According to the International Labour Organization (ILO) classification, what is the primary purpose of the ILO 1971 classification system for pneumoconiosis?

Explanation

## ILO 1971 Classification System **Key Point:** The ILO 1971 classification is a standardized radiographic system for diagnosing and grading pneumoconiosis (dust-induced lung disease) using chest X-ray findings. ### Purpose and Scope **High-Yield:** The ILO system provides: - **Standardized interpretation** of chest radiographs across countries and clinicians - **Reproducible grading** of pneumoconiosis severity - **Epidemiological consistency** for occupational health surveillance - **Medico-legal documentation** of occupational lung disease ### ILO Classification Structure 1. **Profusion categories** (0–3): Based on density and extent of small opacities - Category 0: Normal or minimal findings - Category 1: Mild pneumoconiosis - Category 2: Moderate pneumoconiosis - Category 3: Severe pneumoconiosis 2. **Type of opacities**: - Rounded (p, q, r): Silicosis, coal worker's pneumoconiosis - Irregular (s, t, u): Asbestosis, talcosis 3. **Pleural abnormalities**: Thickening, plaques, calcification **Mnemonic:** **ILO = Imaging (radiographic) Lung Opacities** — a visual grading tool, not a functional or mortality predictor. ### What ILO Does NOT Do - Does NOT replace pulmonary function testing - Does NOT predict prognosis or survival - Does NOT classify workers by job type - Does NOT diagnose the specific causative agent (clinical correlation needed)