Demographic and environmental determinants of lung function in rural Northern Thailand

• Lung function impairment prevalent in rural Northern Thailand. • Age ≥51, asthma, and agricultural work linked to impairment. • Living in concrete housing increases risk of lung function decline. • Socioeconomic factors such as education influence lung health. • Findings support targeted public health interventions in rural areas. Lung function impairment is a growing health concern, particularly in low- and middleincome countries, where demographic characteristics and environmental exposures converge. Northern Thailand, with its seasonal air pollution and prevalent rural occupations, provides a notable context for investigating lung health decline. To evaluate the prevalence of lung impairment and determine its demographic, clinical, and environmental factors among individuals in Northern Thailand. This cross-sectional study included 207 participants who underwent spirometry according to the American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Participants provided demographic, health, and environmental exposure information through structured interviews. Lung impairment risk factors were evaluated using logistic regression and interaction models, characterized by FEV₁ < 80 % and/or FEV₁/FVC < 70 %. Lung function impairment was observed in 19.3 % of participants. The significant independent predictors included age ≥51 years, asthma (adjusted OR = 5.21, p = 0.018), agricultural occupation (adjusted OR = 2.36, p = 0.034), and residence in concrete housing (adjusted OR = 5.22, p = 0.004). Unadjusted models showed associations between high cholesterol levels and congenital illness with lung impairment; however, these associations lost their statistical significance after.