In 2007, an oil tank in an industrial area in Norway exploded and caused a prolonged malodorous pollution. Previous studies have shown that acute physical and psychological health complaints are prevalent in populations recently affected by industrial accidents. However, follow-up studies of human health effects after such accidents are limited, and knowledge about long-term health effects among workers exposed to malodourous emissions following a chemical accident is scarce. The aim of the study was to assess whether subjective health complaints among employees in the industrial area and clean-up workers declined over a four-year period after an oil tank explosion, a period that included removal of the malodorous pollution.Methods
A longitudinal survey from 2008 (1 ½ years after the explosion) to 2012 (5 ½ years after the explosion) was performed using the Subjective Health Complaints Inventory, a validated questionnaire. Data were analysed using a linear mixed effects model.Results
In 2008, exposed workers (n=147) had significantly more health complaints such as headache, tiredness, sleep problems, dizziness and depression, compared to unexposed controls living far away from the explosion site (n=137). In 2012, there was a reduction of subjective health complaints among the exposed workers, but they still had significantly more subjective neurological symptoms (p<0.01) than controls, adjusted for gender, age, smoking habits, educational level and proximity to the explosion.Discussion
It is likely that the overall decrease of subjective health complaints among exposed workers could be due to decreased exposure to malodorous pollutants or time passed since explosion. However, the persistent subjective neurological complaints might be mediated by perceived pollution and health risk perception. Worry might have caused a chronic effect, manifested by a dysfunctional and persistent neuropsychological response. A possible implication is that quick clean-up of malodorous chemical spills is important to avoid persistent health effects.