The OCEAN-ILD study is designed to prospectively evaluate the prevalence and clinical relevance of environmental and occupational exposures in a large Italian cohort of patients affected by any ILD, using a standardised exposure questionnaire applied across multiple centres.

Interstitial lung diseases (ILDs) represent a diverse group of parenchymal lung disorders associated with significant morbidity and mortality, with few FDA-approved treatment options available. While certain subtypes-such as hypersensitivity pneumonitis and pneumoconiosis-are clearly linked to environmental exposures, the role of such exposures in other ILD forms remains less well defined. Recent evidence has showed that most patients across all types of ILD had potentially relevant inhalational exposures. Exposures were associated with worse transplant-free survival. Thus, identification and avoidance of exposures represent actionable targets in ILD management.

Different questionnaires have been proposed to evaluate occupational and environmental exposure in such patients. However, to date, there aren't standardized and validated questionnaires addressing exposures in patients with ILD. Interstitial lung diseases (ILDs) represent a diverse group of parenchymal lung disorders associated with significant morbidity and mortality, with few FDA-approved treatment options available. While certain subtypes-such as hypersensitivity pneumonitis and pneumoconiosis-are clearly linked to environmental exposures, the role of such exposures in other ILD forms remains less well defined. Recent evidence has showed that most patients across all types of ILD had potentially relevant inhalational exposures. Exposures were associated with worse transplant-free survival. Thus, identification and avoidance of exposures represent actionable targets in ILD management.

Different questionnaires have been proposed to evaluate occupational and environmental exposure in such patients. However, to date, there aren't standardized and validated questionnaires addressing exposures in patients with ILD. Moreover, frequency of exposure across different types of ILDs are not well defined in Italy.

Inclusion Criteria:

• Age ≥ 18 years old
• Any gender
• Any race
• Ability to give informed consent according to ICH/EU GCP, and national/local regulations.
• New diagnosis of ILD according to classified according to American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias

Exclusion Criteria:

• Sarcoidosis
• Primary diagnosis of COPD and/or Asthma

Eligible participants will be identified during routine ILD outpatient visits and enrolled after written informed consent. Baseline data collection will occur at the time of enrollment.

Diagnostic consistency will be ensured through multidisciplinary discussion (MDD). The contribution of exposure history to diagnostic refinement and additional testing will be systematically recorded.

Data will be prospectively collected using a standardised CRF at baseline and every 6 months (±2 months), in line with clinical practice.

A structured questionnaire assessing environmental and occupational exposures will be:

• Administered at baseline
• Re-administered at each follow-up visit

Exposure domains will include:

• Occupational exposures (dusts, fibres, chemicals)
• Domestic exposures (mould, animals, biomass)
• Hobbies and recreational exposures
• Drug-related exposures Exposure relevance will be evaluated during MDD.