A follow-up study of airway symptoms and lung function among residents and workers 5.5years after an oil tank explosion

Abstract

Background: Assess if people who lived or worked in an area polluted after an oil tank explosion had persistent respiratory health impairment as compared to a non-exposed population 5.5years after the event. Methods: A follow-up study 5.5years after the explosion, 330 persons aged 18-67 years, compared lung function, lung function decline and airway symptoms among exposed persons (residents <6km from the accident site or working in the industrial harbour at the time of the explosion) with a non-exposed group (residence >20km away). Also men in the exposed group who had participated in accident related tasks (firefighting or clean-up of pollution) were compared with men who did not. Data were analysed using Poisson regression, adjusted for smoking, occupational exposure, atopy and age. Results: Exposed men who had participated in accident related tasks had higher prevalence of lower airway symptoms after 5.5years (n=24 [73%]) than non-exposed men (28 [48%]), (adjusted relative risk 1.51 [95% confidence interval 1.07, 2.14]). Among men who participated in accident related tasks FEV1 decline was 48mL per year, and 12mL among men who did not (adjusted difference 34mL per year [67mL, 1mL]), and at follow-up FEV1/FVC ratio was 71.4 and 74.2% respectively, (adjusted difference 3.0% [6.0, 0.0%]). Conclusion: Residents and workers had more airway symptoms and impaired lung function 5.5years after an oil tank explosion, most significant for a group of men engaged in firefighting and clean-up of pollution after the accident. Public health authorities should be aware of long-term consequences after such accidents.