A study led by the EAP Dreta de l’Eixample and EAP Sardenya Primary Care teams, together with the Institut de Recerca Sant Pau (IR Sant Pau), shows that patients with chronic obstructive pulmonary disease (COPD) experience more frequent and more severe respiratory exacerbations during periods with high levels of environmental pollution. The work was carried out by Dr. Marta García, Dr. Daniel Planchuelo, Dr. Lluís Cuixart, and Dr. Carles Brotons, all members of the Primary Care research group.
Published in Revista Clínica de Medicina de Familia, the study compares a year with high pollution levels (2017) with a year of better air quality (2021), a period marked by restrictions associated with the COVID-19 pandemic, which led to a significant reduction in traffic and urban activity. The findings reinforce the importance of public policies aimed at reducing atmospheric pollutants.
Air pollution is a major public health issue and has a particularly strong impact on people with chronic respiratory diseases. As highlighted by Dr. Lluís Cuixart, “People with COPD are especially vulnerable to environmental pollution, because any deterioration in air quality can act as a trigger for exacerbations with a relevant clinical impact.”
In cities such as Barcelona, exposure to pollutants like nitrogen dioxide and fine particulate matter has been consistently associated with a higher risk of COPD exacerbations, a phenomenon that this study analyzes from a clinical and healthcare perspective.
The study included 150 patients with COPD treated at a primary care center in Barcelona, distributed into two equivalent cohorts. In 2017, a year with high pollution levels, 41.3% of patients experienced at least one respiratory exacerbation, compared with 25.3% in 2021, when air quality improved markedly.
In addition to being more frequent, exacerbations were also more severe in the year with higher environmental pollution. In 2017, more emergency department visits and hospital admissions were recorded, whereas in 2021 most exacerbations could be managed in the outpatient setting.
According to Dr. Marta García, principal investigator of the study, “The results show that not only do exacerbations increase when air quality is worse, but they also tend to be more severe and to require more complex healthcare, with the resulting impact on both patients and the healthcare system.”
The analysis considered several clinical and demographic variables, including age, smoking status, lung function, and cardiovascular comorbidities. In this regard, Dr. Cuixart emphasizes that “in patients with COPD, it is essential to interpret the effects of pollution in the context of associated diseases, since common conditions such as arterial hypertension can modulate both the frequency and the severity of exacerbations.”
Regarding cardiovascular events, the study did not find significant differences in incidence between the two years. However, a trend toward less severe episodes in 2021 was observed, with a higher proportion of patients managed on an outpatient basis. The authors stress that these findings should be interpreted with caution, as the sample size does not allow firm conclusions to be drawn for this outcome.
The context of the COVID-19 pandemic in 2021 is another factor to consider. Mobility restrictions, widespread mask use, and the reduction in non-COVID respiratory infections may have contributed, at least in part, to the lower incidence of exacerbations observed that year.
Despite its limitations, the study provides local evidence that reinforces the role of environmental pollution as a modifiable risk factor in COPD. “Improving air quality is not only an environmental issue but also a health intervention with a direct impact on particularly vulnerable patients,” notes Dr. Cuixart. “Our data support the need to integrate pollution monitoring into the prevention and management of COPD, together with the control of comorbidities.”
The researchers highlight the need for future prospective and multicenter studies to further explore the causal relationship between exposure to pollutants and respiratory and cardiovascular clinical outcomes. Meanwhile, the results support emission reduction strategies and urban policies aimed at improving air quality as a key measure to reduce the disease burden in patients with COPD.
García Torres M, Planchuelo Calatayud D, Cuixart Costa L, Brotons Cuixart C. Impact of Environmental Pollution on Respiratory Exacerbations and Cardiovascular Events in Patients With Chronic Obstructive Pulmonary Disease. A Retrospective Cohort Study. Rev Clin Med Fam. 2025;18(4):324–330. doi:10.55783/rcmf.180404.
