Chronology of the control of risk of soybean asthma outbreaks in Barcelona, 1982–98
| 1982–83 | Identification of epidemic asthma outbreaks in the ICU of the Hospital Clinic, Barcelona. |
| 1983 | Municipal public health services rule out the possibility that the outbreaks are an artefact, or caused by common atmospheric pollution. |
| 1987 | Identification of soybean dust as the allergenic vehicle causing the outbreaks of asthma. |
| Adoption of control measures based on installation of sleeve filters. | |
| 1987–89 | Absence of epidemic outbreaks and improvement in allergen inmision levels. Sensitisation in patients persists, with decreases in the average IgE levels. |
| 1994 | Cluster of asthma cases. Plants are checked and a station installed in the port to permit monitoring of allergen levels near their source. |
| 1996 | Asthma 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. | |
| 1997 | Study of emissions, identification of new filters to achieve greater reductions in allergen emission. |
| Tentative implementation of new filters to control channelled emissions (November 1997). | |
| 1998 | New 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. |