Asthma and air pollution: how pollution affects asthma and what you can do

Asthma is a common condition that affects breathing. The NHS says that it cannot currently be cured but that well-treated asthma should not cause problems with symptoms, and that symptoms can be triggered by exercise, high levels of air pollution, cold air or contact with something you are allergic to. Air pollution does not cause asthma in everyone, but it can make airways react more.

Asthma + Lung UK explains that air pollution can irritate your airways and increase lung symptoms, and that some types of pollutant get deep into the lungs and cause inflammation. The Office for Health Improvement and Disparities, in its All Our Health guidance, says short-term increases in air pollution can cause effects on lung function and exacerbation of asthma, and increase respiratory hospital admissions, while long-term exposure contributes to chronic respiratory disease.

Asthma + Lung UK names particulate matter, nitrogen dioxide, ozone and sulphur dioxide as particularly damaging. Particulate matter (PM) includes dust, dirt and smoke. The charity says domestic wood burning is now the largest producer of PM in the UK, that PM is higher on busy roads and near industrial and building sites, and that fireworks and bonfires can create winter smog. Fine particles known as PM10 and PM2.5 are the most damaging: PM10 can reach your airways and PM2.5 can reach the breathing sacs in your lungs.

Nitrogen dioxide is higher on busy roads, especially when traffic is slow, and can irritate the airway lining and make it more inflamed. Ozone is formed when sunlight combines with other pollutants, is higher in spring and summer and in the afternoon, and can make breathing uncomfortable and prompt people with asthma to need their reliever more. Sulphur dioxide comes mainly from burning coal and oil and can cause coughing and chest tightness. The All Our Health guidance adds that indoor air pollution matters too, since the average person spends around 80% of their time indoors, with pollutants coming from gas appliances, stoves and fires, cleaning products and second-hand smoke.

Asthma + Lung UK says air pollution harms everyone but is especially harmful if you have a lung condition, and that children, older people and pregnant people are more at risk. Its clean air campaign states that people on the lowest incomes and those from ethnically minoritised backgrounds are exposed to disproportionately high levels of air pollution.

The NHS lists being exposed to high levels of air pollution or cigarette smoke as a child among the factors that may make asthma more likely, alongside allergies, family history, premature birth and being overweight. Asthma + Lung UK says that being exposed to pollution as a child increases the risk of developing asthma and COPD as an adult.

Asthma + Lung UK lists signs that pollution is affecting you, and they overlap with the usual asthma symptoms described by the NHS: wheezing, coughing, shortness of breath and chest tightness.

• Coughing more, wheezing or having difficulty breathing.

• Irritation in the nose and throat, or pain when taking a breath.

• Becoming more breathless doing activity outdoors.

• Asthma symptoms that are worse than usual, or asthma attacks.

• Needing your reliever inhaler more often.

The NHS says to use inhalers as recommended by your care team, to try to avoid things that trigger your symptoms, such as air pollution, smoke, pollen or animals, to exercise regularly (getting advice on exercising safely if exercise triggers symptoms), to keep to a healthy weight and to have vaccinations such as the flu vaccine. It says not to smoke.

Government guidance on air pollution suggests, for people who are vulnerable during high pollution episodes, limiting strenuous activity in high pollution areas, particularly if you have symptoms such as a cough or sore eyes, using asthma relievers as necessary, closing external doors and windows facing a busy street during congested periods and keeping up to date with forecasts through Defra UK-AIR and local text alert services. Follow your personal asthma action plan, which records your medicines and what to do if symptoms get worse.

The NHS says an asthma attack is when you have severe symptoms and it is difficult to breathe, and that it can be life-threatening. Sit up straight, stay calm and use your reliever inhaler as set out in your plan. Call 999 if you or someone else is having an asthma attack and starts to feel worse at any time, does not feel better after the maximum dose of a reliever or does not have an inhaler. Do not drive yourself to A&E.

The NHS also says that after an attack, even if you feel better, you should see a GP within 2 days to discuss your treatment, and that you should ask for a GP appointment if your inhaler use is increasing or symptoms are stopping you doing your usual activities or waking you at night.

The NHS says a GP or nurse will ask questions, listen to your chest and may arrange a simple breathing test, sometimes a blood test, and a peak flow meter for use at home for a few weeks. Asthma can take time to diagnose because the symptoms vary and breathing problems can have different causes. The main treatment is medicine breathed in through an inhaler: an anti-inflammatory reliever, a maintenance and reliever inhaler, or a daily preventer with a separate reliever, and you should have check-ups at least once a year.

If you feel that pollution is a regular trigger, tell your asthma team. They can review your treatment and action plan and discuss whether your symptoms are controlled.

Asthma + Lung UK campaigns for cleaner air and states that levels in the UK are above World Health Organization guidelines. Individual action helps, but reducing pollution depends largely on wider change in transport, heating and policy. Walking and cycling improve your own health and, as government guidance notes, air quality, though you may prefer to choose quieter routes away from busy roads on high-pollution days.