Background: A major explosion occurred in the AZF chemical factory in Toulouse in September 2001. A comprehensive programme of epidemiological surveillance was set up.
Objectives: To present an overview of the programme and discuss the methods and potential utility of post-disaster epidemiology. The programme had three objectives: (1) to analyse comprehensively the short-term and long-term effects of air, water and secondary soil pollution on health; (2) to identify health problems needing special attention; and (3) to investigate the long-term direct and indirect effects on the population's health.
Methods: The programme was organised through three committees: (1) a scientific committee, (2) an executive programme committee and (3) an institutional committee which aimed to facilitate exchanges between the epidemiologists, the regional authorities, the population and the media. As the catastrophe was an industrial disaster that had a major effect on workers and companies, and also caused severe damage to many schools and buildings all over the city, routine and ad hoc surveillance systems were used and three specific ad hoc questionnaire surveys in workers, schoolchildren and the general population were planned.
Results and conclusions: Although the routine surveillance systems had limitations, several sources provided useful information for public health decisions and were found to be concordant with ad hoc epidemiological studies. Defining a victim was central to the choice of a programme design based on an approach either to victims of the disaster or to the entire population in the surrounding region. Anticipation and preparation for such disasters are thus required.