Others have previously shown that annual average levels of air pollution exposure are associated with lung function decrease and an increased likelihood of pulmonary exacerbation in CF. Acute day to day changes in air pollution have not been studied. Therefore, the aim was to evaluate whether exacerbations needing additional treatment with antibiotics were associated with daily fluctuations in air pollution.
Why is this important?
Pulmonary exacerbations in cystic fibrosis accelerate the progression of the disease/shorten life and increase the burden of disease, with a negative impact on lung function and quality of life. Identifying risk factors triggering exacerbations is therefore important. Moreover, data on the impact of traffic-related air pollution on health in the general population as well as patients with lung diseases are raising the awareness of potentially harmful effects of air pollution.
What did you do?
Using data collected over 12 years, we linked daily fluctuations in air pollution near 215 patients’ home addresses with the start of intravenous or oral antibiotic treatment due to pulmonary exacerbation. The air pollutants that were measured, were nitrogen dioxide, ozone and particulate matter with a diameter smaller than 10-µm (PM10). Data from before and after the time the patients first became unwell were used to describe the ‘background’ air pollution.
What did you find?
We found that acute increases in air pollution were associated with an increased likelihood of receiving additional antibiotic treatment due to a CF exacerbation. For each increase in the concentration of every pollutant by 10-µg/m³, the risk of receiving antibiotics in the next 48 hours increased significantly. The effect seemed to be more pronounced during the months April till September and for patients colonized with Pseudomonas aeruginosa.
What does this mean and reasons for caution?
Our results suggest that air pollution impacts upon the respiratory health of people with CF. Together with other data, the data suggest patients may experience fewer pulmonary exacerbations than they otherwise would by avoiding areas where there is sustained high air pollution and/or areas susceptible to acute increases in air pollution. Additional research is needed to examine other factors that may have influenced these results, to look into why the effect seemed more pronounced from April to September and in patients with Pseudomonas aeruginosa; and to test the hypothesis in a controlled study before definitive conclusions can be reached.
It remains to be determined whether moving where people with CF live to areas of reduced air pollution, or wearing a protective mask during a rise in pollution of 10-µg/m³ or more, may reduce exacerbation rate in patients with cystic fibrosis.