Pulmonary function among rural residents in high air pollution area in northern Thailand

BackgroundAir pollution has become a serious environmental and health issue in several countries. This condition leads to respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD). This study aimed to determine pulmonary functions and prevalence of respiratory diseases among rural residents in an area in northern Thailand with a high concentration of air pollution. MethodsA cross-sectional study was conducted in people aged 18 years or older, living in Lamphun, Thailand in December 2021. Demographics, pre-existing diseases, respiratory symptoms, and pulmonary functions by spirometry including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiration flow (PEF), forced expiration flow rate at 25-75% of FVC (FEF25-75), and bronchodilator responsiveness (BDR; FEV1 improvement after BDR test >12% and 200 mL) were collected. ResultsA total of 127 people (78.7%male) were included. Mean age was 43.76{+/-}11.32 years. Smoking was 52.0% and 4.44{+/-}5.45 pack-years. Self-reported respiratory diseases were allergic rhinitis (7.1%), asthma (0.8%), and COPD (0.8%). Respiratory symptoms were presented in 33.1% (14.2% runny nose, 10.2% nasal obstruction, 9.4% cough, 7.9% sputum production, and 6.3% breathlessness). Lung functions showed FVC in 96.74{+/-}12.91%, FEV1 in 97.52{+/-}12.99%, PEF in 102.46{+/-}19.18%, and FEF25-75 in 96.77{+/-}29.88%. Abnormal lung functions were found in 15.7%. Small airway disease (FEF25-75<65%) was 7.1%. Restrictive defect (FVC<80%) was 6.3%. Airway obstruction (FEV1/FVC<70%) was 2.4%. There was no BDR. Compared to people with normal lung functions, the abnormal lung function group was older (48.00{+/-}8.68 years vs 42.96{+/-}11.61 years, P=0.036), and had a higher proportion of breathlessness (20.0% vs 3.7%, P=0.021). ConclusionsAbnormal pulmonary functions, especially small airway disease, were relatively common in rural residents in a polluted air area in northern Thailand. These abnormal pulmonary functions were associated with more respiratory symptoms. Clinicaltrials.in.th numberTCTR20211223001