Definition | Code identifying the research location | Category of evacuation zone: 0 = Non-evacuation zone, 1 = Zone designated in preparation for the lifting of the evacuation order (Zone 1), 2 = Restricted residence area (Zone 2), 3 = Difficult-to-return-to zone (Zone 3) | Date in 2013 when a site was designated an evacuation zone; ‘NA’ was assigned to sites that have never been designated an evacuation zone |