest in spring and summer.

Agriculture is the dominant source of NH3 ammonia, a gas, emissions (85 – 90%). It is emitted during storage and spreading of manures, slurries and fertilisers.

The main health impacts of NH3 arise through its role in secondary PM2.5 formation and health effects associated with exposure to PM, as described above. This PM is transported large distances and adds to the suspended background levels of particulates in the atmosphere.

Agricultural emissions of NH3 have been reported to be key contributor to some short-term episodes of high PM pollution in recent years, for example smog in London in 2014.

NMVOCs are a very large group of organic compounds, which differ widely in their chemical composition but can display similar behaviour in the atmosphere.

Anthropogenic sources include fossil fuel use (petrol vapour) and production; solvents used in coatings, paints, and inks and biomass combustion.

Indoor exposure can come from cleaning and personal care products, building materials and household consumer products (paints, carpets, laminate, furniture, cleaning products, air fresheners, polishing).

Most VOCs are not acutely toxic, but may have long-term chronic health effects including cancer, central nervous system disorders, liver and kidney damage, reproductive disorders, and birth defects.

VOCs emitted from consumer products are not thought be to a significant public health issue when homes are well ventilated and when the products are used according to the manufacturers’ instructions. But some people may suffer irritation of the upper airway system (eyes, nose and throat), respiratory effects, headaches and dizziness if they are exposed. A growing body of research links indoor air pollutants and carcinogenicity risk.

They are also a key contributor to the formation of ozone, as outlined above.

 

Cost of air pollution to society

In September 2020, CBI Economics produced ‘Breathing Life into the UK Economy, a report that quantifies the economic benefit to the UK of meeting WHO Air Quality guidelines. The report commissioned by the Clean Air Fund states:

‘Air pollution impacts human health and the productivity of the UK workforce, which in turn impacts the economy. Analysis conducted by CBI Economics in 2020 estimated that clean air in line with the World Health Organisation’s (WHO) guidelines could deliver a £1.6bn boost to the UK economy each year. This would be on top of savings to NHS and social care budgets from treating fewer patients with health conditions associated with pollution.’

In 2018, Public Health England (PHE)’s cost of air pollution project quantified the potential costs to the NHS and social care system due to the health impacts of PM2.5 and NO2 in England. It estimated that between 2017 and 2025, the total cost of air pollutants for which there was more robust evidence for an association, was £1.60 billion for PM2.5 and NO2 combined (£1.54 billion for PM2.5 and £60.81 million for NO2) increasing to £5.56 billion when diseases with less robust evidence are included.

The total costs are estimated to increase by 2035 to £230million due to health impacts of NO2 and £5.1 billion for PM2.5 where there is robust evidence for an association. This rises to a total of £18.6 billion for PM2.5 and NO2 combined by 2035 when diseases with less robust evidence are included.

Further information:

Look at the interactive maps of Current Air Quality to find out the current status of monitored pollutants in Worcestershire.

Click the link for more information on air pollutants, their sources and impacts.

See the Local Air Quality Reporting section for details of monitoring and annual assessment of pollutants in the county and local authority plans for tackling high concentrations of NO2.

Source References

Follow the following links for further information on impacts of air pollution from medical and health professionals

Chief Medical Officer’s Annual Report 2022: Air pollution

Public Health England Guidance Health Matters: air pollution

The Royal College of Physicians ‘Every Breath We Take: the lifelong impact of air pollution’ (Report 2016)

Global Action Plan Clean Air Hub

Clean Air Strategy 2019

CBI Economics (2020) Breathing Life Into The UK Economy

Public Health England (2018) Estimation of costs to the NHS and social care due to the health impacts of air pollution: summary report