• Asthma
• COPD epidemiology
• Lung Cancer
• Asthma Epidemiology

The Global Burden of Disease Study has estimated that over 500 million subjects, around 7% of the global population, are affected by chronic respiratory diseases, with substantial individual and societal costs concerning morbidity, disability and mortality.1 Identifying and mitigating potentially modifiable risk factors are crucial in preventing the associated public health burden. Extensive literature has provided compelling evidence that air pollution, especially fine particulate matter (PM)2.5 (diameter <2.5 µm), is a leading risk factor for the incidence and mortality of acute and chronic respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD).2 3 In addition, in 2013, the International Agency for Research on Cancer classified outdoor air pollution as a known carcinogen for the lung.4

The recent large multicentre project ‘Effects of Low-Level Air Pollution: A Study in Europe’ has shown that adverse respiratory effects, including incidence of asthma in adults5 and COPD,6 occur even at exposure levels below the current European Union air quality limit values. Furthermore, the new 2021 WHO Air Quality Guidelines have halved from 10 mg/m³ to 5 mg/m³ the recommended annual average outdoor concentrations of PM2.5.7

Although the vast literature on air pollution and respiratory effects, important unanswered queries remain on the aetiopathogenetic mechanisms and dynamics underlying the progression from a lung disease-free status to subsequent chronic lung diseases and, ultimately, death. To elucidate, these deadly trajectories would inform and guide focused preventive strategies in agreement with a modern precision public health approach.

In the study of Wang et al, the Authors …