Organic dusts are mixtures of particles originating from plants, animals and often endotoxins from gram-negative bacteria. Several occupations, including farming (where exposures can occur during grain, animal handling and feeding), woodworking (where exposures can occur from wood dust) and textile work (during cotton processing), are the primary sources of occupational exposure to organic dust.1 2 Cross-sectional analysis has suggested a relationship between organic dust exposure and interstitial lung diseases (ILDs), specifically hypersensitivity pneumonitis (HP), mostly among farmers.3 HP, also known as extrinsic allergic alveolitis, is an immune-mediated disease triggered by the inhalation of organic dust, which contains antigens from bacteria, fungi, animal proteins and other sources.4 These antigens trigger an immune response in susceptible individuals, leading to the activation of alveolar macrophages and T-cells, releasing cytokines and chemokines, resulting in lung parenchyma inflammation and granuloma formation.5 The evidence for the association between organic dust exposure and HP is primarily from the case reports6 and workplace-based studies7 while the evidence from population-based studies using reliable data sources is largely missing. In this issue, Iversen et al investigated this association in a Danish population-based occupational cohort over three decades.8

The study examined data from a vast cohort of Danish residents born in 1956 or later who had been employed for at least a year …