Background Foul-smelling environmental pollution was a major concern following a chemical workplace explosion. Malodorous pollution has previously been associated with aggravated physical and psychological health. Furthermore, in persons affected by a trauma, an incidence-related odour can act as a traumatic reminder. Olfaction may even be of significance in the development and persistence of post-traumatic stress symptoms (PTSS).

Aims To assess whether perceived smell related to malodorous environmental pollution in the aftermath of the explosion was a determinant of subjective health complaints (SHC) and PTSS among gainfully employed adults before and after clean-up of the malodorous pollution.

Methods Questionnaire data from validated instruments, the Subjective Health Complaints Inventory and the Impact of Event Scale-Revised, were analysed using mixed effects models in a longitudinal study design comprising three surveys. Individual odour scores were computed, and the participants (n=486) were divided into high (n=233) and low (n=253) odour score groups.

Results Participants in the high odour score group reported more SHC and PTSS than those in the low odour score group, before and also after the pollution was eliminated. The difference between the groups lasted for at least three years after the pollution was eliminated.

Conclusion Perception of malodorous environmental air pollution was a determinant of both SHC and PTSS. Prompt clean-up might be important to avoid persistent health effects after malodorous chemical spills.