Respiratory health status and its predictors: a cross-sectional study among coal-based sponge iron plant workers in Barjora, India

OBJECTIVES: During the past decade, coal-based sponge iron plants, a highly polluted industry, have grown rapidly in Barjora, India. The toxic effects of particulate matters and gaseous pollutants include various respiratory diseases. Understanding workers’ perception of respiratory health is essential in people-centred healthcare. The aim of the study was to assess their respiratory health status and to determine its predictors. DESIGN: Cross-sectional study. SETTING: Coal-based sponge iron plants in Barjora, India. PARTICIPANTS: 258 coal-based sponge iron plant workers. PRIMARY OUTCOME MEASURE: Respiratory health status was measured using the St. George's respiratory questionnaire (SGRQ) total score. 100 and 0 represent the worst and best possible respiratory health status, respectively. STATISTICAL ANALYSES: The two-part model (frequency (any worse respiratory health status) and severity (amount of worse respiratory health status)) was developed for the score, as the data were positively skewed with many zeros. RESULTS: The mean (SD) SGRQ total score was 7.7 (14.5), the median (IQR) was 0.9 (9.0), and the observed range was 0–86.6. The best possible SGRQ total score was reported by 46.9% of workers. Independent predictors of worse respiratory health status were cleaner domestic cooking fuel (coefficient −0.76, 95% CI −1.46 to −0.06, p=0.034) and personal history of any respiratory disease (1.76, 1.04 to 2.47, p<0.001) in case of frequency; and family history of any respiratory disease (0.43, 0.02 to 0.83, p=0.039) and personal history (1.19, 0.83 to 1.54, p<0.001) in case of severity. CONCLUSIONS: Less than half of the coal-based sponge iron plant workers in Barjora have the best possible respiratory health status. The predictors of worse respiratory health status were identified. The study findings could be taken into consideration in future interventional studies aimed at improving the respiratory health status of these workers.