Phases and indicators available during the study period. Barcelona, 1996–98
| Phase 1 | Phase 2 | Phase 3 | Phase 4 | |
|---|---|---|---|---|
| June 1996 | Up to November 1997 | Up to June 1998 | Up to December 1998 | |
| Operational situation of the plants | ||||
| Simultaneous unloading | X | X | ||
| Restrictions on timetable and flux | X | X | ||
| Meteorological restrictions | X | X | X | |
| Installation of new filters | X | X | ||
| Indicators available | ||||
| Epidemic asthma outbreaks | X | X | X | X |
| Panel of patients | X | |||
| Allergen concentration | X | X | X | X |
| Allergen emission levels | X | X | ||