Epidemiology of Traumatic Injuries from Earthquakes

Abstract

Morethan500,000earthquakesaredocumentedeachyear.Although the vast majority are too small or too remotelylocated to be felt by humans, approximately 3,000 areperceptible by human populations, of which seven to 11result in significant loss of life (1, 2). Over the last 30 years,a yearly average of 21 earthquakes were reported, disastersdefinedaseventsresultinginmorethan10deaths,morethan100peopleaffected,arequestforinternationalassistance,ora declaration of a state of emergency (3). This average hasincreased to more than 30 in the last 5 years. In addition toloss of life, earthquakes cause considerably more nonfataltraumatic injuries and long-term damage to transportation,communication, and financial infrastructures; yet, onlyrecentlyhastherebeenarecognizedneedtoroutinelycollectdata on these less severe effects.Inthepast25years,over530,000deathshavebeenreportedfrom earthquakes, with death tolls from major earthquakesranging from fewer than five to more than 240,000 (1, 3).Table 1 shows characteristics of 32 selected earthquakes thatoccurred from 1985 to 2003. These earthquakes show sub-stantial variabilityinthenumberofdeathsandinmagnitude.Epidemiologicmethodsfordescribingcausalassociationsarea promising approach to account for this variability and toidentify potential avenues for preparedness and mitigation.Earthquakes are not randomly distributed but are con-centrated in regions where tectonic plates that compose theearth’s surface coincide (4–7). Populations located aboveplate activity are at greatest risk of earthquake-related mor-bidity and mortality, such as communities along the PacificRim (e.g., the western edge of North and South America),along island chains (e.g., Japan and the Aleutians), andboundaries between certain continents (e.g., along theHimalayas to central Asia to the Caucasus Mountains andto the Mediterranean Sea) (4, 7).Populationscontinuetogrowinmanyoftheseseismicallyactive regions, particularly urban communities along thewestern United States and in Japan, China, South America,and India (6, 8, 9). By 2030, it is anticipated that 5 billionpeople, about 60 percent of the world’s population, willoccupyurbanareas.Thefastestratesofgrowthareprojectedin the less developed regions of the world (9). Earthquakesthat strike urban centers have the potential to cause sub-stantialdamage and death giventhegreater concentration ofpeople, modern construction materials and building tech-niques, and complex transportation, communication, com-mercial, and residential infrastructures (10). However, ruralpopulationsatriskfacedifferentchallenges,suchasisolationfromrespondersandthepotentialforsubstandardhousesandbuildings. Hence, we face multiple challenges as publichealth professionals to prevent and reduce earthquake-relatedmorbidityandmortalityin thisincreasingly complexenvironment.Todesignprogramstoprepareforearthquakesand mitigatetheir effects, we must achievea comprehensiveunderstanding of the risks for earthquake-related injuries.In this paper, we highlight findings from and methodsutilized in various population-based epidemiologic studiesidentifiedthroughanextensiveliteraturesearchofpublished