Long-Term Impact of Earthquakes on Sleep Quality
Figure 1
Seismic and sleep disturbance intensity.
Left Panel: Plot of the seismic intensity of the earthquake who hit L'Aquila on 6 april 2009. The map covers a large portion of central Italy (as shown in red in the small inset map), from the Thyrrenian to the Adriatic sea. Data are plotted according to the European Macroseismic Scale (EMS-98), the basis for evaluation of seismic intensity in European countries (Grünthal, 1998). At variance with the earthquake magnitude scales, which express the seismic energy released by an earthquake, EMS-98 intensity denotes how strongly an earthquake affects a specific place. The EMS-98 has 12 divisions, from I (not felt) to XII (completely devastating). In this case, the maximal intensity reached was IX-X (IX = Destructive: monuments and columns fall or are twisted. Many ordinary buildings partially collapse and a few collapse completely; X = Very destructive: many ordinary buildings collapse). Right Panel: Plot of the mean colour-coded scores to the Pittsburgh Sleep Quality Index (PSQI) obtained two years after the earthquake by each of the seven groups numbered (within the ovals) as in Table 1. Higher PSQI scores (>5, red-orange colours) indicate the presence of clinically relevant sleep disturbances. The geographic area interested by this effect is appreciably broader than the area affected by the most destructive effects of the earthquake (Left Panel, red areas).