Additional file 1: of Exposure to cooking oil fumes and chronic bronchitis in nonsmoking women aged 40 years and over: a health-care based study

Table S1. Distributions of demographic characteristics categorized by study cases and controls among non-smoking women (N = 644). Table S2. The distribution across our study subjects with different health statuses. Table S3. Relationships between major variable of cooking oil fume exposure and other covariates in non-cook women and the risk of chronic bronchitis among non-smoking women (N = 644). Table S4. Relationships between cooking and ventilation conditions in home kitchens between 20 and 40 years old and the severity of COPD according to GOLD criteria (N = 632). Figure S1. Study area. (DOCX 64 kb