Study on impact of air pollution on lung function in people with CF
Many studies have found that high air pollution is linked to poor lung health in people with asthma and chronic obstructive pulmonary disease (COPD). However, there are fewer studies looking at links between lung health in people with CF and air quality. Over a 10-year period, Dr Muhammad Saleem Khan compared the lung health of people with CF across different levels of air pollution, where they lived in London. Dr Khan was a PhD student funded by Cystic Fibrosis Trust, under the supervision of Associate Professor Frédéric B. Piel from the School of Public Health, Imperial College London, and Professor Nicholas Simmonds from the Royal Brompton Hospital.
The researchers had access to detailed models of air pollution levels in London and focused their study on people with CF living in Greater London. There are many sources and types of pollutants affecting air quality. For this study they looked at the level of particulates (a measure known as PM2.5) and the levels of nitrogen dioxide (NO2) in the air.
Using secure servers and rigorous data management processes, Dr Khan and colleagues had permission to access data about people with CF who lived in London from the UK CF Registry. They were able to investigate whether air pollution levels in the local area where people with CF lived, were related to their changes in lung function. Lung function was measured using FEV1 percent predicted, for each person with CF included in the analysis. This is calculated from FEV1 values, taking into account the age, sex, height and ethnicity of the person. Data from around 300 people with CF were included in the analysis, covering the period 2008-2017. Requests to access anonymised data from UK CF Registry are carefully reviewed by the UK CF Registry steering committee. The committee is made up of a group of statistical experts, CF doctors and members of the CF community.
What were the results of the study?
They found that people with CF who had higher exposure to air quality particulates had a slightly greater decline in lung function than those who had lower exposures.
Further research is needed to better understand the impact of air quality on people with CF. In particular, we need national-level studies covering a larger number of people, alongside studies looking at different ages; the effects of modulators and indoor air quality
Associate Professor Frédéric B. Piel, School of Public Health, Imperial College London
The full study results were published in the scientific journal Thorax in March this year. Khan et al Thorax 2026 Feb 5:thorax-2024-222710. doi: 10.1136/thorax-2024-222710.
Catherine's story
Catherine’s daughter Kate has cystic fibrosis. Continuing to live in London after her diagnosis of CF was a difficult decision, but the whole family have made steps to make sure Kate is protected.
Catherine said: “When you’ve got a child with a chronic lung condition, you have to think about what is best for them. But we have always tried to take measures to improve air quality for Kate. One of the things that we do for Kate getting to school is we always walk on back roads to avoid walking on the busy road that the school is located on.
“We’ve also worked with the school – myself and other parents without children with cystic fibrosis, but who were also concerned about air quality – to try to improve the air quality for our children within the school.”
Catherine is also backing calls Cystic Fibrosis Trust is making to the Government to ensure clean air is at the top of the agenda.
We were lucky because we had a big cohort of parents that were fighting for better air quality for our children. We shouldn’t have to do that ourselves because there’s always going to be communities that aren’t benefitting from having these proactive people trying to fight for the next generation and ourselves.
Catherine, whose daughter Kate has CF
Our calls to Government to tackle dirty air
Air Quality and Cystic Fibrosis: A Pragmatic Review is a systematic review of existing research into air quality and CF health compiled with the York Health Economics Forum. It highlights the impact of poor air quality on people with CF, revealing the extra damage caused to the lungs by breathing in unclean air. The review pulls together information from many studies and calls on Governments to commit to clean air policies to protect the health of people with CF. A number of links between indoor and outdoor air pollution and poorer health outcomes for people with CF were identified, including decline in lung function, hospitalisations and increased presence of harmful bacteria and fungi in the airways
Cystic Fibrosis Trust is calling on Governments across the UK to prioritise the health of people with long-term health conditions, such as cystic fibrosis, and ensure a commitment to clean air policies by:
- strengthening air quality standards and monitoring with stricter regulations on outdoor pollutants
- expanding access to air quality alerts so everyone can access localised air pollution forecasts and receive alerts
- tightening building codes to prioritise minimising indoor pollutant exposure and improve indoor air quality in homes and public spaces
- investing in research on CF-air quality interventions to evaluate the effectiveness of interventions to protect people with CF from poor air quality.
You can read the full news story about the report here.