THURSDAY, Nov. 3, 2011 (HealthDay News) --When an earthquake hits, up to 8 percent of a city's population can suffer fatal injuries, a new report suggests.
That's because the mass casualties, lacerations, broken bones and crushing injuries associated with these natural disasters occur when bridges and roads may be impassable and local and regional emergency medical care is disrupted, according to a group of Boston researchers who report their findings online Nov. 3 in The Lancet.
Millions of people live in major cities, such as New York, Los Angeles, Tokyo, Delhi and Shanghai, that are situated on fault lines, the researchers noted.
In the past decade, earthquakes have caused more than 780,000 deaths, according to the report. Many people died immediately, while others died from their injuries in the hours and weeks that followed.
Hours after an earthquake, a second wave of deaths occurs among victims with serious injuries, such as liver or spleen lacerations, broken pelvises and head injuries, the researchers revealed, and the fatalities don't stop there.
In the days and weeks following an earthquake, more people with sepsis (blood infection) and multi-organ failure also die from their injuries. People with sepsis are two and a half times more likely to die than those without it, the report revealed.
Moreover, earthquake victims with chronic diseases, like diabetes and heart disease, are at greater risk of death due to limited access to medical care.
Up to 15 percent of a city's population could also be crushed by heavy loads, resulting in amputations and kidney failure, according to the report. The death rate for people in kidney failure in the wake of an earthquake ranges from 14 percent to 48 percent, the researchers added.
Still, they noted, the most common earthquake-related injuries include the following:
- Lacerations (65 percent)
- Broken bones (22 percent)
- Bruises or sprains (6 percent)
- Crush injuries (3 percent to 20 percent)
Earthquakes could also trigger heart attacks. The report revealed heart attacks rose by 35 percent in the week following the 1994 earthquake in Northridge, Calif. Similar surges were reported in other places, such as Taiwan. An increase in arrhythmias and cases of high blood pressure were also recorded following this type of natural disaster.
Earthquakes can also harm the health of people who are displaced from their homes, according to the report. Overcrowded shelters can lead to epidemics of infectious diseases. Bodies, however, generally do not play a major role in the spread of disease, the researchers noted.
Mental health issues, particularly depression and post-traumatic stress disorder, also increase in the wake of major earthquakes.
Children are often at higher risk of injury and death than are adults during earthquakes, the researchers said. The elderly are also more likely to be adversely affected, since they may not be able to respond as quickly or may be unwilling to evacuate their homes.
The U.S. Federal Emergency Management Agency provides more information on earthquakes.