A longitudinal study of the health impacts of a petroleum refinery.

Emissions from a petroleum refinery in Oakville, Ont., have been the source of longstanding health concerns among residents in the surrounding community. Between 1992 and 1997, the refinery implemented extensive odour reduction measures through improvements in waste water treatment, in sulphur recovery and combustion. In this paper, we present the main findings of a recent longitudinal analysis using data from community health surveys conducted in 1992 and 1997, before and after implementation of the odour reduction plan. The results show a decline in the frequency of odour perception and annoyance by residents whereas the reporting of cardinal and general symptoms among adults and children was virtually unchanged. Odour perception and annoyance were strongly related to symptom reporting in both years supporting the hypothesis that the effect of refinery emissions on residents' health is odour mediated. The findings extend our understanding of the psychosocial basis of symptom reporting in the vicinity of refineries.