Two-thirds of people with asthma in the UK say poor air quality makes their asthma worse, which puts them at higher risk of an asthma attack.
There is also evidence that being exposed long-term to high concentrations of air pollution plays a part in causing asthma. Women who are exposed to high levels of pollution when they are pregnant, regardless of whether they have asthma or not, could see their baby more likely to develop asthma because particulates can cross through the placenta to the developing baby.
When pollution levels are high we all breathe in harmful substances, but those with asthma are more likely to feel the harmful effects, including coughing or wheezing, chest tightness, or a scratchy feeling in the nose and throat.
Pollutants, such as the chemicals in traffic fumes, can quickly irritate the airways and trigger asthma symptoms. The tiny particles found in dust, soot, and diesel fumes are small enough to get right into the lungs, causing inflammation and making asthma symptoms worse. Pollution can also make asthmatic patients more sensitive to other asthma triggers, such as house dust mites, pollen, pets, moulds and fungi.
Pollution is an asthma trigger that is hard to avoid, which is why it is important that patients are counselled by pharmacists on how to manage their condition well. This includes reminding them that their preventer medicines should be taken regularly every day as prescribed because this will keep the inflammation in the airways down, making them more likely to cope on high pollution days. It is also important to remind patients to have regular asthma reviews and to use a written asthma action plan.
The Department for Environment, Food and Rural Affairs produces daily and five-day UK-wide pollution forecasts. Patients should be encouraged to check to see if their local area is likely to be affected in advance. They can also follow Asthma UK on Twitter and Facebook for asthma-specific advice when there are high pollution alerts.
Patients should be advised to try to limit the time they spend outside on high pollution days. For example, they should try to go out earlier in the day when air quality tends to be better and stick to back streets if possible if they are walking or cycling. Also they should avoid physical activities and exercise close to main roads, cigarette smoke whether indoors or out and being outside during rush hour if possible. They should also keep car windows closed, especially if stuck in a jam of slow-moving traffic, and keep windows and doors closed when inside so pollutants cannot get in.
Patients should also be reminded to take their reliever inhaler with them so they can quickly deal with symptoms if they occur.
Air pollution is a risk factor for everyone with asthma, but children and young adults with asthma are more at risk from the effects of pollution because they have faster breathing rates, and their lungs are still developing. Children living in areas with high pollution are more likely to have reduced lung function as adults.
The best way to cut children’s risk of having an asthma attack is to make sure they have an up-to-date written asthma action plan, attend an asthma review at least every six months and take their asthma medicines regularly as prescribed.
More information about how pollution affects asthma and ways to minimise its impact are available at https://www.asthma.org.uk/advice/triggers/pollution/.
Clinical lead and in-house GP