Table 1

Chronology of the control of risk of soybean asthma outbreaks in Barcelona, 1982–98

1982–83Identification of epidemic asthma outbreaks in the ICU of the Hospital Clinic, Barcelona.
1983Municipal public health services rule out the possibility that the outbreaks are an artefact, or caused by common atmospheric pollution.
1987Identification of soybean dust as the allergenic vehicle causing the outbreaks of asthma.
Adoption of control measures based on installation of sleeve filters.
1987–89Absence of epidemic outbreaks and improvement in allergen inmision levels. Sensitisation in patients persists, with decreases in the average IgE levels.
1994Cluster of asthma cases. Plants are checked and a station installed in the port to permit monitoring of allergen levels near their source.
1996Asthma outbreak (11–12 June). Suspension of soybean unloading. Checks carried out of the plants and diffuse emission control measures, as well as intensive monitoring of allergen concentrations.
Post-outbreak phase: crude control of emissions, by restricting activity on each boat unloading.
1997Study of emissions, identification of new filters to achieve greater reductions in allergen emission.
Tentative implementation of new filters to control channelled emissions (November 1997).
1998New operating licences to the three firms (June 1998), specifying a pilot phase for evaluation, eliminating all restrictions in unloading (except under extremely unfavourable meteorological conditions).
Follow up of the pilot phase passed without incidents.